Multi-component putter

Abstract

To provide a multi-component putter comprising an upper portion and a lower portion.SOLUTION: An upper portion is formed from first material having first density and a lower portion is formed from second material having second density. The first density is less than the second density. The upper portion is affixed to the lower portion via an adhesive or a combination of adhesives and interlocking geometry. Multi-component putter design provides increased tolerance and moment of inertia compared to a putter formed from single material.SELECTED DRAWING: None

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This claims the benefit of U.S. Provisional Patent Application No. 63 / 260,612, filed August 26, 2021, U.S. Provisional Patent Application No. 63 / 203,257, filed July 14, 2021, U.S. Provisional Patent Application No. 63 / 190,691, filed May 19, 2021, and U.S. Provisional Patent Application No. 63 / 130,312, filed December 23, 2020. It is also a continuation-in-part of U.S. Patent Application No. 17 / 444,468, filed August 4, 2021, which is a continuation-in-part of U.S. Design Application No. 29 / 720,679, filed January 15, 2020, which issued as U.S. Patent No. D930,097 on September 7, 2021, and is a continuation of U.S. Patent Application No. 17 / 243,338, filed April 28, 2021, which is a continuation of U.S. Patent Application No. 16 / 590,270, filed October 1, 2019, which issued as U.S. Patent No. 11,020,640 on June 1, 2021, and claims the benefit of U.S. Provisional Patent Application No. 62 / 739,747, filed October 1, 2018, the contents of all of which are incorporated herein by reference in their entirety.

[0002] The present disclosure relates generally to golf clubs, and more particularly, to multi-component putter-type golf club heads. [Background technology]

[0003] Many putter-type golf club heads use weight distribution devices to change the center of gravity or increase the moment of inertia (MOI) of the golf club head. Common weight distribution devices include removable weight ports in the heel and toe regions of the sole, weighted face plate inserts, inserts for the back of a portion of the face, and attachments for the periphery of the toe and heel regions. In particular, putter-type golf club heads often use weight ports in the heel and toe regions. The weight ports can be removably attached by fasteners or permanently attached by various epoxies, adhesives, or machining methods. The use of weight ports in the heel and toe regions increases the MOI of the putter head, which results in a straighter ball path after impact.

[0004] Although these weight ports in the heel and toe regions increase the MOI, they also increase the weight of the golf club head, making the golf club head heavier than the ideal weight for a putter. Furthermore, attaching weight ports to a golf club putter head requires cavities or recesses in which to place these weight ports in the putter head during manufacturing, thereby increasing the cost of the putter head. In addition, the weight ports may create vibrations in the cavity or recesses during impact when the golf club head contacts the golf ball. These cavities and recesses also change the sound of the club head, creating a hollow sound within the club head. There is a need in the art to develop a putter that has a desirable sound, perimeter weighting, and ideal weight for balanced putting, while at the same time being pleasing to the user's eyes, to create a repeatable putt. [Brief description of the drawings]

[0005] [Figure 1A] FIG. 2 is an exploded view of a blade putter-type golf club head.

[0006] [Figure 1B] FIG. 1B is an isometric view of the blade putter-style golf club head of FIG. 1A.

[0007] [Figure 1C] FIG. 1B is a side view of the blade putter-type golf club head of FIG. 1A.

[0008] [Figure 2A] FIG. 2 is an exploded view of a blade putter-type golf club head.

[0009] [Figure 2B] FIG. 2B is an isometric view of the blade putter-style golf club head of FIG. 2A.

[0010] [Figure 2C] FIG. 2B is a side view of the blade putter-type golf club head of FIG. 2A.

[0011] [Figure 3A] 1 shows an exploded view of a crescent putter type golf club head.

[0012] [Figure 3B] 3B shows an isometric view of the crescent putter golf club head of FIG. 3A.

[0013] [Figure 3C] 3B shows a side view of the crescent putter golf club head of FIG. 3A.

[0014] [Figure 4A] 1 shows an exploded view of a semicircular putter-type golf club head.

[0015] [Figure 4B] FIG. 4B is an isometric view of the semicircular putter-style golf club head of FIG. 4A.

[0016] [Figure 4C] FIG. 4B is a side view of the semicircular putter-type golf club head of FIG. 4A.

[0017] [Figure 5A] 1 shows an exploded view of another semi-circular putter-type golf club head.

[0018] [Figure 5B] FIG. 5B is an isometric view of the semicircular putter-style golf club head of FIG. 5A.

[0019] [Figure 5C] FIG. 5B is a side view of the semicircular putter-type golf club head of FIG. 5A.

[0020] [Figure 6A] 1 shows an exploded view of a wing putter type golf club head.

[0021] [Figure 6B] FIG. 6B is an isometric view of the wing putter type golf club head of FIG. 6A.

[0022] [Figure 6C] 6B shows a side view of the wing putter type golf club head of FIG. 6A.

[0023] [Figure 7A] 1 shows an exploded view of a spade putter type golf club head.

[0024] [Figure 7B] 7B shows an isometric view of the spade putter style golf club head of FIG. 7A.

[0025] [Figure 7C] 7B shows a side view of the spade putter type golf club head of FIG. 7A.

[0026] [Figure 7D] 7B shows a bottom perspective view of the spade putter type golf club head of FIG. 7A.

[0027] [Figure 8A]FIG. 1 is an exploded view of a T-shaped putter type golf club head having a perimeter span.

[0028] [Figure 8B] FIG. 8B is an isometric view of a T-shaped putter type golf club head having the perimeter span of FIG. 8A.

[0029] [Figure 8C] FIG. 8B is a side view of a T-shaped putter type golf club head having the perimeter span of FIG. 8A.

[0030] [Figure 8D] FIG. 8B is a bottom perspective view of a T-shaped putter type golf club head having the perimeter span of FIG. 8A.

[0031] [Figure 9A] FIG. 2 is an exploded view of a dual rail putter type golf club head.

[0032] [Figure 9B] FIG. 9B is an isometric view of the dual rail putter style golf club head of FIG. 9A.

[0033] [Figure 9C] FIG. 9B is a side view of the dual rail putter style golf club head of FIG. 9A.

[0034] [Figure 9D] FIG. 9B is a bottom perspective view of the dual rail putter style golf club head of FIG. 9A.

[0035] [Figure 10A] 1 shows an exploded view of a circular putter-type golf club head.

[0036] [Figure 10B] FIG. 10B is an isometric view of the circular putter-style golf club head of FIG. 10A.

[0037] [Figure 10C] FIG. 10B is a side view of the circular putter-type golf club head of FIG. 10A.

[0038] [Figure 10D] FIG. 10B is a bottom perspective view of the circular putter-style golf club head of FIG. 10A.

[0039] [Figure 11A] 1 illustrates an exploded view of a putter-type golf club head with a striking face insert having a single component system.

[0040] [Figure 11B] 1 shows an exploded view of a putter-type golf club head with a striking face having a two-component system.

[0041] [Figure 11C] FIG. 13 shows a front view of a putter-type golf club head with a striking face insert according to a third embodiment.

[0042] [Figure 12A] FIG. 1 shows a top perspective view of a two-piece putter-type club head including a sole plate.

[0043] [Figure 12B] 12B shows a sole view of the two-part putter of FIG. 12A.

[0044] [Figure 12C] 12B shows an exploded view of the two-part putter of FIG. 12A.

[0045] [Figure 12D] 12B shows a bottom view of the two-piece putter of FIG. 12A with the lower section removed.

[0046] [Figure 12E] 12B shows a heel view of the two-part putter of FIG. 12A.

[0047] [Figure 13A] FIG. 1 shows a rear perspective view of a two-piece putter-style club head with a pocket.

[0048] [Figure 13B] 13B shows an exploded view of the two-part putter of FIG. 13A.

[0049] [Figure 13C] 13B shows a sole view of the two-part putter of FIG. 13A.

[0050] [Figure 13D] 13B shows a heel view of the two-piece putter of FIG. 13A with the lower portion removed.

[0051] [Figure 13E] 13B shows a toe view of the two-piece putter of FIG. 13A with the lower section removed.

[0052] [Figure 14A] 1 shows a top perspective view of a two-part putter head including a ball retrieval mechanism according to a first embodiment.

[0053] [Figure 14B] 14B shows a bottom perspective view of the putter head of FIG. 14A.

[0054] [Figure 14C] 14B shows an exploded view of the putter head of FIG. 14A.

[0055] [Figure 14D] 14B shows an exploded view of the putter head of FIG. 14A.

[0056] [Figure 14E] 1 shows a bottom perspective view of a two-part putter head including a ball retrieval mechanism according to a second embodiment.

[0057] [Figure 14F] 13 shows a bottom perspective view of a two-part putter head including a ball retrieval mechanism according to a third embodiment.

[0058] [Figure 14G] 13 shows a bottom perspective view of a two-part putter head including a ball retrieval mechanism according to a fourth embodiment.

[0059] [Figure 14H] 13 shows a bottom perspective view of a two-part putter head including a ball retrieval mechanism according to a fifth embodiment.

[0060] [Figure 15A] FIG. 1 shows a rear perspective view of a two-part putter head including a ball profile alignment aid.

[0061] [Figure 15B] 15B shows a rear perspective exploded view of the two-part putter head of FIG. 15A.

[0062] [Figure 15C] 15B shows a bottom view of the two-part putter head of FIG. 15A.

[0063] [Figure 15D] 15B shows a top view of a two-part putter head including the ball profile alignment aid of FIG. 15A.

[0064] [Figure 15E] 1 shows a top view of a two-part putter head including a ball contour alignment aid according to a second embodiment.

[0065] [Figure 15F] 13 shows a top view of a two-part putter head including a ball contour alignment aid according to a third embodiment.

[0066] [Figure 16A] FIG. 1 shows a front perspective view of a putter head including separate toe and heel masses.

[0067] [Figure 16B] 16B shows a rear perspective exploded view of the putter head of FIG. 16A.

[0068] [Figure 16C] 16B shows a sole view of the putter head of FIG. 16A.

[0069] [Figure 16D] 16B shows an underside view of the toe and heel masses of the putter head of FIG. 16A.

[0070] [Figure 17A] 1 shows a rear perspective exploded view of a two-part blade putter head according to a first embodiment.

[0071] [Figure 17B] 1 shows a rear perspective exploded view of a two-part blade putter head according to a second embodiment having an opening through the striking face.

[0072] [Figure 17C] 17B shows a rear perspective view of the two-piece blade putter head of FIG. 17A.

[0073] [Figure 17D] 17B shows a front perspective view of the top of the two-piece blade putter head of FIG. 17A.

[0074] [Figure 17E] 17C shows a front perspective view of the two-piece blade putter head of FIG. 17B.

[0075] [Figure 18A] 1 illustrates a rear perspective exploded view of a three-part putter head according to one embodiment.

[0076] [Figure 18B] 18B shows a rear perspective view of the three-part putter head of FIG. 18A.

[0077] [Figure 18C] 18B shows a bottom perspective view of the three-part putter head of FIG. 18A with the lower section removed.

[0078] [Figure 18D] 18B shows a sole view of the three-part putter head of FIG. 18A.

[0079] Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0080] I. putter golf club head Described herein is a two-part putter head having an upper portion made of a first material, such as a low density metal (i.e., but not limited to, aluminum), and a lower portion made of a second material, such as a high density metal (i.e., but not limited to, steel). The upper portion has a crown that extends from the striking face to the back edge. The upper portion is affixed to the lower portion and is further from the ground plane than the lower portion. The lower portion, in most embodiments, is less than 35% of the total real volume of the putter head, but more than 45% of the mass. The lower portion provides a perimeter structure and a sole. This combination of perimeter structure and high density lower portion provides an increase in MOI of at least 30% over a putter having the same volume, mass, and single material construction (i.e., a single material putter milled such as a steel putter or a single material putter investment casting).

[0081] The two-part putter head lower portion further includes a sole plate. The sole plate is formed of a high density material. As described in more detail below, the two-part putter head includes an upper portion and a lower portion including a sole plate. The lower portion including the sole plate includes mass structures, ball retrieval mechanisms, and / or ball profile alignment aids to enhance the putting experience. The putter head with the upper portion and the lower portion including the sole plate enhances perimeter weighting, MOI, and forgiveness while being comfortable to the eye. The putter head with the upper portion and the lower portion including the sole plate further provides consistent ball speed and ball travel distance for repeated putts.

[0082] Terms such as "first," "second," "third," and "fourth" in the detailed description and claims, when present, are used to distinguish between similar elements and are not necessarily used to describe a particular sequential or chronological order. It should be understood that such terms used are interchangeable under appropriate circumstances, and that the embodiments described herein are capable of, for example, sequences of operation other than those illustrated or otherwise described herein. Moreover, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that includes a list of elements is not necessarily limited to those elements, but can include other elements not expressly recited or inherent in such process, method, system, article, device, or apparatus.

[0083] The terms "left," "right," "front," "rear," "upper," "lower," "upper," "lower," "upper," "lower," and the like in the description and claims are used for explanatory purposes and are not necessarily intended to describe permanent relative positions. Terms so used are interchangeable under appropriate circumstances. Thus, it is to be understood that the embodiments of the apparatus, methods, and / or articles of manufacture described herein can operate in orientations other than those shown or otherwise described herein, for example.

[0084] Before any embodiment of the present disclosure is described in detail, it is to be understood that the disclosure is not limited in its application to the details or the construction and arrangement of components as set forth in the following description or illustrated in the drawings. The present disclosure is capable of supporting other embodiments and may be practiced or carried out in various ways.

[0085] In many embodiments, the golf club head can include a putter-type golf club head (such as putter-type golf club heads 100, 200, 300, 400, etc.). Figures 1-12B show several embodiments of putter-type golf club heads having upper and lower portions made of separate different materials and joined together. The putter-type golf club head can be a mallet-type putter head, a mid-mallet-type putter head, a blade-type putter head, a high MOI putter head, or any other type of putter-type golf club head.

[0086] In many embodiments, the putter-type golf club head can have a loft angle of less than 10 degrees. In many embodiments, the loft angle of the club head can be 0-5 degrees, 0-6 degrees, 0-7 degrees, or 0-8 degrees. For example, the loft angle of the club head can be less than 10°, less than 9°, less than 8°, less than 7°, less than 6°, or less than 5°. As a further example, the loft angle of the club head can be 0 degrees, 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, or 10 degrees.

[0087] The putter-type golf club head includes an upper portion and a lower portion. The golf club head may include a toe end and a heel end opposite the toe end. The putter-type golf club head may include a striking face. The putter-type golf club head may include a rear wall opposite the striking face. Additionally, the putter-type golf club head may include an alignment feature. Additionally, the putter-type golf club head may include a hosel attached to the heel end of the golf club head. The hosel may be attached to the center of the putter-type golf club head. The hosel may be attached to the heel end of the putter-type golf club head. The hosel may be integrally formed with the upper portion of the putter-type golf club head. The hosel may be integrally formed with the lower portion of the putter-type golf club head.

[0088] The upper portion is made of a first material. The lower portion is made of a second material. The first material is different from the second material. The first material has a first density. The second material has a second density. The first density is not the same as the second density.

[0089] In many embodiments, the putter-type golf club head can have a mass in the range of 340 to 385 grams. In other embodiments, the mass of the putter-type golf club head can be in the range of 340 to 345 grams, 345 to 350 grams, 350 to 355 grams, 355 to 360 grams, 360 to 365 grams, 365 to 370 grams, 370 to 375 grams, 375 to 380 grams, or 380 to 385 grams. In some embodiments, the mass of the putter-type golf club head can be 340 grams, 341 grams, 342 grams, 343 grams, 344 grams, 345 grams, 346 grams, 347 grams, 348 grams, 349 grams, 350 grams, 351 grams, 352 grams, 353 grams, 354 grams, 355 grams, 356 grams, 357 grams, 358 grams, 359 grams, 360 grams, 361 grams, 362 grams, 363 grams, 364 grams, 365 grams, 366 grams, 367 grams, 368 grams, 369 grams, 370 grams, 371 grams, 372 grams, 373 grams, 374 grams, 375 grams, 376 grams, 377 grams, 378 grams, 379 grams, 381 grams, 382 grams, 383 grams, 384 grams.

[0090] In many embodiments, the putter-type golf club head can be configured with a club head volume ranging from 25cc to 125cc. In some embodiments, the club head volume can be in the range of 25cc to 30cc, 30cc to 35cc, 35cc to 40cc, 40cc to 45cc, 45cc to 50cc, 50cc to 55cc, 55cc to 60cc, 60cc to 65cc, 65cc to 70cc, 70cc to 75cc, 75cc to 80cc, 80cc to 85cc, 85cc to 90cc, 90cc to 95cc, 95cc to 100cc, 100cc to 105cc, 105cc to 110cc, 110cc to 115cc, 115cc to 120cc, or 120cc to 125cc. In one embodiment, the club head volume can be in the range of 40cc to 110cc. In some embodiments, the club head volume may be greater than 25 cc, greater than 50 cc, greater than 75 cc, or greater than 100 cc.

[0091] In some embodiments, the putter-type golf club head can include a striking face made of a first material. In other embodiments, the striking face can be made of a second material. In these embodiments, the striking face material can be any of the following materials or combinations thereof: 8620 alloy steel (7.83 g / cc), S25C steel (7.85 g / cc), carbon steel (7.85 g / cc), maraging steel (8.00 g / cc), 17-4 stainless steel (7.81 g / cc), 303 stainless steel (8.03 g / cc), 304 stainless steel (8.00 g / cc), stainless steel alloy (7.75 g / cc to 8.05 g / cc), tungsten (19.25 g / cc), aluminum (2.70 g / cc), aluminum alloy (2.64 g / cc to 2.81 g / cc), ADC-12 (2.75 g / cc). In some embodiments, the striking face can be integrally formed on the upper portion. In other embodiments, the striking face can be integrally formed on the lower portion. The striking face can be integrally formed on the club head by co-molding, injection molding, casting, additive manufacturing, or other molding processes.

[0092] 11A-11C show various striking face features 1100 that may be used in the multi-component putters described in this disclosure. As described in more detail below, the striking face feature 1100 may include a single component system, a two-component system, or a single component system combined with a metal portion. A single component system includes a single striking face insert or component. A two-component system includes multiple striking face inserts or components. In many embodiments, the striking face feature 1100 may include a striking face insert. In these embodiments, the striking face is formed independently before being bonded to the club head. The side of the striking face insert that contacts the club head may be geometry complementary to the geometry of the corresponding portion of the club head that contacts the striking face. In some embodiments, the striking face insert may be made of a first material or a second material. In other embodiments, the striking face insert may be made of a third material. In some implementations, the striking face insert may be integrally formed with the upper or lower portion. In other embodiments, the striking face insert may be formed separately from both the upper and lower portions.

[0093] The striking face can be secured to the club head by being integrally formed with a portion of the club head or by a fastening means. In some embodiments, the striking face is secured to the upper portion. In these embodiments, the upper portion can define an insert cavity 1110 at a front portion of the upper portion. The upper insert cavity 1110 is configured to receive the striking face insert. Further, in these embodiments, when the striking face insert is secured to the upper portion, the upper portion surrounds and mates with the insert cavity 1110. In other embodiments, the striking face can be secured to the lower portion. In these embodiments, the lower portion can include an insert cavity (not shown). The lower insert cavity functions to receive the striking face insert. Further, in these embodiments, when the insert is secured to the lower portion, the lower portion surrounds and mates with the insert cavity. The striking face can be secured by an adhesive, such as a glue, a Very High Bond (VHB®) tape, an epoxy, or another adhesive. Alternatively or additionally, the striking face may be secured by welding, soldering, screws, rivets, pins, mechanical interlocking structures, or another fastening method.

[0094] The striking face insert can be constructed of any one or laminate combination of the following materials: aluminum, stainless steel, copper, thermoplastic copolyester elastomer (TPC), thermoplastic elastomer (TPE), thermoplastic urethane (TPU), steel, nickel, TPU / aluminum, TPE / aluminum, plastic / metal screen insert, polyethylene, polytetrafluoroethylene, polyisobutylene, polyvinyl chloride, PEBAX®, or other suitable materials. PEBAX® is a polyether block amide, which is a thermoplastic elastomer made from soft polyethers and hard polyamides. The hard polyamides can include nylon. PEBAX® can include different compounds corresponding to different Shore D hardness values, polyether percentages, and / or polyamide percentages. In many embodiments, PEBAX® can include PEBAX® 4033 (Arkema, Paris France) or PEBAX® 6333 (Arkema, Paris France). PEBAX® 4033 (Arkema, Paris France) contains tetramethylene oxide (53% by weight) and nylon 12. PEBAX® 6333 (Arkema, Paris France) contains nylon 11. In some embodiments, the face insert can include a material such as steel, steel alloy, tungsten, tungsten alloy, aluminum, aluminum alloy, titanium, titanium alloy, vanadium, vanadium alloy, chromium, chromium alloy, cobalt, cobalt alloy, nickel, nickel alloy, other metals, other metal alloys, composite polymeric materials, or any combination thereof.

[0095] PEBAX® can include a volume percentage of polyether. In some embodiments, PEBAX® can include 0%-10%, 10%-20%, 15%-30%, 20%-30%, 30%-40%, 30%-50%, 30%-60%, 40%-50%, 40%-60%, 50%-60%, or 60%-70% polyether by volume. For example, PEBAX® can include 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70% polyether by volume. In some embodiments, PEBAX® can contain 0%-10%, 10%-20%, 15%-30%, 20%-30%, 30%-40%, 40%-50%, 40%-60%, 50%-60%, or 60%-70% polyamide by volume. For example, PEBAX® can contain 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70% polyamide by volume. As the percentage of polyether increases, the hardness of PEBAX® decreases. As the percentage of polyamide increases, the hardness of PEBAX® increases. For example, PEBAX® 4033 (Arkema, Paris France) may contain 40% to 60% by volume of polyether and 15% to 30% by volume of polyamide. For example, PEBAX® 6333 (Arkema, Paris France) may contain 15% to 30% by volume of polyether and 40% to 60% by volume of polyamide.

[0096] In many embodiments, PEBAX® can include a hardness ranging from Shore 25D to Shore 75D. In some embodiments, the hardness of PEBAX can range from Shore 25D to Shore 35D, Shore 35D to Shore 45D, Shore 36D to Shore 44D, Shore 38D to Shore 42D, Shore 45D to Shore 55D, Shore 55D to Shore 65D, Shore 56D to Shore 64D, Shore 60D to Shore 65D, or Shore 65D to Shore 75D. For example, the hardness of PEBAX can be Shore D25, 30, 35, 40, 45, 50, 55, 60, 65, or 70.

[0097] In many embodiments, PEBAX® 4033 (Arkema, Paris France) can include a lower hardness than PEBAX® 6333 (Arkema, Paris France). In many embodiments, PEBAX® 4033 (Arkema, Paris France) can include a hardness range of Shore 35D to Shore 55D. In some embodiments, PEBAX® 4033 (Arkema, Paris France) can include a hardness range of Shore 38D to Shore 42D, or Shore 39D to Shore 41D. For example, PEBAX® 4033 (Arkema, Paris France) can include a Shore D hardness of 40. In many embodiments, PEBAX® 6333 (Arkema, Paris France) can include a hardness range of Shore 50D to Shore 75D. In some embodiments, PEBAX® 6333 (Arkema, Paris France) can include a hardness range of Shore 55D to Shore 70D, or Shore 60D to Shore 65D. For example, PEBAX® 6333 (Arkema, Paris France) can include a Shore D hardness of 63.

[0098] 11A, the striking face feature 1100 can include a striking face insert system 1120. The striking face insert system 1120 can be a single component system including a ball striking layer 1122 and an adhesive layer 1124. The striking face insert 1120 is configured to be adhered to the insert cavity 1110 via the adhesive layer 1124. The striking face insert 1120 can include a polymer type material as described herein. The striking face insert 1120 can include PEBAX® as described herein.

[0099] As shown in FIG. 11B, the striking face mechanism 1100 can include a striking face insert system 1130. The striking face insert system 1130 can be a two-component system including a ball striking face plate 1132 and a face insert base 1134. The striking face insert system 1130 having a two-component system is configured to be received in the insert cavity 1110 via one or more adhesive layers. The ball striking face plate 1132 of the striking face insert 1130 can include a first insert material. The face insert base 1134 of the striking face insert 1130 can include a second insert material. In many embodiments, the first insert material of the ball striking face plate 1132 and the second insert material of the face insert base 1134 can be different. In some embodiments, the first insert material of the ball striking face plate 1132 and the second insert material of the face insert base 1134 can be similar. In many embodiments, the first insert material of the ball striking face plate 1122 can include a polymer type material. In some embodiments, the first insert material of the ball striking face plate 1122 can include a metallic material. In many embodiments, the second insert material of the face insert base 1134 can include a polymer type material.

[0100] The first insert material can include a metal such as steel, a steel alloy, tungsten, a tungsten alloy, aluminum, an aluminum alloy, titanium, a titanium alloy, vanadium, a vanadium alloy, chromium, a chromium alloy, cobalt, a cobalt alloy, nickel, a nickel alloy, other metals, other metal alloys, composite polymeric materials, or any combination thereof.

[0101] The first insert material or the second insert material can include a polymer type material. The polymer type material can include polyethylene, polypropylene, polytetrafluoroethylene, polyisobutylene, polyvinyl chloride, or any other polymer type material. In many embodiments, the face insert can include PEBAX®. More specifically, PEBAX® is a polyether block amide, which is a thermoplastic elastomer made from flexible polyether and hard polyamide. The hard polyamide can include nylon. PEBAX® can include different compounds corresponding to different Shore D hardness values, polyether percentages, and / or polyamide percentages. In many embodiments, PEBAX® can include PEBAX® 4033 (Arkema, Paris France) or PEBAX® 6333 (Arkema, Paris France). PEBAX® 4033 (Arkema, Paris France) includes tetramethylene oxide (53% by weight) and nylon 12. PEBAX® 6333 (Arkema, Paris France) comprises nylon 11. The first and second insert materials may comprise the same polyether percentages, polyamide percentages, or Shore D hardness values ​​as described above.

[0102] The ball striking face plate 1132 of the striking face insert 1130 can have a thickness. In many embodiments, the thickness of the ball striking face plate 1132 can range from 0.015 to 0.115 inches. In some embodiments, the thickness of the ball striking face plate 1132 can range from 0.015 to 0.045 inches, 0.020 to 0.050 inches, 0.025 to 0.055 inches, 0.050 to 0.100 inches, 0.055 to 0.105 inches, 0.060 to 0.110 inches, or 0.065 to 0.115 inches. In some embodiments, the thickness of the ball striking face plate 1132 can be at least 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.10, 0.105, 0.110, or 0.115 inches. In some embodiments, the thickness of the ball striking face plate 1132 can be 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.10, 0.105, 0.110, or 0.115 inches or more. In some embodiments, the thickness of the ball striking face plate 1132 can be 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.10, 0.105, 0.110, or 0.115 inches or less. For example, the thickness of the ball striking face plate 1132 can be 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.10, 0.105, 0.110, or 0.115 inches.

[0103] In other embodiments, the thickness of the ball striking face plate 1132 can range from 0.115 to 0.40 inches. In some embodiments, the thickness of the ball striking face plate 1132 can range from 0.115 to 0.20 inches, 0.15 to 0.30 inches, 0.20 to 0.30 inches, 0.25 to 0.35 inches, or 0.30 to 0.40 inches. In some embodiments, the thickness of the ball striking face plate 1132 can be at least 0.15, 0.20, 0.25, 0.30, 0.35, or 0.40 inches. In some embodiments, the thickness of the ball striking face plate 1132 can be 0.15, 0.20, 0.25, 0.30, 0.35, or 0.40 or more. In some embodiments, the thickness of the ball striking face plate 1132 can be less than or equal to 0.15 inches, 0.20 inches, 0.25 inches, 0.30 inches, 0.35 inches, or 0.40 inches. For example, the thickness of the ball striking face plate 1132 can be 0.15 inches, 0.20 inches, 0.25 inches, 0.30 inches, 0.35 inches, or 0.40 inches.

[0104] The face insert base 1134 of the striking face insert 1130 can have a thickness. In many embodiments, the thickness of the face insert base 1134 can range from 0.05 to 0.20 inches. In some embodiments, the thickness of the face insert base 1134 can range from 0.05 to 0.10 inches, or 0.10 to 0.20 inches. In some embodiments, the thickness of the face insert base 1134 can be at least 0.05 inches, 0.10 inches, 0.15 inches, or 0.20 inches. In some embodiments, the thickness of the face insert base 1134 can be 0.05 inches, 0.10 inches, 0.15 inches, or 0.20 inches or more. In some embodiments, the thickness of the face insert base 1134 can be 0.05 inches, 0.10 inches, 0.15 inches, or 0.20 inches or less. For example, the thickness of the face insert base 1134 can be 0.05 inches, 0.10 inches, 0.15 inches, or 0.20 inches.

[0105] In other embodiments, the thickness of the face insert base 1134 can range from 0.20 to 0.80 inches. In some embodiments, the thickness of the face insert base 1134 can range from 0.20 to 0.50 inches, 0.30 to 0.60 inches, 0.40 to 0.70 inches, or 0.50 to 0.80 inches. In some embodiments, the thickness of the face insert base 1134 can range from 0.20 to 0.40 inches, 0.30 to 0.50 inches, 0.40 to 0.60 inches, 0.50 to 0.70 inches, or 0.60 to 0.80 inches. In some embodiments, the face insert base 1134 of the striking face insert 1130 can be at least 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, or 0.80 inches. In some embodiments, the face insert base 1134 of the striking face insert 1130 can be 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, or 0.80 inches or more. In some embodiments, the face insert base 1134 of the striking face insert 1130 can be less than or equal to 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, or 0.80 inches. For example, the thickness of the face insert base 1134 can be 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, or 0.80 inches.

[0106] As shown in FIG. 11C, the striking face mechanism 1100 can include a striking face insert system 1140. The striking face insert system 1140 includes a striking face insert 1144 and a metal portion 1142. The striking face insert 1144 includes the single component system described above. The metal portion 1142 surrounds the striking face insert 1144. The striking face insert 1144 can be formed from a polymeric material as described herein. The striking face insert 1144 is further surrounded by an epoxy boundary 1146. The epoxy boundary 1146 extends around the perimeter of the striking face insert 1144. The combination of the striking face insert 1144 formed from a polymeric type material and the epoxy boundary 1146 can provide an enhanced feel and sound upon impact with a golf ball. Additionally, removing material from the striking face or top to accommodate the striking face insert 1144 reduces the weight of the putter head at or near the central region of the putter head. By removing material from the central and / or front regions of the putter head, more weight can be placed on the perimeter of the putter head, thereby increasing the moment of inertia and the moment of forgiveness.

[0107] The epoxy boundary 1146 surrounding the striking face insert 1144 can include a width. The width of the epoxy boundary 1146 can be measured as a lateral width. In many embodiments, the width of the epoxy boundary can range from 0.01 inches to 0.08 inches. In some embodiments, the width of the epoxy boundary 1146 can range from 0.01 inches to 0.04 inches, or 0.04 inches to 0.08 inches. In some embodiments, the width of the epoxy boundary 1146 can range from 0.02 inches to 0.05 inches, 0.03 inches to 0.06 inches, 0.04 inches to 0.07 inches, or 0.05 inches to 0.07 inches. For example, the width of the epoxy boundary can be 0.01, 0.02, 0.03, 0.035, 0.04, 0.045, 0.05, 0.06, 0.07, or 0.08 inches. In one example, the width of the epoxy boundary 1146 can be 0.03 inches.

[0108] The metal portion 1142 may further include a milling pattern 1148. The milling pattern 1148 may include a plurality of milling lines extending in a vertical, horizontal, curvilinear, arcuate, or circular direction across the striking face. The milling pattern 1148 may extend in a crown-to-sole direction and / or in a heel-to-toe direction across the striking face. The milling pattern 1148 enhances the surface finish of the putter head or striking face and improves the appearance of the putter head.

[0109] The striking face insert systems (1120, 1130, 1140) disclosed herein can be formed by many different processes. The different molding processes include injection molding, casting, blow molding, compression molding, co-molding, laser molding, film insert molding, gas-assisted molding, rotational molding, thermoforming, laser cutting, 3-D printing, forging, stamping, electroforming, machining, molding, or any combination thereof. Additionally, the striking face insert can have any combination of the hardness, volume, thickness, and molding process described above.

[0110] In many embodiments, the upper portion of the putter-type golf club head having a first material includes a first density in the range of 1.0 g / cc to 6.0 g / cc. The first density can be in the range of 2.0 g / cc to 5.0 g / cc. In some embodiments, the first density can be in the range of 1.0-1.25 g / cc, 1.25-1.5 g / cc, 1.5-1.75 g / cc, 1.75-2.75 g / cc, 2.0-2.25 g / cc, 2.25-2.5 g / cc, 2.5-2.75 g / cc, 2.75-3.75 g / cc, 3.25-3.5 g / cc, 3.5-3.75 g / cc, 3.75-4.0 g / cc, 4.0-4.25 g / cc, 4.5-4.75 g / cc, 4.75-5.0 g / cc, 5.0-5.25 g / cc, 5.25 g / cc-5.5 g / cc, 5.5-5.75 g / cc, or 5.75-6.0 g / cc. In one embodiment, the first density of the lower portion can be in the range of 2.0 to 3.0 g / cc. In some embodiments, the first density can be less than 6.0 g / cc, less than 5.0 g / cc, less than 4.0 g / cc, less than 3.0 g / cc, or less than 2.0 g / cc. In some embodiments, the first density can be 1.25 g / cc, 1.50 g / cc, 1.75 g / cc, 2.0 g / cc, 2.25 g / cc, 2.50 g / cc, 2.75 g / cc, 3.0 g / cc, 3.25 g / cc, 3.50 g / cc, 3.75 g / cc, 4.0 g / cc, 4.25 g / cc, 4.50 g / cc, 4.75 g / cc, 5.0 g / cc, 5.25 g / cc, 5.50 g / cc, 5.75 g / cc, 6.0 g / cc.

