Multi-component putter

Abstract

To provide a putter which has peripheral weighting without adding a complicated structure such as a weight port, and has an ideal weight for balanced putting.SOLUTION: A putter type golf club head includes an upper portion 904 and a lower portion 908. The upper portion is made from a first material having first density, and the lower portion is made from a second material having second density. The first density is smaller than the second density. The lower portion is provided with a toe side peripheral part 956, a heal side peripheral part 960 facing the toe side peripheral part, a front edge, and a rear peripheral part 952 facing the front edge. An opening is bounded by the toe side peripheral part, the heel side peripheral part, the front edge, and the rear peripheral part of the lower portion and the upper portion is fixed to the lower portion; the upper portion is separate from a ground plane rather than the lower portion; and the lower portion configures 30% or less of volume and 50% or more of mass of the putter type golf club head.SELECTED DRAWING: Figure 9A

Description

Cross - reference to Related Applications

[0001] This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent No. 62 / 739,747, filed on October 1, 2018. The entire content thereof is hereby incorporated by reference in its entirety into this specification.

Technical Field

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

Background Art

[0003] In many putter - type golf club heads, weight distribution devices are used to change the center of gravity of the golf club head or increase the moment of inertia (MOI). 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 outer perimeter 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. By using weight ports in the heel and toe regions, the MOI of the putter head is increased, thereby making the ball path more straight after impact.

[0004] These weight ports in the heel and toe regions increase the MOI, but they increase the weight of the golf club head and make the golf club head heavier than the ideal weight of a putter. Further, to attach the weight ports to the golf club putter head, cavities or recesses are required during manufacturing to place these weight ports in the putter head, thereby increasing the cost of the putter head. In addition, the weight ports may cause vibrations within the cavity or recess 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. In the art, there is a need to develop a putter having perimeter weighting and an ideal weight for balanced putting without adding complex structures such as weight ports.

Brief Description of the Drawings

[0005]

Figure 1A

[0006]

Figure 1B

[0007]

Figure 1C

[0008]

Figure 2A

[0009]

Figure 2B

[0010]

Figure 2C

[0011]

Figure 3A

[0012]

Figure 3B

[0013]

Figure 3C

[0014]

Figure 4A

[0015]

Figure 4B

[0016]

Figure 4C

[0017]

Figure 5A

[0018]

Figure 5B

[0019]

Figure 5C

[0020]

Figure 6A

[0021]

Figure 6B

[0022]

Figure 6C

[0023]

Figure 7A

[0024]

Figure 7B

[0025]

Figure 7C

[0026]

Figure 8A

[0027]

Figure 8B

[0028]

Figure 8C

[0029]

Figure 9A

[0030]

Figure 9B

[0031]

Figure 9C

[0032]

Figure 10A

[0033]

Figure 10B

[0034]

Figure 10C

[0035]

Figure 11A

[0036]

Figure 11B

[0037] Other aspects of the present disclosure will become apparent by considering the detailed description and the accompanying drawings.

Best Mode for Carrying Out the Invention

[0038] (I. Putter Golf Club Head) In this specification, a two-piece putter having an upper portion made of a first material such as a low-density metal (i.e., aluminum, but not limited thereto) and a lower portion made of a second material such as a high-density metal (i.e., steel, but not limited thereto) is described. The upper portion has a crown that extends from the striking face to the back edge. This upper portion is fixed to the lower portion and is farther from the ground plane than the lower portion. The lower portion, in most embodiments, is less than 35% of the total physical volume of the putter head but more than 45% of the mass. The lower portion provides a peripheral structure and a sole. This combination of the peripheral structure and the high-density lower portion provides an increase in MOI of at least 30% compared to a putter having the same volume, mass, and a single-material structure (i.e., a single-material putter milled from steel or a single-material investment cast putter).

[0039] Terms such as "first," "second," "third," and "fourth" in the detailed description and claims are used, if at all, to distinguish between similar elements and are not necessarily used to describe a particular sequential or chronological order. Such terms are interchangeable under appropriate circumstances, and it should be understood that the embodiments described herein are capable of operating in sequences other than, for example, those illustrated or otherwise described herein. Moreover, the terms "comprising" and "having," and any variations thereof, are intended to cover 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 may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.