[0111] In many embodiments, the lower portion of the putter-type golf club head has a second material. The second material can include a density. The density is a second density relative to the first density of the first material in the upper portion. The second density of the second material in the lower portion can be in the range of 7.0 g / cc to 20.0 g / cc. In some embodiments, the second density is 7.0-7.5 g / cc, 7.5-8.0 g / cc, 8.0-8.5 g / cc, 8.5-9.0 g / cc, 9.0-9.5 g / cc, 9.5-10.0 g / cc, 10.0-10.5 g / cc, 10.5-11.0 g / cc, 11.0-11.5 g / cc, 11.5-12.0 g / cc, 12.0-12.5 g / cc, 12.5-13.0 g / cc, 13.0-13.5 g / cc, 13.5-14.0 g / cc, 14.0-14.5 g / cc, 14.5-15.0 g / cc, 15.0-16.0 g / cc, 16.0-17.0 g / cc, 17.0-18.0 g / cc, 18.0-19.0 g / cc, 19.0-20.0 g / cc, 20.0-21.0 g / cc, 21.0-22.0 g / cc, 22.0-23.0 g / cc, 23.0-24.0 g / cc, 24.0-25.0 g / cc, 25.0-26.0 g / cc, 26.0-27.0 g / cc, 27.0-28.0 g / cc, 28.0-29.0 g / cc, 29.0-30.0 g / cc, 30.0-31.0 g / cc, 31.0-32.0 g / cc, 32.0-33.0 g / cc, 33.0-34.0 g / cc, 34.0-35.0 g / cc, 35.0-36.0 0 g / cc, 16.0-16.5 g / cc, 16.5-17.0 g / cc, 17.0-17.5 g / cc, 17.5-18.0 g / cc, 18.0-18.5 g / cc, 18.5-19.0 g / cc, or 19.0-19.5 g / cc, or 19.5-20.0 g / cc. In one embodiment, the second density of the second material in the lower portion can be in the range of 8.0-9.0 g / cc. In some embodiments, the second density can be 7.0 g / cc, 7.5 g / cc, 8.0 g / cc, 8.5 g / cc, 9.0 g / cc, 9.5 g / cc, 10.0 g / cc, 10.5 g / cc, 11.0 g / cc, 11.5 g / cc, 12.0 g / cc, 12.5 g / cc, 13.0 g / cc, 13.5 g / cc, 14.0 g / cc, 14.5 g / cc, 15.0 g / cc, 15.5 g / cc, 16.0 g / cc, 16.5 g / cc, 17.0 g / cc, 17.5 g / cc, 18.0 g / cc, 18.5 g / cc, 19.0 g / cc, 19.5 g / cc, or 20.0 g / cc. In some embodiments, the second density of the lower portion can be at least two times the first density, at least three times the first density, at least four times the first density, or at least five times the first density. In some embodiments, the second density can be greater than 7.0 g / cc, greater than 9.0 g / cc, greater than 10.0 g / cc, greater than 11.0 g / cc, or greater than 12.0 g / cc.

[0112] The upper portion of the putter-type golf club having the first material may be made from any one or combination of the following: 8620 alloy steel (7.83 g / cc), S25C steel (7.85 g / cc), carbon steel (7.85 g / cc), maraging steel (8.00 g / cc), 17-4 stainless steel (7.81 g / cc), 303 stainless steel (8.03 g / cc), 304 stainless steel (8.00 g / cc), stainless steel alloy (7.75 g / cc-8.05 g / cc), tungsten (19.25 g / cc), aluminum (2.70 g / cc), aluminum alloy (2.64 g / cc-2.81 g / cc), ADC-12 (2.75 g / cc), or other metals suitable for making golf club heads. In many embodiments, the upper portion is made of aluminum alloy or ADC-12.

[0113] The lower portion of the putter-type golf club having the second material may be made from any one or combination of the following: 8620 alloy steel (7.83 g / cc), S25C steel (7.85 g / cc), carbon steel (7.85 g / cc), maraging steel (8.00 g / cc), 17-4 stainless steel (7.81 g / cc), 303 stainless steel (8.03 g / cc), 304 stainless steel (8.00 g / cc), stainless steel alloy (7.75 g / cc to 8.05 g / cc), tungsten (19.25 g / cc), aluminum (2.70 g / cc), aluminum alloy (2.64 g / cc to 2.81 g / cc), ADC-12 (2.75 g / cc), or other metals suitable for making golf club heads. In many embodiments, the lower portion is made of 304 stainless steel, 8620 alloy steel, 17-4 stainless steel, or 1380 stainless steel. However, the lower portion and upper portion are not made of the same one or combination of materials.

[0114] Additionally, the upper and lower portions of the putter-type golf club head may be joined by any method or combination of welding, soldering, brazing, swedging, adhesives, epoxies, or mechanical fastening. In some embodiments, the upper and lower portions may be joined by adhesion with epoxies, polyurethanes, resins, hot melts, or any other adhesive.

[0115] II. Embodiment a. Blade embodiment In one embodiment, the putter-type golf club head can be a blade-type putter head 100. With reference to Figures 1A and 1B, the blade-type putter head 100 has an upper portion 104 and a lower portion 108. The upper portion 104 is made from a first material having a first density and the lower portion 108 is made from a second material having a second density. The first density is less than the second density. The upper portion 104 and the lower portion 108 combine to create a balanced putter head 100 while maintaining a desired volume and mass.

[0116] The lower portion 108 includes a toe end 124, a heel end 128 opposite the toe end 124, a rear wall 132 opposite the front face 112, a rear portion 156, and a lower surface (not shown). The lower surface and the upper portion 104 form a sole 168. The rear wall 132 is opposite and generally parallel to the front face 112. The toe end 124 is opposite the heel end 128 and adjacent the striking face 112 and the rear portion 156. The rear portion 156 spans from the heel end 128 to the toe end 124 while extending away from the rear wall 132 and the front face 112. The rear portion 156 is adjacent the sole. The lower surface extends from the heel end 128 to the toe end 124 and is adjacent the rear portion 156 and the front face 112.

[0117] Additionally, the toe end 124, the heel end 128, and the front surface 112 of the lower portion 108 form a recess 140 that extends inwardly from the front surface 112 toward the rear wall 132. The recess serves to receive the upper portion 104. In most embodiments, the recess 140 comprises a corresponding geometric shape that is similar or identical to the geometric shape of the upper portion 104. When the upper portion 104 is secured to the lower portion 108, the upper portion 104 surrounds and mates with the lower portion 108 to fit within the recess 140.

[0118] The lower portion 108 of the blade-type putter head 100 may further include an alignment feature 136. The alignment feature 136 may be any one or combination of the following: a line, a circle, a dashed line, a triangle, a channel, or any other suitable alignment feature 136. With reference to Figures 2A-2C, in some embodiments, the blade-type putter head 200 may include an alignment feature 236 on the upper portion 204 rather than the lower portion 208.

[0119] The upper portion 104 of the blade-type putter 100 head has a striking face 113 and an adhesive surface 115. The striking face 113 includes an upper edge 116 and a lower edge 121, with the upper edge 116 being farther away from a ground plane 172 than the lower edge 121. The ground plane 172 contacts the lower portion 108 when the putter head is in an address position to strike a golf ball. The upper edge 116 is adjacent to the striking face 113 and adhesive surface 115 and opposite the lower edge 121. In most embodiments, the striking face 113 and adhesive surface 115 are parallel, but in other embodiments, the striking face 113 and adhesive surface 115 are not parallel.

[0120] When the top 104 and bottom 108 are joined together, the adhesive surface 115 is secured in the recess 140 in the bottom 108. The striking face 113 of the top 104 and the front face 112 of the bottom align to form a striking face 120 that functions to strike a golf ball.

[0121] The lower edge 121 of the upper portion 104 and the underside of the lower portion 108 combine to form a sole 168. The sole 168 is perpendicular to a ground plane 172. The ground plane 172 is tangent to the sole 168 when the putter 100 is in the address position to strike the golf ball. The sole 168 of the putter 100 extends from the toe end 124 of the putter head 100 to the heel end 128 of the putter head 100.

[0122] 1C , in most embodiments, the sole 168 of the putter head 100 may be completely flat. In some embodiments, the sole 168 of the putter head 100 may have a slight arch in the direction from the heel 128 to the toe 124. The slight arch may be a linear or polynomial function. In some embodiments, the sole 168 of the putter head 100 may have a strong arch in the direction from the heel 128 to the toe 124, and the strong arch may be a linear or polynomial function. The sole 168 functions to provide a surface for resting the putter head 100 on the ground plane 172.

[0123] The striking face 120 of the blade-type putter head 100 comprises a striking face center point 176 and a loft plane 180. The striking face center point 176 is equidistant from the lower edge 120 and the upper edge 116 of the striking face 120, as well as equidistant from the heel end 128 and the toe end 124 of the blade-type putter head 100. The loft plane 180 is tangent to the striking face 112 of the blade-type putter head 100. Additionally, a midplane 184 intersects the striking face center point 176 and is perpendicular to the loft plane 180. Additionally, a y-axis 188 intersects the striking face center point 176 and is perpendicular to the ground plane 172.

[0124] In some embodiments, when the lower portion 108 and upper portion 104 are joined, the upper edge 116 of the upper portion 104 can overlap at least a portion of the rear wall 132 of the lower portion 108 and project away from the striking face 120. Additionally, the lower edge 121 of the upper portion 104 can project away from the striking face 120 toward at least a portion of the lower surface of the lower portion 108, thereby forming part of the sole 168. In these embodiments, the rear wall 132 of the lower portion 108 does not form part of the sole 168.

[0125] The combination of a lower density first material upper portion 104 and a higher density second material lower portion 108 increases the MOI of the putter 100 over a putter with a single solid block construction. The two-part construction of the putter 100 (upper portion 104 and lower portion 108) moves the denser material toward the heel 128 and toe 124 while placing the lighter material (upper portion 104) near the center, thereby increasing the MOI of the putter 100, with more mass further away from the center of gravity. The denser material at the lower portion helps increase the MOI of the putter-type golf club head by shifting the weight of the putter head 100 toward the outer portion of the putter-type golf club head. A single material putter does not allow the high density material to be allocated to the periphery. In some embodiments, a putter-type golf club head 100 with two different material upper portions 104 and lower portions 108 increases the MOI around the y-axis center of gravity by at least 15% over a putter with the same volume, mass, and single material construction.

[0126] b. Blade embodiment with heel and toe mass In some embodiments of the present invention, the putter-type golf club head may be a blade-type putter head 1700. Referring to FIGS. 17A-17E, the blade-type putter head 1700 has an upper portion 1704 and a lower portion 1708. The upper portion 1704 is made from a first material having a first density and the lower portion 1708 is made from a second material having a second density. The first density is less than the second density. The two-part blade-type putter head 1700 is formed by the upper portion 1704 covering the rear end of the lower portion 1708 without disturbing the striking face 1720. The upper portion 1704 and lower portion 1708 combine to provide a high moment of inertia (3500 g cm) while maintaining a desired volume and mass. 2 ~5000g cm 2 ) to create a balanced putter head 1700.

[0127] As described above, the lower portion 1708 is constructed of a high density material (i.e., the second material). With reference to FIG. 17A, the lower portion 1708 includes a toe end 1724, a heel end 1728 opposite the toe end 1724, a front surface 1712 defining a striking face 1720, a rear wall 1732 opposite the front surface 1712, a rear portion 1756, and a sole 1768. The rear wall 1732 is opposite and generally parallel to the front surface 1712. The toe end 1724 is opposite the heel end 1728 while adjacent the striking face 1720 and the rear portion 1756. The rear portion 1756 extends from the heel end 1728 to the toe end 1724 while also extending away from the rear wall portion 1732 and the front surface 1712. The rear portion 1756 is adjacent the sole 1768. The sole 1768 extends from the heel end 1728 to the toe end 1724 and is adjacent the rear portion 1756 and the front portion 1712 .

[0128] In many embodiments, the sole 1768 includes a variable thickness. The sole 1768 includes a central portion 1744, a heel portion 1746, and a toe portion 1748, with the heel portion 1746 and the toe portion 1748 each including a greater thickness than the central portion 1744. In many embodiments, a transition region 1750 may be provided between the heel portion 1746 and the central portion 1744, and between the central portion 1744 and the toe portion 1748. The transition region 1750 provides a gradual and smooth transition between the different thicknesses of the sole 1768. Making the sole 1768 less thick in the central portion 1744 and more thick in the heel portion 1746 and the toe portion 1748 allocates more mass toward the perimeter of the putter head 1700, thus increasing the MOI. As discussed further below, the lower portion 1708 may further include a heel mass 1741 and a toe mass 1743 to further increase the perimeter weighting of the putter head 1700 and increase the MOI.

[0129] In many embodiments, the sole 1768 of the putter head 1700 may be flat or planar. In some embodiments, the sole 1768 of the putter head 1700 may have a slight bow from the heel 1728 to the toe 1724, where the slight bow may be linear or may be a function of a polynomial. In some embodiments, the sole 1768 of the putter head 1700 may have a strong bow from the heel 1728 to the toe 1724, where the strong bow may be linear or may be a function of a polynomial. The sole 1768 functions to provide a surface for the putter head 1700 to rest on the ground.

[0130] In some embodiments, referring to FIG. 17B, the lower portion 1708 includes an opening 1764 extending through the front surface 1712 and the rear wall 1732. The opening 1764 is located in the center of the front surface 1712 and is configured to receive at least a portion of the low density upper portion 1704. As shown in FIG. 17B, the opening 1764 is generally rectangular. In other embodiments, the opening 1764 may be circular, curvilinear, triangular, trapezoidal, parabolic, golf ball shaped, square, or any other desired shape. The opening 1764 allows mass to be removed from the center of the lower front surface 1712 and reallocated to other areas of the putter head 1700 to increase perimeter weighting and provide a higher MOI.

[0131] As described above, the upper portion 1704 is constructed from a low density material (i.e., a first material). The upper portion 1704 is configured to cover the lower portion 1708 to create a putter head 1700 having a solid structure. The upper portion 1704 covers a rear end of the lower portion 1708. In some embodiments, the upper portion 1704 can form a portion of the striking face 1720, as described in further detail below. With reference to FIG. 17D , the upper portion 1704 comprises a body 1790, a heel extension 1792 formed between the body 1790 and the heel side perimeter 1760, and a toe extension 1794 formed between the body 1790 and the toe side perimeter 1756. The upper portion 1704 further includes a front edge 1770, a back edge 1734 opposite the front edge 1770, and a crown 1742 that extends across the entire extent of the upper portion 1704 from the front edge 1770 to the back edge 1734 and from the heel side perimeter 1760 to the toe side perimeter 1756.

[0132] The body 1790 is a substantially solid structure. The body 1790 has a shape configured to correspond to the shape of the lower portion 1708. The body 1790 abuts the central portion 1744 of the sole 1768 and is disposed between the heel portion 1746 and the toe portion 1748. In many embodiments, referring to FIG. 17A , the body 1790 abuts the rear wall 1732 of the lower portion 1708.

[0133] Referring now to the embodiment of FIG. 17B, in some embodiments, the body 1790 includes a protrusion 1786 that forms a forward-most portion of the body 1790. As shown in FIG. 17D, the protrusion 1786 extends from the body 1790 toward the front face 1712 of the lower portion. The protrusion 1786 penetrates and fills an opening 1764 formed in the front face 1712 of the lower portion 1708. The protrusion 1786 includes a shape that matches the shape of the opening 1764 provided in the front face 1712 of the lower portion such that when the upper portion 1704 and lower portion 1708 are joined, the body 1790 completely fills the opening 1764. As shown in FIG. 17E, when joined to the lower portion 1708, the front face 1788 of the body 1790 is flush with the front face 1712 of the lower portion 1708. In this manner, the lower front face 1712 and the upper body 1790 combine to form a continuous, solidly constructed striking face 1720. As a result, the striking face 1720 is formed as a high density material (i.e., the second material) with an opening 1764 located substantially in the center and filled with a low density material (i.e., the first material). The striking face 1720 includes a low density first material near the center surrounded by a higher density second material toward the periphery of the striking face 1720.

[0134] The crown 1742 of the upper portion 1704 forms the entire upper surface of the upper portion 1704. The crown 1742 extends from the front edge 1770 to the back edge 1734 and from the toe side perimeter 1756 to the heel side perimeter 1760, covering the entire span of the upper portion 1704. When joined to the lower portion 1708, the crown 1742 forms a majority of the upper portion of the putter head 1700, although a smaller portion of the upper portion of the putter head 1700 may be formed by the lower portion 1708. In many embodiments, the crown 1742 comprises a smooth continuous surface. In the embodiment shown in FIG. 17C, the crown 1742 comprises a concave curvature. In some embodiments, the concave curvature of the crown 1742 can substantially match the curvature of the sole 1768. In other embodiments, the crown 1742 can be substantially flat. In still other embodiments, the crown 1742 is not substantially smooth, but instead can include one or more surface features (not shown) that provide roughness or discontinuities to the crown 1742.

[0135] In some embodiments, the lower surface 1774 of the upper portion 1704 can form a first cavity 1796. The first cavity 1796 is recessed into the lower surface of the toe extension 1794. The first cavity 1796 is recessed toward the crown 1742 but does not extend completely through the crown 1742. The first cavity 1796 is bounded by the back edge 1734, the crown 1742, the front edge 1770, and the toe side perimeter 1756. The toe extension 1794 covers the toe mass 1741 of the lower portion 1708, completely hiding the toe mass 1741 within the first cavity 1796.

[0136] In some embodiments, the underside of the upper portion 1704 can form a second cavity 1798. The second cavity 1798 is recessed into the underside of the heel extension 1792. The second cavity 1798 is recessed toward the crown 1742 but does not extend completely through the crown 1742. The second cavity 1798 is bounded by the back edge 1734, the crown 1742, the front edge 1770, and the heel side perimeter 1760. The heel extension 1792 covers the heel mass 1743 of the lower portion 1708, completely hiding the heel mass 1741 within the second cavity 1798.

[0137] The first and second cavities 1796, 1798 can include any desired shape. However, in most embodiments, the first and second cavities include shapes similar or identical to the shapes of the corresponding toe mass 1741 and heel mass 1743. Additionally, when the upper portion 1704 is attached to the lower portion 1708, the upper portion 1704 covers the lower portion 1708 such that the toe mass 1741 is contained within the first cavity 1796 and the heel mass 1743 is contained within the second cavity 1798.

[0138] The upper portion 1704 and lower portion 1708 are joined to form a putter head 1700 of rigid construction with a high MOI. The upper portion 1704 and lower portion 1708 are complementarily shaped to fit together without any internal voids or hollow spaces. As described above, the upper portion 1704 covers the lower portion 1708 and fills the opening 1764 formed in the front surface 1712 of the lower portion. The body 1790 of the lower portion 1708 fits accordingly within the sole 1768 and protrudes through the opening 1764 to form a continuous striking face 1720. The toe extension 1794 and heel extension 1792 cover the toe mass 1741 and heel mass 1743, respectively.

[0139] As noted above, in some embodiments, the putter head 1700 may further include a toe mass 1741 and a heel mass 1743. The weights of the heel mass 1741 and the toe mass 1743 may be adjusted to achieve a desired swing weight or overall putter head mass. With reference to FIGS. 17A and 17B, the toe mass 1741 and the heel mass 1743 are disposed in the toe portion 1748 and the heel portion 1746 of the sole 1768, respectively. The heel mass 1741 and the toe mass 1743 may be integral with the lower portion 1708 and may be formed of a second material of the lower portion 1708. In other embodiments, the toe mass 1741 and the heel mass 1743 may be formed of a third material having a third density greater than the second density of the lower portion 1708. The toe mass 1741 and the heel mass 1743 extend vertically from the lower portion 1708. The toe mass 1741 and heel mass 1743 provide a means for positioning and aligning the upper portion 1704 with the lower portion 1708 of the putter head 1700 .

[0140] Additionally, the toe mass 1741 and heel mass 1743 provide an additional means of adding mass to the perimeter to increase the MOI of the blade-shaped putter head 1700 when compared to a putter without such mass features. The heel mass 1741 and toe mass 1743 can include a density equal to or greater than the second density of the remainder of the lower portion 1708. The toe mass 1741 and heel mass 1743 can have a mass in the range of 10-40 grams. In some embodiments, the toe mass 1741 and heel mass 1743 can each include a mass of approximately 25 grams. In some embodiments, the toe mass 1741 and heel mass 1743 can have a mass in the range of 10-25 grams, 15-30 grams, 20-35 grams, or 25-40 grams. In some embodiments, the toe mass 1741 and heel mass 1743 can have a mass in the range of 10 to 20 grams, 15 to 25 grams, 20 to 30 grams, 25 to 35 grams, or 30 to 40 grams. In some embodiments, the toe mass 1741 and heel mass 1743 can include a mass of approximately 15 grams, 16 grams, 17 grams, 18 grams, 19 grams, 20 grams, 21 grams, 22 grams, 23 grams, 24 grams, 25 grams, 26 grams, 27 grams, 28 grams, 29 grams, 30 grams, 31 grams, 32 grams, 33 grams, 34 grams, or 35 grams.

[0141] The toe mass 1741 and heel mass 1743 can each have the same mass or can include different masses within the ranges provided above. The toe mass 1741 and heel mass 1743 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, crescent, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0142] 17A and 17B, the toe mass 1741 and the heel mass 1743 can be positioned away from one or more of the rear perimeter 1752, the toe side perimeter 1756, and the heel side perimeter 1760, where the toe mass 1741 and the heel mass 1743 do not touch or intersect the rear perimeter 1752, the toe side perimeter 1756, and / or the heel side perimeter 1760. However, in other embodiments, the toe mass 1741 and the heel mass 1743 can be positioned at one or more of the rear perimeter 1752, the toe side perimeter 1756, and the heel side perimeter 1760, where the toe mass 1741 and the heel mass 1743 are integral to and intersect the rear perimeter 1752, the toe side perimeter 1756, and / or the heel side perimeter 1760.

[0143] 17A and 17B, the toe mass 1741 and the heel mass 1743 can be spaced rearwardly from the rear wall 1732, and the toe mass 1741 and the heel mass 1743 do not contact or intersect the rear wall 1732. However, in other embodiments, the toe mass 1741 and the heel mass 1743 are integrally formed with the rear wall 1732, and the front of the heel mass 1743 and the toe mass 1741 intersect the rear wall 1732.

[0144] The toe mass 1741 and heel mass 1743 provide areas of concentrated mass such that the toe mass 1741 and heel mass 1743 function to increase the moment of inertia of the putter head 1700. Locating the toe mass 1741 and heel mass 1743 at or near the front surface 1712 and at or near the toe side perimeter 1756 and heel side perimeter 1760, respectively, increases the MOI by shifting the mass away from the center of gravity of the putter head 1700. The toe mass 1741 and heel mass 1743 can be integrally formed from a second material, the second material being denser than the first material.

[0145] The toe mass 1741 and heel mass 1743 serve dual functions, such that the toe mass 1741 and heel mass 1743 function to increase the MOI of the putter head 1700 as well as provide an additional surface for the upper portion 1704 to bond to the lower portion 1708. Thus, the toe mass 1741 may also be referred to as the front toe attachment portion 1741 and the heel mass 1743 may also be referred to as the front heel attachment portion 1743.

[0146] The lower portion 1708 of the blade-type putter head 1700 may further include an alignment feature (not shown). The alignment feature may be any one or combination of lines, circles, dashed lines, triangles, channels, or any other desired alignment features. In some embodiments, the blade-type putter head 1700 may include an alignment feature on the upper portion 1704 rather than the lower portion 1708.

[0147] The combination of a low density first material upper portion 1704 and a high density second material lower portion 1708 increases the MOI of the putter head 1700 over a single solid block construction putter. The two part construction of the putter head 1700 (upper portion 1704 and lower portion 1708) increases the MOI of the putter head 1700 because more mass is farther from the center of gravity by moving the denser material toward the heel 1728 and toe 1724 while placing the less dense material (upper portion 1704) closer to the center. The denser material of the lower portion 1708 helps to increase the MOI of the putter head 1700 by shifting the mass of the putter head 1700 toward the outer portion of the putter head 1700. A single material putter cannot allocate the denser material to the periphery while maintaining the desired volume (50cc-75cc) and mass (340 grams-385 grams). In one example, the putter head 1700 has a high MOI (4187 g cm 2), desired volume (55 cc), and desired mass (361 grams). In some embodiments, a putter head 1700 with an upper portion 1704 and a lower portion 1708 of two different materials provides at least a 15% increase in MOI centered around the y-axis center of gravity over a putter of the same volume, mass, and single material construction.

[0148] In this embodiment, the lower portion 1708 may comprise a greater proportion of the volume of the putter head 1700 as compared to other putter-style head embodiments disclosed herein. In many embodiments, the lower portion 1708 may comprise less than 80% of the volume of the putter head 1700. In some embodiments, the lower portion 1708 comprises less than 79% of the total volume of the putter head 1700, less than 78% of the total volume of the putter head 1700, less than 77% of the total volume of the putter head 1700, less than 76% of the total volume of the putter head 1700, less than 75% of the total volume of the putter head 1700, less than 74% of the total volume of the putter head 1700, less than 73% of the total volume of the putter head 1700, less than 72% of the total volume of the putter head 1700, less than 71% of the total volume of the putter head 1700, or less than 70% of the total volume of the putter head 1700.

[0149] Due to the high percentage of volume comprised by the lower portion 1708, the lower portion can also comprise a sufficiently high percentage of the mass of the putter head 1700. The lower portion 1708 comprises at least 85% of the total mass of the putter head 1700. In some embodiments, the lower portion 1708 comprises at least 86% of the total mass of the putter head 1700, at least 87% of the total mass of the putter head 1700, at least 88% of the total mass of the putter head 1700, at least 89% of the total mass of the putter head 1700, at least 90% of the total mass of the putter head 1700, at least 91% of the total mass of the putter head 1700, at least 92% of the total mass of the putter head 1700, at least 93% of the total mass of the putter head 1700, at least 94% of the total mass of the putter head 1700, or at least 95% of the total mass of the putter head 1700.

[0150] The beneficial shift of mass to the periphery of the putter head 1700 increases the MOI of the putter head 1700 through the use of a dense lower portion 1708 and heel mass 1743 and toe mass 1741. The putter head 1700 provides an increased MOI over a putter of the same volume, mass and single material construction (e.g., a putter milled from a single block of stainless steel or a putter investment cast from a single material).

[0151] c. Crescent-shaped embodiment In one embodiment, the putter-type golf club head can be a crescent-shaped putter head 300. Referring to Figures 3A-3C, the crescent-shaped putter head 300 has an upper portion 304 and a lower portion 308. The upper portion 304 is made from a first material having a first density, and the lower portion 308 is made from a second material having a second density. The first density is less than the second density. The upper portion 304 and the lower portion 308 combine to create a balanced putter head 300 while maintaining a desired volume and mass. The high density lower portion 308 and the low density upper portion 304 place more mass near the perimeter of the putter head 300. Thus, the MOI and stability are increased relative to a putter having the same volume, mass, and single material construction.

[0152] As mentioned above, the lower portion 308 is constructed from a high density material (i.e., the second material). The lower portion 308 includes a rear perimeter 352, a toe end 312, a heel end 316, a striking face 320, a rear wall 332, a back edge 334, a crown 342, and a lower surface (not shown). The lower surface and the upper portion 304 form a sole 368. The toe end 312 is opposite the heel end 316. The toe end 312 and heel end 316 of the lower portion 308 include a toe side perimeter 356 and a heel side perimeter 360, respectively. The striking face 320 faces the rear wall 332 from the toe end 312 to the heel end 316. The rear wall 332 is opposite and generally parallel to the striking face 320. The lower portion further includes a heel perimeter 360 , a toe perimeter 356 , a front edge 348 , and an upper edge 312 .

[0153] The front edge 348 is adjacent to a toe side perimeter 356 and a heel side perimeter 360, and is opposite the rear perimeter 352. The toe side perimeter 356 is adjacent to the front edge 348 and the rear perimeter 352, and is opposite the heel side perimeter 360. The heel side perimeter 360 is also adjacent to the front edge 348 and the rear perimeter 352, but is opposite the toe side perimeter 356.

[0154] In most embodiments, the toe side perimeter 356 extends perpendicularly from the front edge 348 toward the back edge 352 such that a right angle (90° angle) is formed at the junction of the toe side perimeter 356 and the front edge 348. However, in other embodiments, the toe side perimeter 356 can extend in any direction from the front edge 348 such that any angle (0°-180°) can be formed at the junction of the toe side perimeter 356 and the front edge 348. Further, in most embodiments, the heel side perimeter 360 extends perpendicularly from the front edge 348 such that a right angle (90° angle) is formed at the junction of the heel side perimeter 360 and the front edge 348. However, in other embodiments, the heel side perimeter 360 can extend in any direction from the front edge 348 such that any angle (0°-180°) can be formed at the junction of the heel side perimeter 360 and the front edge 348.

[0155] The front edge 348, the toe side perimeter 356, and the heel side perimeter 360 form an opening 364. The opening 364 is bounded by the front edge 348, the toe side perimeter 356, and the heel side perimeter 360. The opening 364 moves the majority of the putter's volume and mass to the end of the lower portion 308. Although the opening 364 can include any shape, in one embodiment, the opening 364 is approximately rectangular. In other embodiments, the opening 364 can be circular, curvilinear, triangular, trapezoidal, parabolic, golf ball shaped, square, or any other desired geometric shape.

[0156] The top 304 of the putter head 300 includes a crown 342, a front edge 370, and a back edge 334. The crown 342 extends away from the front edge 370 to the back edge 334 of the top 304. With the crown 342 spanning from the front edge 348 to the back edge 334, the underside is opposite.

[0157] In some embodiments, the heel side perimeter 360 and the toe side perimeter 356 may be parallel, but in some embodiments, the heel side perimeter 360 and the toe side perimeter 356 are not parallel. In some embodiments, the rear perimeter 352 and the front edge 348 may be parallel, but in some embodiments, the rear perimeter 352 and the front edge 348 are not parallel. The rear perimeter 352 of the crescent putter head 300 is approximately crescent shaped, and thus the rear perimeter 352 and the front edge 348 are not parallel. The rear perimeter 352 may be a curve extending from the heel side perimeter 360 to the toe side perimeter 356. The rear perimeter 352 includes a curved length measured along the rear perimeter 352 from the junction between the heel side perimeter 360 and the rear perimeter 352 to the junction between the toe side perimeter 356 and the rear perimeter 352. In some embodiments, the curvilinear length of the rear perimeter 352 can be between 4.5 inches and 6.5 inches. In some embodiments, the curvilinear length of the rear perimeter can be between 4.5 inches and 4.75 inches, 4.75 inches and 5.0 inches, 5.0 inches and 5.25 inches, 5.25 inches and 5.5 inches, 5.5 inches and 5.75 inches, 5.75 inches and 6.0 inches, 6.0 inches and 6.25 inches, or 6.25 inches and 6.5 inches.

[0158] When the upper and lower portions 304, 308 are joined, the crown 342 extends between the striking face 320 to the rear perimeter 352. In most embodiments, the crown 342 spans approximately the inner 25% of the overall club head 300 width from the toe perimeter 356 and approximately the inner 25% of the overall club head 300 width from the heel perimeter 360. In other embodiments, the crown 342 may span the entire width of the entire club head 300 from the heel 316 to the toe 312, either continuously or discontinuously. In some embodiments, the crown 342 may span less than 90% of the overall width of the club head 300, less than 80% of the overall width of the club head 300, less than 70% of the overall width of the club head 300, less than 60% of the overall width of the club head 300, less than 50% of the overall width of the club head 300, less than 40% of the overall width of the club head 300, or less than 30% of the overall width of the club head 300. Additionally, in some embodiments, the crown 342 can be substantially flat from the striking face 320 to the back edge 334, or can rise from the striking face 320 to the back edge 334. In most embodiments, the rise or fall of the crown 342 can be a linear, curvilinear, parabolic, sinusoidal, or polynomial function.

[0159] The crown 342 further includes an alignment trough 355. The alignment trough 355 is equidistant from the heel end 316 and the toe end 312. The alignment trough 355 is adjacent the rear wall 328 and is approximately perpendicular to the striking face. The alignment trough 355 is bounded by the back edge 334, the rear wall 332, and the crown 342 on the heel end 316 and on the toe end 312. In most embodiments, the alignment trough provides the viewer with a visual alignment field approximately equal to and extending the width of a golf ball (approximately 4.27 cm).

[0160] Additionally, the top 304 of the putter head 300 may include one or more alignment features 344 on the crown 342. The alignment features 344 may be any one or combination of a line, a series of lines, a milled trough, a circle, a dashed line, a triangle, a channel, or any other desired alignment features 344. The alignment features 344 may be evenly spaced across the entire crown 342, a portion of the crown 342, or on the alignment troughs 355. The alignment features 344 extending along the alignment troughs 355 function to provide the viewer with a visual alignment field that extends the width of a golf ball from the rear wall 332 to the back edge 334 of the putter 300. The objective is to align the entire putter 300 with a golf ball using these alignment features 344 along the crown 342 and / or alignment troughs 355.