[0040] The terms "left", "right", "front", "rear", "upper", "lower", "above", "below", "upward", "downward", etc. in the description and claims are used for the purpose of explanation and are not necessarily intended to describe permanent relative positions. Such terms are interchangeable with each other under appropriate circumstances. Therefore, it should be understood that the embodiments of the apparatus, method, and / or product described herein can operate in an orientation different from that shown or otherwise described herein.

[0041] Before any embodiment of the present disclosure is described in detail, it should be understood that the present disclosure is not limited to the details of components or construction and arrangement as described in the following description or as illustrated in the drawings in its application. The present disclosure is capable of supporting other embodiments and can be practiced or implemented in various ways.

[0042] 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.). FIGS. 1-12B show multiple embodiments of putter-type golf club heads made of different materials separately and having upper and lower portions 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.

[0043] 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 degree, 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, or 10 degrees.

[0044] The putter-type golf club head includes an upper portion and a lower portion. The golf club head can include a toe end and a heel end opposite the toe end. The putter-type golf club head can include a striking face. The putter-type golf club head can include a rear wall on the opposite side of the striking face. Further, the putter-type golf club head can include an alignment mechanism. Further, the putter-type golf club head can 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 can 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 can be integrally formed with the lower portion of the putter-type golf club head.

[0045] 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.

[0046] 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 grams to 345 grams, 345 grams to 350 grams, 350 grams to 355 grams, 355 grams to 360 grams, 360 grams to 365 grams, 365 grams to 370 grams, 370 grams to 375 grams, 375 grams to 380 grams, or 380 grams 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.

[0047] In many embodiments, the putter-type golf club head can be configured with a club head volume in the range of 25 cc to 125 cc. In some embodiments, the club head volume can be in the range of 25 cc to 30 cc, 30 cc to 35 cc, 35 cc to 40 cc, 40 cc to 45 cc, 45 cc to 50 cc, 50 cc to 55 cc, 55 cc to 60 cc, 60 cc to 65 cc, 65 cc to 70 cc, 70 cc to 75 cc, 75 cc to 80 cc, 80 cc to 85 cc, 85 cc to 90 cc, 90 cc to 95 cc, 95 cc to 100 cc, 100 cc to 105 cc, 105 cc to 110 cc, 110 cc to 115 cc, 115 cc to 120 cc, or 120 cc to 125 cc. In one embodiment, the club head volume can be in the range of 40 cc to 110 cc. In some embodiments, the club head volume can be greater than 25 cc, greater than 50 cc, greater than 75 cc, or greater than 100 cc.

[0048] 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 material of the striking face can be any of the following materials, or a combination 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 at the top. In other embodiments, the striking face can be integrally formed at the bottom. The striking face can be integrally formed with the club head by co-molding, injection molding, casting, 3D printing (additive manufacturing), or other molding processes.

[0049] Referring to FIGS. 11A and 11B, in some embodiments, the putter-type golf club head can include a striking face insert. In these embodiments, the striking face is formed independently before being coupled to the club head. The side surface of the striking face insert that contacts the club head can constitute geometry complementary to the corresponding portion of the club head that contacts the striking face. In some embodiments, the striking face insert can be made of a first material or a second material. In other embodiments, the striking face insert can be made of a third material. In some embodiments, the striking face insert can be integrally formed with the upper or lower part. In other embodiments, the striking face insert can be separately formed from both the upper and lower parts.

[0050] The striking face can be integrally formed as part of the club head or fixed to the club head by fastening means. In some embodiments, the striking face is fixed to the upper part. In these embodiments, the upper part can include an insert cavity. The upper insert cavity functions to receive the striking face insert. Further, in these embodiments, when the insert is fixed to the upper part, the upper part surrounds the insert cavity and mates with the insert cavity. In other embodiments, the striking face is fixed to the lower part. In these embodiments, the lower part can include an insert cavity. The lower insert cavity functions to receive the striking face insert. Further, in these embodiments, when the insert is fixed to the lower part, the lower part surrounds the insert cavity and mates with the insert cavity. The striking face can be fixed by an adhesive such as an adhesive, very high bond (VHB (registered trademark)) tape, epoxy, or another adhesive. Alternatively or additionally, the striking face can be fixed by welding, soldering, screws, rivets, pins, a mechanical interlock structure, or another fastening method.

[0051] The impact face inserts of these embodiments can be composed of any one of the following materials, or by a laminated combination: 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® (registered trademark), or other preferred materials. PEBAX® (registered trademark) is a polyether block amide, a thermoplastic elastomer made from a soft polyether and a hard polyamide. The hard polyamide can include nylon. PEBAX® (registered trademark) can include different compounds corresponding to different Shore D hardness values, polyether percentages, and / or polyamide percentages. In many embodiments, PEBAX® (registered trademark) 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) includes nylon 11. In some embodiments, the face insert can include materials 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 polymer materials, or any combination thereof.

[0052] PEBAX® can include a volume percentage of polyether. In some embodiments, PEBAX® can include 0% to 10%, 10% to 20%, 15% to 30%, 20% to 30%, 30% to 40%, 30% to 50%, 30% to 60%, 40% to 50%, 40% to 60%, 50% to 60%, or 60% to 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 volume % polyether. In some embodiments, PEBAX® can include 0% to 10%, 10% to 20%, 15% to 30%, 20% to 30%, 30% to 40%, 40% to 50%, 40% to 60%, 50% to 60%, or 60% to 70% polyamide by volume. For example, PEBAX® can include 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70 volume % polyamide. As the percentage of polyether increases, the hardness of PEBAX® decreases. As the polyamide percentage increases, the hardness of PEBAX® increases. For example, PEBAX® 4033 (Arkema, Paris France) can include 40 volume % to 60 volume % polyether and 15 volume % to 30 volume % polyamide. For example, PEBAX® 6333 (Arkema, Paris France) can include 15 volume % to 30 volume % polyether and 40 volume % to 60 volume % polyamide.

[0053] In many embodiments, PEBAX® can include a hardness in the range of Shore 25D to Shore 75D. In some embodiments, the hardness of PEBAX can be in the range of 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 D 25, 30, 35, 40, 45, 50, 55, 60, 65, or 70.

[0054] 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.

[0055] In some embodiments, the face insert can include a two-component system. The two-component system can comprise a ball-striking face plate and a face insert base. The ball-striking face plate of the face insert can include a first insert material. The face insert base of the face insert can include a second insert material. In many embodiments, the first insert material of the ball-striking face plate and the second material of the face insert base may be different. In some embodiments, the first insert material of the ball-striking face plate and the second insert material of the face insert base may be similar. In many embodiments, the first insert material of the ball-striking face plate can include a polymer-type material. In some embodiments, the first insert material of the ball-striking face plate can include a metallic material. In many embodiments, the second insert material of the face insert base can include a polymer-type material.

[0056] The first insert material can include metals such as steel, steel alloys, tungsten, tungsten alloys, aluminum, aluminum alloys, titanium, titanium alloys, vanadium, vanadium alloys, chromium, chromium alloys, cobalt, cobalt alloys, nickel, nickel alloys, other metals, other metal alloys, composite polymer materials, or any combination thereof.

[0057] 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, a thermoplastic elastomer made from a flexible polyether and a rigid polyamide. The rigid 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 wt%) and nylon 12. PEBAX® 6333 (Arkema, Paris France) includes nylon 11. The first insert material and the second insert material can include polyether percentages, polyamide percentages, or Shore D hardness values similar to those described above.

[0058] The ball striking face plate of the face insert can have a thickness. In many embodiments, the thickness of the ball striking face plate can range from 0.015 to 0.115 inches. In some embodiments, the thickness of the ball striking face plate 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 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 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 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 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.

[0059] In other embodiments, the thickness of the ball striking face plate can range from 0.115 to 0.40 inches. In some embodiments, the thickness of the ball striking face plate 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 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 can be 0.15, 0.20, 0.25, 0.30, 0.35, or 0.40 inches or more. In some embodiments, the thickness of the ball striking face plate can be 0.15 inches, 0.20 inches, 0.25 inches, 0.30 inches, 0.35 inches, or 0.40 inches or less. For example, the thickness of the ball striking face plate can be 0.15 inches, 0.20 inches, 0.25 inches, 0.30 inches, 0.35 inches, or 0.40 inches.