[0161] 3C, the upper portion 304 can be affixed to the lower portion 308 such that the upper portion 304 is further from the ground plane than the lower portion 308. Here, the ground plane 372 contacts the lower portion 308 when the putter head 300 is in an address position to strike a golf ball.

[0162] 3C, the striking face 320 of the putter head 300 includes a striking face center point 376 and a loft plane 380. The striking face center point 376 is equidistant from the crown 342 and the underside of the top portion 304, as well as equidistant from the heel end 316 and the toe end 312 of the putter head 300. The loft plane 380 is tangent to the striking face 320 of the putter head 300. Additionally, the mid-plane 316 intersects the striking face center point 376 and is perpendicular to the loft plane 380. Additionally, with reference to FIG. 3B, a y-axis 388 intersects the mid-plane 384 and is perpendicular to the ground plane 372.

[0163] When the upper portion 304 and lower portion 308 are joined, the heel end 316 overlaps at least a portion of the toe side perimeter 356. Additionally, when the upper portion 304 and lower portion 308 are joined, the toe end 312 overlaps at least a portion of the heel side perimeter 360. Additionally, when the upper portion 304 and lower portion 308 are joined, the striking face 320 overlaps at least a portion of the front edge 316. Finally, the upper portion 304 and lower portion 308 are joined such that the back edge 364 overlaps at least a portion of the rear perimeter 332.

[0164] The front edge 316, rear perimeter 332, toe perimeter 356, and heel perimeter 360 of the lower portion 308 combine with the upper portion 304 to form a sole 368. The sole 368 is perpendicular to a ground plane 372, which is tangent to the sole 368 when the putter head 300 is in an address position to strike a golf ball. The sole 368 of the putter head 300 extends from the toe end 312 of the putter head 300 to the heel end 316 of the putter head 300.

[0165] In most embodiments, the sole 368 of the putter head 300 may be completely flat. In some embodiments, the sole 368 of the putter head 300 may have a slight arch in the direction from the heel 324 to the toe 320, where the slight arch may be a linear or polynomial function. In some embodiments, the sole 368 of the putter head 300 may have a strong arch in the direction from the heel 324 to the toe 320, where the strong arch may be a linear or polynomial function. The sole 368 functions to provide a surface for the putter head 300 to rest on the ground plane 372.

[0166] 3A , in one embodiment, the lower portion 308 can further comprise a toe mass 341 and a heel mass 343. The toe mass 341 and the heel mass 343 are integral with the lower portion 308 and are in contact with the toe side perimeter 356 and the heel side perimeter 360, respectively. The toe mass 341 and the heel mass 343 extend from the lower portion 308 in a direction away from the ground plane 372 and towards the upper portion 304. The toe mass 341 and the heel mass 343 provide a means for positioning and aligning the upper portion 304 with the lower portion 308 of the putter head 300.

[0167] Additionally, the toe mass 341 and heel mass 343 provide additional means of adding weight to the periphery to increase the MOI of the crescent putter head 300 when compared to a putter without these mass features. These mass features can have weights ranging from 2-5 grams, 3-7 grams, or 1-6 grams. The mass features can all have the same weight or can be of different weights within the above ranges. The weights of the mass features can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The toe mass 341 and heel mass 343 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, crescent, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0168] 3A , the toe mass 341 and the heel mass 343 can be positioned away from the rear perimeter 352, where the toe mass 341 and the heel mass 343 do not contact or intersect the rear perimeter 352. However, in other embodiments, the toe mass 341 and the heel mass 343 can be positioned on the rear perimeter 352, where the toe mass 341 and the heel mass 343 are integral with and intersect the rear perimeter 352.

[0169] In one embodiment, the toe mass 341 is located on the front edge 348 at the junction of the toe side perimeter 356 and the front edge 348, but in other embodiments, the toe mass 341 can be located anywhere along the toe side perimeter 356. In one embodiment, the heel mass 343 is located on the front edge 348 at the junction of the heel side perimeter 360 and the front edge 348, but in other embodiments, the heel mass 343 can be located anywhere along the heel side perimeter 360.

[0170] The toe mass 341 and heel mass 343 provide an area of ​​concentrated mass such that the toe mass 341 and heel mass 343 function to increase the moment of inertia of the putter head 300. Because the toe mass 341 and heel mass 343 are far from the center of gravity of the putter 300, locating the toe mass 341 on or near the front edge 348 and on or near the toe side perimeter 356 and the heel mass 343 on or near the front edge 348 and on or near the heel side perimeter 360, respectively, increases the MOI. The toe mass 341 and heel mass 343 can be integrally formed from a second material, the second material being denser than the first material.

[0171] The toe mass 341 and heel mass 343 serve two functions, as the toe mass 341 and heel mass 343 not only increase the MOI of the putter 300, but also provide an additional surface for the upper portion 304 to bond to the lower portion 308. Thus, the toe mass 341 may also be referred to as the front toe attachment portion 341, and the heel mass 343 may also be referred to as the front heel attachment portion 343.

[0172] In some embodiments, the underside of the upper portion 304, the crown 342, the front edge 370, and the back edge 334 can form a first cavity (not shown). The first cavity extends inwardly from the underside of the toe end 312 toward, but not to, the crown 342. The first cavity is bounded by the back edge 334, the crown 342, and the front edge 370. The first cavity functions to receive the toe mass 341 of the lower portion 308.

[0173] In some embodiments, the underside of the upper portion 304, the crown 342, the front edge 370, and the back edge 334 can form a second cavity (not shown). The second cavity extends inwardly from the underside of the heel end 316 toward, but not to, the crown 342. The second cavity is bounded by the back edge 334, the crown 342, and the front edge 370. The second cavity functions to receive the heel mass 343 of the lower portion 308.

[0174] The first and second cavities can include any desired geometric shape. However, in most embodiments, the first and second cavities comprise a geometric shape similar or identical to that of the corresponding toe mass 341 or heel mass 343. Furthermore, when the upper portion 304 is secured to the lower portion 308, the first cavity is positioned such that the first cavity surrounds the toe mass 341 and the second cavity is positioned such that the second cavity surrounds the heel mass 343.

[0175] The combination of the lower density first material upper portion 304 and the higher density second material lower portion 308 creates a high MOI putter 300 without creating an excessively heavy putter. The large opening 364 formed by the rear wall 332, rear perimeter 352, toe perimeter 356, and heel perimeter 360 of the lower portion 308 creates a high density, but low volume portion that can increase the MOI of the putter (compared to a putter milled from a single material). A single material putter cannot allocate high density material to the perimeter while maintaining the desired volume (50cc-75cc) and mass (340g-385g).

[0176] The lower portion 308, in most embodiments, comprises less than 38% of the volume of the putter 300. In some embodiments, the lower portion 308 comprises less than 37% of the total volume of the putter 300, less than 36% of the total volume of the putter 300, less than 35% of the total volume of the putter 300, less than 34% of the total volume of the putter 300, less than 33% of the total volume of the putter 300, less than 32% of the total volume of the putter 300, less than 31% of the total volume of the putter 300, less than 30% of the total volume of the putter 300, less than 29% of the total volume of the putter 300, less than 28% of the total volume of the putter 300, or less than 27% of the total volume of the putter 300.

[0177] Although the lower portion 308 comprises less than half the volume of the putter 300, the lower portion 308 comprises at least 45% of the total mass of the putter 300. In some embodiments, the lower portion 308 comprises at least 46% of the mass of the putter 300, at least 46% of the mass of the putter 300, at least 47% of the mass of the putter 300, at least 48% of the mass of the putter 300, at least 49% of the mass of the putter 300, at least 50% of the mass of the putter 300, at least 51% of the mass of the putter 300, at least 52% of the mass of the putter 300, at least 53% of the mass of the putter 300, at least 54% of the mass of the putter 300, or at least 55% of the total mass of the putter 300.

[0178] The beneficial shift of mass to the perimeter of the putter head 300 increases the MOI of the putter 300 over a putter having the same volume, mass, and single-material construction (i.e., a putter milled out of a single stainless steel block, or a single-material putter investment cast).

[0179] d. Semicircular embodiment In one embodiment, the putter-type golf club head may be a semi-circular putter head 400. With reference to FIGS. 4A-4C, the semi-circular putter head 400 has an upper portion 404 and a lower portion 408. The upper portion 404 is made from a first material having a first density and the lower portion 408 is made from a second material having a second density. The first density is less than the second density. The upper portion 404 and the lower portion 408 combine to provide a high MOI putter head 400 (5000 g cm) while maintaining a desired volume and mass. 2 -6500g·cm 2 )

[0180] As described above, the lower portion 408 is constructed from a high density material (i.e., the second material). The lower portion 408 includes a front edge 448, a rear perimeter 452, a toe span 456, and a heel span 460. The lower portion 408 and the underside of the upper portion 404 combine to form a sole 468. The front edge 448 is adjacent to the toe span 456 and the heel span 460, and opposite the rear perimeter 452. The toe span 456 is adjacent to the front edge 448 and the rear perimeter 452, and opposite the heel span 460. The heel span 460 is also adjacent to the front edge 448 and the rear perimeter 452, but opposite the toe span 456. The toe span 456 and the heel span 460 extend beyond the rear perimeter 448 of the upper portion 404. In some embodiments, the heel span 460 and the toe span 456 can be parallel, but in some embodiments, the heel span 460 and the toe span 456 are not parallel. In some implementations, the rear perimeter 452 and the front edge 448 can be parallel, but in some implementations, the rear perimeter 452 and the front edge 448 are not parallel. In this embodiment, the rear perimeter 452 is approximately semicircular, and thus the rear perimeter 452 and the front edge 448 are not parallel.

[0181] In most embodiments, the toe span 456 extends perpendicularly from the front edge 448 such that a right angle (90° angle) is formed at the junction of the toe span 456 and the front edge 448. However, in other embodiments, the toe span 456 can extend in any direction from the front edge 448 such that any angle (0°-180°) can be formed at the junction of the toe span 456 and the front edge 448. Further, in most embodiments, the heel span 460 extends perpendicularly from the front edge 448 such that a right angle (90° angle) is formed at the junction of the heel span 460 and the front edge 448. However, in other embodiments, the heel span 460 can extend in any direction from the front edge 448 such that any angle (0°-180°) can be formed at the junction of the heel span 460 and the front edge 448.

[0182] The front edge 448, the toe span 456, and the heel span 460 form a gap 464. The gap 464 is bounded by the front edge 448, the toe span 456, and the heel span 460. The gap 464 formed by the front edge 448, the toe span 456, and the heel span 460 moves the majority of the putter's volume and mass to the end of the lower portion 408. While the gap 464 can include any shape, in one embodiment, the gap is approximately rectangular. In other embodiments, the gap 464 can be circular, curvilinear, triangular, trapezoidal, parabolic, golf ball shaped, square, or any other desired geometric shape.

[0183] The top 404 of the putter head 400 includes a toe end 412, a heel end 416, a striking face 420, a rear wall 432, a back edge 434, a crown 442, and an underside (not shown). The toe end 412 is opposite the heel end 416. The striking face 420 extends from the toe end 412 to the heel end 416 and is opposite the rear wall 432. The rear wall 432 is opposite and generally parallel to the striking face 420. The crown 442 extends away from the striking face 420 to the back edge 434 of the top 404. Additionally, the underside is opposite the crown 442, which spans from the striking face 420 to the back edge 434.

[0184] The crown 442 further descends from the striking face 420 to the back edge 434. Additionally, the crown 442 extends away from the striking face 420, past the front edge 448 of the lower portion 408, to the back edge 434 of the upper portion 404. In most embodiments, the crown 442 spans approximately the inner 25% of the width of the entire club head 400 from the toe span 456 and approximately the inner 25% of the width of the entire club head 400 from the heel span 460. In other embodiments, the crown 442 can span the entire width of the entire club head 400 in a heel-to-toe direction, either continuously or discontinuously. In some embodiments, the crown 442 can span less than 90% of the overall width of the club head 400, less than 90% of the overall width of the club head 400, less than 80% of the overall width of the club head 400, less than 70% of the overall width of the club head 400, less than 60% of the overall width of the club head 400, less than 50% of the overall width of the club head 400, less than 40% of the overall width of the club head 400, or less than 30% of the overall width of the club head 400. Further, in some embodiments, the crown 442 can be substantially flat from the striking face 420 to the back edge 434 or can rise from the striking face 420 to the back edge 434. In most embodiments, the rise or fall of the crown 442 can be a linear, curvilinear, parabolic, sinusoidal, or polynomial function.

[0185] The crown 442 further includes an alignment trough 455. The alignment trough 455 is equidistant from the heel end 416 and the toe end 412. The alignment trough 455 is adjacent the rear wall 432 and is approximately perpendicular to the striking face 420. The alignment trough 455 is bounded by the back edge 434, the rear wall 432, and the crown 442 on the heel end 416, and toe end 412. In most embodiments, the alignment trough 455 provides the viewer with a visual alignment field approximately equal to and extending across the width of a golf ball (approximately 4.27 cm or 1.68 inches).

[0186] Additionally, the top 404 of the putter head 400 may include one or more alignment features 444 on the crown 442. The alignment features 444 may be any one or combination of lines, a series of lines, milled troughs, circles, dashed lines, triangles, channels, or any other desired alignment features 444. The alignment features 444 may be evenly spaced across the entire crown 442, a portion of the crown 442, or on the alignment troughs 455. The alignment features 444 extending along the alignment troughs 455 function to provide the viewer with a visual alignment field that extends the width of a golf ball from the rear wall 432 to the back edge 434 of the putter 400. The objective is to align the entire putter 400 to the golf ball using these alignment features 444 along the crown 442 and / or alignment troughs 455.

[0187] 4C, the upper portion 404 is affixed to the lower portion 408 such that the upper portion 404 is further away from the ground plane 472 than the lower portion 408, where the ground plane 472 contacts the lower portion 408 when the putter head 400 is in an address position to strike a golf ball.

[0188] Additionally, the striking face 420 of the putter head 400 comprises a striking face center point 476 and a loft plane 480. The striking face center point 476 is equidistant from the crown 442 and the underside of the top portion 404, as well as equidistant from the heel end 416 and the toe end 412 of the putter head 400. The loft plane 480 is tangent to the striking face 420 of the putter head 400. Additionally, a mid-plane 484 intersects the striking face center point 476 and is perpendicular to the loft plane 480. Additionally, a y-axis 488 intersects the mid-plane 484 and is perpendicular to the ground plane 472.

[0189] When the upper portion 404 and the lower portion 408 are joined, the heel end 416 overlaps at least a portion of the toe span 456. Additionally, when the upper portion 404 and the lower portion 408 are joined, the toe end 412 overlaps at least a portion of the heel span 460. Additionally, when the upper portion 404 and the lower portion 408 are joined, the striking face 420 overlaps at least a portion of the front edge 448. Finally, the upper portion 404 and the lower portion 408 are joined such that the back edge 434 overlaps at least a portion of the rear perimeter 452.

[0190] The rear perimeter 452 may be curvilinear from the heel side 416 to the toe side 416. The rear perimeter 452 includes a curvilinear length measured along the rear perimeter 452 from the junction between the heel side 416 and the rear perimeter 452 to the junction between the toe side 416 and the rear perimeter 452. In some embodiments, the curvilinear length of the rear perimeter 452 may be between 4.5 inches and 8.0 inches. In some embodiments, the curvilinear length of the rear perimeter 452 may be between 4.5 inches and 4.75 inches, between 4.75 inches and 5.0 inches, between 5.25 inches and 5.5 inches, between 5.75 inches and 6.0 inches, between 6.25 inches and 6.5 inches, between 6.5 inches and 6.75 inches, between 6.75 inches and 7.0 inches, between 7.25 inches and 7.50 inches, or between 7.75 inches and 8.0 inches.

[0191] The front edge 448, rear perimeter 452, toe span 456, and heel span 460 of the lower portion 408 combine with the upper portion 404 to form a sole 468. The sole 468 is perpendicular to a ground plane 472, which contacts the sole 468 when the putter head 400 is in an address position for striking a golf ball. The sole 468 of the putter head 400 extends from the toe end 412 of the putter head 400 to the heel end 416 of the putter head 400.

[0192] In most embodiments, the sole 468 of the putter head 400 may be completely flat. In some embodiments, the sole 468 of the putter head 400 may have a slight arch in the direction from the heel 416 to the toe 412, where the slight arch may be a linear or polynomial function. In some embodiments, the sole 468 of the putter head 400 may have a strong arch in the direction from the heel 416 to the toe 412, where the strong arch may be a linear or polynomial function. The sole 468 functions to provide a surface for resting the putter head 400 on the ground plane 472.

[0193] Referring to FIG. 4A, in one embodiment, the lower portion 408 can further comprise a front toe mass 441 and a front heel mass 443. The front toe mass 441 and the front heel mass 443 are integral to the lower portion 408. The front toe mass 441 and the front heel mass 443 extend from the lower portion 408 in a direction away from the ground plane 472 and towards the upper portion 404. These mass features provide a means to position and align the upper portion 404 with the lower portion 408 of the putter head 400. Additionally, these mass features (i.e., the front toe mass 441 and the front heel mass 443) provide an additional means to add weight to the perimeter to increase the MOI of the putter 400 over a putter without these mass features. These mass features can have weights ranging from 2-5 grams, 3-7 grams, or 1-6 grams. The mass features can all have the same weight or can be of different weights within the above ranges. The mass function can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front toe mass 441 and the front heel mass 443 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0194] In FIG. 4A, the front toe mass 441 and the front heel mass 443 are located away from the rear perimeter 452. Here, the front toe mass 441 and the front heel mass 443 do not contact or intersect the rear perimeter 452. However, referring to FIGS. 5A-5C, a modified semicircular shaped putter 500 is shown. The putter 500 has the same features as the putter 400, but the front toe mass 541 and the front heel mass 543 of the putter 500 are located on the rear perimeter 552. The front toe mass 541 and the front heel mass 543 are integral with and intersect the rear perimeter 452.

[0195] In one embodiment, the front toe mass 441 is located on the front edge 448 at the junction of the toe side span 456 and the front edge 448. However, in other embodiments, the front toe mass 441 may be located anywhere along the toe side span 456. In one embodiment, the front heel mass 443 is located on the front edge 448 at the junction of the heel side span 460 and the front edge 448. However, in other embodiments, the front heel mass 443 may be located anywhere along the heel side span 460.

[0196] The front toe mass 441 and the front heel mass 443 provide an area of ​​concentrated mass such that each mass 441, 443 functions to increase the moment of inertia of the putter head 400. Locating each mass 441, 443 at the front edge 448 and spans 456, 460 increases the MOI because each mass 441, 443 is away from the center of gravity of the putter 400. Each mass 441, 443 on the perimeter 448 and spans 456, 460 is integrally formed from a second material, the second material being denser than the first material.

[0197] The front toe mass 441 and the front heel mass 443 serve two functions, as the front toe mass 441 and the front heel mass 443 not only increase the MOI of the putter 400, but also provide an additional surface for the upper portion 404 to bond to the lower portion 408. Thus, the front toe mass 441 may also be referred to as the front toe attachment portion 441, and the front heel mass 443 may also be referred to as the front heel attachment portion 443.

[0198] In some embodiments, the underside of the upper portion 404, the striking face 420, and the rear wall 432 can form a first cavity (not shown). The first cavity extends inwardly from the underside of the toe end 412 toward, but not to, the crown 442. The first cavity is bounded by the rear wall 432, the striking face 420, and the toe 412. The first cavity functions to receive a front toe mass 441 of the lower portion 408.

[0199] In some embodiments, the underside of the upper portion 404, the striking face 420, and the rear wall 432 can form a second cavity (not shown). The second cavity extends inwardly from the underside of the heel end 416 toward, but not to, the crown 442. The second cavity is bounded by the rear wall 432, the striking face 420, and the heel 416. The second cavity functions to receive the front heel mass 443 of the lower portion 408.

[0200] The first and second cavities can include any desired geometric shape, however, in most embodiments, the first and second cavities include geometric shapes similar or identical to the geometric shapes of the front toe mass 441 and the front heel mass 443. Furthermore, when the upper portion 704 is secured to the lower portion 408, the first cavity is positioned such that the first cavity surrounds the front toe mass 441 and the second cavity is positioned such that the second cavity surrounds the front heel mass 443.

[0201] The combination of a lower density first material upper portion 404 and a higher density second material lower portion 408 creates a high MOI putter 400 without creating an excessively heavy putter. The large gap 464 formed by the spans 456, 460 of the rear perimeter 452 and lower portion 408 creates a high density, but low volume portion that increases the MOI of the putter (compared to a putter milled from a single material). A single material putter cannot allocate high density material to the perimeter while maintaining the desired volume (75cc-100cc) and mass (340 grams-385 grams).

[0202] The lower portion 408, in most embodiments, comprises less than 38% of the volume of the putter 400. In some embodiments, the lower portion 408 comprises less than 37% of the total volume of the putter 400, less than 36% of the total volume of the putter 400, less than 35% of the total volume of the putter 400, less than 34% of the total volume of the putter 400, less than 33% of the total volume of the putter 400, less than 32% of the total volume of the putter 400, less than 31% of the total volume of the putter 400, less than 30% of the total volume of the putter 400, less than 29% of the total volume of the putter 400, less than 28% of the total volume of the putter 400, or less than 27% of the total volume of the putter 400.

[0203] Although the lower portion 408 comprises less than half the volume of the putter 400, the lower portion 408 comprises at least 45% of the total mass of the putter 400. In some embodiments, the lower portion 408 comprises at least 46% of the mass of the putter 400, at least 46% of the mass of the putter 400, at least 47% of the mass of the putter 400, at least 48% of the mass of the putter 400, at least 49% of the mass of the putter 400, at least 50% of the mass of the putter 400, at least 51% of the mass of the putter 400, at least 52% of the mass of the putter 400, at least 53% of the mass of the putter 400, at least 54% of the mass of the putter 400, or at least 55% of the mass of the putter 400.

[0204] The beneficial shift of mass to the periphery of the putter head 400, through the use of a high density, low volume lower portion 408, increases the MOI of the putter 400 over a putter having the same volume, mass, and single material construction (i.e., a putter milled from a single stainless steel block, or a single material putter investment casting).

[0205] e. Wing-shaped embodiment In one embodiment, the putter-type golf club head can be a wing-shaped putter head having a perimeter span 600. With reference to FIGS. 6A and 6B , the wing-shaped putter head 600 has an upper portion 604 and a lower portion 608. The upper portion 604 is made from a first material having a first density and the lower portion 608 is made from a second material having a second density. The first density is less than the second density. The upper portion 604 and the lower portion 608 combine to provide a high MOI putter head 600 (5000 g cm) while maintaining a desired volume and mass. 2 -6500g·cm 2 )

[0206] As discussed above, the lower portion 608 is constructed from a high density material (i.e., the second material). The lower portion 608 includes a front perimeter 648, a sole 668, a rear perimeter 652, a toe wing 656, and a heel wing 660. As discussed below, FIG. 6C shows the front perimeter 648, rear perimeter 652, toe wing 656, and heel wing 660 of the lower portion 608 combining with the upper portion 604 to create the sole 668. The front perimeter 648 is adjacent to the toe perimeter 656 and heel perimeter 660 and opposite the rear perimeter 652. The toe wing 656 is adjacent to the front perimeter 648 and rear perimeter 652 and opposite the heel wing 660. Additionally, the heel side wing 660 is adjacent to the front perimeter 648 and the rear perimeter 652, but opposite the toe side wing 656. The toe side wing 656 and the heel side wing 660 extend beyond the rear perimeter 648 of the upper 604. In some embodiments, the heel side wing 660 and the toe side wing 656 may be parallel, while in some embodiments, the heel side wing 660 and the toe side wing 656 are not parallel. In some implementations, the rear perimeter 652 and the front perimeter 648 may be parallel, while in some implementations, the rear perimeter 652 and the front perimeter 648 are not parallel.

[0207] In most embodiments, the toe side wing 656 extends perpendicularly from the rear perimeter 652 such that a right angle (90° angle) is formed at the junction of the toe side wing 656 and the rear perimeter 652. However, in other embodiments, the toe side wing 656 can extend in any direction from the rear perimeter 652 such that any angle (0°-180°) can be formed at the junction of the toe side wing 656 and the rear perimeter 652. Further, in most embodiments, the heel side wing 660 extends perpendicularly from the rear perimeter 652 such that a right angle (90° angle) is formed at the junction of the heel side wing 660 and the rear perimeter 652. However, in other embodiments, the heel side wing 660 can extend in any direction from the rear perimeter 652 such that any angle (0°-180°) can be formed at the junction of the heel side wing 660 and the rear perimeter 652.

[0208] The front perimeter 648 of the lower portion 608 comprises a front width. The front width is measured from the junction of the toe wing 656 and the front perimeter 648 to the junction of the heel wing 660 and the front perimeter 648. Additionally, the lower portion 608 has a rear width. The rear width is measured from the tip 657 of the toe wing 656 and the tip 661 of the heel wing 660, where the tip 657 is the point of the toe wing 656 that is furthest from the front perimeter 648 and the tip 661 is the point of the heel wing 660 that is furthest from the front perimeter 648. In most embodiments, the front width is greater than the rear width, however, in some embodiments, the front width can be less than or equal to the rear width.

[0209] The rear perimeter 652, the toe wing 656, and the heel wing 660 form a gap 664. The gap 664 is bounded by the rear perimeter 652, the toe wing 656, and the heel wing 660. The gap 664 formed by the rear perimeter 652, the toe wing 656, and the heel wing 660 moves the majority of the putter's volume and mass to the end of the lower portion 608. While the gap 664 can include any shape, in one embodiment, the gap is approximately rectangular. In other embodiments, the gap 664 may be circular, curvilinear, triangular, trapezoidal, parabolic, golf ball shaped, square, or any other desired geometric shape.

[0210] The top 604 of the putter head 600 includes a toe end 612, a heel end 616, a striking face 620, a rear wall 632, a back edge 634, a crown 642, and an underside (not shown). The toe end 612 is opposite the heel end 616. The striking face 620 extends from the toe end 612 to the heel end 616 and is opposite the rear wall 632. The rear wall 632 is opposite and generally parallel to the striking face 620. The crown 642 extends away from the striking face 620 to the back edge 634 of the top 604. Additionally, the underside is opposite the crown 642, which spans from the striking face 620 to the back edge 634.

[0211] The crown 642 further descends from the striking face 620 to the back edge 634. Additionally, the crown 642 extends away from the striking face 620, past the front perimeter 648 of the lower portion 608, to the back edge 634 of the upper portion 604. The crown 642 in most embodiments spans approximately the inner 25% of the total club head 600 width from the toe wing 656 and approximately the inner 25% of the total club head 600 width from the heel wing 660. In other embodiments, the crown 642 can span the entire width of the entire club head 600 in a heel-to-toe direction, either continuously or discontinuously. In some embodiments, the crown 642 can span less than 90% of the overall width of the club head 600, less than 90% of the overall width of the club head 600, less than 80% of the overall width of the club head 600, less than 70% of the overall width of the club head 600, less than 60% of the overall width of the club head 600, less than 50% of the overall width of the club head 600, less than 40% of the overall width of the club head 600, or less than 30% of the overall width of the club head 600. Further, in some embodiments, the crown 642 can be substantially flat from the striking face 620 to the back edge 634 or can rise from the striking face 620 to the back edge 634. In most embodiments, the rise or fall of the crown 642 can be a linear, curvilinear, parabolic, sinusoidal, or polynomial function.

[0212] The crown 642 further includes an alignment trough 655. The alignment trough 655 is equidistant from the heel end 616 and the toe end 612. The alignment trough 655 is adjacent the rear wall 632 and is approximately perpendicular to the striking face 620. The alignment trough 655 is bounded by the back edge 634, the rear wall 632, and the crown 642 on the heel end 616, and toe end 612. In most embodiments, the alignment trough provides the viewer with a visual alignment field approximately equal to the width of a golf ball (approximately 4.27 cm) and extending the width of the golf ball.

[0213] Additionally, the top 604 of the putter head 600 may include one or more alignment features 644 on the crown 642. The alignment features 644 may be any one or combination of lines, a series of lines, milled troughs, circles, dashed lines, triangles, channels, or any other desired alignment features 644. The alignment features 644 may be evenly spaced across the entire crown 642, a portion of the crown 642, or on the alignment troughs 655. The alignment features 644 extending along the alignment troughs 655 function to provide the viewer with a visual alignment field that extends the width of a golf ball from the rear wall 632 to the back edge 634 of the putter 600. The objective is to align the entire putter 600 to the golf ball using these alignment features 644 along the crown 642 and / or alignment troughs 655.

[0214] The upper portion 604 is affixed to the lower portion 608 such that the upper portion 604 is farther away from the ground plane 672 than the lower portion 608. The ground plane 672 contacts the lower portion 608 when the putter head 600 is in an address position to strike a golf ball.

[0215] Additionally, the striking face 620 of the putter head 600 comprises a striking face center point 676 and a loft plane 680. The striking face center point 676 is equidistant from the crown 642 and the underside of the top portion 604, as well as equidistant from the heel end 616 and the toe end 612 of the putter head 600. The loft plane 680 is tangent to the striking face 620 of the putter head 600. Additionally, a mid-plane 684 intersects the striking face center point 676 and is perpendicular to the loft plane 680. Additionally, a y-axis 688 intersects the mid-plane 684 and is perpendicular to the ground plane 672.

[0216] When the upper portion 604 and lower portion 608 are joined, the heel end 616 overlaps at least a portion of the toe wing 656. Additionally, when the upper portion 604 and lower portion 608 are joined, the toe end 612 overlaps at least a portion of the heel wing 660. Additionally, when the upper portion 604 and lower portion 608 are joined, the striking face 620 overlaps at least a portion of the front perimeter 648. Finally, the upper portion 604 and lower portion 608 are joined such that the back edge 634 overlaps at least a portion of the rear perimeter 652.

[0217] 6C, the front perimeter 648, rear perimeter 652, toe wing 656, and heel wing 660 of the lower part 608 combine with the upper part 604 to create a sole 668. The sole 668 is perpendicular to a ground plane 672. The ground plane 672 is tangent to the sole 668 when the putter head 600 is in an address position to strike a golf ball. The sole 668 of the putter head 600 extends from a toe end 612 of the putter head 600 to a heel end 616 of the putter head 600.

[0218] In most embodiments, the sole 668 of the putter head 600 may be completely flat. In some embodiments, the sole 668 of the putter head 600 may have a slight arch in the direction from the heel 616 to the toe 612, where the slight arch may be a linear or polynomial function. In some embodiments, the sole 668 of the putter head 600 may have a strong arch in the direction from the heel 616 to the toe 612, where the strong arch may be a linear or polynomial function. The sole 668 functions to provide a surface for the putter head 600 to rest on the ground plane 672.

[0219] 6A , in one embodiment, the lower portion 608 can further comprise a front toe mass 641, a front heel mass 643, a toe wing mass 645, and a heel wing mass 647. The front toe mass 641, the front heel mass 643, the toe wing mass 645, and the heel wing mass 647 are integral to the lower portion 608. The front toe mass 641, the front heel mass 643, the toe wing mass 645, and the heel wing mass 647 extend from the lower portion 608 in a direction away from the ground plane 672 and towards the upper portion 604. These masses provide a means for positioning and aligning the upper portion 604 with the lower portion 608 of the putter head 600. Additionally, these mass features (i.e., front toe mass 641, front heel mass 643, toe wing mass 645, and heel wing mass 647) provide additional means of adding weight to the perimeter to increase the MOI of the putter 600 over a putter without these mass features. These mass features can have weights ranging from 2-5 grams, 3-7 grams, or 1-6 grams. The mass features can all have the same weight or can be different weights within the above ranges. The mass features can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front toe mass 641, front heel mass 643, toe wing mass 645, and heel wing mass 647 can each be any one or combination of rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0220] In one embodiment, the front toe mass 641 is located on the front perimeter 648 at the junction of the toe wing 656 and the front perimeter 648. However, in other embodiments, the front toe mass 641 may be located anywhere along the front perimeter 648. In one embodiment, the front heel mass 643 is located on the front perimeter 648 at the junction of the heel wing 660 and the front perimeter 648. However, in other embodiments, the front heel mass 643 may be located anywhere along the front perimeter 648. In one embodiment, the toe wing mass 645 may be located on a portion of the toe wing 656, while in other embodiments, the toe wing mass 645 may be located anywhere along a portion or the entirety of the toe wing 656. In one embodiment, the heel wing mass 647 may be located on a portion of the heel wing 660, while in other embodiments, the heel wing mass 647 may be located along a portion or the entirety of the heel wing 660.

[0221] The front toe mass 641, the front heel wing mass 643, the toe wing mass 645, and the heel wing mass 647 provide areas of concentrated mass such that each mass 641, 643, 645, and 647 functions to increase the moment of inertia of the putter head 600. Locating each mass 641, 643, 645, and 647 on the perimeter 648 and wings 656, 660 increases the MOI by moving each mass 641, 643, 645, and 647 away from the center of gravity of the putter 600. Each mass 641, 643, 645, 647 on the perimeter 648 and wings 656, 660 is integrally formed from a second material, the second material being denser than the first material.

[0222] The front toe mass 641 and the front heel mass 643 serve two functions, as the front toe mass 641 and the front heel mass 643 not only increase the MOI of the putter 600, but also provide an additional surface for the upper portion 604 to bond to the lower portion 608. Thus, the front toe mass 641 may also be referred to as the front toe attachment portion 641, and the front heel mass 643 may also be referred to as the front heel attachment portion 643.

[0223] In some embodiments, the underside of the upper portion 604, the striking face 620, and the rear wall 632 can form a first cavity (not shown). The first cavity extends inwardly from the underside above the toe end 612 toward, but not to, the crown 642. The first cavity is bounded by the rear wall 632, the striking face 620, and the toe 612. The first cavity functions to receive the front toe mass 641 of the lower portion 608.

[0224] In some embodiments, the underside of the upper portion 604, the striking face 620, and the rear wall 632 can form a second cavity (not shown). The second cavity extends inwardly from the underside above the heel end 616 toward, but not to, the crown 642. The second cavity is bounded by the rear wall 632, the striking face 620, and the heel 616. The second cavity functions to receive the front heel mass 643 of the lower portion 608.

[0225] The first and second cavities can include any desired geometric shape, however, in most embodiments, the first and second cavities include geometric shapes similar or identical to the geometric shapes of the front toe mass 641 and the front heel mass 643. Furthermore, when the upper portion 604 is secured to the lower portion 608, the first cavity is positioned such that the first cavity surrounds the front toe mass 641 and the second cavity is positioned such that the second cavity surrounds the front heel mass 643.

[0226] The combination of a lower density first material upper portion 604 and a higher density second material lower portion 608 creates a high MOI putter 600 without creating an excessively heavy putter. The large gap 664 formed by the rear perimeter 652 and wings 656, 660 of the lower portion 608 creates a high density, but low volume portion that increases the MOI of the putter (compared to a putter milled from a single material). A single material putter cannot allocate high density material to the perimeter while maintaining the desired volume (75cc-100cc) and mass (340g-385g).

[0227] The lower portion 608, in most embodiments, comprises less than 38% of the total volume of the putter 600. In some embodiments, the lower portion 608 comprises less than 37% of the total volume of the putter 600, less than 36% of the total volume of the putter 600, less than 35% of the total volume of the putter 600, less than 34% of the total volume of the putter 600, less than 33% of the total volume of the putter 600, less than 32% of the total volume of the putter 600, less than 31% of the total volume of the putter 600, less than 30% of the total volume of the putter 600, less than 29% of the total volume of the putter 600, less than 28% of the total volume of the putter 600, or less than 27% of the total volume of the putter 600.

[0228] Although the lower portion 608 comprises less than half the volume of the putter 600, the lower portion 608 comprises at least 45% of the overall mass of the putter 600. In some embodiments, the lower portion 608 comprises at least 46% of the overall mass of the putter 600, at least 46% of the overall mass of the putter 600, at least 47% of the overall mass of the putter 600, at least 48% of the overall mass of the putter 600, at least 49% of the overall mass of the putter 600, at least 50% of the overall mass of the putter 600, at least 51% of the overall mass of the putter 600, at least 52% of the overall mass of the putter 600, at least 53% of the overall mass of the putter 600, at least 54% of the overall mass of the putter 600, or at least 55% of the overall mass of the putter 600.

[0229] The beneficial shift of mass to the perimeter of the putter head 600 by using a high density, low volume lower portion 608 increases the MOI of the putter 600 over a putter having the same volume, mass, and single material construction (i.e., a putter milled out of a single stainless steel block, or a single material putter investment cast).

[0230] f. Spade embodiment In one embodiment, the putter-type golf club head may be a spade-shaped putter head having a perimeter span 700. With reference to FIGS. 7A and 7B, the spade-shaped putter head 700 has an upper portion 704 and a lower portion 708. The upper portion 704 is made from a first material having a first density and the lower portion 708 is made from a second material having a second density. The first density is less than the second density. The upper portion 704 and the lower portion 708 combine to provide a high MOI putter head 700 (5000 g cm) while maintaining a desired volume and mass. 2 -6500g·cm 2 )

[0231] As discussed above, the lower portion 708 is constructed from a high density material (i.e., the first material), thereby lowering mass below the midline 784. The lower portion 708 includes a front perimeter 748, a rear perimeter 752, a toe side perimeter 756, and a heel side perimeter 760. The front perimeter 748 is adjacent to the toe side perimeter 756 and the heel side perimeter 760 and is opposite the rear perimeter 752. The toe side perimeter 756 is adjacent to the front perimeter 748 and the rear perimeter 752 and is opposite and opposite the heel side perimeter 760. The heel side perimeter 760 is also adjacent to the front perimeter 748 and the rear perimeter 752, but is opposite the toe side perimeter 756. In some embodiments, the heel side perimeter 760 and the toe side perimeter 756 can be parallel, but in some embodiments, the heel side perimeter 760 and the toe side perimeter 756 are not parallel. In some embodiments, the rear perimeter 752 and the front perimeter 748 can be parallel, while in some embodiments, the rear perimeter 752 and the front perimeter 748 are not parallel.

[0232] The front perimeter 748 of the lower portion 708 comprises a front width. The front width is measured from the junction of the toe side perimeter 756 and the front perimeter 748 to the junction of the heel side perimeter 760 and the front perimeter 748. And, the rear perimeter 752 of the lower portion 708 comprises a rear width. The rear width is measured from the junction of the toe side perimeter 756 and the rear perimeter 752 to the junction of the heel side perimeter 760 and the rear perimeter 752. In most embodiments, the front width is greater than the rear width, but in some embodiments, the front width can be less than or equal to the rear width.

[0233] The front perimeter 748, rear perimeter 752, toe side perimeter 756, and heel side perimeter 760 join to form an opening 764, where the opening 764 is bounded by four perimeters (front 748, rear 752, toe side 756, and heel side 760). The four perimeters 756, 752, 756, 760 form a perimeter around the opening 764. The central opening 764 formed by the perimeters 756, 752, 756, 760 of the lower portion 708 moves the majority of the putter's volume and mass to the end of the lower portion 708.

[0234] The top 704 of the putter head 700 includes a toe end 712, a heel end 716, a striking face 720, a rear wall 732, a back edge 734, a crown 742, and a lower surface (not shown). The toe end 712 is opposite the heel end 716. The striking face 720 extends from the toe end 712 to the heel end 716 and is opposite the rear wall 732. The rear wall 732 is opposite and generally parallel to the striking face 720. The crown 742 extends away from the striking face 720, over at least a portion of the rear wall 732, to the back edge 734 of the top 704. Additionally, the lower surface is opposite the crown 742 and extends from the striking face 720 to the back edge 734.

[0235] The crown 742 further descends from the striking face 720 to the back edge 734. Additionally, the crown 742 extends away from the striking face 720, over at least a portion of the rear wall 732 and the opening 764 in the lower portion 708, to the back edge 734 of the upper portion 704. The crown 742 in most embodiments spans the inner 25% of the width of the entire club head 700 from the toe side perimeter 756 and the heel side perimeter 760. In this embodiment, the crown 742 spans approximately 50% of the width of the club head 700. In other embodiments, the crown 742 can span the entire width of the entire club head 700 in a heel-to-toe direction. In some embodiments, the crown 742 can span less than 90% of the overall width of the club head 700, less than 90% of the overall width of the club head 700, less than 80% of the overall width of the club head 700, less than 70% of the overall width of the club head 700, less than 60% of the overall width of the club head 700, less than 50% of the overall width of the club head 700, less than 40% of the overall width of the club head 700, or less than 30% of the overall width of the club head 700. Further, in some embodiments, the crown 742 can be substantially flat from the striking face 720 to the back edge 734 or can rise from the striking face 720 to the back edge 734. In most embodiments, the rise or fall of the crown 742 can be a linear, curvilinear, parabolic, sinusoidal, or polynomial function.

[0236] Additionally, the top 704 of the putter head 700 may include one or more alignment features 744 on the crown 742. The alignment features 744 may be any one or combination of lines, a series of lines, milled troughs, circles, dashed lines, triangles, channels, or any other desired alignment features 744. The alignment features 744 are evenly spaced across the crown 742, which is configured to be the width of a golf ball (approximately 4.27 cm). The alignment features 744 extending along the crown 742 function to provide the viewer with a visual alignment field that extends the width of a golf ball from the striking face 720 to the back edge 734 of the putter 700. The objective is to use these alignment features 744 along the crown 742 to align the entire putter 700 to the golf ball.

[0237] 7C, the upper portion 704 is affixed to the lower portion 708 such that the upper portion 704 is further away from the ground plane 772 than the lower portion 708, where the ground plane 772 contacts the lower portion 708 when the putter head 700 is in an address position to strike a golf ball.

[0238] Additionally, the striking face 720 of the putter head 700 comprises a striking face center point 776 and a loft plane 780. The striking face center point 776 is equidistant from the crown 742 and the underside of the top portion 704 as well as equidistant from the heel end 716 and toe end 712 of the putter head 700. The loft plane 780 is tangent to the striking face 720 of the putter head 700. Additionally, a mid-plane 784 intersects the striking face center point 776 and is perpendicular to the loft plane 780. Additionally, a y-axis 788 intersects the mid-plane 784 and is perpendicular to the ground plane 772.

[0239] When the upper portion 704 and lower portion 708 are joined, the heel end 716 overlaps at least a portion of the heel side perimeter 760. Additionally, when the upper portion 704 and lower portion 708 are joined, the toe end 712 overlaps at least a portion of the toe side perimeter 756. Additionally, when the upper portion 704 and lower portion 708 are joined, the striking face 720 overlaps at least a portion of the front perimeter 748. Finally, the upper portion 704 and lower portion 708 are joined such that the back edge 734 overlaps at least a portion of the rear perimeter 752.

[0240] 7D , the four perimeter portions of the lower portion 708 (front 748, rear 752, toe side 756, and heel side 760) combine with the upper portion 704 to create a sole 768. The sole 768 is perpendicular to a ground plane 772. The ground plane 772 contacts the sole 768 when the putter head 700 is in an address position to strike a golf ball. The sole 768 of the putter head 700 extends from a toe end 712 of the putter head 700 to a heel end 716 of the putter head 700.

[0241] In most embodiments, the sole 768 of the putter head 700 may be completely flat. In some embodiments, the sole 768 of the putter head 700 may have a slight arch in the direction from the heel 716 to the toe 712, where the slight arch may be a linear or polynomial function. In some embodiments, the sole 768 of the putter head 700 may have a strong arch in the direction from the heel 716 to the toe 712, where the strong arch may be a linear or polynomial function. The sole 768 functions to provide a surface for resting the putter head 700 on the ground plane 772.

[0242] 7A, in one embodiment, the lower portion 708 can further comprise a front mass 741, a rear mass 743, a toe mass 745, and a heel mass 747. The front mass 741, the rear mass 743, the toe mass 745, and the heel mass 747 are integral to the lower portion 708. The front mass 741, the rear mass 743, the toe mass 745, and the heel mass 747 extend from the lower portion 708 in a direction away from the ground plane 772 and towards the upper portion 704. These masses provide a means for positioning and aligning the upper portion 704 with the lower portion 708 of the putter head 700. Additionally, these masses (i.e., the front mass 741, the rear mass 743, the toe mass 745, and the heel mass 747) provide an additional means for adding weight to the perimeter to increase the MOI of the putter 700 over putters that do not have these mass features. These mass features can have weights ranging from 2-5 grams, 3-7 grams, or 1-6 grams. The mass features can all have the same weight or can be different weights within the above ranges. The mass features can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front mass 741, rear mass 743, toe mass 745, and heel mass 747 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0243] In one embodiment, the front mass 741 is located on the front perimeter 748 and is equidistant from the toe side perimeter 756 and the heel side perimeter 760. However, in other embodiments, the front mass 741 may be located anywhere along the front perimeter 748. In one embodiment, the rear mass 743 is located on the rear perimeter 752 and is equidistant from the toe side perimeter 756 and the heel side perimeter 760. However, in other embodiments, the rear mass 743 may be located anywhere along the rear perimeter 752. In one embodiment, the toe mass 745 may be located at the junction of the toe side perimeter 756 and the rear perimeter 752. However, in other embodiments, the toe mass 745 may be located anywhere along the toe side perimeter 756. In one embodiment, the heel mass 747 may be located at the junction of the heel side perimeter 760 and the rear perimeter 752. However, in other embodiments, the heel mass 747 may be located anywhere along the heel side perimeter 760.

[0244] The front mass 741, rear mass 743, toe mass 745, and heel mass 747 provide areas of concentrated mass such that each mass 741, 743, 745, and 747 functions to increase the moment of inertia of the putter head 700. By locating each mass 741, 743, 745, and 747 on each mass 748, 752, 756, 760, the MOI is increased since each mass 741, 743, 745, and 747 is away from the center of gravity of the putter 700. Each mass 741, 743, 745, 747 on the periphery 748, 752, 756, 760 is integrally formed from a second material, the second material being denser than the first material.

[0245] The front mass 741 and rear mass 743 serve two functions, as the front mass 741 and rear mass 743 not only increase the MOI of the putter 700, but also function to provide an additional surface for the upper portion 704 to interface with the lower portion 708. Thus, the front mass 741 can also be referred to as the front attachment 741 and the rear mass 743.

[0246] In some embodiments, the lower surface of the upper portion 704, the striking face 720, and the rear wall 732 can form a first cavity (not shown). The first cavity extends inwardly from the lower surface toward, but does not reach, the crown 742. The first cavity is bounded by the rear wall 732 and the striking face 720. The first cavity functions to receive the front mass 741 of the lower portion 708.

[0247] In some embodiments, the lower surface, the back edge 734, and the crown 742 form a second cavity (not shown). The second cavity extends inward from the lower surface toward the crown 742, but does not reach the crown 742. The second cavity is bounded by the back edge 734 and the crown 742. In most embodiments, the second cavity is positioned equidistant between the toe side perimeter 756 and the heel side perimeter 760 when the lower portion 708 is joined to the upper portion 704. The second cavity functions to receive the rear mass 743 of the lower portion 708.

[0248] The first and second cavities can include any desired geometric shape, but in most embodiments the first and second cavities include geometric shapes similar or identical to the geometric shapes of the front mass 741 and the rear mass 743. Furthermore, when the upper portion 704 is secured to the lower portion 708, the first cavity is positioned such that the first cavity surrounds the front mass 741 and the second cavity is positioned such that the second cavity surrounds the rear mass 743.

[0249] The combination of the low density first material upper portion 704 and the high density second material lower portion 708 creates a high MOI putter 700 without creating an excessively heavy putter. The large opening 764 formed by the perimeter portions 748, 752, 756, 760 of the lower portion 708 creates a high density, but low volume portion that increases the MOI of the putter (compared to a putter milled from a single material). A single material putter cannot allocate high density material to the perimeter while maintaining the desired volume (75cc-100cc) and mass (340 grams-385 grams).

[0250] The lower portion 708, in most embodiments, comprises less than 35% of the total volume of the putter 700. In some embodiments, the lower portion 708 comprises less than 34% of the total volume of the putter 700, less than 33% of the total volume of the putter 700, less than 32% of the total volume of the putter 700, less than 31% of the total volume of the putter 700, less than 30% of the total volume of the putter 700, less than 29% of the total volume of the putter 700, less than 28% of the total volume of the putter 700, or less than 27% of the total volume of the putter 700.

[0251] Although the lower portion 708 comprises less than half the volume of the putter 700, the lower portion 708 comprises at least 45% of the total mass of the putter 700. In some embodiments, the lower portion 708 comprises at least 46% of the mass of the putter 700, at least 47% of the mass of the putter 700, at least 48% of the mass of the putter 700, at least 49% of the mass of the putter 700, at least 50% of the mass of the putter 700, at least 51% of the mass of the putter 700, at least 52% of the mass of the putter 700, at least 53% of the mass of the putter 700, at least 54% of the mass of the putter 700, or at least 55% of the mass of the putter 700.

[0252] The beneficial shift of mass to the periphery of the putter head 700, through the use of a high density, low volume lower portion 708, increases the MOI of the putter 700 versus a putter having the same volume, mass, and single material construction (i.e., a putter milled from a single stainless steel block, or a single material putter investment casting).

[0253] g. T-Shaped Embodiments with Peripheral Span In one embodiment, the putter-type golf club head can be a T-shaped putter head having a perimeter span 800. With reference to FIGS. 8A and 8B , the T-shaped putter head having a perimeter span 800 has an upper portion 804 and a lower portion 808. The upper portion 804 is made from a first material having a first density and the lower portion 808 is made from a second material having a second density. The first density is less than the second density. The upper portion 804 and the lower portion 808 combine to provide a high MOI putter head 800 (5000 g cm) while maintaining a desired volume and mass. 2 -6500g·cm 2 )

[0254] As discussed above, the lower portion 808 is constructed from a high density material (i.e., the second material), thereby lowering mass below the midline 884. The lower portion 808 includes a front perimeter 848, a rear perimeter 852, a toe side perimeter 856, and a heel side perimeter 860. The front perimeter 848 is adjacent to the toe side perimeter 856 and the heel side perimeter 860 and is opposite the rear perimeter 852. The toe side perimeter 856 is adjacent to the front perimeter 848 and the rear perimeter 852 and is opposite the heel side perimeter 860. The heel side perimeter 860 is also adjacent to the front perimeter 848 and the rear perimeter 852, but is opposite the toe side perimeter 856. In some embodiments, the heel side perimeter 860 and the toe side perimeter 856 can be parallel, but in some embodiments, the heel side perimeter 860 and the toe side perimeter 856 are not parallel. In some embodiments, the rear perimeter 852 and the front perimeter 848 can be parallel, while in some embodiments, the rear perimeter 852 and the front perimeter 848 are not parallel.

[0255] The front perimeter 848 of the lower portion 808 comprises a front width. The front width is measured from the junction of the toe side perimeter 856 and the front perimeter 848 to the junction of the heel side perimeter 860 and the front perimeter 848. And, the rear perimeter 852 of the lower portion 808 comprises a rear width. The rear width is measured from the junction of the toe side perimeter 856 and the rear perimeter 852 to the junction of the heel side perimeter 860 and the rear perimeter 852. In most embodiments, the front width is greater than the rear width, but in some embodiments, the front width can be less than or equal to the rear width.

[0256] The front perimeter 848, rear perimeter 852, toe side perimeter 856, and heel side perimeter 860 join to form an opening 864, where the opening 864 is bounded by four perimeters (front 856, rear 852, toe side 856, and heel side 860). The four perimeters 856, 852, 856, 860 form a perimeter around the opening 864. The central opening 864 formed by the perimeters 856, 852, 856, 860 of the lower portion 808 moves the majority of the putter's volume and mass to the end of the lower portion 808.

[0257] In some embodiments, the opening 864 formed by the front perimeter 848, the rear perimeter 852, the toe side perimeter 856, and the heel side perimeter 860 can be any one of the following shapes: rectangular, triangular, semicircular, circular (golf ball size), circular (larger than a golf ball), circular (smaller than a golf ball), square, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0258] The top 804 of the putter head 800 includes a toe end 812, a heel end 816, a striking face 820, a rear wall 832, a back edge 834, a crown 842, and a lower surface (not shown). The toe end 812 is opposite the heel end 816. The striking face 820 extends from the toe end 812 to the heel end 816 and is opposite the rear wall 832. The rear wall 832 is opposite and generally parallel to the striking face 820. The crown 842 extends away from the striking face 820, over at least a portion of the rear wall 832, to the back edge 834 of the top 804. Additionally, the lower surface is opposite the crown 842 and extends from the striking face 820 to the back edge 834.

[0259] The crown 842 further descends from the striking face 820 to the back edge 834. Additionally, the crown 842 extends away from the striking face 820, over at least a portion of the rear wall 832 and the opening 864 in the lower portion 808, to the back edge 834 of the upper portion 804. The crown 842 in most embodiments spans the inner 25% of the width of the entire club head 800 from the toe perimeter 856 and the heel perimeter 860. In this embodiment, the crown 842 spans approximately 50% of the width of the club head 800, thus forming a "T-shape" with the striking face. In other embodiments, the crown 842 can span the entire width of the entire club head 800 in a heel-to-toe direction. In some embodiments, the crown 842 can span less than 90% of the overall width of the club head 800, less than 90% of the overall width of the club head 800, less than 80% of the overall width of the club head 800, less than 70% of the overall width of the club head 800, less than 60% of the overall width of the club head 800, less than 50% of the overall width of the club head 800, less than 40% of the overall width of the club head 800, or less than 30% of the overall width of the club head 800. Further, in some embodiments, the crown 842 can be substantially flat from the striking face 820 to the back edge 834 or can rise from the striking face 820 to the back edge 834. In most embodiments, the rise or fall of the crown 842 can be a linear, curvilinear, parabolic, sinusoidal, or polynomial function.

[0260] Additionally, the top 804 of the putter head 800 may include one or more alignment features 844 on the crown 842. The alignment features 844 may be any one or combination of lines, a series of lines, milled troughs, circles, dashed lines, triangles, channels, or any other desired alignment features 844. The alignment features 844 are evenly spaced across the crown 842, which is configured to be the width of a golf ball (approximately 4.27 cm). The alignment features 844 extending along the crown 842 function to provide the viewer with a visual alignment field that extends the width of a golf ball from the striking face 820 to the back edge 834 of the putter 800. The purpose is to use these alignment features 844 along the crown 842 to align the entire putter 800 with a golf ball.

[0261] 8C, the upper portion 804 is affixed to the lower portion 808 such that the upper portion 804 is farther from the ground plane 872 than the lower portion 808, where the ground plane 872 contacts the lower portion 808 when the putter head 800 is in an address position to strike the golf ball.

[0262] Additionally, the striking face 820 of the putter head 800 comprises a striking face center point 876 and a loft plane 880. The striking face center point 876 is equidistant from the crown 842 and the underside of the top portion 804, as well as equidistant from the heel end 816 and the toe end 812 of the putter head 800. The loft plane 880 is tangent to the striking face 820 of the putter head 800. Additionally, a mid-plane 884 intersects the striking face center point 876 and is perpendicular to the loft plane 880. Additionally, a y-axis 888 intersects the mid-plane 884 and is perpendicular to the ground plane 872.

[0263] When the upper portion 804 and the lower portion 808 are joined, the heel end 816 overlaps at least a portion of the toe side perimeter 856. Additionally, when the upper portion 804 and the lower portion 808 are joined, the toe end 812 overlaps at least a portion of the heel side perimeter 860. Additionally, when the upper portion 804 and the lower portion 808 are joined, the striking face 820 overlaps at least a portion of the front perimeter 848. Finally, the upper portion 804 and the lower portion 808 are joined such that the back edge 834 overlaps at least a portion of the rear perimeter 852.

[0264] 8D , the four perimeter portions of the lower portion 808 (front 848, rear 852, toe side 856, and heel side 860) combine with the upper portion 804 to form a sole 868. The sole 868 is perpendicular to a ground plane 872. The ground plane 872 contacts the sole 868 when the putter head 800 is in an address position to strike a golf ball. The sole 868 of the putter head 800 extends from a toe end 812 of the putter head 800 to a heel end 816 of the putter head 800.

[0265] In most embodiments, the sole 868 of the putter head 800 may be completely flat. In some embodiments, the sole 868 of the putter head 800 may have a slight arch in the direction from the heel 816 to the toe 812, where the slight arch may be a linear or polynomial function. In some embodiments, the sole 868 of the putter head 800 may have a strong arch in the direction from the heel 816 to the toe 812, where the strong arch may be a linear or polynomial function. The sole 868 functions to provide a surface for resting the putter head 800 on the ground plane 872.

[0266] 8A, in one embodiment, the lower portion 808 can further comprise a front mass 841, a rear mass 843, a toe mass 845, and a heel mass 847. The front mass 841, the rear mass 843, the toe mass 845, and the heel mass 847 are integral with the lower portion 808. The front mass 841, the rear mass 843, the toe mass 845, and the heel mass 847 extend from the lower portion 808 in a direction away from the ground plane 872 and toward the upper portion 804. These masses provide a means for positioning and aligning the upper portion 804 with the lower portion 808 of the putter head 800. Additionally, these masses (i.e., the front mass 841, the rear mass 843, the toe mass 845, and the heel mass 847) provide an additional means for adding weight to the perimeter to increase the MOI of the putter 800 over putters that do not have these mass features. These mass features can have weights ranging from 2-5 grams, 3-7 grams, or 1-6 grams. The mass features can all have the same weight or can be different weights within the above ranges. The mass features can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front mass 841, rear mass 843, toe mass 845, and heel mass 847 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0267] In one embodiment, the front mass 841 is located on the front perimeter 848 and is equidistant from the toe side perimeter 856 and the heel side perimeter 860. However, in other embodiments, the front mass 841 may be located anywhere along the front perimeter 848. In one embodiment, the rear mass 843 is located on the rear perimeter 852 and is equidistant from the toe side perimeter 856 and the heel side perimeter 860. However, in other embodiments, the rear mass 843 may be located anywhere along the rear perimeter 852. In one embodiment, the toe mass 845 may be located at the junction of the toe side perimeter 856 and the rear perimeter 852. However, in other embodiments, the toe mass 845 may be located anywhere along the toe side perimeter 856. In one embodiment, the heel mass 847 may be located at the junction of the heel side perimeter 860 and the rear perimeter 852. However, in other embodiments, the heel mass 847 may be located anywhere along the heel side perimeter 860.

[0268] The front mass 841, rear mass 843, toe mass 845, and heel mass 847 provide areas of concentrated mass such that each mass 841, 843, 845, and 847 functions to increase the moment of inertia of the putter head 800. The placement of each mass 841, 843, 845, and 847 on the perimeter 848, 852, 856, 860 increases the MOI since each mass 841, 843, 845, and 847 is further from the center of gravity of the putter 800. Each mass 841, 843, 845, 847 on the perimeter 848, 852, 856, 860 is integrally formed from a second material, the second material being denser than the first material.

[0269] The front mass 841 and rear mass 843 serve two functions, as the front mass 841 and rear mass 843 not only increase the MOI of the putter 800, but also function to provide an additional surface for the upper portion 804 to bond to the lower portion 808. Thus, the front mass 841 can also be referred to as the front attachment 841 and the rear mass 843.

[0270] In some embodiments, the lower surface of the upper portion 804, the striking face 820, and the rear wall 832 can form a first cavity (not shown). The first cavity extends inwardly from the lower surface toward, but does not reach, the crown 842. The first cavity is bounded by the rear wall 832 and the striking face 820. The first cavity functions to receive the front mass 841 of the lower portion 808.

[0271] In some embodiments, the lower surface, the back edge 834, and the crown 842 form a second cavity (not shown). The second cavity extends inward from the lower surface toward the crown 842, but does not reach the crown 842. The second cavity is bounded by the back edge 834 and the crown 832. In most embodiments, the second cavity is positioned equidistant between the toe side perimeter 856 and the heel side perimeter 860 when the lower portion 808 is joined to the upper portion 804. The second cavity functions to receive the rear mass 843 of the lower portion 808.

[0272] The first and second cavities can include any desired geometric shape, but in most embodiments the first and second cavities include geometric shapes similar or identical to the geometric shapes of the front mass 841 and the rear mass 843. Furthermore, when the upper portion 804 is secured to the lower portion 808, the first cavity is positioned such that the first cavity surrounds the front mass 841 and the second cavity is positioned such that the second cavity surrounds the rear mass 843.

[0273] The combination of a lower density first material upper portion 804 and a higher density second material lower portion 808 creates a high MOI putter 800 without creating an excessively heavy putter. The large opening 864 formed by the perimeter portions 848, 852, 856, 860 of the lower portion 808 creates a high density, but low volume portion that increases the MOI of the putter (compared to a putter milled from a single material). A single material putter cannot allocate high density material to the perimeter while maintaining the desired volume (75cc-100cc) and mass (340 grams-385 grams).

[0274] The lower portion 808, in most embodiments, comprises less than 35% of the total volume of the putter 800. In some embodiments, the lower portion 908 comprises less than 34% of the total volume of the putter 800, less than 33% of the total volume of the putter 800, less than 32% of the total volume of the putter 800, less than 31% of the total volume of the putter 800, less than 30% of the total volume of the putter 800, less than 29% of the total volume of the putter 800, less than 28% of the total volume of the putter 800, or less than 27% of the total volume of the putter 800.

[0275] Although the lower portion 808 comprises less than half the volume of the putter 800, the lower portion 808 comprises at least 45% of the overall mass of the putter 800. In some embodiments, the lower portion 808 comprises at least 46% of the mass of the putter 800, at least 46% of the mass of the putter 800, at least 46% of the mass of the putter 800, at least 47% of the mass of the putter 800, at least 48% of the mass of the putter 800, at least 49% of the mass of the putter 800, at least 50% of the mass of the putter 800, at least 51% of the mass of the putter 800, at least 52% of the mass of the putter 800, at least 53% of the mass of the putter 800, at least 54% of the mass of the putter 800, or at least 55% of the mass of the putter 800.

[0276] The beneficial shift of mass to the periphery of the putter head 800, through the use of a high density, low volume lower portion 808, increases the MOI of the putter 800 versus a putter having the same volume, mass, and single material construction (i.e., a putter milled from a single stainless steel block, or a single material putter investment casting).

[0277] h. Dual rail embodiment In another embodiment, the putter-type golf club head can be a dual rail putter head 900. With reference to FIGS. 9A and 9B, the dual rail putter head 900 has an upper portion 904 and a lower portion 908. The upper portion 904 is made from a first material having a first density and the lower portion 908 is made from a second material having a second density. The first density is less than the second density. The upper portion 904 and the lower portion 908 combine to provide a high MOI putter head 900 (5000 g cm) while maintaining a desired volume and mass. 2 -6500g·cm 2 )

[0278] As mentioned above, the lower portion 908 is constructed from a high density material (i.e., the second material), thereby lowering the mass below the midline 984. The lower portion 908 comprises a front perimeter 948, a rear perimeter 952, a toe side perimeter 956, and a heel side perimeter 960. The front perimeter 948 is adjacent to the toe side perimeter 956 and the heel side perimeter 960 and is opposite the rear perimeter 952. The toe side perimeter 956 is adjacent to the front perimeter 948 and the rear perimeter 952 and is opposite the heel side perimeter 960. The heel side perimeter 956 is also adjacent to the front perimeter 948 and the rear perimeter 952, but is opposite the toe side perimeter 956. In some embodiments, the heel side perimeter 960 and the toe side perimeter 956 may be parallel, while in some embodiments, the heel side perimeter 960 and the toe side perimeter 956 are not parallel. In some embodiments, the rear perimeter 952 and the front perimeter 948 can be parallel, while in some embodiments, the rear perimeter 952 and the front perimeter 948 are not parallel.

[0279] The front perimeter 948 of the lower portion 908 has a front width. The front width is measured from the junction of the toe side perimeter 956 and the front perimeter 948 to the junction of the heel side perimeter 960 and the front perimeter 948. Additionally, the rear perimeter 952 of the lower portion 908 has a rear width. The rear width is measured from the junction of the toe side perimeter 956 and the rear perimeter 952 to the junction of the heel side perimeter 960 and the rear perimeter 952. In most embodiments, the front width is greater than the rear width, however, in some embodiments, the front width can be less than or equal to the rear width.

[0280] The front perimeter 948, rear perimeter 952, toe side perimeter 956, and heel side perimeter 960 join to form an opening 964, where the opening 964 is bounded by four perimeters (front 948, rear 952, toe side 956, and heel side 960). The four perimeters 948, 952, 956, 960 form a perimeter around the opening 964. The central opening 964 formed by the perimeters 948, 952, 956, 960 of the lower portion 908 moves the majority of the putter's volume and mass to the ends of the lower portion 908.

[0281] In some embodiments, the opening 964 formed by the front perimeter 948, the rear perimeter 952, the toe side perimeter 956, and the heel side perimeter 960 can be any one of the following shapes: rectangular, triangular, semicircular, circular (golf ball size), circular (larger than a golf ball), circular (smaller than a golf ball), square, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0282] The top 904 of the dual rail putter head 900 includes a toe end 912, a heel end 916, a striking face 920, a rear wall 932, a back edge 934, a crown 942, and a lower surface (not shown). The toe end 912 is opposite the heel end 916. The striking face 920 extends from the toe end 912 to the heel end 916 and is opposite the rear wall 932. The rear wall 932 is opposite and generally parallel to the striking face 920. The crown 942 extends away from the striking face 920, over at least a portion of the rear wall 932, to the back edge 934 of the top 904. Additionally, the lower surface is opposite the crown 942 and extends from the striking face 920 to the back edge 934.

[0283] The crown 942 of the upper portion 904 further comprises a toe-end mid-rail 936 and a heel-end mid-rail 940. In most embodiments, the toe-end mid-rail 936 and the heel-end mid-rail 940 are generally parallel while perpendicular to the striking face 920. Additionally, the toe-end mid-rail 936 and the heel-end mid-rail 940 do not contact the toe-side perimeter 956 or the heel-side perimeter 960. The toe-end mid-rail 936 and the heel-end mid-rail 940 are approximately 1 / 3 of the total club head width inboard from the perimeters of the toe-side perimeter 956 and the heel-side perimeter 960, respectively. However, in other embodiments, the toe-end mid-rail 936 and the heel-end mid-rail 940 can be more than 1 / 3 of the total club head width inboard from the perimeters of the toe-side perimeter and the heel-side perimeter, respectively. The toe-end mid-rail 936 and the heel-end mid-rail 940 descend from the striking face 920 to the back edge 934. In some embodiments, the toe-end mid-rail 936 and heel-end mid-rail 940 are not parallel and are not perpendicular to the striking face 920. In some embodiments, the toe-end mid-rail 936 and heel-end mid-rail 940 may be substantially flat from the striking face 920 to the back edge 934, or may rise from the striking face 920 to the back edge 934. In most embodiments, the rise or fall of the mid-rails 936, 940 may be a linear, curvilinear, parabolic, sinusoidal, or polynomial function.