[0060] The face insert base of the face insert can have a thickness. In many embodiments, the thickness of the face insert base can range from 0.05 to 0.20 inches. In some embodiments, the thickness of the face insert base 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 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 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 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 can be 0.05 inches, 0.10 inches, 0.15 inches, or 0.20 inches.

[0061] In other embodiments, the thickness of the face insert base can range from 0.20 to 0.80 inches. In some embodiments, the thickness of the face insert base can range from 0.20 to 0.50 inches, from 0.30 to 0.60 inches, from 0.40 to 0.70 inches, or from 0.50 to 0.80 inches. In some embodiments, the thickness of the face insert base can range from 0.20 to 0.40 inches, from 0.30 to 0.50 inches, from 0.40 to 0.60 inches, from 0.50 to 0.70 inches, or from 0.60 to 0.80 inches. In some embodiments, the face insert base of the face insert 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 of the face insert 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 of the face insert 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 less. For example, the thickness of the face insert base 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.

[0062] The face insert can be formed by many different processes. Different molding processes include injection molding, casting, blow molding, compression molding, co-molding, laser molding, film insert molding, gas assist molding, rotational molding, thermoforming, laser cutting, 3-D printing, forging, stamping, electroforming, machining, molding, or any combination thereof. Further, the face insert can have any combination of the hardness, volume, thickness, and molding processes described above.

[0063] In many embodiments, the upper portion of the patterned golf club head having the 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 is in the range of 1.0 to 1.25 g / cc, 1.25 to 1.5 g / cc, 1.5 to 1.75 g / cc, 1.75 to 2.75 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 3.75 g / cc, 3.25 to 3.5 g / cc, 3.5 to 3.75 g / cc, 3.75 to 4.0 g / cc, 4.0 to 4.25 g / cc, 4.5 to 4.75 g / cc, 4.75 to 5.0 g / cc, 5.0 to 5.25 g / cc - 5.5 g / cc, 5.5 to 5.75 g / cc, or 5.75 to 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.

[0064] In many embodiments, the lower portion of the putter-type golf club head has a second material. The second material can include density. The density is the second density relative to the first density of the first material at the upper portion. The second density of the second material in the lower portion can range from 7.0 g / cc to 20.0 g / cc. In some embodiments, the second density can range from 7.0 to 7.5 g / cc, 7.5 to 8.0 g / cc, 8.0 to 8.5 g / cc, 8.5 to 9.0 g / cc, 9.0 to 9.5 g / cc, 9.5 to 10.0 g / cc, 10.0 to 10.5 g / cc, 10.5 to 11.0 g / cc, 11.0 to 11.5 g / cc, 11.5 to 12.0 g / cc, 12.0 to 12.5 g / cc, 12.5 to 13.0 g / cc, 13.0 to 13.5 g / cc, 13.5 to 14.0 g / cc, 14.0 to 14.5 g / cc, 14.5 to 15.0 g / cc, 16.0 to 16.5 g / cc, 16.5 to 17.0 g / cc, 17.0 to 17.5 g / cc, 17.5 to 18.0 g / cc, 18.0 to 18.5 g / cc, 18.5 to 19.0 g / cc, or 19.0 to 19.5 g / cc, or 19.5 to 20.0 g / cc. In one embodiment, the second density of the second material in the lower portion can range from 8.0 to 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, 20.0 g / cc. In some embodiments, the second density in the lower portion can be at least twice 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 exceed 7.0 g / cc, exceed 9.0 g / cc, exceed 10.0 g / cc, exceed 11.0 g / cc, or exceed 12.0 g / cc.

[0065] The upper portion of the putter-type golf club having the first material can 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.

[0066] The lower portion of the putter-type golf club having the second material can 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 lower portion is made of 304 stainless steel, 8620 alloy steel, 17-4 stainless steel, or 1380 stainless steel. However, the lower portion and the upper portion are not made from the same single material or the same combination of materials.

[0067] Furthermore, the upper and lower portions of the putter-type golf club head can be joined by any method or combination of welding, soldering, brazing, swedging, adhesion, epoxy, or mechanical fastening. In some embodiments, the upper and lower portions can be joined by adhesion with epoxy, polyurethane, resin, hot melt, or any other adhesive.