[0284] Additionally, the top 904 of the dual rail putter head 900 may include one or more alignment features 944 on the toe end mid-rail 936 and heel end mid-rail 940. The alignment features 944 may be any one or combination of lines, circles, dashed lines, triangles, channels, or any other desired alignment features 944. The alignment features 944 are spaced apart on the rails 936, 940 to be the width of a golf ball (approximately 4.27 cm). The alignment features 944 extend along the rails to provide the viewer with a visual alignment field that extends from the golf ball striking face 920 to the entire putter 900. The objective is to use these alignment features 944 along the toe end mid-rail 936 and heel end mid-rail 940 to align the entire putter 900 to the golf ball.

[0285] The upper portion 904 is affixed to the lower portion 908 such that the upper portion 904 is farther away from the ground plane 972 than the lower portion 908. The ground plane 972 contacts the lower portion 908 when the dual rail putter head 900 is in an address position to strike a golf ball.

[0286] Additionally, the striking face 920 of the dual rail putter head 900 comprises a striking face center point 976 and a loft plane 980. The striking face center point 976 is equidistant from the crown 942 and the underside of the top portion 904, as well as equidistant from the heel end 916 and the toe end 912 of the dual rail putter head 900. The loft plane 980 is tangent to the striking face 920 of the dual rail putter head 900. Additionally, a mid-plane 984 intersects the striking face center point 976 and is perpendicular to the loft plane 980. Additionally, a y-axis 988 intersects the mid-plane 984 and is perpendicular to the ground plane 972.

[0287] When the upper portion 904 and lower portion 908 are joined, the heel end 916 overlaps at least a portion of the toe side perimeter 956. Additionally, when the upper portion 904 and lower portion 908 are joined, the toe end 912 overlaps at least a portion of the heel side perimeter 960. Additionally, when the upper portion 904 and lower portion 908 are joined, the striking face 920 overlaps at least a portion of the front perimeter 948. Finally, the upper portion 904 and lower portion 908 are joined such that the back edge 934 overlaps at least a portion of the rear perimeter 952.

[0288] 9C and 9D , the four perimeter portions of the lower portion 908 (front 948, rear 952, toe side 956, and heel side 960) combine with the upper portion 904 to form a sole 968. The sole 968 is perpendicular to a ground plane 972. The ground plane 972 contacts the sole 968 when the dual rail putter head 900 is in an address position to strike a golf ball. The sole 968 of the dual rail putter head 900 extends from a toe end 912 of the dual rail putter head 900 to a heel end 916 of the dual rail putter head 900.

[0289] In most embodiments, the sole 968 of the dual rail putter head 900 may be completely flat. In some embodiments, the sole 968 of the putter head 900 may have a slight arch in the heel-to-toe direction, where the slight arch may be a linear or polynomial function. In some embodiments, the sole 968 of the putter head 900 may have a strong arch in the heel-to-toe direction, where the strong arch may be a linear or polynomial function. The sole 968 functions to provide a surface for resting the dual rail putter head 900 on the ground plane 972.

[0290] Referring to FIG. 9A, in one embodiment, the lower portion 908 can further comprise a front mass 941, a rear mass 943, a toe mass 945, and a heel mass 947. The front mass 941, the rear mass 943, the toe mass 945, and the heel mass 947 are integral to the lower portion 908. The front mass 941, the rear mass 943, the toe mass 945, and the heel mass 947 extend from the lower portion 908 in a direction away from the ground plane 972 and towards the upper portion 904. These mass portions provide a means for positioning and aligning the upper portion with the lower portion of the dual rail putter head 900. Additionally, these mass portions (i.e., the front mass 941, the rear mass 943, the toe mass 945, and the heel mass 947) provide an additional means for adding weight to the perimeter to increase the MOI of the putter over putters that do not have these mass features. These mass features can have weights in the range of 2-5 grams, 3-7 grams, or 1-6 grams. The mass features can all have the same weight or can be of different weights within the ranges mentioned above. The mass features can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front mass 941, rear mass 943, toe mass 945, and heel mass 947 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0291] In one embodiment, the front mass 941 is located on the front perimeter 948 and is equidistant from the toe side perimeter 956 and the heel side perimeter 960. However, in other embodiments, the front mass 941 may be located anywhere along the front perimeter 948. In one embodiment, the rear mass 943 is located on the rear perimeter 952 that is equidistant from the toe side perimeter 956 and the heel side perimeter 960. However, in other embodiments, the rear mass 943 may be located anywhere along the rear perimeter 952. In one embodiment, the toe mass 945 may be located at the junction of the toe side perimeter 956 and the rear perimeter 952. However, in other embodiments, the toe mass 945 may be located anywhere along the toe side perimeter 956. In one embodiment, the heel mass 947 may be located at the junction of the heel side perimeter 960 and the rear perimeter 952. However, in other embodiments, the heel mass 947 may be located anywhere along the heel side perimeter 960.

[0292] The front mass 941, rear mass 943, toe mass 945, and heel mass 947 provide areas of concentrated mass such that each mass 941, 943, 945, and 947 functions to increase the moment of inertia of the putter head 900. By locating each mass 941, 943, 945, and 947 on the perimeters 948, 952, 956, 960, each mass 941, 943, 945, and 947 increases the MOI because each mass is farther from the center of gravity of the putter 900. Each mass 941, 943, 945, and 947 on the perimeters 948, 952, 956, 960 is integrally formed from a second material, the second material being denser than the first material.

[0293] The front mass 941, rear mass 943, toe mass 945, and heel mass 947 serve two functions, as each mass 941, 943, 945, and 947 not only increases the MOI of the putter 900, but also provides an additional surface for the upper portion 904 to bond to the lower portion 908. Thus, the front mass 941 may also be referred to as the front bonded portion 941, the rear mass 943 may also be referred to as the rear bonded portion 943, the toe mass 945 may also be referred to as the toe bonded portion 945, and the heel mass 947 may also be referred to as the heel bonded portion 947.

[0294] Additionally, the crown 942 of the upper 904 includes a toe end cap 949 and a heel end cap 951. The toe end cap 949 and the heel end cap 951 function to fit over the toe mass 945 and the heel mass 947, respectively. The toe end cap 949 is adjacent to the toe end mid rail 936 and the back edge 934. The heel end cap 951 is adjacent to the heel end mid rail 940 and the back edge 934. In most embodiments, the toe end cap 949 and the heel end cap 951 include the same geometric shape, however, in some embodiments, the toe end cap 949 and the heel end cap 951 can include different geometric shapes.

[0295] In most embodiments, the toe end cap 949 and heel end cap 951 of the crown 942 are larger than the toe mass 945 and heel mass 947, respectively. As a result, the toe end cap 949 and heel end cap 951 cover the toe mass 945 and heel mass 947 when the upper portion 904 is secured to the lower portion 908. Furthermore, when the upper portion 904 is secured to the lower portion 908, the toe end cap 949 is positioned such that the toe end cap 949 overlaps at least a portion of the toe side perimeter 956 and the toe mass 945. Furthermore, when the upper portion 904 is secured to the lower portion 908, the heel end cap 951 is positioned such that the heel end cap 951 covers at least a portion of the heel side perimeter 960 and the heel mass 960.

[0296] In some embodiments, the lower surface of the upper portion 904, the striking face 920, and the rear wall 932 can form a first cavity (not shown). The first cavity extends inwardly from the lower surface toward, but does not reach, the crown 942. The first cavity is bounded by the rear wall 932 and the striking face 920. The first cavity functions to receive the front mass 941 of the lower portion 908.

[0297] In some embodiments, the lower surface, the back edge 934, and the crown 942 form a second cavity (not shown). The second cavity extends inward from the lower surface toward the crown 942, but does not reach the crown 942. The second cavity is bounded by the back edge 934, the toe cap 949, and the heel end cap 951. In most embodiments, the second cavity is located equidistant between the toe end cap 949 and the heel end cap 951. The second cavity functions to receive the rear mass 943 of the lower portion 908.

[0298] The first and second cavities can include any desired geometric shape, however, in most embodiments, the first and second cavities include geometric shapes similar or identical to the geometric shapes of the front mass 941 and the rear mass 943. Furthermore, when the upper portion 904 is secured to the lower portion 908, the first cavity is positioned such that the first cavity surrounds the front mass 941 and the second cavity is positioned such that the second cavity surrounds the rear mass 943.

[0299] The combination of a lower density first material upper portion 904 and a higher density second material lower portion 908 creates a high MOI putter 900 without creating an excessively heavy putter. The large opening 964 formed by the perimeter portions 948, 952, 956, 960 of the lower portion 908 creates a high density, but low volume portion that increases the MOI of the putter (compared to a putter milled from a single material). A single material putter cannot allocate high density material to the perimeter while maintaining the desired volume (75cc-100cc) and mass (340 grams-385 grams).

[0300] The lower portion 908, in most embodiments, comprises less than 35% of the total volume of the putter 900. In some embodiments, the lower portion 908 comprises less than 34% of the total volume of the putter 900, less than 33% of the total volume of the putter 900, less than 32% of the total volume of the putter 900, less than 31% of the total volume of the putter 900, less than 30% of the total volume of the putter 900, less than 29% of the total volume of the putter 900, less than 28% of the total volume of the putter 900, or less than 27% of the total volume of the putter 900.

[0301] Although the lower portion 908 comprises less than half the volume of the putter 900, the lower portion 908 comprises at least 45% of the total mass of the putter 900. In some embodiments, the lower portion 908 comprises at least 46% of the mass of the putter 900, at least 46% of the mass of the putter 900, at least 46% of the mass of the putter 900, at least 47% of the mass of the putter 900, at least 48% of the mass of the putter 900, at least 49% of the mass of the putter 900, at least 50% of the mass of the putter 900, at least 51% of the mass of the putter 900, at least 52% of the mass of the putter 900, at least 53% of the mass of the putter 900, at least 54% of the mass of the putter 900, or at least 55% of the mass of the putter 900.

[0302] The beneficial shift of mass to the periphery of the putter head 900, through the use of a high density, low volume lower portion 908, increases the MOI of the putter 900 versus a putter having the same volume, mass, and single material construction (i.e., a putter milled from a single stainless steel block, or a single material putter investment casting).

[0303] i. Circular embodiment In another embodiment, the putter-type golf club head 1000 can be a circular putter head 1000. With reference to FIGS. 10A-10C, the circular putter head 1000 has an upper portion 1004 and a lower portion 1008. The lower portion 1008 is made from a first material having a first density, and the upper portion 1004 is made from a second material having a second density. The first density is less than the second density. The upper portion 1004 and the lower portion 1008 combine to provide a high MOI putter head 1000 (5000 g cm) while maintaining a desired volume and mass. 2 -6500g·cm 2 )

[0304] As described above, the upper portion 1004 is constructed from a high density material (i.e., the second material). The upper portion 1004 includes a toe end 1012, a heel end 1016, a hitting face 1020, a rear wall 1032, and a lower surface (not shown). The toe end 1012 is opposite the heel end 1016. The hitting face 1020 extends from the toe end 1012 to the heel end 1016 and is opposite the rear wall 1032. The rear wall 1032 is opposite and generally parallel to the hitting face 1020.

[0305] The upper portion 1004 further comprises a toe span 1056 and a heel span 1060. The toe span 1056 is adjacent to the toe end 1012 and opposite the heel span 1060. The heel span 1060 is also adjacent to the heel end 1016 and opposite the toe span 1056. In some embodiments, the heel span 1060 and the toe span 1056 can be parallel, but in some embodiments, the heel span 1060 and the toe span 1056 are not parallel. The toe span 1056 and the heel span 1060 extend in a direction away from the rear wall 1032 and the striking face 1020.

[0306] In most embodiments, the toe side span 1056 extends perpendicularly from the rear wall 1032 such that a right angle (90° angle) is formed at the junction of the toe side span 1056 and the rear wall 1032. However, in other embodiments, the toe side span 1056 can extend in any direction from the rear wall 1032 such that any angle (0°-180°) can be formed at the junction of the toe side span 1056 and the rear wall 1032. Further, in most embodiments, the heel side span 1060 extends perpendicularly from the rear wall 1032 such that a right angle (90° angle) is formed at the junction of the heel side span 1060 and the rear wall 1032. However, in other embodiments, the heel side span 1060 can extend in any direction from the rear wall 1032 such that any angle (0°-180°) can be formed at the junction of the heel side span 1060 and the rear wall 1032.

[0307] The rear wall 1032, the toe span 1056, and the heel span 1060 form a gap 1064. The gap 1064 is bounded by the rear wall 1032, the toe span 1056, and the heel span 1060. The gap 1064 formed by the rear wall 1032, the toe span 1056, and the heel span 1060 transfers most of the putter's volume and mass to the end of the top 1008. The gap 1064 can include any shape, but in one embodiment, the gap is approximately rectangular. In other embodiments, the gap 1064 may be circular, curvilinear, triangular, trapezoidal, parabolic, golf ball shaped, square, or any other desired geometric shape.

[0308] The lower portion 1008 of the putter head 1000 includes a front edge 1041, a rear edge 1034, a toe edge 1043, and a heel edge 1045. The front edge 1041 is adjacent to the toe edge 1043 and the heel edge 1045 and is opposite the rear edge 1034. The toe edge 1034 is adjacent to the front edge 1041 and the rear edge 1034 and is opposite the heel edge 1045. Also, the heel edge 1045 is adjacent to the front edge 1041 and the rear edge 1034 and is opposite the toe edge 1043. In some embodiments, the toe edge 1043 and the heel edge 1045 can be parallel, but in some embodiments, the toe edge 1043 and the heel edge 1045 are not parallel. In some embodiments, the front edge 1041 and the rear edge 1034 can be parallel, but in some embodiments, the front edge 1041 and the rear edge 1034 are not parallel.

[0309] The front edge 1041, the rear edge 1034, the toe edge 1043, and the heel edge 1045 join to form an opening 1065. The opening 1065 is bounded by four edges: the front 1041, the rear 1034, the toe 1043, and the heel 1045. The four edges 1041, 1034, 1043, 1045 form a perimeter around the opening 1065.

[0310] In some embodiments, the opening 1065 formed by the front edge 1041, the rear edge 1034, the toe edge 1043, and the heel edge 1045 can be any one of the following shapes: rectangular, triangular, semicircular, circular (golf ball size), circular (larger than a golf ball), circular (smaller than a golf ball), square, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0311] 10C, the lower portion 1008 is affixed to the upper portion 1004 such that a portion of the upper portion 1004 and the lower portion 1008 intersect with a ground plane 1072. The ground plane 1072 contacts the lower portion 1008 when the putter head 1000 is in an address position to strike a golf ball.

[0312] Additionally, the striking face 1020 of the putter head 1000 comprises a striking face center point 1076 and a loft plane 1080. The striking face center point 1076 is equidistant from the upper rail 1050 of the top 1004 and the ground plane 1072. The upper rail 1050 is adjacent to the striking face 1020 and the rear wall 1032 while facing the ground plane 1072. The striking face center point 1076 is also equidistant from the heel end 1016 and the toe end 1012 of the putter head 1000. The loft plane 1080 is tangent to the striking face 1020 of the putter head 1000. Additionally, a midplane 1084 intersects the striking face center point 1076 and is perpendicular to the loft plane 1080. Additionally, a y-axis 1088 intersects the midplane 1084 and is perpendicular to the ground plane 1072 .

[0313] When the upper portion 1004 and the lower portion 1008 are joined, the toe span 1056 overlaps at least a portion of the toe edge 1043. Additionally, when the upper portion 1004 and the lower portion 1008 are joined, the heel span 1060 overlaps at least a portion of the heel edge 1045. Additionally, when the upper portion 1004 and the lower portion 1008 are joined, the hitting face 1020 overlaps at least a portion of the front edge 1048. Finally, when the upper portion 1004 and the lower portion 1008 are joined such that the lower portion 1008 is secured to the hitting face 1020, the toe span 1056, and a portion of the heel span 1060, thereby filling at least a portion of the gap 1064 formed by the rear wall 1032, the toe span 1056, and the heel span 1060.

[0314] 10D, when the lower portion 1008 is combined with the toe span 1056 and heel span 1060 of the upper portion 1004, a sole 1068 is formed. The sole 1068 is perpendicular to a ground plane 1072, where the ground plane 1072 is tangent to the sole 1068 when the putter head 1000 is in an address position to strike the golf ball. The sole 1068 of the putter head 1000 extends from the toe end 1012 of the putter head 1000 to the heel end 1016 of the putter head 1000.

[0315] In most embodiments, the sole 1068 of the putter head 1000 may be completely flat. In some embodiments, the sole 1068 of the putter head 1000 may have a slight arch in the direction from the heel 1016 to the toe 1012, where the slight arch may be a linear or polynomial function. In some embodiments, the sole 1068 of the putter head 1000 may have a strong arch in the direction from the heel 1016 to the toe 1012, where the strong arch may be a linear or polynomial function. The sole 1068 functions to provide a surface for resting the putter head 1000 on the ground plane 1072.

[0316] In some embodiments, the upper portion 1004 can further comprise a crown (not shown). The crown extends from the striking face 1020 to a back edge 1034 of the lower portion 1008. The crown further extends from the striking face 1020 to the back edge 1034, covering at least a portion of the lower opening 1065 and covering at least a portion of the rear wall 1032.

[0317] The crown may extend further down from the striking face 1020 to the back edge 1034. In most embodiments, the crown extends from the toe span 1056 to approximately the inner 25% of the overall club head 1000 width and from the heel span 1060 to approximately the inner 25% of the overall club head 1000 width. In other embodiments, the crown may extend continuously or discontinuously across the overall width of the overall club head 1000 in a heel-to-toe direction. In some embodiments, the crown may extend less than 90% of the overall width of the club head 1000, less than 90% of the overall width of the club head 1000, less than 80% of the overall width of the club head 1000, less than 70% of the overall width of the club head 1000, less than 60% of the overall width of the club head 1000, less than 50% of the overall width of the club head 1000, less than 40% of the overall width of the club head 1000, or less than 30% of the overall width of the club head 1000. Additionally, in some embodiments, the crown can be substantially flat from the striking face 1020 to the back edge 1034, or can rise from the striking face 1020 to the back edge 1034. In most embodiments, the rise or fall of the crown can be a linear, curvilinear, parabolic, sinusoidal, or polynomial function.

[0318] Additionally, the top 1004 of the putter head 1000 may include one or more alignment features 1044 on the toe span 1065 and the heel span 1060. The alignment features 1044 may be any one or combination of lines, a series of lines, milled troughs, circles, dashed lines, triangles, channels, or any other desired alignment features 1044. The alignment features 1044 may be evenly spaced throughout the toe span 1065 and the heel span 1060, a portion of the crown, or the entire crown. The alignment features 1044 extending along the toe span 1056 and the heel span 1060 function to provide the viewer with a visual alignment field that extends the width of a golf ball, from the rear wall 1032 to the back edge 1034 of the putter 1000. The purpose is to use these alignment features 1044 along the toe span 1056 and heel span 1060 and / or crown to align the entire putter 1000 to the golf ball.

[0319] The combination of a high density first material upper portion 1004 and a low density second material lower portion 1008 produces a high MOI putter 1000 without producing an excessively heavy putter. The large gap 1064 formed by the spans 1056, 1060 of the rear wall 1032 and upper portion 1004 creates a high density but low width perimeter that increases the MOI of the putter (compared to a putter milled from a single material). A single material putter cannot allocate high density material to the perimeter while maintaining the desired volume (75cc-100cc) and mass (340 grams-385 grams).

[0320] The beneficial shift of mass to the periphery of the putter head 1000 through the use of a high density upper portion 1004 and a low volume, low mass lower portion 1008 increases the MOI of the putter 1000 versus a putter having the same volume, mass, and single material construction (i.e., a putter milled from a single stainless steel block, or a single material putter investment casting).

[0321] III. Sole Plate Embodiment Described below are additional multi-component putter head embodiments including an upper portion and a lower portion. The lower portion further includes a sole plate formed from a high density material, and the upper portion is formed from a low density material. The material density of the upper portion is less than the material density of the lower portion including the sole plate. The sole plate embodiments described below include mass structures, ball retrieval mechanisms, and / or ball profile alignment aids to provide more consistent and more forgiving putts. As described below, the putter heads including the upper portion and the lower portion including the sole plate are pleasing to the eye while increasing perimeter weighting, MOI, and forgiveness to create a consistent putting stroke. Additionally, the putter heads including the upper portion and the lower portion including the sole plate provide consistent ball speed and ball travel distance for repeated putts.

[0322] a. a putter head having a sole plate with heel and toe masses In another embodiment, the putter-type golf club head can be a semicircular putter head 1200 that includes a sole plate. With reference to FIGS. 12A-12E, the semicircular putter head 1200 has an upper portion 1204 and a lower portion 1208. The upper portion 1204 is formed from a first material having a first density, and the lower portion 1208 is made from a second material having a second density. The first density is less than the second density. The sole plate of the putter head 1200 increases the perimeter weighting and MOI. The upper portion 1204 and lower portion 1208 combine to provide a high MOI putter head 1200 (3000 g cm) while maintaining a desired volume and mass. 2 ~4000g cm 2 For example, the putter head 1200 is made of 3000g cm 2 ~3500g cm 2 or 3500g cm 2 ~4000g cm 2The putter head 1200 may have an MOI in the range of 2%-15% increase in MOI about the y-axis over putter heads lacking a multi-material construction (i.e., a single material). For example, the putter head 1200 may include an increase of 2%-5%, 5%-10%, or 10%-15% over a single material putter.

[0323] The putter head 1200 can include the striking face mechanism 1100, as described above and shown in Figures 11A-11C. The putter head 1200 can include a striking face insert formed from a single component system 1120, or a two component system 1130. The putter head 1200 can include a striking face insert disposed between one or more metal portions 1142. The striking face mechanism 1100 can improve the sound and feel during impact with the striking face of the putter head 1200.

[0324] The lower portion 1208 includes a high density material (i.e., a second material) to lower the mass below the midline 1284. The lower portion 1208 further includes a sole plate formed from a high density material. As shown in FIG. 12C, the lower portion 1208 includes a front perimeter 1248, a rear perimeter 1252, a toe side perimeter 1256, and a heel side perimeter 1260. The front perimeter 1248 is adjacent to the toe side perimeter 1256 and the heel side perimeter 1260 and is opposite the rear perimeter 1252. The toe side perimeter 1256 is adjacent to the front perimeter 1248 and the rear perimeter 1252 and is opposite the heel side perimeter 1260. The heel side perimeter 1260 is also adjacent to the front perimeter 1248 and the rear perimeter 1252, but is opposite the toe side perimeter 1256. 12B , the heel side perimeter 1260 and the toe side perimeter 1256 may be symmetrical about a horizontal centerline that extends through the striking face center point 1276 in a direction extending from the striking face 1220 to the back edge 1234. The horizontal centerline extends parallel to the ground plane 1272. In many embodiments, the heel side perimeter 1260 and the toe side perimeter 1256 may include similar curved edges or may follow a similar curved path around the perimeter of the putter head 1200.

[0325] The front perimeter 1248 of the lower portion 1208 includes a front width. The front width is measured from the junction of the toe side perimeter 1256 and the front perimeter 1248 to the junction of the heel side perimeter 1260 and the front perimeter 1248. Additionally, the rear perimeter 1252 of the lower portion 1208 includes a rear width. The rear width is measured from the junction of the toe side perimeter 1256 and the rear perimeter 1252 to the junction of the heel side perimeter 1260 and the rear perimeter 1252. In many embodiments, the front width is greater than the rear width, while in some embodiments, the front width may be less than or equal to the rear width.

[0326] The top 1204 of the putter head 1200 includes a toe end 1212, a heel end 1216, a striking face 1220, a back edge 1234, a crown 1242, and a lower surface 1290 (shown in FIG. 12D ). The toe end 1212 is opposite the heel end 1216. The striking face 1220 extends from the toe end 1212 to the heel end 1216. The crown 1242 extends the entire width of the toe end 1212 of the striking face 1220 toward the heel end 1216. The crown 1242 extends between the striking face 1220 and the back edge 1234 of the top 1204. Additionally, the lower surface 1290 is opposite the crown 1242 and extends from the striking face 1220 to the back edge 1234.

[0327] The crown 1242 further descends from the striking face 1220 to the back edge 1234. Additionally, the crown 1242 extends away from the striking face 1220 across most of the lower portion 1208 to the back edge 1234 of the upper portion 1204. The crown 1242 spans the entire width of the putter head 1200 in a heel-to-toe direction from the toe side perimeter 1256 and the heel side perimeter 1260 in most embodiments. Additionally, in some embodiments, the crown 1242 can be substantially flat from the striking face 1220 to the back edge 1234 or can ascend from the striking face 1220 to the back edge 1234. In many embodiments, the descent of the crown 1242 towards the back edge 1234 can be a linear, curvilinear, parabolic, sinusoidal, or polynomial function.

[0328] Additionally, the top 1204 of the putter head 1200 may include one or more alignment features 1244 on the crown 1242. The alignment features 1244 may be any one or combination of lines, a series of lines, milled troughs, circles, dashed lines, triangles, channels, or any other desired alignment features 1244. The alignment features 1244 are evenly spaced throughout the crown 1242, which is configured to be the width of a golf ball (approximately 4.27 cm). The alignment features 1244 extending along the crown 1242 function to provide the viewer with a visual alignment field that extends the width of a golf ball from the striking face 1220 to the back edge 1234 of the putter head 1200. The purpose is to use these alignment features 1244 along the crown 1242 to align the putter head 1200 with a golf ball.

[0329] Referring to FIG. 12D, the upper portion 1204 is attached to the lower portion 1208 such that the upper portion 1204 is farther from the ground plane 1272 than the lower portion 1208, and the ground plane 1272 contacts the lower portion 1204 when the putter head 1200 is in an address position to strike a golf ball.

[0330] Additionally, the striking face 1220 of the putter head 1200 includes a striking face center point 1276 and a loft plane 1280. The striking face center point 1276 is equidistant from the crown 1242 and the underside of the top portion 1204, and is also equidistant from the heel end 1216 and the toe end 1212 of the putter head 1200. The loft plane 1280 is tangent to the striking face 1220 of the putter head 1200. Additionally, a mid-plane 1284 intersects the striking face center point 1276 and is perpendicular to the loft plane 1280. Additionally, a y-axis 1288 intersects the mid-plane 1284 and is perpendicular to the ground plane 1272.

[0331] When the upper portion 1204 and the lower portion 1208 are joined, the heel end 1216 covers at least a portion of the heel side perimeter 1260. Also, when the upper portion 1204 and the lower portion 1208 are joined, the toe end 1212 covers at least a portion of the toe side perimeter 1256. Furthermore, when the upper portion 1204 and the lower portion 1208 are joined, the striking face 1220 covers at least a portion of the front perimeter 1248. Finally, when the upper portion 1204 and the lower portion 1208 are joined, the back edge 1234 covers at least a portion of the rear perimeter 1252.

[0332] The four periphery portions of the lower portion 1208 (front portion 1248, rear portion 1252, toe side 1256, and heel side 1260) combine with the upper portion 1204 to form a sole 1268. The sole 1268 may extend approximately parallel to a ground plane 1272, which is in contact with the sole 1268 when the putter head 1200 is in an address position to strike a golf ball. The sole 1268 of the putter head 1200 extends from a toe end 1212 of the putter head 1200 to a heel end 1216 of the putter head 1200.

[0333] In most embodiments, the sole 1268 of the putter head 1200 can be flat. In some embodiments, the sole 1268 of the putter head 1200 can have a slight bow from the heel 1216 to the toe 1212, where the slight bow can be linear or a function of a polynomial. In some embodiments, the sole 1268 of the putter head 1200 can have a strong bow from the heel 1216 to the toe 1212, where the strong bow can be linear or a function of a polynomial. The sole 1268 functions to provide a surface for the putter head 1200 to rest on the ground plane 1272.

[0334] 12C, the lower portion 1208 can further include a toe mass 1245 and a heel mass 1247. The toe mass 1245 and the heel mass 1247 are integral to the lower portion 1208. The toe mass 1245 and the heel mass 1247 extend from the lower portion 1208 in a direction away from the ground plane 1272 toward the upper portion 1204. These mass portions provide a means for positioning and aligning the upper portion 1204 with the lower portion 1208 of the putter head 1200. Additionally, these mass features (i.e., the toe mass 1245 and the heel mass 1247) provide an additional means for adding weight to the perimeter of the putter head 1200. Increasing the perimeter weighting can increase the moment of inertia (i.e., MOI) of the putter head 1200 compared to a putter without or lacking these mass features. Additionally, the weights of the heel mass 1247 and toe mass 1245 can be adjusted to achieve a desired swing weight or overall putter head mass. These mass features can have weights ranging from 2-5 grams, 3-7 grams, or 1-6 grams. The toe mass 1245 and heel mass 1247 can have similar weights or can include different weights within the ranges provided above. The mass features can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The toe mass 1245 and heel mass 1247 can each be any one or combination of rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0335] In one embodiment, the toe mass 1245 may be located at the junction of the toe side perimeter 1256 and the rear perimeter 1252, but in other embodiments, the toe mass 1245 may be located anywhere along the toe side perimeter 1256. In many embodiments, the toe mass 1245 may be located closer to the front perimeter 1248 than to the rear perimeter 1252. In one embodiment, the heel mass 1247 may be located at the junction of the heel side perimeter 1260 and the rear perimeter 1252, but in other embodiments, the heel mass 1247 may be located anywhere along the heel side perimeter 1260. In many embodiments, the heel mass 1247 may be located closer to the front perimeter 1248 than to the rear perimeter 1252.

[0336] The toe mass 1245 and heel mass 1247 provide areas of concentrated mass such that each mass 1245 and 1247 functions to increase the moment of inertia of the putter head 1200. Locating each mass 1245 and 1247 on the perimeters 1256 and 1260, respectively, increases the MOI because each mass 1245 and 1247 is located away from the center of gravity of the putter head 1200. Each mass 1245 and 1247 on the perimeters 1256 and 1260 is integrally formed from a second material, the second material being denser than the first material.

[0337] In many embodiments, the upper portion 1204 can form at least one cavity. The at least one cavity is formed in a lower surface 1290 of the upper portion 1204. As shown in FIG. 12D, the upper portion 1204 can form a first cavity 1292 and a second cavity 1294. The first cavity 1292 and the second cavity 1294 extend from the lower surface 1290 of the upper portion 1204 inwardly toward but through the crown 1242. The first cavity 1292 is disposed near the toe side perimeter 1256 and the second cavity 1294 is disposed near the heel side perimeter 1260 when the lower portion 1208 is joined to the upper portion 1204. The first cavity 1292 functions to receive the toe mass 1245 of the lower portion 1208. The second cavity 1294 serves to receive a heel mass 1247 of the lower portion 1208 .

[0338] The first cavity 1292 and the second cavity 1294 can include any desired shape, however, in most embodiments, the first cavity 1292 and the second cavity 1294 include a shape similar or identical to the shape of the toe mass 1245 and the heel mass 1247. In one embodiment, the first cavity 1292 and the second cavity 1294, and the respective toe mass 1245 and heel mass 1247, can include a generally triangular shape. Furthermore, when the upper portion 1204 is attached to the lower portion 1208, the first cavity 1292 is positioned such that the first cavity 1292 encompasses the toe mass 1245 and the second cavity 1294 is positioned such that the second cavity 1294 encompasses the heel mass 1260.

[0339] The combination of an upper portion 1204 including a low density first material and a lower portion 1208 including a high density second material provides a high MOI putter head 1200. The putter head 1200 includes a high MOI while maintaining an acceptable weight (i.e., not creating an excessively heavy putter). A single material putter cannot allocate high density material to the periphery while maintaining a desired volume. The putter head 1200 includes a high MOI, a desired volume (75cc-110cc), and a desired mass (340 grams-385 grams). In one example, the putter head has a high MOI (3134 g·cm 2 ), desired volume (103 cc), and desired mass (357 grams).

[0340] The lower portion 1208, in most embodiments, comprises less than 25% of the total volume of the putter head 1200. In some embodiments, the lower portion 1208 comprises less than 24% of the total volume of the putter head 1200, less than 23% of the total volume of the putter head 1200, less than 22% of the total volume of the putter head 1200, less than 21% of the total volume of the putter head 1200, less than 20% of the total volume of the putter head 1200, less than 19% of the total volume of the putter head 1200, less than 18% of the total volume of the putter head 1200, or less than 17% of the total volume of the putter head 1200. In one example, the lower portion 1208 can comprise 16% of the total volume of the putter head 1200.

[0341] Although the lower portion 1208 is less than half the volume of the putter head 1200, the lower portion 1208 comprises at least 45% of the total mass of the putter head 1200. In some embodiments, the lower portion 1208 comprises at least 46% of the mass of the putter head 1200, at least 46% of the mass of the putter head 1200, at least 46% of the mass of the putter head 1200, at least 47% of the mass of the putter head 1200, at least 48% of the mass of the putter head 1200, at least 49% of the mass of the putter head 1200, at least 50% of the mass of the putter head 1200, at least 51% of the mass of the putter head 1200, at least 52% of the mass of the putter head 1200, at least 53% of the mass of the putter head 1200, at least 54% of the mass of the putter head 1200, or at least 55% of the mass of the putter head 1200. In one example, the lower portion 1208 comprises 60% of the mass of the putter head 1200 .

[0342] The putter head 1200 including a high density lower portion shifts mass to the perimeter of the putter head 1200. The perimeter weighting increases the MOI of the putter head 1200. The putter head 1200 includes a greater MOI as compared to a putter formed from a single material construction (i.e., a putter milled from a single stainless steel block, or a single material putter skin casting) having a similar volume and mass.