[0068] (A. Advantages) The putter-type golf club head provides the advantages of MOI, CG, feel, and weighting in a putter-type golf club head having upper and lower portions with different densities and / or upper and lower portions that do not use mechanically-fixed weights or weight ports. By creating the upper and lower portions of the putter-type golf club head from two different materials, without weight ports or attachments to the heel and toe ends of the putter-type golf club head, the weight of the club head shifts towards the perimeter of the putter-type golf club head. This shift of the weight towards the perimeter of the putter-type golf club head increases the MOI of the club head about the y-axis (Iyy). Thus, rotation about the y-axis is prevented, ensuring that the striking face is square to the golf ball during impact. The increase in MOI about the y-axis helps to achieve a more straight ball path and improve the results of off-center strikes (impacts at the heel or toe ends).

[0069] By creating a putter-type golf club head from two portions of two different materials, the putter-type golf club head can be optimized to improve the MOI while maintaining the golf club head at a desired total weight. In some embodiments, the moment of inertia of the golf club head about the y-axis center of gravity is between 3500 g·cm2 - 6500 g·in2. In other embodiments, the moment of inertia of the golf club head about the y-axis center of gravity can be between 3500 g·cm2 - 4000 g·cm2, 4000 g·cm2 - 4500 g·cm2, 4500 g·cm2 - 5000 g·cm2, 5000 g·cm2 - 5500 g·cm2, 5500 g·cm2 - 6000 g·cm2, or 6000 g·cm2 - 6500 g·cm2.

[0070] 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% relative to a putter having the same volume, mass, and single material construction (i.e., a single material milled putter like a steel putter, or a single material putter investment casting). In some embodiments, 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 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% relative to a putter having the same volume, mass, and single material construction.

[0071] (II. Embodiment) (a. Embodiment of the Blade) In one embodiment, the putter-type golf club head can be a blade-type putter head 100. Referring to FIGS. 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 of a first material having a first density, and the lower portion 108 is made of a second material having a second density. The first density is smaller than the second density. The upper portion 104 and the lower portion 108 are joined to create a balanced putter head 100 while maintaining a desired volume and mass.

[0072] 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 bottom surface (not shown). The bottom surface and the upper portion 104 form a sole 168. The rear wall 132 is opposite and substantially parallel to the front face 112. The toe end 124 is on the opposite side of the heel end 128 and is adjacent to the striking face 112 and the rear portion 156. The rear portion 156 extends from the heel end 128 across the toe end 124 and away from the rear wall 132 and the front face 112. The rear portion 156 is adjacent to the sole. The bottom surface extends from the heel end 128 to the toe end 124 and is adjacent to the rear portion 156 and the front face 112.

[0073] Also, the toe end 124, the heel end 128, and the front face 112 of the lower portion 108 form a recess 140 that extends inwardly from the front face 112 toward the rear wall 132. The recess functions to receive the upper portion 104. In most embodiments, the recess 140 has a corresponding geometric shape that is similar or identical to the geometric shape of the upper portion 104. When the upper portion 104 is fixed to the lower portion 108, the upper portion 104 surrounds and mates with the lower portion 108 so as to fit within the recess 140.

[0074] The lower portion 108 of the blade - type putter head 100 can further include an alignment mechanism 136. The alignment mechanism 136 can be any one or a combination of the following: a line, a circle, a dashed line, a triangle, a channel, or any other suitable alignment mechanism 136. Referring to FIGS. 2A - 2C, in some embodiments, the blade - type putter head 200 can include an alignment mechanism 236 on the upper portion 204 instead of the lower portion 208.

[0075] 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, and the upper edge 116 is farther from the ground plane 172 than the lower edge 121. The ground plane 172 is in contact with the lower portion 108 when the putter head is in the address position where it strikes the golf ball. The upper edge 116 is adjacent to the striking face 113 and the adhesive surface 115 and is on the opposite side of the lower edge 121. In most embodiments, the striking face 113 and the adhesive surface 115 are parallel, but in other embodiments, the striking face 113 and the adhesive surface 115 are not parallel.

[0076] When the upper portion 104 and the lower portion 108 are joined, the adhesive surface 115 is fixed to the recess 140 of the lower portion 108. The striking face 113 of the upper portion 104 and the front face 112 of the lower surface are aligned to form a striking face 120, which functions to strike the golf ball.

[0077] The lower edge 121 of the upper portion 104 and the lower surface of the lower portion 108 combine to form a sole 168. The sole 168 is perpendicular to the ground plane 172. The ground plane 172 is tangent to the sole 168 when the putter 100 is in the address position where it strikes 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.

[0078] Referring to FIG. 1C, in most embodiments, the sole 168 of the putter head 100 can be completely flat. In some embodiments, the sole 168 of the putter head 100 can have a slight arch in the direction from the heel 128 to the toe 124. The slight arch can be a linear or polynomial function. In some embodiments, the sole 168 of the putter head 100 can have a strong arch in the direction from the heel 128 to the toe 124, and the strong arch can 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.

[0079] The striking face 120 of the blade - type putter head 100 includes a striking - face center point 176 and a loft face 180. The striking - face center point 176 is equidistant from the lower edge 12112 and the upper edge 116 of the striking face 120, and is similarly equidistant from the heel end 128 and the toe end 124 of the blade - type putter head 100. The loft face 180 is in contact with the striking face 112 of the blade - type putter head 100. Further, the central plane 184 intersects the striking - face center point 176 and is perpendicular to the loft face 180. Further, the y - axis 188 intersects the striking - face center point 176 and is perpendicular to the ground plane 172.

[0080] In some embodiments, when the lower portion 108 and the upper portion 104 are joined, the upper edge 116 of the upper portion 104 can project away from the striking face 120 by overlapping at least a part of the rear wall 132 of the lower portion 108. Further, the lower edge 121 of the upper portion 104 can project away from the striking face 120 towards at least a part of the lower surface of the lower portion 108, thereby forming a part of the sole 168. In these embodiments, the rear wall 132 of the lower portion 108 does not form a part of the sole 168.

[0081] The combination of the upper portion 104 of the low-density first material and the lower portion 108 of the high-density second material increases the MOI of the putter 100 over that of a single solid block structure pattern. The two sub-configurations (upper portion 104 and lower portion 108) of the putter 100 move the denser material towards the heel 128 and toe 124, placing the lighter material (upper portion 104) near the center, thereby increasing the MOI of the putter 100 as more mass is further away from the center of gravity. The denser material in the lower portion helps increase the MOI of the putter-type golf club head by shifting the weight of the putter head 100 towards the outer portion of the putter-type golf club head. In a single material putter, the denser material cannot be allocated to the perimeter. In some embodiments, a putter-type golf club head 100 having upper portion 104 and lower portion 108 of two different materials increases the MOI about the y-axis center of gravity by at least 15% over a putter having the same volume, mass, and single material structure.

[0082] (b. Crescent-shaped embodiment) In one embodiment, the putter-type golf club head can be a crescent-shaped putter head 300. Referring to FIGS. 3A - 3C, the crescent-shaped putter head 300 has an upper portion 304 and a lower portion 308. The upper portion 304 is made of a first material having a first density, and the lower portion 308 is made of 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 are combined to create a balanced putter head 300 while maintaining the 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 structure.

[0083] As described above, the lower portion 308 is composed of a high-density material (i.e., the second material). The lower portion 308 includes a rear peripheral portion 352, a toe end portion 312, a heel end portion 316, a striking face 320, a rear wall 332, a back edge 334, a crown 342, and a bottom surface (not shown). The bottom surface and the upper portion 304 form a sole 368. The toe end portion 312 is on the opposite side of the heel end portion 316. The toe end portion 312 and the heel end portion 316 of the lower portion 308 each include a toe-side peripheral portion 356 and a heel-side peripheral portion 360. The striking face 320 faces the rear wall 332 from the toe end portion 312 to the heel end portion 316. The rear wall 332 is opposite to and substantially parallel to the striking face 320. The lower portion further includes a heel-side peripheral portion 360, a toe-side peripheral portion 356, a front edge 348, and an upper edge 312.

[0084] The front edge 348 is adjacent to the toe-side peripheral portion 356 and the heel-side peripheral portion 360 and is on the opposite side of the rear peripheral portion 352. The toe-side peripheral portion 356 is adjacent to the front edge 348 and the rear peripheral portion 352 and is on the opposite side of the heel-side peripheral portion 360. The heel-side peripheral portion 360 is also adjacent to the front edge 348 and the rear peripheral portion 352 but is on the opposite side of the toe-side peripheral portion 356.