[0343] b. A putter head with a pocket and a sole plate In another embodiment, as shown in FIGS. 13A-13E, a putter-type golf club head can include a putter head 1300 having a pocket and a sole plate. As described in more detail below, the pocket of the putter head 1300 allows for weight to be removed from the putter head 1300, and the sole plate allows for increased perimeter weighting. The putter head 1300 includes an upper portion 1304 and a lower portion 1308. The upper portion 1304 is formed from a first material having a first density, and the lower portion 1308 is formed from a second material having a second density. The first density is less than the second density. The upper portion 1304 and the lower portion 1308 combine to provide a high MOI putter head (4000 g cm) while maintaining a desired volume and mass. 2 ~5500g cm 2 For example, the putter head 1300 is made of 4000g cm 2 ~4500g cm 2 , 4500g·cm 2 ~5000g cm 2 , or 5000 g cm 2 ~5500g cm 2 The putter head 1300 may have an MOI in the range of 2%-15% increase in MOI about the y-axis over putter heads lacking a multi-material construction (i.e., a single material). For example, the putter head 1300 may include an increase of 2%-5%, 5%-10%, or 10%-15% over a single material putter.

[0344] The putter head 1300 includes a toe end 1312, a heel end 1316, a striking face 1320, a back end 1334, a crown 1336, and a sole 1368. The toe end 1312 is opposite the heel end 1316. The striking face 1320 extends in a heel-to-toe direction from the toe end 1312 to the heel end 1314. The back end 1334 is opposite the striking face 1320 and is located at the rearmost portion of the putter head 1300. The crown 1336 extends away from the striking face 1320 toward the back end 1334.

[0345] The upper portion 1304 includes a low density material (i.e., a second material). The second material of the upper portion 1304 is less than the first density of the lower portion 1308. The upper portion 1304 includes a striking face 1320, a back end 1334, a crown 1336, and a lower surface 1342. The lower surface 1342 may be the bottom-most surface of the upper portion 1304 (i.e., the surface that is closest to the ground when the putter head 1300 is assembled and in the address position). The lower surface 1342 of the upper portion 1304 is configured to be attached to the lower portion 1308 via an adhesive.

[0346] The upper portion 1304 further includes a crown bridge 1338 extending between the striking face 1320 and the rear end 1334. The crown bridge 1338 includes a crown 1336. The upper portion 1304 further includes an upright member 1340 extending generally perpendicularly from the crown bridge 1338. The upright member 1340 provides structural support to the crown bridge 1338 and may provide additional structural support to the upper portion 1304.

[0347] To further remove mass from the top 1304, the top 1304 defines a pocket 1372. Specifically, as shown in FIGS. 13B, 13D and 13E, the top 1304 includes a front pocket wall 1376 opposite the striking face 1320, a rear pocket wall 1380 opposite the rear end 1334, a pocket ceiling 1384 opposite the crown 1384, and a pocket floor 1388 opposite the lower surface 1342 of the top 1304. The front pocket wall 1376, the rear pocket wall 1380, the pocket ceiling 1384, and the pocket floor 1388 together define the pocket 1372. The pocket 1372 in the top 1304 allows weight to be removed from the center of the putter head 1300, thereby allowing weight to be reallocated to the periphery of the putter head 1300. Increasing the perimeter weighting increases the MOI of the putter head 1300, thereby providing greater forgiveness.

[0348] A crown bridge 1338 extends from the striking face 1320 to the rear end 1334 and beyond the front pocket wall 1376. An upright member 1340 extending from the crown bridge 1338 divides the pocket 1372 into a toe pocket 1392 and a heel pocket 1396. The toe pocket 1392 and heel pocket 1396 allow weight to be removed from the upper portion 1304 and reallocated to the lower portion 1308, the toe mass 1345, and / or the heel mass 1347.

[0349] As shown in FIGS. 13A and 13B, the top 1304 of the putter head 1300 can include one or more alignment features 1344 disposed on the crown 1336. The alignment features 1344 can be any one or combination of lines, a series of lines, milled troughs, circles, dashed lines, triangles, channels, or any other desired alignment features 1344. The alignment features 1344 are evenly spaced on the crown 1336, which is configured to be the width of a golf ball (approximately 4.27 cm or 1.68 inches). The alignment features 1344 extending along the crown 1336 function to provide the viewer with a visual alignment field that extends the width of a golf ball from the striking face 1320 to the back end 1334 of the putter 1300. The objective is to align the putter 1300 with a golf ball using these alignment features 1344 along the crown 1342 at the address position of the putting surface.

[0350] The upper portion 1304 is attached to the lower portion 1308 such that the upper portion 1304 is further from the ground than the lower portion 1308. The upper portion 1304 can be attached to the lower portion 1308 via an adhesive. In other embodiments, the upper portion 1304 can be attached to the lower portion 1308 via a combination of adhesive and interlocking features (e.g., cavities that receive protrusions). The upper portion 1304 is attached to the lower portion 1308 such that the crown bridge 1340 is disposed between a toe mass 1345 and a heel mass 1347.

[0351] Additionally, the pocket 1372 can be located between the toe mass 1345 and the heel mass 1347. Specifically, as shown in FIG. 13A, the toe side pocket 1392 can be located between the toe mass 1345 and the upright member 1340, and the heel side pocket 1396 can be located between the heel mass 1347 and the upright member 1340. The pocket 1372 allows weight to be removed from the upper portion 1304 (i.e., the central portion of the upper portion 1304) and reassigned to the lower portion 1304, the toe mass 1345, and / or the heel mass 1347. The combination of the weight removal mechanism and the perimeter mass mechanism increases the MOI of the putter head 1300. The assembled putter head 1300 allows the toe mass 1345 and the heel mass 1347 to be located at the perimeter of the putter head 1300. The toe mass 1345 and heel mass 1347 increase the perimeter weighting of the putter head 1300, thereby increasing the MOI and forgiveness. Additionally, the weighting of the heel mass 1347 and toe mass 1345 can be adjusted to achieve a desired swing weight or overall putter head mass.

[0352] When the upper portion 1304 and the lower portion 1308 are joined, the upper portion 1304 can cover a front perimeter 1348 of the lower portion 1308. When the upper portion 1304 and the lower portion 1308 are joined, the upper portion 1304 can cover a rear perimeter 1352 of the lower portion 1308. Additionally, the upper portion 1304 and the lower portion 1308 are joined such that the rear end 1334 covers a portion of the rear perimeter 1352 of the lower portion 1308. Additionally, when the upper portion 1304 and the lower portion 1308 are joined, they together form a sole 1368. The sole 1368 of the putter head 1300 sits on the ground or ground plane when the putter head 1300 is in an address position.

[0353] The lower portion 1308 further includes a sole plate including a high density material (i.e., the first material), thereby moving the mass closer to the ground. As shown in FIGS. 13B and 13C, the lower portion 1308 includes a perimeter having a front perimeter 1348, a rear perimeter 1352, a toe perimeter 1356, and a heel perimeter 1360. The front perimeter 1348 is located near or adjacent to the striking face 1320. The rear perimeter 1352 is located near or adjacent to the rear end 1334. The toe perimeter 1356 forms a portion of the toe end 1312, and the heel perimeter 1360 forms a portion of the heel end 1314.

[0354] 13A and 13B, the lower portion 1308 can further include a toe mass 1345 and a heel mass 1347. The toe mass 1345 and the heel mass 1347 are integral to the lower portion 1308. The toe mass 1345 is located at a toe side perimeter 1356 of the lower portion 1308, and the heel mass 1347 is located at a heel side perimeter 1360 of the lower portion 1308. Both the toe mass 1345 and the heel mass 1347 extend away from the ground or upward from the lower portion 1308. Additionally, the toe mass 1345 and the heel mass 1347 provide an additional means of adding weight to the perimeter of the putter head 1300. Increasing the weight at the perimeter of the putter head 1300 increases the MOI of the putter 1300. The toe mass 1345 and heel mass 1347 can have weights ranging from 2-5 grams, 3-7 grams, or 1-6 grams. The mass features can all have the same weight within the above ranges or can be different weights. The mass features can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The toe mass 1345 and heel mass 1347 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0355] The toe mass 1345 and heel mass 1347 provide areas of concentrated mass such that each mass 1345 and 1347 functions to increase the moment of inertia of the putter head 1300. Locating the toe mass 1345 on the toe perimeter 1356 and the heel mass on the heel perimeter 1360 increases the MOI of the putter head 1300 because the masses 1345, 1347 are located at the perimeter of the putter head 1300 the greatest distance from the center of gravity of the putter head 1300. Each mass 1345 and 1347 is integrally formed of a second material, the second material being denser than the first material.

[0356] The combination of the upper portion 1304 including a low density first material and the lower portion 1308 including a high density second material forms a high MOI putter 1300. The putter head 1300 includes a high MOI while maintaining an acceptable weight (i.e., does not create an excessively heavy putter). The pocket 1372 formed by the pocket walls of the upper portion 1304 increases the MOI of the putter 1300 by removing weight from the center of the putter 1300. The lower portion 1308 including the high density second material, the toe mass 1345, and the heel mass 1347 increases the MOI of the putter 1300 by increasing the weighting of the periphery of the putter 1300. The multi-component design of the putter 1300 provides an increased MOI compared to a putter milled from a single material. A putter formed from a single material putter cannot allocate a high density material to the periphery while maintaining the desired volume (75cc-100cc) and mass (340g-385g).

[0357] The lower portion 1308 comprises less than 35% of the total volume of the putter 1300. In other embodiments, the lower portion 1308 comprises less than 34% of the total volume of the putter 1300, less than 33% of the total volume of the putter 700, less than 32% of the total volume of the putter 1300, less than 31% of the total volume of the putter 1300, less than 30% of the total volume of the putter 1300, less than 29% of the total volume of the putter 1300, less than 28% of the total volume of the putter 1300, or less than 27% of the total volume of the putter 1300.

[0358] Although the lower portion 1308 comprises less than half the volume of the putter 1300, the lower portion 1308 comprises at least 45% of the total mass of the putter 1300. In some embodiments, the lower portion 1308 comprises at least 46% of the mass of the putter 700, at least 47% of the mass of the putter 700, at least 48% of the mass of the putter 1300, at least 49% of the mass of the putter 1300, at least 50% of the mass of the putter 1300, at least 51% of the mass of the putter 1300, at least 52% of the mass of the putter 1300, at least 53% of the mass of the putter 1300, at least 54% of the mass of the putter 1300, or at least 55% of the mass of the putter 1300.

[0359] The putter head 1300, including the high density lower portion 1308, shifts mass to the perimeter of the putter head 1300. The perimeter weighting increases the MOI of the putter head 1300. The putter head 1300 includes a greater MOI compared to putters formed from a single material construction (i.e., a putter milled from a single stainless steel block, or a single material putter skin casting) having a similar volume and mass. The advantages of the putter head 1300 over putter heads formed from a single material construction are illustrated in the following examples.

[0360] c. A putter head with a sole plate and ball retrieval mechanism In another embodiment, the putter head 1400 may be a mallet-type putter head. With reference to FIGS. 14A-14D , the putter head 1400 comprises an upper portion 1404 and a lower portion 1408. The lower portion 1408 is a sole plate including a toe mass 1446, a heel mass 1448, and a rear mass 1450. The putter head 1400 further comprises a ball retrieval mechanism 1422. The ball retrieval mechanism 1422 is configured to pick up and retain a golf ball. The ball retrieval mechanism and sole plate increase the perimeter weighting, thereby increasing the MOI and forgiveness of the putter head 1400. The putter head 1400 has a weight of 4000 g·cm 2 ~5000g cm 2For example, the putter head 1400 may have an MOI in the range of 400 g cm 2 ~4500g cm 2 or 4500g cm 2 ~5000g cm 2 The putter head 1400 may have an MOI in the range of 2%-15% increase in MOI about the y-axis over a putter head without a multi-material construction (i.e., a single material). For example, the putter head 1400 may include an increase of 2%-5%, 5%-10%, or 10%-15% over a single material putter.

[0361] The upper portion 1404 includes a low density material (i.e., the first material). The upper portion 1404 includes a toe end 1412, a heel end 1416, and a striking face 1420. The putter head 1400 may further include the striking face features from the putter head 1100, as described above. In this embodiment, the striking face 1420 is an insert that is formed separately and then attached to the putter head 1400. In other embodiments, the striking face 1420 may be formed by the upper portion 1404.

[0362] The upper portion 1404 further includes an alignment feature 1446. The alignment feature is located in the crown 1444 of the putter head. In this embodiment, the alignment feature is defined by three lines that extend vertically rearwardly to the striking face. In other embodiments, the alignment feature can take on a variety of shapes and sizes in accordance with aspects of the present invention.

[0363] The lower portion 1408 includes a high density material (i.e., the second material). The lower portion 1408 is a sole plate, thereby forming the sole 1442 of the putter head 1400. The lower portion 1408 includes a toe side perimeter 1438, a heel side perimeter 1440, a front perimeter 1434, a rear perimeter 1436, a toe mass 1446, a heel mass 1448, and a rear mass 1450. The toe mass 1446 and the heel mass 1448 improve the overall MOI of the putter head. Additionally, the weight of the heel mass 1448 and the toe mass 1446 can be adjusted to achieve a desired swing weight or overall putter head mass. In this embodiment, the lower portion 1408 includes less than 37% of the total volume of the putter head 1400. In other embodiments, the lower portion 1408 may comprise less than 35%, 34%, 33%, 32%, 31%, 30%, 29%, or 28% of the total volume of the putter head 1400. The lower portion 1408 may comprise less than 37% of the total volume of the putter head 1400, but the lower portion 1408 comprises at least 63% of the total mass of the putter head 1400. In other embodiments, the lower portion 1408 comprises at least 50%, 55%, 58%, 60%, 62%, 65%, 68%, or 70% of the total mass of the putter head 1400.

[0364] The top portion 1404 and bottom portion 1408 are assembled and secured together via an adhesive layer disposed on the interlocking features of the respective portions. The top portion 1404 and bottom portion 1408 may also be assembled via other fastening means known in the art. For example, the top portion 1404 and bottom portion 1408 may be assembled via screws and threads, tape, or welding.

[0365] The putter head 1400 further comprises a ball retrieval mechanism 1422. The ball retrieval mechanism 1422 is disposed in the sole 1442 of the putter head 1400. In this embodiment, the ball retrieval mechanism 1422 is defined by a recess formed in the sole 1442. In other embodiments, the ball retrieval mechanism 1422 can be defined by a cavity or an opening. The ball retrieval mechanism 1422 increases the MOI of the putter head by removing material and mass from the central region of the putter head so that the majority of the mass is distributed around the periphery of the putter head 1400. The ball retrieval mechanism 1422 improves the MOI with a perimeter weighted mallet type putter head while incorporating a ball retrieval mechanism to provide a forgiving putter head that facilitates retrieving golf balls from the putting surface during a round of golf. The advantages of the putter head 1400 over putter heads formed from a single material construction are illustrated in the following examples.

[0366] In this embodiment, the ball-return mechanism 1422 is formed by the upper portion 1404 and the lower portion 1408, such that the upper portion 1404 includes a recess that forms a portion of the ball-return mechanism 1422 and the lower portion 1408 includes an opening that forms the remaining portion of the ball-return mechanism 1422. In other embodiments, the ball-return mechanism 1422 can be formed only by the upper portion 1404 or only by the lower portion 1408. In this embodiment, the upper portion 1404 and the lower portion 1408 include complementary shapes such that when positioned together, the upper portion 1404 and the lower portion 1408 form the ball-return mechanism 1422.

[0367] The ball retrieval mechanism 1422 includes a ball retaining portion 1424. The ball retaining portion 1424 is configured to receive and retain a golf ball. The ball retaining portion 1424 is defined by a circular shape having a diameter smaller than the diameter of a golf ball (i.e., the diameter of a golf ball is approximately 1.6 inches). The diameter of the ball retaining portion 1424 can range from 1.45 inches to 1.75 inches to accommodate golf balls of different sizes. To properly retain the golf ball, the ball retaining portion 1424 includes a ball retaining edge 1428. The ball retaining edge 1428 is configured to grip the surface of the golf ball. Thus, the ball retaining edge 1428 engages with approximately 75% to 90% of the circumference of the golf ball. In other embodiments, the ball removal edge 1430 engages with 5% to 90% of the circumference of the golf ball.

[0368] The ball retrieval mechanism 1422 further comprises a ball retriever 1426. The ball retriever 1426 is defined by a semicircular slot shape and is configured to receive a user's finger to reach under the golf ball and retrieve the ball from the ball retaining portion 1424. The semicircular slot shape can have a width ranging from 0.25 inches to 1 inch. The ball retriever 1426 comprises a ball retriever edge 1430 that does not engage or contact the ball while it is received in the ball retaining portion 1424. The ball retriever edge 1430 is offset from the ball retaining edge 1428 to allow the user to reach around the golf ball. The ball retriever 1426 allows the user to grasp around and under the golf ball (i.e., pull and rotate the golf ball from the ball retaining portion) and retrieve it from the putter head 1400. Pulling the golf ball away from the putter head 1400 to rotate (ie, two degrees of movement) is more advantageous than a pulling force (ie, one degree of movement).

[0369] 14E-14H show additional embodiments of ball retrieval mechanisms for use with the putter head 1400. FIG. 14E shows a ball retrieval mechanism 1460 including a ball retaining portion 1462, a ball retrieval portion 1464, and a number of prongs 1461. In this embodiment, the ball retrieval mechanism 1460 has two prongs 1461. Each prong 1461 is located on an opposite side of the ball retrieval mechanism 1460. In this embodiment, one prong 1461 is located proximate the striking face and the other prong 1461 is located near the rear. The prongs 1461 define a ball retaining portion 1462 and a ball retaining edge 1466 that engage the ball. The ball retrieval portion 1464 has a ball retrieval edge 1468 located adjacent the prong 1461. As discussed above, the ball retrieval edge 1468 does not engage the ball.

[0370] FIG. 14F illustrates a ball retrieval mechanism 1470 comprising a ball retaining portion 1472, a ball retrieval portion 1474, and a number of prongs 1471. In this embodiment, the ball retrieval mechanism 1470 has four prongs 1471. The prongs 1471 are grouped into a first set and a second set. The first set of two prongs 1471 is located proximate to the striking face and the second set of prongs 1471 is located near the rear. The prongs 1471 include a ball retaining edge 1432. The ball retaining edge 1432 is defined by a circle having a diameter of a golf ball. The ball retrieval portion 1474 has a ball retrieval edge 1478 located adjacent to the prongs 1471. As described above, the ball retrieval edge 1478 does not engage the ball.

[0371] FIG. 14G illustrates a ball retrieval mechanism 1480 including a ball retaining portion 1482, a ball retrieval portion 1484, and a number of prongs 1481. The ball retaining portion 1482 is defined by a circle having a diameter slightly smaller than a golf ball, as described above. In this embodiment, the ball retaining portion 1482 has four prongs 1481 arranged around the periphery of the circle. The prongs 1481 are spaced 90 degrees apart around the circle. The prongs 1481 further define a ball retaining edge 1486. ​​The ball retaining edge 1486 is curved due to the circle defining the ball retaining portion. The ball retrieval portion 1484 is defined by a circle that is larger than the ball retaining portion 1482. The ball retrieval portion 1484 is further defined by a first recess having a first depth, and the ball retaining portion 1482 is further defined by a second recess having a second depth such that the first depth is less than the second depth. The ball removal portion 1484 has a ball removal edge 1488 disposed adjacent to the prong 1481. As noted above, the ball removal edge 1488 does not engage the ball.

[0372] FIG. 14H illustrates a ball retrieval mechanism 1490 comprising a ball retaining portion 1492 and a ball retrieval portion 1494. The ball retrieval mechanism 1490 is pear-shaped such that the ball retaining portion 1492 is located at the larger end of the pear shape and the ball retrieval portion 1494 is located at the smaller end of the pear shape. The ball retaining portion 1492 is defined by a circular shape having a diameter slightly smaller than a golf ball. The ball retrieval portion 1494 is defined by a circular shape having a diameter smaller than the diameter of the ball retaining portion 1492. The positioning and size of the ball retaining portion 1492 and the ball retrieval portion 1494 form a pear shape. The pear shape may also be described as an oval shape. As described above, the ball retaining portion 1492 includes a ball retaining edge 1496 and the ball retrieval portion 1494 includes a ball retrieval edge 1498. As described above, the ball retrieval edge 1498 does not engage the ball.

[0373] d. Putter head with ball contour alignment aid and sole plate In one embodiment, the putter-type golf club head includes a two-part construction and includes an alignment aid with ball profile features. The two-part construction allows the putter-type club head to be formed of multiple materials. With reference to FIGS. 15A and 15B, the putter-type golf club head 1500 includes an upper portion 1504 and a lower portion 1508. The upper portion 1504 is attached to the lower portion 1508. The upper portion 1504 is formed from a first material having a first density and the lower portion 1508 is formed from a second material having a second density. In some embodiments, the first density is less than the second density. As described in more detail below, the upper portion 1504 and the lower portion 1508 can be combined to form a high MOI putter-type club head 1500 (5000 g cm) while maintaining a desired volume and mass. 2 ~6500g cm 2 For example, the putter head 1500 is made of 5000g cm 2 ~5500g cm 2 , 5500g·cm 2 ~6000g cm 2 , 6000g·cm 2 ~6500g cm 2 The putter head 1500 may have an MOI in the range of 2%-15% increase in MOI about the y-axis over a putter head lacking a multi-material construction (i.e., a single material). For example, the putter head 1500 may include an increase of 2%-5%, 5%-10%, or 10%-15% over a single material putter.

[0374] The putter-type club head 1500 further comprises a crown 1536, a sole 1568, a striking face 1520, a back end 1534, a toe end 1512, and a heel end 1516. The outermost points of the striking face 1520, the back end 1534, the toe end 1512, and the heel end 1516 define a perimeter 1510 of the putter-type club head 1500. The upper portion 1504 and the lower portion 1508 are attached together and each form a portion of the crown 1536, a portion of the sole 1568, a portion of the toe end 1512, a portion of the heel end 1516, and a portion of the perimeter 1510. The crown 1536 gradually slopes from the striking face 1520 to the back end 1534 such that the putter-type club head 1500 is thicker near the striking face 1520 and gradually thins toward the back end 1534. The slope of the crown 1536 may be a linear, curvilinear, parabolic, sinusoidal, or polynomial function. Additionally, the striking face 1520 includes a striking face center point that is equidistant from the heel end 1516 and the toe end 1512, and equidistant from the crown 1536 and the sole 1568.

[0375] In many embodiments, the sole 1568 can be flat. In some embodiments, the sole 1568 can have a slight bow from the heel end 1516 to the toe end 1512, where the slight bow can be linear or a function of a polynomial. In some embodiments, the sole 1568 can have a strong bow from the heel end 1516 to the toe end 1512, where the strong bow can be linear or a function of a polynomial. The sole 1568 functions to provide a surface for the putter-type club head 1500 to rest on the ground plane 1590. As described above, the putter-type club head 1500 includes an upper portion 1504 and a lower portion 1508, where the lower portion 1508 forms the majority of the sole 1568 and rests on the ground plane. The upper portion 1504 is located above the lower portion 1508 when the putter-type club head 1500 is assembled.

[0376] As described above, the upper portion 1504 includes a low density material (i.e., the first material). In many embodiments, the upper portion 1504 is formed from aluminum. The upper portion 1504 is attached to the lower portion 1508 to define a crown 1536, a sole 1568, a toe end 1512, a heel end 1516, and a perimeter 1510. The upper portion 1504 includes an upper upper surface 1526 and an upper lower surface 1528, where the upper upper surface 1526 forms a portion of the crown 1536 and the upper lower surface 1528 forms a portion of the sole 1568. The upper portion 1504 further includes a forward portion 1522 and a rearward extension 1524. The forward portion 1522 includes a striking face 1520. The rearward extension 1524 extends rearward from the forward portion 1522 toward the rear end 1534. The rearward extension 1524 is approximately perpendicular to the striking face 1520 such that the forward portion 1522 and the rearward extension 1524 form a T-shape.

[0377] The forward portion 1522 includes a rear wall opposite the striking face 1520 near the heel end 1516 and the toe end 1512. The rear extension 1524 includes a sidewall near the heel end 1516 and the toe end 1512. The rear wall and the sidewall near the toe end 1512 define a toe wall 1529, and the rear wall and the sidewall near the heel end 1516 define a heel wall 1530. The toe wall 1529 and the heel wall 1530 border the T-shape of the upper part 1504. Additionally, the toe and heel walls 1529, 1530 define a cutout area that allows the upper part 1504 to receive the lower part 1508. The cutout area extends inward from the toe end 1512 or the heel end 1516 toward the center of the upper part 1504. The cutout area is bounded by the crown 1536, the perimeter 1510, and either a toe wall 1529 or a heel wall 1530. The toe and heel walls 1529, 1530 define the boundary between the cutout area and the forward portion 1522, as well as the boundary between the cutout area and the rearward extension 1524. The cutout portions remove mass from the less dense upper portion 1504 and replace it with the more dense lower portion 1508, increasing the perimeter weight of the putter-type club head 1500.

[0378] To further reduce the mass of the top 1504, the top 1504 defines a central recess 1570 extending from the forward portion 1522 to the rear end 1536. The central recess 1570 removes mass from the center of the top 1504, thereby allowing mass to move toward the periphery 1510. The central recess 1570 is defined by recess walls 1572 and a recess floor 1574. The recess floor 1574 is recessed into the top 1504 away from the top surface 1526 of the top, and the recess walls 1572 circumscribe the recess floor 1574. The recess walls 1572 define a transition between the top surface 1526 of the top and the recess floor 1574.

[0379] The recess walls 1572 include a height. In some embodiments, the recess wall height slopes with the slope of the crown 1536 such that the recess wall height is greater near the striking face 1520 and less near the rear end 1534. In such embodiments, the recess walls 1572 include a height near the rear end 1534 such that the recess floor 1574 is not flush with the top surface 1526 of the top. In other embodiments, the recess wall height remains constant throughout the central recess 1570. The recess floor 1574 is parallel to the ground plane and provides a surface parallel to the ground plane for a portion of the alignment aid 1544. The central recess 1570 is located near the center of the putter-type club head 1500 within the front portion 1522 and rear extension 1524 and provides a central feature for the alignment aid 1544. The central recess 1570 further contributes to the alignment aid 1544 as described in more detail below.

[0380] 15D-15F, the top 1504 further includes an alignment aid 1544. The alignment aid 1544 extends along the top 1504 from the forward portion 1522 to the rear end 1534. The alignment aid 1544 includes several features that function in conjunction with the central recess 1570 to provide the viewer with a visual alignment field that extends from the striking face 1520 to the rear end 1534. The purpose is to use the alignment aid 1544 to align the entire putter-style club head 1500 to the golf ball.

[0381] The alignment aid 1544 includes several corresponding features carefully positioned relative to the central recess 1570. Referring to FIGS. 15D-15F, the alignment aid 1544 includes a ball contour feature 1580, a centerline 1576, and a number of grooves 1578. The ball contour feature 1580 is integrally formed with the top 1504. The ball contour feature 1580 is centered about the striking face midpoint and offset from the striking face 1520. The ball contour feature 1580 is approximately the width of a golf ball (1.68 inches) which aids in edging the golf ball during a swing. In some embodiments, the ball contour feature 1580 is slightly wider than the width of a golf ball to allow for forgiveness when edging the ball. The ball contour feature 1580 is generally a golf ball molded near the striking face 1520.

[0382] The ball contour feature 1580 is disposed on the upper surface 1526 of the upper portion above the central recess 1570. However, the ball contour feature 1580 generally follows the perimeter of the central recess 1570. The ball contour feature 1580 includes one or more arcuate portions 1582 and a set of parallel lines 1584 connected to the one or more arcuate portions 1582. At least one arcuate portion 1582 is arcuate near the striking face 1520 and offset from the striking face 1520. Referring to FIG. 15D, in some embodiments, the ball contour feature 1580 includes two arcuate portions 1582, one arcuate near the striking face 1520 and the other arcuate near the trailing end 1534. The one or more arcuate portions 1582 generally resemble half of a golf ball. Parallel lines 1584 extend rearward from the arcuate portion 1582 toward the rear end 1534. The parallel lines 1584 are generally parallel to the rear extension 1524. The parallel lines 1584 are approximately equal to the width of a golf ball (1.68 inches). The ball profile feature 1580 is generally the width of a golf ball and generally resembles an elongated golf ball to aid the viewer in visualizing the trajectory of the golf ball. The ball profile feature is disposed on the upper surface 1526 of the top and outlines the central recess 1570.

[0383] The ball-profile feature 1580 partially or completely circumscribes the central recess 1570. In some embodiments, parallel lines 1584 connect multiple arcuate sections 1582 to form a circular or rectangular ball-profile feature 1580 that completely surrounds the central recess 1570, as shown in FIG. 15D. In other embodiments having only one arcuate section 1582, the parallel lines 1584 extend rearward, thereby defining a U-shaped ball-profile feature 1580 that partially circumscribes the central recess 1570. In some embodiments, the parallel lines 1584 extend completely to the rear end 1534, as shown in FIG. 15E. In other embodiments, the parallel lines 1584 extend partially to the rear end 1534, as shown in FIG. 15F. The ball-profile feature 1580 is generally disposed on the upper surface 1526 of the top, following the perimeter of the central recess 1570.

[0384] In some embodiments, the ball contour feature 1580 is recessed into the top 1504 away from the top surface 1526 of the top, thereby defining a channel. However, in other embodiments, the ball contour feature 1580 is flush with the top surface 1526 of the top. Additionally, in other embodiments, the ball contour feature 1580 protrudes from the top surface 1526 of the top. The ball contour feature 1580 is disposed on the top surface 1526 of the top outside of the central recess 1570. The alignment aid 1544 further comprises a centerline 1576 and a number of grooves 1578 disposed within the central recess 1570. These features can work in conjunction with the ball contour feature 1580 to provide the viewer with an elongated alignment aid 1544 that extends from the striking face 1520 to the rear end 1534.

[0385] The centerline 1576 is located within the central recess 1570 of the recess floor 1574. The centerline 1576 is located behind the striking face center point and extends the entire length of the central recess 1570. The centerline 1576 extends perpendicularly from the striking face 1520 toward the rear end 1534. The centerline 1576 also extends parallel to the parallel line 1584 of the ball profile feature 1580. In some embodiments, the centerline 1576 is further recessed into the recess floor 1574. In other embodiments, the centerline 1576 is flush with the recess floor 1574. In some further embodiments, the centerline 1576 protrudes from the recess floor 1574. The centerline 1576 assists the viewer in locating the center of the alignment aid 1544. The centerline 1576 is located in the center of the recess floor 1574.

[0386] The alignment aid further comprises a plurality of grooves 1578 disposed on the recess floor 1574 on either side of the centerline 1576. The plurality of grooves 1578 are further recessed into the recess floor 1574. In some embodiments, the plurality of grooves 1578 are equally spaced from one another. In other embodiments, the plurality of grooves 1578 are concentrated near the centerline 1576 or near the toe end 1512 and heel end 1516. The plurality of grooves 1578 are parallel to the centerline 1576 and parallel lines 1584 of the ball profile feature 1580. The plurality of grooves 1578 provide a series of alignment lines perpendicular to the striking face 1520, thereby further assisting the viewer in properly aligning the golf ball.

[0387] As described above, the features of the alignment aid 1544 assist the viewer in aligning the putter-style club head 1500 with the golf ball. The ball contour feature 1580 is approximately the width of a golf ball and generally resembles a rectangular golf ball. The ball contour feature 1580 allows the user to outline the edges of the golf ball with parallel lines to frame the ball. The center line 1576 is located in the center of the ball contour feature 1580 and is located behind the striking face center point to assist the viewer in aligning the center of the golf ball with the center of the putter-style club head 1500. The multiple grooves 1578 are parallel to the parallel lines 1584 and the center line 1576 and further assist the user in orthogonally aligning the golf ball with the putter-style club head 1500.

[0388] The alignment aid 1544 further utilizes a central recess 1570. The central recess 1570 provides a structure for the ball contour features 1580 to outline. The central recess 1570 also houses a centerline 1576 and a number of grooves 1578. The ball contour features 1580 are located near the top surface 1526 of the top, and the centerline 1576 and the number of grooves 1578 are located on the recess floor 1574 vertically offset from the ball contour features 1580. When the putter-type club head 1500 is viewed from above and below, the centerline 1576 appears slightly offset from the ball contour features. The offset aids in aligning the ball contour features 1580 on the top surface 1526 of the top with the centerline 1576 on the recess floor 1574. Also, in a top-down view, the recess walls 1572 disappear when the putter-type club head 1500 is aligned, as shown in FIG. 15D. Different portions of the alignment aid 1544 can work in conjunction with the central recess 1570 to assist the user in aligning the golf ball. The alignment aid 1544 can include multiple colors to help a viewer distinguish between different features of the alignment aid 1544.

[0389] Each portion of the alignment aid 1544 includes a color. The ball-shaped feature 1580 includes a first color and the center line 1576 includes a second color. Additionally, the top portion 1504 includes a third color. The colors can be white, black, gray, silver, red, blue, yellow, green, orange, purple, or any other suitable color. In some embodiments, the first, second, and third colors are similar. In other embodiments, the first, second, and third colors are different from one another. The different colors provide a visual contrast between the different features of the alignment aid 1544, which helps the viewer distinguish between the various features.