[0085] In most embodiments, the toe side peripheral portion 356 extends vertically from the front edge 348 towards the back edge 352 such that a right angle (90° angle) is formed at the junction of the toe side peripheral portion 356 and the front edge 348. However, in other embodiments, the toe side peripheral portion 356 can extend in any direction from the front edge 348 such that any angle (0° to 180°) can be formed at the junction of the toe side peripheral portion 356 and the front edge 348. Further, in most embodiments, the heel side peripheral portion 360 extends vertically from the front edge 348 such that a right angle (90° angle) is formed at the junction of the heel side peripheral portion 360 and the front edge 348. However, in other embodiments, the heel side peripheral portion 360 can extend in any direction from the front edge 348 such that any angle (0° to 180°) can be formed at the junction of the heel side peripheral portion 360 and the front edge 348.

[0086] The front edge 348, the toe side peripheral portion 356, and the heel side peripheral portion 360 form an opening 364. The opening 364 is bounded by the front edge 348, the toe side peripheral portion 356, and the heel side peripheral portion 360. The opening 364 moves most of the volume and mass of the putter to the end of the lower portion 308. The opening 364 can include any shape, but in one embodiment, the opening 364 is substantially rectangular. In other embodiments, the opening 364 can be circular, curved, triangular, trapezoidal, parabolic, golf ball-shaped, square, or any other desired geometric shape.

[0087] The upper portion 304 of the putter head 300 includes a crown 342, a front edge 370, and a back edge 334. The crown 342 extends from the front edge 370 to the back edge 334 of the upper portion 304 away from the front edge 370. The lower surface is opposite to the crown 342 spanning from the front edge 348 to the back edge 334.

[0088] 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-shaped pattern head 300 is substantially 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 curve 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 curve length of the rear perimeter 352 can be between 4.5 inches and 6.5 inches. In some embodiments, the rear perimeter curve length can be 4.5 inches to 4.75 inches, 4.75 inches to 5.0 inches, 5.0 inches to 5.25 inches, 5.25 inches to 5.5 inches, 5.5 inches to 5.75 inches, 5.75 inches to 6.0 inches, 6.0 inches to 6.25 inches, or 6.25 inches to 6.5 inches.

[0089] When the upper portion 304 and the lower portion 308 are joined, the crown 342 extends between the striking faces 320 to the rear peripheral portion 352. In most embodiments, the crown 342 extends to approximately the inner 25% of the entire club head 300 width from the toe side peripheral portion 356 and to approximately the inner 25% of the entire club head 300 width from the heel side peripheral portion 360. In other embodiments, the crown 342 can extend continuously or discontinuously across the entire width of the entire club head 300 in the direction from the heel 316 to the toe 312. In some embodiments, the crown 342 can extend to less than 90% of the entire width of the club head 300, less than 80% of the entire width of the club head 300, less than 70% of the entire width of the club head 300, less than 60% of the entire width of the club head 300, less than 50% of the entire width of the club head 300, less than 40% of the entire width of the club head 300, or less than 30% of the entire width of the club head 300. Further, 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, curved, parabolic, sine wave, or polynomial function.

[0090] 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 to the rear wall 328 and is substantially 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 the toe end 312. In most embodiments, the alignment trough is approximately equal to the width of a golf ball (about 4.27 cm) and provides a viewer with a visual alignment field that widens the width of the golf ball.

[0091] Furthermore, the upper portion 304 of the putter head 300 can include one or more alignment mechanisms 344 on the crown 342. The alignment mechanisms 344 can be a line, a series of lines, a milled trough, a circle, a dashed line, a triangle, a channel, or any one or combination of any other desired alignment mechanisms 344. The alignment mechanisms 344 can be equally spaced across the entire crown 342, a portion of the crown 342, or on the alignment trough 355. The alignment mechanisms 344 extending along the alignment trough 355 function to provide a viewer with a visual alignment field that extends the width of the golf ball from the rear wall 332 to the back edge 334 of the putter 300. The purpose is to align the entire putter 300 with the golf ball using these alignment mechanisms 344 along the crown 342 and / or the alignment trough 355.