[0390] In some embodiments, the contrast is defined by colors that are opposite each other. For example, the first, second, or third color may be a primary color selected from the group consisting of red, yellow, and blue, while the other of the first, second, or third color may be a secondary color selected from the group consisting of green, orange, and purple. Alternatively, the first, second, or third color may be white or black, while the other of the first, second, or third color may be the other of white or black. The different or contrasting colors of each mechanism further aid in the alignment of the viewer by improving the brain's ability to detect misalignment between parallel lines. This is a phenomenon known as vernier vision.

[0391] The placement of the parallel lines 1584 of the ball outline features 1580 and the center line 1576 take advantage of the viewer's vernier vision. In some embodiments, the positioning of the parallel lines 1584 and the contrasting colors of the ball outline features 1580 and center line 1576 still the viewer's eye, allowing the viewer's eye to remain naturally focused on the center line 1576 to better align the target golf ball. In some embodiments, the ball outline features 1580 and center line 1576 are filled with paint. The shading and sizing of the features are selected to provide an alignment aid 1544 that generally resembles a golf ball.

[0392] The ball profile feature 1580 defines a width measured between the furthest extents of the parallel lines 1584. The width may be slightly larger than the width of the golf ball to provide forgiveness when edging the golf ball. The width is between 1.65 inches and 1.80 inches. In some embodiments, the width is about 1.65 inches, 1.66 inches, 1.67 inches, 1.68 inches, 1.69 inches, 1.70 inches, 1.71 inches, 1.72 inches, 1.73 inches, 1.74 inches, 1.75 inches, 1.76 inches, 1.77 inches, 1.78 inches, 1.79 inches, or 1.80 inches. In one embodiment, the width is about 1.78 inches.

[0393] The ball profile feature 1580 further defines a thickness. The thickness may be sufficient to provide a substantial ball profile feature 1580. The thickness is between 0.03 inches and 0.15 inches. In some embodiments, the thickness is about 0.03 inches, 0.04 inches, 0.05 inches, 0.06 inches, 0.07 inches, 0.08 inches, 0.09 inches, 0.10 inches, 0.11 inches, 0.12 inches, 0.13 inches, 0.14 inches, or 0.15 inches.

[0394] The ball profile feature 1580 further defines a length. The length is measured in a front-to-back direction between the endpoints of the ball profile feature 1580. The length is between 2.9 inches and 3.1 inches. In some embodiments, the length is about 2.90 inches, 2.91 inches, 2.92 inches, 2.93 inches, 2.94 inches, 2.95 inches, 2.96 inches, 2.97 inches, 2.98 inches, 2.99 inches, 3.00 inches, 3.01 inches, 3.02 inches, 3.03 inches, 3.04 inches, 3.05 inches, 3.06 inches, 3.07 inches, 3.08 inches, 3.09 inches, or 3.10 inches. In one embodiment, the length is 3.08 inches.

[0395] The alignment aid 1544 is designed to provide a golf ball-like feature that is approximately the width of a golf ball. As mentioned above, the alignment aid 1544 comprises different features located near or within the central recess 1570. Each feature provides a function to the alignment aid 1544, thereby allowing the user to better align the golf ball to the desired spot on the putter-type golf club head to achieve a more accurate shot. Additionally, the alignment aid 1544 utilizes the central recess 1570 to further assist with viewer alignment. The alignment aid 1544 and central recess 1570 are located near the center of the putter-type club head 1500 within the front portion 1522 and rear extension 1524. The rear extension 1524 is configured to allow the upper portion 1504 to receive the lower portion 1508.

[0396] The lower portion 1508 includes a material (i.e., the second material) that is denser than the upper portion 1504. In many embodiments, the lower portion 1508 is formed from stainless steel. Referring to FIG. 15B, the lower portion 1508 includes a central portion 1538, a toe mass 1545, and a heel mass 1547. The central portion 1538 is a thinned area relative to the toe and heel masses 1545, 1547 to allow the upper portion 1504 to be received into the lower portion 1508. The thinned central portion 1538 also removes mass from the center of the lower portion 1508 that can be reassigned to the toe and heel masses 1545, 1547 to improve the moment of inertia of the putter-type club head 1500. The central portion 1538 includes a central upper surface 1540 that is proximate to the upper lower surface 1528. The central upper surface 1540 includes a shape that corresponds to the upper lower surface 1528. In some embodiments, the top surface 1528 of the central portion includes one or more recesses, as shown in FIG. 15B. The one or more recesses can further reduce mass from the center of the lower portion 1508. The mass can be redistributed to toe and heel masses 1545, 1547 configured to distribute mass around the perimeter of the putter-type club head 1500.

[0397] The toe and heel masses 1545, 1547 are raised portions relative to the central portion 1538. The toe and heel masses 1545, 1547 are located near the perimeter 1510 to provide perimeter weighting to increase the moment of inertia of the putter-type club head 1500. Additionally, the weight of the toe and heel masses 1545, 1547 can be adjusted to achieve a desired swing weight or overall putter head mass. The toe and heel masses 1545, 1547 include a mass upper surface 1541 that forms a portion of the crown 1536. The upper portion 1504 and lower portion 1508 form a portion of the crown 1536 and sole 1568, respectively. The lower portion 1508 further includes a lower surface 1542 of the lower portion that forms a portion of the sole. The toe and heel masses 1545, 1547 further include an inner surface 1561 located near the toe and heel walls 1529, 1530 and an outer surface 1543 forming a portion of the perimeter 1510. In some embodiments, the outer surface 1543 forms a portion of the toe end 1512, the heel end 1516, or the rear end 1534. The inner surface 1561 defines a transition between the toe mass 1545 and the central portion 1538, as well as a transition between the heel mass 1547 and the central portion 1538. The inner surface 1561 includes a shape corresponding to the toe and heel walls 1529, 1530. The lower portion 1508 is configured to receive the upper portion 1504 such that the rearward extension 1524 is located above the central portion 1538 and between the toe and heel masses 1545, 1547.

[0398] In some embodiments, the toe and heel masses 1545, 1547 are formed to fit snugly with the upper portion 1504. In other embodiments, the inner surface 1561 and the toe and heel walls 1529, 1530 define gaps 1595, 1597 therebetween. The gaps 1595, 1597 allow for various sizes of toe and heel masses 1545, 1547 to be held within the cutout area to adjust the weighting of the putter-type club head 1500. The gaps 1595, 1597 define a width measured between the respective inner surface 1561 and the toe and heel walls 1529, 1530. The gap width may remain constant throughout the gaps 1595, 1597 or the gap width may vary throughout the gaps 1595, 1597. The gap width may be between 0.05 inches and 0.21 inches. In some embodiments, the gap width is between 0.05 inches and 0.09 inches, 0.07 inches and 0.13 inches, 0.10 inches and 0.18 inches, and 0.15 inches and 0.21 inches. In some embodiments, the gap width is 0.05 inches, 0.06 inches, 0.07 inches, 0.08 inches, 0.09 inches, 0.10 inches, 0.11 inches, 0.12 inches, 0.13 inches, 0.14 inches, 0.15 inches, 0.16 inches, 0.17 inches, 0.18 inches, 0.19 inches, 0.20 inches, or 0.21 inches. In one embodiment, the gap width is 0.16 inches. The gap width depends on the size and shape of the toe and heel masses 1545, 1547 and the corresponding cutout areas.

[0399] The toe and heel masses 1545, 1547, respectively, can be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape. The shape of the toe and heel masses 1545, 1547 corresponds to the shape of the respective cutout areas of the upper portion 1504.

[0400] The toe and heel masses 1545, 1547 provide an additional means of adding mass to the perimeter 1510 to increase the MOI of the putter-type club head 1500 on a putter without these mass features. The lower portion 1508 includes a mass between 200 grams and 215 grams. In some embodiments, the mass is between 200 grams and 210 grams, 205 grams and 210 grams, and 210 grams and 215 grams. The mass can be 200 grams, 201 grams, 202 grams, 203 grams, 204 grams, 205 grams, 206 grams, 207 grams, 208 grams, 209 grams, 210 grams, 211 grams, 212 grams, 213 grams, 214 grams, or 215 grams. In one embodiment, the mass is 205.7 grams.

[0401] The lower portion, and the toe and heel masses 1545, 1547, in particular, provide an area of ​​concentrated mass near the perimeter 1510 such that the toe and heel masses 1545, 1547 function to increase the moment of inertia of the putter-type club head 1500. Locating the toe and heel masses 1545, 1547 in the perimeter 1510 increases the MOI since each mass is farther from the center of gravity of the putter-type club head 1500. The upper portion 1504 is attached to the lower portion 1508 formed using a second material, the second material being denser than the first material. The upper portion 1504 may be attached to the lower portion 1508 using an adhesive.

[0402] In many embodiments, the lower portion 1508 comprises less than 35% of the total volume of the putter-type club head 1500. In some embodiments, the lower portion 1508 comprises less than 34%, less than 33%, less than 32%, less than 31%, less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, or less than 23% of the total volume. In one embodiment, the lower portion 1508 comprises 30.1% of the total volume.

[0403] The lower portion 1508 comprises less than half the volume of the putter-type club head 1500, but the lower portion 1508 comprises at least 50% of the total mass of the putter-type club head 1500. In some embodiments, the lower portion 1508 comprises at least 51%, at least 52%, at least 53%, at least 54%, at least 55%, at least 56%, at least 57%, at least 58%, at least 59%, or at least 60% of the total mass. In one embodiment, the lower portion 1508 comprises 56.1% of the total mass. As described in more detail below, the lower portion 1508 comprises a low proportion of the putter-type club head 1500's volume (less than 50%) and a high proportion of the putter-type club head 1500's mass (greater than 50%).

[0404] The combination of the low density upper portion 1504 and the high density lower portion 1508 creates a high MOI putter-type club head 1500 without creating an excessively heavy putter. The central recess 1570 shifts the majority of the volume and mass of the putter-type club head 1500 to the periphery 1510. This shift creates a minor portion that increases the MOI compared to a putter milled from a single material. A single material putter-type club head cannot allocate high density material to the periphery while maintaining the desired volume (75cc-100cc) and mass (340g-385g). The advantages of the putter head 1500 over putter heads formed from a single material structure are illustrated in the following examples.

[0405] IV. Putter Head with Ball-Contour Alignment Aid and Individual Weights In one embodiment, the putter-type club head can include a two-part construction and can include an alignment aid with ball-profile features. The two-part construction allows the putter-type club head to be formed of multiple materials. With reference to FIGS. 16A and 16B, the putter-type club head 1600 includes a body 1604, a toe weight 1645, and a heel weight 1647. In some embodiments, the body 1604 is formed from a first material having a first density, and the toe and heel weights 1645, 1647 are formed from a second material having a second density. In some embodiments, the first density is less than the second density. As described in more detail below, the body 1604 and the toe and heel weights 1645, 1647 are combined to provide a high MOI putter-type club head 1600 (5000 g·cm) while maintaining a desired volume and mass. 2 ~6500g cm 2 For example, the putter head 1600 has a force of 5000g cm 2 ~5500g cm 2 , 5500g·cm 2 ~6000g cm 2 , 6000g·cm 2 ~6500g cm 2 The putter head 1600 may have an MOI in the range of 2%-15% increase in MOI about the y-axis over putter heads lacking a multi-material construction (i.e., a single material). For example, the putter head 1600 may include an increase of 2%-5%, 5%-10%, or 10%-15% over a single material putter.

[0406] The putter-type club head 1600 further comprises a crown 1636, a sole 1668, a striking face 1620, a back end 1634, a toe end 1612, and a heel end 1616. The outermost points of the striking face 1620, the back end 1634, the toe end 1612, and the heel end 1616 define a perimeter 1610 of the putter-type club head 1600. The body 1604 and the toe and heel weights 1645, 1647 respectively form a portion of the crown 1636, a portion of the sole 1668, a portion of the toe end 1612, a portion of the heel end 1616, and a portion of the perimeter 1610. The crown 1636 gradually slopes from the striking face 1620 to the back end 1634 such that the putter-type club head 1600 is thicker near the striking face 1620 and gradually thins toward the back end 1634. The slope of the crown 1636 may be a linear, curvilinear, parabolic, sinusoidal, or polynomial function. Additionally, the striking face 1620 includes a striking face center point that is equidistant from the heel end 1616 and the toe end 1612, and equidistant from the crown 1636 and the sole 1668.

[0407] In many embodiments, the sole 1668 can be flat. In some embodiments, the sole 1668 can have a slight bow in the heel 1616 to toe 1612 direction, where the slight bow can be linear or a function of a polynomial. In some embodiments, the sole 1668 can have a strong bow in the heel 1616 to toe 1612 direction, where the strong bow can be linear or a function of a polynomial. The sole 1668 functions to provide a surface for the putter-type club head 1600 to rest on the ground plane. As described above, the putter-type club head 1600 includes a body 1604, a toe weight 1645, and a heel weight 1647, where the body 1604 forms the majority of the sole 1668 and rests on the ground plane. The toe weight 1645 and the heel weight 1647 sit on the body 1604 when the putter-type club head 1600 is assembled.

[0408] As described above, the body 1604 includes a low density material (i.e., the first material). In many embodiments, the body 1604 is formed from aluminum. A toe weight 1645 and a heel weight 1647 are attached to the body 1604 to define a crown 1636, a sole 1668, a toe end 1612, a heel end 1616, and a perimeter 1610. The body 1604 includes an upper surface 1626 and a lower surface 1628, where the upper surface 1626 forms a portion of the crown 1636 and the lower surface 1628 forms a portion of the sole 1668. The body 1604 further includes a forward portion 1622 and a rear portion 1623, where the forward portion 1622 includes the striking face 1620. The rear portion 1623 includes a rearward extension 1624 extending rearward from the forward portion 1622 toward the rear end 1634. The rearward extension 1624 is generally perpendicular to the striking face 1620. The forward portion 1622 and the rearward extension 1624 form a T-shape.

[0409] The body 1604 defines a central recess 1670 extending from the forward portion 1622 to the rear end 1634. The central recess 1670 removes mass from the center of the body 1604, thereby allowing mass to move toward the periphery 1610. The central recess 1670 is defined by recess walls 1672 and a recess floor 1674. The recess floor 1674 is recessed into the body 1604 away from the body top surface 1626, and the recess walls 1672 circumscribe the recess floor 1674.

[0410] The recess walls 1672 include a height. In some embodiments, the recess wall height slopes with the slope of the crown 1636, such that the recess wall height is greater near the striking face 1620 and less near the rear end 1634. In such embodiments, the recess walls 1672 include a height near the rear end 1634 such that the recess floor 1674 is not flush with the body top surface 1626. In other embodiments, the recess wall height remains constant throughout the central recess 1670. The recess floor 1674 is parallel to the ground plane and provides a surface parallel to the ground plane for a portion of the alignment aid 1644. The central recess 6570 is located near the center of the putter-type club head 1600 within the front portion 1622 and rear extension 1624 and provides a central feature for the alignment aid 1644. The central recess 1670 further contributes to the alignment aid 1644 as described in more detail below.

[0411] Body 1604 further comprises alignment aid 1644. Alignment aid 1644 is similar to alignment aid 1544 and will be described using similar reference numbers as alignment aid 1544. For example, alignment aid 1644 includes one or more arcuate portions 1682 and a set of parallel lines 1684 that are similar to the one or more arcuate portions 1582 and the set of parallel lines 1584 of alignment aid 1544. However, alignment aid 1544 is disposed on body upper surface 1626 instead of top upper surface 1526 as alignment aid 1544.

[0412] The alignment aid 1644 includes a ball profile feature 1680, a centerline 1676, and a number of grooves 1678. The ball profile feature 1680 can be similar to the ball profile feature 1580 shown in FIGS. 15D-15E. For example, the ball profile feature 1680 can partially or completely surround the central recess 1670. In some embodiments, parallel lines 1684 connect multiple arcuate portions 1682 to form a circular or rectangular ball profile feature 1680 that completely circumscribes the central recess 1670, as shown in FIG. 15D. In other embodiments having only one arcuate portion 1682, the parallel lines 1684 extend rearward, thereby defining a U-shaped ball profile feature 1680 that partially circumscribes the central recess 1670. In some embodiments, the parallel lines 1684 extend completely to the rear end 1634, as shown in FIG. 15E. In other embodiments, the parallel lines 1684 extend partially to the rear end 1634, as shown in Figure 15F. The ball profile feature 1680 generally follows the periphery of the central recess 1670 and is disposed on the body upper surface 1626.

[0413] Additionally, the centerline 1676 and the plurality of grooves 1678 may be similar to the centerline 1576 and the plurality of grooves 1578 of the alignment aid 1544. The centerline 1676 and the plurality of grooves 1678 are located on the recess floor 1674. The centerline 1676 is located rearward of the striking face center point and extends the entire length of the central recess 1670. The plurality of grooves 1678 are recessed into the recess floor 1674 on either side of the centerline 1676. The features of the alignment aid 1644 assist the viewer in aligning the putter-type club head 1600 with the golf ball. The alignment aid 1644 also utilizes a central recess 1670. The central recess 1670 provides a structure for the ball contour features 1670 to contour. The central recess 1670 also houses the centerline 1676 and the plurality of grooves 1678. As described above, the alignment aid 1644 is disposed near the body top surface 1526 and extends from the forward portion 1622 through the rearward extension 1623 to the rearward end 1634. The rearward portion 1623 is further configured to receive one or more weights.

[0414] The rear portion 1623 further includes toe and heel wings 1629 and 1630 that receive a toe weight 1645 and a heel weight 1647. The wings 1629, 1630 are disposed near the periphery 1610 toward the rear end 1634 such that the rearward extension 1624 extends between the wings 1629, 1630. The wings 1629, 1630 are defined between a wing floor 1632 and the sole 1668. The wing floor 1632 is recessed into the body 1604 away from the body top surface 1626. The wing floor 1632 forms a base for the wings 1629, 1630 to receive the weights 1645, 1647.

[0415] The rear defines a toe weight recess 1638 and a heel weight recess 1639. The weight recesses 1638, 1639 are located above the wings 1629, 1630 and function to receive weights 1645, 1647. The weight recesses 1638, 1639 are defined in the wing walls 1631 and the wing floor 1632, with the wing walls 1631 adjacent the respective recess floors 1632. The toe weight recess 1638 extends inwardly from the toe end 1612 toward the center of the body 1604. The heel weight recess 1639 extends from the heel end 1616 toward the center of the body 1604. The weight recesses 1638, 1639 are bounded by the crown 1636, the perimeter 1610, the recess floor 1632, and the wing walls 1631.

[0416] The wing wall 1631 defines a boundary between the wings 1629, 1630 and the forward portion 1622, as well as a boundary between the wings 1629, 1630 and the rearward extension 1624. In some embodiments, the wing wall 1631 can completely encapsulate the weights 1645, 1647. In other embodiments, the wing wall 1631 can partially encapsulate the weights 1645, 1647. For example, in some embodiments, the wing wall 1631 can encapsulate between 30% to 45%, 40% to 65%, 50% to 90%, or 60% to 95% of the weights 1645, 1647.

[0417] The wing recesses 1638, 1669 are configured to receive weights 1645, 1647 such that the weights 1645, 1647 sit on the wings 1629, 1630. Referring to FIG. 16B, the wings 1629, 1630 include attachment points 1633 that receive the respective weights 1645, 1647. Each attachment point 1633 protrudes from the wing floor 1632 into a respective weight recess 1638, 1639. Each attachment point 1633 can be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0418] The weight recesses 1638, 1369 and wings 1629, 1630 can include any desired shape. However, in many embodiments, the weight recesses 1638, 1369 and wings 1629, 1630 include a shape similar or identical to the shape of the weights 1645, 1647. Each weight recess 1638, 1369 corresponds to a respective wing 1629, 1630 and attachment point 1633 of a respective weight 1645, 1647.

[0419] 16A , the putter-type club head 1600 includes a heel weight 1647 and a toe weight 1645 that correspond to the respective wings 1629, 1630, weight recesses 1638, 1639, and attachment points 1633. However, the putter-type club head 1600 is not limited to the heel weight 1647 and the toe weight 1645. In some embodiments, the putter-type club head 1600 can include 1, 2, 3, 4, 5, 6, 7, or 8 weights. In these embodiments, the putter-type club head 1600 can include 1, 2, 3, 4, 5, 6, 7, or 8 corresponding wings and attachment points.

[0420] The weights 1645, 1647 include a material that is denser than the body 1604 (i.e., the second material). In many embodiments, the weights 1645, 1647 are formed from stainless steel. The weights 1645, 1647 are disposed near the perimeter 1610 and secured to the body 1604. With reference to FIGS. 16B and 16D , the weights 1645, 1647 include an inner surface 1661 located near the wing wall 1631 and an outer surface 1643 that forms a portion of the perimeter 1610. In some embodiments, the outer surface 1643 forms a portion of the toe end 1612, the heel end 1616, or the rear end 1634. The inner surface 1661 includes a shape that corresponds to the wing wall 1631.

[0421] In some embodiments, the weights 1645, 1647 fit snugly with the body 1604. In other embodiments, the inner surface 1661 and the wing walls 1631 define gaps 1695, 1697 therebetween. The gaps 1695, 1697 allow various sizes of weights 1629, 1630 to be retained within the weight recesses 1638, 1639 to adjust the weighting of the putter-type club head 1600. The gaps 1695, 1697 define a width measured between the respective inner surface 1661 and the wing walls 1631. The gap width may remain constant throughout the gaps 1695, 1697 or the gap width may vary throughout the gaps 1695, 1697. The gap width may be between 0.05 inches and 0.21 inches. In some embodiments, the gap width is between 0.05 inches and 0.09 inches, 0.07 inches and 0.13 inches, 0.10 inches and 0.18 inches, and 0.15 inches and 0.21 inches. In some embodiments, the gap width is 0.05 inches, 0.06 inches, 0.07 inches, 0.08 inches, 0.09 inches, 0.10 inches, 0.11 inches, 0.12 inches, 0.13 inches, 0.14 inches, 0.15 inches, 0.16 inches, 0.17 inches, 0.18 inches, 0.19 inches, 0.20 inches, or 0.21 inches. In one embodiment, the gap width is 0.16 inches.

[0422] The weights 1645, 1647 further include a weight upper surface 1640 and a weight lower surface 1642. The weight upper surface 1640 forms a portion of the crown 1636, and the weight lower surface 1642 forms a portion of the sole 1668. The weight lower surface 1642 is proximate the wing floor 1632 and includes a shape corresponding to the respective wings 1629, 1630 and attachment points 1633. Referring to FIG. 16D, the weight lower surface 1642 includes a stepped shape corresponding to the shape of the respective wings 1629, 1630 and attachment points 1633. The weights 1645, 1647 slide over the attachment points 1633 and are further secured with an epoxy material. In some embodiments, the wing floor 1632 includes a number of grooves that increase the surface area of ​​the wing floor 1632. The number of grooves increases the surface area available for bonding, thereby strengthening the bond between the weights 1645, 1647 and the floor 1632. The shape of the weight underside 1642 facilitates a tight connection between the weights 1645, 1647 and the wings 1629, 1630.

[0423] The weights 1645, 1647 may each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape. The geometric shape of the weights 1645, 1647 corresponds to the geometric shape of the respective weight recesses 1638, 1639.

[0424] The weights 1645, 1647 provide an additional means of adding mass to the perimeter 1610 to increase the MOI of the putter-type club head 1600 over putters without these mass features. Additionally, the weights 1645, 1647 can be adjusted to achieve a desired swing weight or overall putter head mass. The weights 1645, 1647 have a combined mass between 45 grams and 70 grams. In some embodiments, the mass is 45 grams to 60 grams, 55 grams to 70 grams, and 55 grams to 65 grams. The combined mass is 45 grams, 46 grams, 47 grams, 48 ​​grams, 49 grams, 50 grams, 51 grams, 52 grams, 53 grams, 54 grams, 55 grams, 56 grams, 57 grams, 58 grams, 59 grams, 60 grams, 61 grams, 62 grams, 63 grams, 64 grams, 65 grams, 66 grams, 67 grams, 68 grams, 69 grams, or 70 grams. The weights 1645, 1647 provide an area of ​​concentrated mass near the perimeter 1610 such that each weight 1645, 1647 functions to increase the moment of inertia of the putter-type club head 1600. Placing each weight 1645, 1647 in the perimeter 1610 increases the MOI because each mass is further from the center of gravity of the putter-type club head 1600. Each weight 1645, 1647 is secured to the body 1604 using a second material, the second material being denser than the first material.

[0425] In many embodiments, the weights 1645, 1647 comprise less than 25% of the total volume of the putter-type club head 160. In some embodiments, the weights 1645, 1647 comprise less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, or less than 13% of the total volume.

[0426] The weights 1645, 1647 comprise at least 30% of the total mass of the putter-type club head 160, although they comprise less than half of the total volume of the putter-type club head 160. In some embodiments, the weights 1645, 1647 comprise at least 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40% of the total mass.

[0427] The combination of the low density body 1604 and the high density weights 1645, 1647 allows for the creation of a high MOI putter-type club head 1600 without creating an excessively heavy putter. The central recess 1670 shifts the majority of the volume and mass of the putter-type club head 1600 to the ends of the body 1604. This shift creates a small amount of mass that increases the MOI compared to a putter milled from a single piece of material. A single material putter-type club head cannot allocate high density material to the perimeter while maintaining the desired volume (75cc-100cc) and mass (340g-385g).

[0428] V.3 Putter Head In some embodiments, rather than a two-part putter, the putter-type golf club head can include a three-part structure that includes an upper and lower portion as well as a crown portion 1802. By providing a three-part putter head that includes an upper and lower portion as well as a crown portion 1802, the mass distribution throughout the putter head can be more precisely controlled and optimized to increase the MOI of the putter head.

[0429] The upper portion of the three-part putter-type golf club head can be similar to one or more of the upper portions described with reference to the prior embodiments and can be made of the first material described above. Similarly, the lower portion of the three-part putter-type golf club head can be similar to one or more of the lower portions described with reference to the prior embodiments and can be constructed of the second material described above.

[0430] The three-part putter head further includes a crown portion made of a third material that is different from both the first material of the upper portion and the second material of the lower portion. The third material can be lightweight and can include a density that is lower than both the first density and the second density. In many embodiments, the crown portion 1802 can be joined onto the upper portion and form the top portion of the putter head.

[0431] In many embodiments, the crown portion of the putter head having the third material has a third density in the range of 0.5 g / cc to 3.5 g / cc. The third density may range from 1.5 g / cc to 2.5 g / cc. In some embodiments, the third density may range from 0.5 to 0.75 g / cc, 0.75 to 1.0 g / cc, 1.0 to 1.25 g / cc, 1.25 to 1.5 g / cc, 1.5 to 1.75 g / cc, 1.75 to 2.0 g / cc, 2.0 to 2.25 g / cc, 2.25 to 2.5 g / cc, 2.5 to 2.75 g / cc, 2.75 to 3.0 g / cc, or 3.25 to 3.5 g / cc. In one embodiment, the third density of the crown portion 1802 may range from 1.0 to 2.0 g / cc. In some embodiments, the third density can be less than 3.5 g / cc, less than 3.0 g / cc, less than 2.5 g / cc, less than 2.0 g / cc, less than 1.5 g / cc, or less than 1.0 g / cc. In some embodiments, the third density can be 0.5 g / cc, 0.75 g / cc, 1.0 g / cc, 1.25 g / cc, 1.50 g / cc, 1.75 g / cc, 2.0 g / cc, 2.25 g / cc, 2.50 g / cc, 2.75 g / cc, 3.0 g / cc, 3.25 g / cc, or 3.50 g / cc.

[0432] The crown portion of the putter head having the third material may be made from any one or combination of the following: aluminum, aluminum alloy, ADC-12, polymeric materials, composite materials, filled thermoplastics, fiber reinforced composite materials, or other suitable low density materials.

[0433] The inclusion of a lower density crown section can increase the MOI of the putter head. Interchanging sections of the club head made of a first material or a second material creates optional mass that can be redistributed throughout the putter head.

[0434] a.3 Partial spade shaped embodiment 18A-18D show a first embodiment of a three-part putter-type golf club head 1800. In this embodiment, the putter head 1800 is a spade-shaped putter head 1800, similar to the two-part spade-shaped putter head 700 of FIGS. 7A-7C. The three-part spade-shaped putter head 1800 includes an upper portion 1804, a lower portion 1808, and a crown portion 1802, and a hollow interior cavity 1850 formed between the upper portion 1804, the lower portion 1808, and the crown portion 1802. The upper portion 1804 is made from a first material having a first density, the lower portion 1808 is made from a second material having a second density, and the crown portion 1802 is made from a third material having a third density. The first density is less than the second density. The third density is less than both the first density and the second density. The upper portion 1804, lower portion 1808, and crown portion 1802 combine to provide a high MOI putter head (3500 g cm) while maintaining a desired volume and mass. 2 ~5000g cm 2 For example, in some embodiments, the putter head 1800 has a ball bearing capacity of about 3500 g cm 2 From 4000g cm 2 , about 4000g cm 2 From 4500g cm 2 , or about 4500g cm 2 From 5000g cm 2 In some embodiments, the putter head 1800 may have an MOI of between about 3500 g cm 2 From 3750g cm 2 , approx. 3750g cm 2 From 4000g cm 2 , about 4000g cm 2 From 4250g cm 2, approx. 4250g cm 2 From 4500g cm 2 , about 4500g cm 2 From 4750g·cm 2 , or about 4750g cm 2 From 5000g cm 2 The MOI may be between 0.01 and 0.1.

[0435] As shown in FIG. 18A , the top 1804 forms a majority of the body of the putter head 1800. The top 1804 includes a base 1830 and a number of walls extending perpendicularly from the base 1830. The top 1804 may include a number of peripheral walls including a front wall 1812, a toe wall 1814, a heel wall 1816, and a rear wall 1832 that define a hitting face 1820. The front wall 1812 is adjacent to the toe wall 1814 and the heel wall 1816 and opposite the rear wall 1832. An outer surface of the front wall 1812 forms the hitting face 1820, while an inner surface of the front wall 1812 forms the rear surface 1824. The toe wall 1814 is adjacent to the front wall 1812 and the rear wall 1832 and opposite the heel wall 1816. The heel wall 1816 is also adjacent to the front wall 1812 and the rear wall 1832 , but is on the opposite side from the toe wall 1814 .

[0436] The multiple perimeter walls can form a majority of the perimeter of the putter head 1800. The base 1830 can extend from the front wall 1812 to the rear wall 1832 and from the toe wall 1814 to the heel wall 1816. The base 1830 further comprises an upper surface 1831 and a lower surface 1833 opposite the upper surface 1831. The lower surface 1833 of the base 1830 forms at least a portion of the sole 1868. In many embodiments, referring to FIG. 18C , the lower surface 1833 can include a recessed area 1840 configured to receive the lower portion 1808 such that the lower surface 1833 of the base 1830 forms a portion of the sole 1868 and a lower surface 1882 of the lower portion 1808 forms the remaining portion of the sole 1868.

[0437] The top 1804 further includes a plurality of interior walls 1838 extending perpendicularly from the base 1830. Each of the plurality of interior walls 1838 is inset relative to the perimeter of the putter head 1800. Thus, the plurality of interior walls 1838 do not form any portion of the perimeter of the club head. As shown in FIG. 18A , the plurality of perimeter walls and the plurality of interior walls 1838 can be interconnected. The interconnections between the plurality of perimeter walls and the plurality of interior walls 1838 can collectively form a cavity profile, when viewed from above, which defines the shape of the hollow interior cavity 1850. The shape of the cavity profile is defined by the orientation and shape of the plurality of perimeter walls and the plurality of interior walls 1838. In some embodiments, such as the embodiment shown in FIG. 18A, the top 1804 can include one or more interior walls 1838 that extend substantially perpendicular to the striking face 1820 and one or more interior walls 1838 that extend substantially parallel to the striking face 1820. In other embodiments, the one or more interior walls 1838 can extend at an angle relative to the striking face 1820. Although FIG. 18A illustrates that the multiple interior walls 1838 are formed as substantially straight walls, in other embodiments, the putter head 1800 can include one or more interior walls 1838 that are curved. The top of the top 1804 can be open such that the top 1804 does not itself enclose a hollow portion or internal cavity.

[0438] The upper portion 1804 may further define one or more outer portions 1835 located outside the cavity profile. The one or more outer portions 1835 form an area of ​​the putter head 1800 where the top surface 1831 of the base 1830 is exposed to the exterior of the putter head 1800. The one or more outer portions 1835 may be bounded in part by an outer surface of one or more inner walls 1838, but the outer portions 1835 are not bounded on either side by any of the multiple peripheral walls.

[0439] The upper portion 1804 further includes a central opening 1864 that extends through a portion of the base 1830. The central opening 1864 extends through both the upper surface 1831 and the lower surface 1833 of the base 1830. The central opening 1864 shifts the majority of the volume and mass of the putter head 1800 to an end of the upper portion 1804. The central opening 1864 can be configured to be covered by the lower portion 1808 to enclose the hollow interior cavity 1850.

[0440] As shown in FIGS. 18A and 18B, the crown portion 1802 forms a majority of the top surface of the putter head 1800. The crown portion 1802 can include a thin cover-like structure configured to cover the top portion 1804. The plurality of walls can provide a surface 1834 to which the crown portion 1802 is attached. As shown in FIG. 18A, the shape of the crown portion 1802 is complementary to the shape of the top portion 1804. In particular, the shape of the crown corresponds to the cavity profile formed by the plurality of top walls. The peripheral edge of the crown portion 1802 can be configured to attach to the top surface 1834 of the top peripheral wall and the top inner wall 1838. As shown in FIG. 18(b), the crown portion 1802 completely surrounds the top of the hollow interior cavity 1850 by covering the top of the bottom portion 1808.

[0441] The crown portion 1802 includes a front edge 1870 extending in a heel-to-toe direction along the front wall 1812. The front edge 1870 can extend from the toe wall 1814 all the way to the heel wall 1816. The crown portion 1802 further includes a central extension 1842, a heel extension 1846, and a toe extension 1848. The central extension 1842 extends rearward from the front edge 1870 near the center of the front wall 1812. The central extension 1842 extends from the front wall 1812 all the way to the rear wall 1832, covering a central region of the cavity profile. The heel extension 1846 extends rearward from the heel side of the front edge 1870. The heel extension 1846 extends along the heel wall 1816 and extends a portion of the way from the front wall 1812 to the rear wall 1832. The toe extension 1848 extends rearward from the toe side of the front edge 1870. The toe extension 1848 extends along the toe wall 1814 and extends part of the way from the front wall 1812 to the rear wall 1832.

[0442] Additionally, the crown portion 1802 of the putter head 1800 may include one or more alignment features 1836. The alignment features 1836 may be any one or combination of a line, a series of lines, a milled trough, a circle, a dashed line, a triangle, a channel, or any other desired alignment features 1836. In the embodiment of FIGS. 18A-18D, the central extension 1842 is configured to be the width of a golf ball (approximately 4.27 cm). The alignment features 1836 extending along the crown portion 1802 function to provide the viewer with a visual alignment field that extends the width of a golf ball from the striking face 1820 to the rear of the putter head 1800. The purpose is to use these alignment features 1836 along the crown portion 1802 to align the entire putter head 1800 with a golf ball.

[0443] As shown in FIG. 18D, the lower portion 1808 can form a majority of the sole 1868. The lower portion 1808 can be formed as a substantially flat dense sole plate. In many embodiments, the lower portion 1808 is received within a recessed region 1840 of the lower surface 1833 of the upper portion. The lower portion 1808 can be received within the upper portion 1804 such that the lower surface 1882 of the lower portion 1808 is flush with the lower surface 1833 of the upper portion 1804. In this manner, the lower surfaces 1833, 1882 of the upper portion 1804 and the lower portion 1808 combine to define a substantially continuous sole surface at the bottom of the putter head 1800. In some embodiments, referring to FIG. 18A, the upper surface 1880 of the lower portion 1808 can include one or more recesses 1886. The one or more recesses 1886 can be located near the center of the lower portion 1808. The one or more recesses 1886 can help shift mass toward the periphery of the lower portion 1808.

[0444] 18D , the lower portion 1808 is located toward the rear wall 1832 of the putter head 1800 and may extend substantially between the heel wall 1816 and the toe wall 1814. Thus, a majority of the sole 1868 proximate the rear wall 1832 may be formed by a lower surface 1882 of the lower portion. In many embodiments, the lower portion 1808 may be spaced rearwardly from the front wall 1812. Thus, a majority of the sole 1868 proximate the striking face 1820 may be formed by the lower surface 1833 of the upper portion 1804.

[0445] The lower portion 1808 is configured to be received over the upper opening 1864 from the bottom of the putter head 1800. The lower portion 1808 may seal off the hollow interior cavity 1850 from the sole 1868 and enclose a bottom of the hollow interior cavity 1850.

[0446] When combined, the top portion 1804, bottom portion 1808, and crown portion 1802 form a hollow interior cavity 1850 within the putter head 1800. The hollow interior cavity 1850 is bounded between the inner surfaces of the perimeter and inner walls 1838 of the top portion 1804, the lower surface (not shown) of the crown portion 1802, and the upper surface 1880 of the bottom portion 1808. The hollow interior cavity 1850 removes a large amount of mass from near the center of gravity. The hollow interior cavity 1850 thereby increases the MOI of the putter head 1800 by shifting mass toward the perimeter of the putter head 1800.

[0447] 18A-18D, hollow interior cavity 1850 is completely surrounded by top portion 1804, bottom portion 1808, and crown portion 1802 such that there is no opening to hollow interior cavity 1850 from the exterior of putter head 1800. Having interior cavity 1850 completely surrounded by top portion 1804, bottom portion 1808, and crown portion 1802 provides putter head 1800 with the high MOI of a hollow putter head while retaining the appearance of a well constructed putter head.

[0448] In some embodiments, the hollow interior cavity 1850 can comprise a filler material (not shown). In some embodiments, the filler material can completely fill the volume of the hollow interior cavity 1850. In other embodiments, the filler material can fill only a portion of the volume of the hollow interior cavity 1850. In some embodiments, the filler material can fill more than 5%, more than 10%, more than 20%, more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, or more than 90% of the volume of the hollow interior cavity 1850. In other embodiments, the filler material can fill less than 90%, less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20%, less than 10%, or less than 5% of the volume of the hollow interior cavity 1850.

[0449] In many embodiments, the filler material can be a polymer. The polymer can include thermoplastics, thermoplastic elastomers, polyurethanes, ethylene, vinyl acetate, ethylene vinyl acetate (EVA), polyolefin copolymers, styrene, styrene butadiene, polymer foam materials, any other suitable polymeric materials, or any combination thereof. In other embodiments, the filler material can include elastomers, polyurethane elastomers, silicones, silicone elastomers, rubber, or vulcanized natural rubber latex. Still in other embodiments, the filler material can be an epoxy, resin, adhesive, polyurethane adhesive, glue, or any other suitable adhesive. For example, the carrier can be a polyurethane adhesive, such as Gorilla Glue (Gorilla Glue Company, Cincinnati Ohio). In another example, the filler material can be a polyurethane elastomer, such as Freeman 1040 (Freeman Manufacturing & Supply Company, Avon, Ohio), or a polyurethane-based thermoplastic elastomer, such as Freeman 3040 (Freeman Manufacturing & Supply Company, Avon, Ohio). In some embodiments, the filler material can be a lattice material. The lattice filler material can be formed from metal using processes such as casting, die casting, co-die casting, additive manufacturing, or metal 3D printing.

[0450] The combination of the low density first material upper portion 1804 and low density third material crown portion 1802 with the high density second material lower portion 1808 creates a high MOI putter head 1800 without creating a very heavy putter head 1800. Providing a hollow interior cavity 1850 allows for the inclusion of a high density but small amount of lower portion 1808 which increases the MOI of the putter head 1800 compared to a putter head milled from a single material. A single material putter head does not allocate high density material to the periphery while maintaining a desired volume (75cc-100cc) and mass (340g-385g). In one example, the putter head 1800 includes a high MOI, a desired volume (91cc), and a desired mass (361g).

[0451] The lower portion 1808, in most embodiments, comprises less than 40% of the total volume of the putter head 1800. In some embodiments, the lower portion 1808 comprises less than 39% of the total volume of the putter head 1800, less than 38% of the total volume of the putter head 1800, less than 37% of the total volume of the putter head 1800, less than 36% of the total volume of the putter head 1800, less than 35% of the total volume of the putter head 1800, less than 34% of the total volume of the putter head 1800, less than 33% of the total volume of the putter head 1800, less than 32% of the total volume of the putter head 1800, less than 31% of the total volume of the putter head 1800, or less than 30% of the total volume of the putter head 1800.

[0452] The inclusion of the hollow interior cavity 1850 allows the majority of the mass of the putter head 1800 to be concentrated in the lower portion 1808 without creating an excessively heavy putter head 1800. The lower portion 1808 comprises less than 40% of the volume of the putter head 1800, however, the lower portion 1808 comprises at least 60% of the overall mass of the putter head 1800. In some embodiments, the lower portion 1808 comprises at least 61% of the mass of the putter head 1800, at least 62% of the mass of the putter head 1800, at least 63% of the mass of the putter head 1800, at least 64% of the mass of the putter head 1800, at least 65% of the mass of the putter head 1800, at least 66% of the mass of the putter head 1800, at least 67% of the mass of the putter head 1800, at least 68% of the mass of the putter head 1800, at least 69% of the mass of the putter head 1800, or at least 70% of the mass of the putter head 1800.

[0453] The beneficial shift of mass to the periphery of the putter head 1800 through the use of a high density, low volume lower portion 1808 and the inclusion of a hollow interior cavity 1850 increases the MOI of the putter head 1800. The putter head 1800 has an increased MOI over a putter head having the same volume, mass, and single material construction (i.e., a putter head milled from a single stainless steel block, or a single material putter head shell casting).

[0454] VI. Benefits The putter-type golf club head provides the MOI, CG, feel, and weighting benefits of a putter-type golf club head with different density top and bottom and / or without the use of mechanically fixed weights or weight ports. By creating the top and bottom of the putter-type golf club head from two different materials, the weighting of the club head is shifted towards the periphery of the putter-type golf club head without weight ports or attachments to the heel and toe ends of the putter-type golf club head. This shift of weight towards the periphery of the putter-type golf club head increases the MOI of the club head about the y-axis (Iyy), thus preventing rotation about the y-axis and ensuring that the striking face is square to the golf ball at impact. The increase in MOI about the y-axis helps achieve a straighter ball path and improves the outcome of off-center hits (impacts at the heel end or toe end).

[0455] By creating a putter-type golf club head from two sections of two different materials, the putter-type golf club head can be optimized to improve the MOI while keeping the golf club head at a desired overall weight. In some embodiments, the moment of inertia of the golf club head about the y-axis center of gravity is 3500 g cm 2 ~6500g cm 2 In another embodiment, the moment of inertia of the golf club head about the y-axis center of gravity is between 3500 g cm 2 ~4000g cm 2 , 4000g cm 2 ~4500g cm 2 , 4500g·cm 2 ~5000g cm 2 , 5000g·cm 2 ~5500g cm 2 , 5500g·cm 2 ~6000g cm 2 , or 6000 g cm 2 ~6500g cm 2The golf club head may include a 2%-15% increase in MOI about the y-axis over a club head lacking a multi-material construction (i.e., a single material). In other embodiments, the golf club head may have a 2%-5%, 5%-10%, or 10%-15% increase over a club head having a single material.

[0456] A putter-type golf club head having upper and lower portions of two different materials increases the MOI about the y-axis center of gravity by at least 30% over a putter of the same volume, mass, and single material construction (i.e., a putter milled from a single material, such as a steel putter or a single material putter shell casting). In some embodiments, a putter-type golf club head having upper and lower portions made of two different materials increases the MOI about the y-axis center of gravity by at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 95%, at least 100%, or at least 105% compared to a putter of the same volume, mass, and single material construction.

[0457] The putter style golf club head with alignment aid 1544 of FIGS. 15A-15D provides visual benefits that are comfortable to the eye and create repeatable putting. The alignment aid 1544 assists the user in properly aligning the putter head with the golf ball consistently. The alignment aid 1544 includes a ball outline feature 1580 that helps the viewer align the putter head with the outside of the golf ball and a centerline 1576 that aligns the center of the golf ball with the putter head. Proper alignment of the putter head with the golf ball allows the user to launch the ball on the intended line. The putter head including the alignment aid 1544 increases the perimeter weighting, MOI, and forgiveness while being comfortable to the eye to create a consistent putting stroke.

[0458] VII. Examples a. Example 1 - Exemplary High MOI Putter Head An exemplary putter head 1300 including a multi-material construction was compared to a similar control putter head, but lacking a multi-material construction. The exemplary putter head 1300 includes an upper portion 1304 formed from a low density material and a lower portion 1308 formed from a high density material, as shown in FIGS. 13A-13E. The lower portion 1308 further includes a sole plate including a toe mass 1345 and a heel mass 1347 to increase perimeter weighting. The upper portion 1300 further included a pocket 1372 that allowed for mass removal from a central portion of the putter head 1300. The control putter head included a similar mass, volume, and weight as the exemplary putter head 1300, but included a single material construction.

[0459] Tests were conducted to compare the moment of inertia about the y-axis (Iyy) between the exemplary putter head 1300 and a control putter head. The moment of inertia about the y-axis is a property that determines the forgiveness of a putter head (i.e., resists twisting motion after impact with a golf ball). Tests resulted in the exemplary putter 1300 having a total mass of 363.2 grams and a total volume of 85.2 cc. The lower portion 1308 included a sole plate mass of 207.4 grams and a sole plate volume of 26.55 cc. The lower portion 1308 included 57.1% of the total mass of the putter 1300, while including 31.16% of the total volume of the putter 1300.

[0460] The exemplary putter 1300 has a ball bearing capacity of 4368 g cm about the y-axis (Iyy). 2 The control putter head had an MOI of 3702 g cm 2The results show that the exemplary putter head 1300 contained an MOI of 10.78% increased over the control putter head. The exemplary putter head 1300 achieves the desired perimeter weighting to increase MOI and forgiveness while maintaining the desired mass and volume. The exemplary putter 1300 achieves a high MOI with a multi-material construction on a putter head formed from a single material.

[0461] b. Example 2 - Exemplary High MOI Putter Head An exemplary putter head 1400 including a multi-material construction was compared to a similar control putter head, but lacking a multi-material construction. The exemplary putter 1400 included an upper portion 1404 formed from a low density material and a lower portion 1408 formed from a high density material, as shown in FIGS. 14A-14D. The lower portion 1408 further included a sole plate including a toe mass 1446, a heel mass 1448, and a rear mass 1450 to increase perimeter weighting. The exemplary putter head 1400 further includes a ball retrieval mechanism 1422 disposed on the sole 1442. The ball retrieval mechanism 1422 further increases perimeter weighting by removing material and mass from a central region of the putter head 1400. The control putter head included a similar mass, volume, and weight to the exemplary putter head 1300, but included a single material construction.

[0462] Tests were conducted to compare the moment of inertia about the y-axis (Iyy) between the exemplary putter head 1300 and the control putter head. The moment of inertia about the y-axis is a property that determines the forgiveness of the putter head (i.e., resists twisting motion after impact with a golf ball). Tests resulted in an exemplary putter 1400 with a total mass of 360 grams and a total volume of 80.79 cc. The lower portion 1408 included a sole plate mass of 228 grams and a sole plate volume of 29.74 cc. The lower portion 1408 included 63% of the total mass of the putter 1400, while including 37% of the total volume of the putter 1400.

[0463] The exemplary putter 1400 has a ball bearing capacity of 4710 g cm about the y-axis (Iyy). 2 The control putter head had an MOI of 4474 g cm 2 The test results showed that the exemplary putter head 1400 had a 5.26% increase in MOI over the control putter head. The exemplary putter head 1400 achieves the desired perimeter weighting to increase MOI and forgiveness while maintaining the desired mass and volume. The exemplary putter 1400 achieves a high MOI with a multi-material construction on a putter head formed from a single material.

[0464] c. Example 3 - Exemplary High MOI Putt An exemplary putter head 1500 including a multi-material construction was compared to a similar control putter head, but lacking a multi-material construction. The exemplary putter head 1500 included an upper portion 1504 formed from a low density material and a lower portion 1508 formed from a high density material, as shown in FIGS. 15A-15D. The lower portion 1508 included a sole plate including a toe mass 1545 and a heel mass 1547 to increase perimeter weighting. The upper portion 1504 further defines a central recess 1570 to allow for mass removal from the central portion of the putter-type club head 1500. The control putter head included a similar mass, volume, and weight as the exemplary putter head 1500, but included a single material construction.

[0465] Tests were conducted to compare the moment of inertia about the y-axis (Iyy) between the exemplary putter head 1300 and the control putter head. The moment of inertia about the y-axis is a property that determines the forgiveness of a putter head (i.e., resists twisting motion after impact with a golf ball). The tests resulted in an exemplary putter-type club head 1500 with a total mass of 366.5 grams and a total volume of 87 cc. The lower portion 1508 included a sole plate mass of 205.7 grams and a sole plate volume of 26.2 cc. The lower portion 1508 included 56.1% of the total mass of the putter-type club head 1500, while including 30.1% of the total volume of the putter-type club head 1500.

[0466] The exemplary putter-type club head 1500 has a ball bearing capacity of 4416 g cm about the y-axis (Iyy). 2 The control putter head had an MOI of 4324 g cm 2 The exemplary putter head included an MOI of 1.07%. Test results show that the exemplary putter head had a 2.12% increase in MOI over the control putter head. The exemplary putter head 1500 achieves the desired perimeter weighting to increase MOI and forgiveness while maintaining the desired mass and volume. The exemplary putter head 1500 achieves a high MOI with a multi-material construction on a putter head formed from a single material. The exemplary putter head 1500 further included a ball profile alignment aid to improve putting consistency while being comfortable to the eye during repeated ball impacts.

[0467] d. Example 4 - Putter Alignment Aid Test Further described herein is a player test comparing two putter-type club heads with different alignment aids. The club heads were mallet-style club heads with similar shapes but included different alignment aid styles. Results compared the impact of the various alignment aid styles on player satisfaction and performance.

[0468] A first putter-type club head (hereinafter, the "control club head") included an alignment aid (hereinafter, the "control aid") similar to that of club head 1200, as shown in FIG. 12A. The control aid was located on the crown and included three parallel lines extending from the striking face to the rear end. A center line was located rearward of the center point of the striking face, and the remaining lines were located on the heel and toe sides of the center line. The three parallel lines were approximately the width of a golf ball (i.e., 1.68 inches). The parallel lines included a color different from the color of the control club head. The control aid further included a plurality of grooves located between the parallel lines.

[0469] A second putter-type club head (hereinafter, "exemplary club head") included an alignment aid (hereinafter, "exemplary aid") similar to alignment aid 1544 associated with club head 1500, as shown in FIG. 15D. The exemplary club head defined a central recess extending from the striking face to the rear end. The exemplary aid included a ball-outline feature that outlined the periphery of the central recess. The ball-outline feature included two arcuate portions, one arcuate near the striking face and the other arcuate near the rear end. The arcuate portions were connected by a series of parallel lines to form a continuous periphery around the central recess. The ball-outline feature was approximately the width of a golf ball and resembled an elliptical golf ball shape due to the arcuate portions. The ball-outline feature included a color that was different from the color of the exemplary club head. The exemplary aid was disposed within the central recess and further included a centerline that extended along the length of the central recess. The centerline was further located behind the striking face center point.

[0470] Player testing was conducted to compare the performance of the alignment aids between the exemplary aids and the control aids. The player testing included 30 players who participated in the study and compared their experience with the exemplary aids with the ball profile features and the con...

Claims

1. a toe end, a heel end, a striking face, a rear end, a crown, a sole, an upper portion, and a lower portion; the upper portion includes a forward portion and a rearward extension portion, the forward portion including the striking face and the rearward extension portion extending rearwardly from the forward portion toward the rear end; the top defines a central recess recessed into the top via a recess floor and a peripheral recess wall; the upper portion further comprises an alignment aid; The alignment aid includes: a ball contour feature surrounding the central recess and comprising one or more arcuate portions and a set of parallel lines, the one or more arcuate portions being positioned near the striking face or the rear end, the set of parallel lines extending from the striking face to the rear end, the ball contour feature comprising a first color; a centerline located on the recess floor, the centerline positioned within the ball profile feature, the centerline comprising a second color; and a plurality of grooves recessed into the recess floor on either side of the centerline; The lower portion includes a central portion, a toe mass, and a heel mass; the lower portion is configured to receive the upper portion such that the rearward extension is positioned above the central portion and between the toe mass and the heel mass; the upper portion comprises a first material having a first density and the lower portion comprises a second material having a second density, the first density being less than the second density; Putter type golf club head.

2. The putter-type golf club head of claim 1 , wherein the second color is different from the first color.

3. The putter-type golf club head of claim 1 having a loft angle of less than 7 degrees.

4. the one or more arcuate portions include a first arcuate portion proximate the striking face and a second arcuate portion proximate the rear end; the set of parallel lines connect the first and second arcuate portions to define a continuous perimeter around the central recess; the ball profile feature comprises an oval shape; 2. The putter-type golf club head according to claim 1.

5. the one or more arcuate portions include a single arcuate portion proximate the striking face; the set of parallel lines extend from the single arcuate portion toward the trailing end to define a discontinuous perimeter about the central recess; the ball profile feature comprises a U-shape; 2. The putter-type golf club head according to claim 1.

6. The putter-type golf club head of claim 1 , wherein the ball profile feature is recessed into the upper portion to define a channel.

7. The putter-type golf club head of claim 1 , wherein the ball profile feature projects outwardly from the top portion.

8. the ball profile feature defines a width measured in a direction from a heel end to a toe end; 2. The putter-type golf club head of claim 1, wherein the width of the ball profile feature is approximately 1.78 inches.

9. 2. The putter-type golf club head of claim 1, wherein the upper portion is secured to the lower portion by an adhesive.

10. 2. The putter-type golf club head of claim 1, wherein the first material and the second material comprise a material selected from the group consisting of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 303 stainless steel, stainless steel alloy, tungsten, aluminum, aluminum alloy, and ADC-12.

11. a toe end, a heel end, a striking face, a rear end, a crown, a sole, an upper portion, and a lower portion; the upper portion includes a forward portion and a rearward extension portion, the forward portion including the striking face and the rearward extension portion extending rearwardly from the forward portion toward the rear end; the top defines a central recess recessed into the top via a recess floor and a peripheral recess wall; the upper portion further comprises an alignment aid; The alignment aid includes: a ball contour feature surrounding the central recess and comprising one or more arcuate portions and a set of parallel lines, the one or more arcuate portions being positioned near the striking face or the rear end, the set of parallel lines extending from the striking face to the rear end, and the ball contour feature comprising a first color; a centerline located on the recess floor, the centerline positioned within the ball profile feature, the centerline comprising a second color; and a plurality of grooves recessed into the recess floor on either side of the centerline; The lower portion includes a central portion, a toe mass, and a heel mass; the lower portion is configured to receive the upper portion such that the rearward extension is positioned above the central portion and between the toe mass and the heel mass; the upper portion comprises a first material having a first density and the lower portion comprises a second material having a second density, the first density being less than the second density; The putter-type golf club head further comprises a volume and a mass, the lower portion comprises less than 35% of the volume of the putter-type golf club head; the lower portion comprises more than 50% of the mass of the putter-type golf club head; Putter type golf club head.

12. The putter-type golf club head of claim 11 , wherein the second color is different from the first color.

13. The putter-type golf club head of claim 11 , comprising a loft angle of less than 7 degrees.

14. the one or more arcuate portions include a first arcuate portion proximate the striking face and a second arcuate portion proximate the rear end; the set of parallel lines connect the first and second arcuate portions to define a continuous perimeter around the central recess; the ball profile feature comprises an oval shape; 12. The putter-type golf club head according to claim 11.

15. the one or more arcuate portions include a single arcuate portion proximate the striking face; the set of parallel lines extending from the single arcuate portion toward the trailing end define a discontinuous perimeter about the central recess; the ball profile feature comprises a U-shape; 12. The putter-type golf club head according to claim 11.

16. The putter-type golf club head of claim 11 , wherein the ball profile feature is recessed into the upper portion to define a channel.

17. The putter-type golf club head of claim 11 , wherein the ball profile feature projects outwardly from the top portion.

18. the ball profile feature defines a width measured in a direction from a heel end to a toe end; the width of the ball profile feature is approximately 1.78 inches; 12. The putter-type golf club head according to claim 11.

19. 12. The putter-type golf club head of claim 11, wherein the upper portion is secured to the lower portion by an adhesive.

20. 12. The putter-type golf rub head of claim 11, wherein the first material and the second material comprise a material selected from the group consisting of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 303 stainless steel, stainless steel alloys, tungsten, aluminum, aluminum alloys, and ADC-12.

21. 1. A putter-type golf club head comprising: a striking face, a back end, a toe end, a heel end, a crown, a sole; an upper portion comprising the striking face; and a lower portion, the upper portion being formed from a first material having a first density and the lower portion being formed from a second material having a second density, the first density being less than the second density, the lower portion comprising a sole plate having a toe mass and a heel mass, the upper portion comprising a crown bridge including the crown and extending from the striking face to the back end, the upper portion comprising: a front pocket wall opposite the striking face, a rear pocket wall opposite the back end, a pocket ceiling opposite the crown, and a pocket floor opposite a lower surface of the upper portion, a front pocket wall, the rear pocket wall, the pocket ceiling, and the pocket floor collectively define a pocket, the upper portion comprising an upright member extending between the crown bridge and the pocket ceiling dividing the pocket into a toe pocket and a heel pocket, the upper portion being secured to the lower portion by an adhesive, the upper portion being secured to the lower portion such that the crown bridge is disposed between the toe mass and the heel mass, the putter-type golf club head further comprising a volume and a mass, the lower portion comprising less than 35% of the volume of the putter-type golf club head and the lower portion comprising more than 50% of the mass of the putter-type golf club head.

22. 22. The putter-type golf club head of claim 21, comprising a loft angle of less than 7 degrees.

23. 22. The putter-type golf club head of claim 21, wherein the putter-type golf club head further comprises a volume and a mass, the lower portion comprising less than 35% of the volume of the putter-type golf club head and the lower portion comprising more than 50% of the mass of the putter-type golf club head.

24. 22. The putter-type golf club head of claim 21, wherein the heel pocket is between the heel mass and the upright member.

25. 22. The putter-type golf club head of claim 21, wherein the toe side pocket is between the toe mass and the upright member.

26. 22. The putter-type golf club head of claim 21, wherein the crown includes one or more alignment aids extending along the crown in a direction from the striking face to the rear end.

27. 22. The putter-type golf club head of claim 21, wherein the first density of the first material is less than 6.0 g / cc.

28. 22. The putter-type golf club head of claim 21, wherein the second density of the second material is greater than 7.0 g / cc.

29. The golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and the putter-type golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and ２ 22. The putter-type golf club head of claim 21, comprising a moment of inertia Iyy about the CG y-axis of greater than .

30. 22. The putter-type golf club head of claim 21, wherein the first material and the second material comprise a material selected from the group consisting of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 303 stainless steel, stainless steel alloys, tungsten, aluminum, aluminum alloys, and ADC-12.

31. The golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and the putter-type golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and ２ 22. The putter-type golf club head of claim 21, comprising a moment of inertia Iyy about the CG y-axis of greater than .

32. 1. A putter-type golf club head comprising: a putter head coupled to an elongated shaft, the putter head defining a heel end, a toe end opposite the heel end, a striking face, a sole, and a crown, the putter head further comprising an upper portion and a lower portion, the upper portion forming the crown and the lower portion forming the sole, the lower portion further comprising a ball retrieval mechanism, the ball retrieval mechanism comprising a ball retaining portion and a ball retrieval portion, the ball retaining portion configured to receive a golf ball, the ball retrieval portion configured to receive a finger of a user, the ball retrieval portion and the ball retaining portion connected together, and the ball retaining portion being defined by a circle having a diameter of 1.650 inches.

33. 33. The putter-type golf club head of claim 32, wherein the ball retaining portion is defined by a semicircular slot having a width between 0.25 inches and 1 inch.

34. 33. The putter-type golf club head of claim 32, wherein the ball return portion is defined by the upper recess and the lower opening.

35. 33. The putter-type golf club head of claim 32, wherein the ball retaining portion comprises a plurality of protrusions.

36. 36. The putter-type golf club head of claim 35, wherein the ball retaining portion comprises two protrusions positioned on opposite sides of the ball retaining portion.

37. 36. The putter-type golf club head of claim 35, wherein the ball retaining portion comprises a first set of two protrusions and a second set of two protrusions, the first set of two protrusions being positioned near the striking face and the second set of two protrusions being positioned near the rear end.

38. 36. The putter-type golf club head of claim 35, wherein the ball retaining portion comprises four protrusions spaced at 90 degree intervals.

39. 33. The putter-type golf club head of claim 32, wherein the ball retrieval mechanism is defined by a pear-shaped configuration.

40. 33. The putter-type golf club head of claim 32, wherein the head body is a mallet-type style putter.

41. 33. The putter-type golf club head of claim 32, wherein the top portion includes an alignment feature that extends the entire length of the crown.

42. The golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and the putter-type golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and ２ 33. The putter-type golf club head of claim 32, comprising a moment of inertia Iyy about the CG y-axis of greater than .

43. 1. A putter-type golf club head comprising: a crown, a sole, a toe end, a heel end, a striking face, a rear end, and a body having a front portion and a rear portion, said front portion comprising said striking face, said rear portion extending rearwardly from said front portion toward said rear end, said rear portion comprising a rear extension, a toe wing and a heel wing, said toe wing and said heel wing recessed into said body via respective wing floors, said respective wing floors and respective wing walls defining toe weight recesses and heel weight recesses, said toe wing and said heel wing comprising attachment points extending from said respective wing floors into said respective weight recesses, said body defining a central recess recessed into said body via recess floors and peripheral recess walls, said body defining an arranging recess.

13. The putter-type golf club head of claim 12, further comprising: an alignment aid comprising: a ball outline feature surrounding the central recess and comprising one or more arcuate portions and a set of parallel lines, the one or more arcuate portions positioned near the striking face or the rear end, the set of parallel lines extending from the striking face to the rear end, the ball outline feature comprising a first color; and a centerline located on a floor of the recess, the centerline positioned within the ball outline feature, the centerline comprising a second color; and a plurality of grooves recessed into the floor of the recess on either side of the centerline; and the putter-type golf club head further comprising one or more weights received by the respective attachment points, the body comprising a first low density material and the weights comprising a second high density material.

44. 44. The putter-type golf club head of claim 43, wherein the second color is different from the first color.

45. 44. The putter-type golf club head of claim 43, wherein the second color is similar to the first color.

46. 44. The putter-type golf club head of claim 43, wherein the body further comprises a third color, the third color being different from the first color and the second color, and the first color, the second color, and the third color aid in alignment of the viewer by improving the vernier vision of the viewer.

47. 44. The putter-type golf club head of claim 43, wherein the one or more arcuate portions comprise a first arcuate portion near the striking face and a second arcuate portion near the rear end, the set of parallel lines connecting the first arcuate portion and the second arcuate portion to define a continuous perimeter around the central recess, and the ball profile feature comprises an oval shape.

48. 44. The putter-type golf club head of claim 43, wherein the one or more arcuate portions comprise a single arcuate portion near the striking face, the set of parallel lines extending from the single arcuate portion toward the rear end to define a discontinuous perimeter around the central recess, and the ball profile feature is U-shaped.

49. 44. The putter-type golf club head of claim 43, wherein the ball profile feature defines a width similar to a width of a golf ball, the width being approximately 1.78 inches.

50. 44. The putter-type golf club head of claim 43, wherein the body further comprises an upper body surface and a lower body surface, the one or more weights each comprising an upper weight surface and a lower weight surface, the upper body surface and the upper weight surface forming the crown, and the lower body surface and the lower weight surface forming the sole.

51. 44. The putter-type golf club head of claim 43, wherein the ball profile feature is recessed into the body away from the crown to define a channel.

52. 51. The putter-type golf club head of claim 50, wherein the ball profile feature projects outwardly from the body top surface.

53. 44. The putter-type golf club head of claim 43, wherein the central recess extends from the front portion to the rear end.

54. 44. The putter-type golf club head of claim 43, wherein the one or more weights comprise any one or combination of shapes selected from the group consisting of rectangular, triangular, pyramidal, spherical, semicircular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

55. The golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and the putter-type golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and ２ 44. The putter-type golf club head of claim 43, comprising a moment of inertia Iyy about the CG y-axis of greater than 0.

05.

56. a shoe having an upper portion and a lower portion, the upper portion being made from a first material having a first density and the lower portion being made from a second material having a second density, the first density being less than the second density, the lower portion having a front portion, a rear wall opposite the front portion, a toe end, a heel end, a rear portion, a sole, and an opening extending through the front portion and the rear wall, the sole having a heel portion, a toe portion, and a central portion between the heel portion and the toe portion, the heel portion and the toe portion having a thickness greater than a thickness of the central portion; 16. A putter-type golf club head comprising: a lower portion further comprising a first transition area between the heel portion and the central portion and a second transition area between the toe portion and the central portion; the upper portion comprising a body, a toe extension and a heel extension, the body overlying the central portion, the toe extension overlying the toe portion and the heel extension overlying the heel portion, a portion of the body extending through and filling the opening in the lower portion, and the front surface of the lower portion and the body of the upper portion combining to form a striking face having a continuous surface.

57. 57. The putter-type golf club head of claim 56, wherein the lower portion further comprises a toe mass integrally formed with the toe portion of the sole, and a heel mass integrally formed with the heel portion of the sole.

58. 58. The putter-type golf club head of claim 57, wherein the upper portion defines a first cavity recessed from an underside of the upper portion at the toe extension and a second cavity recessed from the underside of the upper portion at the heel extension.

59. 59. The putter-type golf club head of claim 58, wherein the toe extension is configured to receive the toe mass in the first cavity such that the toe extension overlaps the toe mass, and the heel extension is configured to receive the heel mass in the second cavity such that the heel extension overlaps the heel mass.

60. 57. The putter-type golf club head of claim 56, wherein the lower portion comprises less than 75% of the volume of the putter-type golf club head.

61. 57. The putter-type golf club head of claim 56, wherein the lower portion comprises greater than 85% of the mass of the putter-type golf club head.

62. 58. The putter-type golf club head of claim 57, wherein the heel mass and the toe mass each comprise a mass between 10 grams and 40 grams.

63. 58. The putter-type golf club head of claim 57, wherein the heel mass and the toe mass are spaced rearwardly from the rear wall.

64. The golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and the putter-type golf club head has a center of gravity that defines the origin of a coordinate system that includes a vertical CG y-axis that is perpendicular to a ground plane when the putter-type golf club head is in an address position, and ２ 57. The putter-type golf club head of claim 56, comprising a moment of inertia Iyy about the CG y-axis of greater than .

Images