[0092] Referring to FIG. 3C, the upper portion 304 can be fixed to the lower portion 308 such that the upper portion 304 is farther from the ground plane than the lower portion 308. Here, the ground plane 372 is in contact with the lower portion 308 when the putter head 300 is in the address position where it contacts the golf ball.

[0093] Referring to FIG. 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 lower surface of the upper portion 304, and similarly, is equidistant from the heel end 316 and the toe end 312 of the putter head 300. The loft plane 380 is in contact with the striking face 320 of the putter head 300. Further, the midplane 316 intersects the striking face center point 376 and is perpendicular to the loft plane 380. Further, referring to FIG. 3B, the y-axis 388 intersects the midplane 384 and is perpendicular to the ground plane 372.

[0094] When the upper portion 304 and the lower portion 308 are joined, the heel end 316 will overlap at least a portion of the toe side peripheral portion 356. Further, when the upper portion 304 and the lower portion 308 are joined, the toe end 312 will overlap at least a portion of the heel side peripheral portion 360. Further, when the upper portion 304 and the lower portion 308 are joined, the striking face 320 will overlap at least a portion of the front edge 316. Finally, the upper portion 304 and the lower portion 308 are joined such that the back edge 364 overlaps at least a portion of the rear peripheral portion 332.

[0095] The front edge 316, the rear peripheral portion 332, the toe side peripheral portion 356, and the heel side peripheral portion 360 of the lower portion 308 combine with the upper portion 304 to form the sole 368. The sole 368 is perpendicular to the ground plane 372. Here, the ground plane 372 is in contact with the sole 368 when the putter head 300 is in the address position where it strikes the 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.

[0096] 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 can have a slight arch in the direction from the heel 324 to the toe 320, and the slight arch can be a linear or polynomial function. In some embodiments, the sole 368 of the putter head 300 can have a strong arch in the direction from the heel 324 to the toe 320, and the strong arch can be a linear or polynomial function. The sole 368 functions to provide a surface for resting the putter head 300 on the ground plane 372.

[0097] Referring to FIG. 3A, in one embodiment, the lower portion 308 can further include 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 peripheral portion 356 and the heel-side peripheral portion 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 toward the upper portion 304. The toe mass 341 and the heel mass 343 provide means for positioning and aligning the upper portion 304 with the lower portion 308 of the putter head 300.

[0098] Furthermore, the toe mass 341 and the heel mass 343 provide additional means for adding weight to the periphery to increase the moment of inertia (MOI) of the crescent-shaped putter head 300 when compared to a putter without these mass functions. These mass functions can have weights in the range of 2 - 5 grams, 3 - 7 grams, or 1 - 6 grams. The mass functions can all have the same weight or can have different weights within the above ranges. The weight of the mass functions can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The toe mass 341 and the heel mass 343 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, crescent-shaped, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0099] Referring to FIG. 3A, the toe mass 341 and the heel mass 343 can be disposed away from the rear peripheral portion 352. Here, the toe mass 341 and the heel mass 343 do not contact or intersect the rear peripheral portion 352. However, in other embodiments, the toe mass 341 and the heel mass 343 can be disposed on the rear peripheral portion 352. At this time, the toe mass 341 and the heel mass 343 are integral with and intersect the rear peripheral portion 352.

[0100] In one embodiment, the toe mass 341 is disposed on the front edge 348 at the junction of the toe side peripheral portion 356 and the front edge 348. However, in other embodiments, the toe mass 341 can be disposed at any location along the toe side peripheral portion 356. In one embodiment, the heel mass 343 is disposed on the front edge 348 at the junction of the heel side peripheral portion 360 and the front edge 348. However, in other embodiments, the heel mass 343 can be disposed at any location along the heel side peripheral portion 360.

[0101] The toe mass 341 and the heel mass 343 provide areas of concentrated mass such that the toe mass 341 and the heel mass 343 function to increase the moment of inertia of the putter head 300. Since the toe mass 341 and the heel mass 343 are far from the center of gravity of the putter 300, placing the toe mass 341 on or near the front edge 348 and on or near the toe side peripheral portion 356, and placing the heel mass 343 on or near the front edge 348 and on or near the heel side peripheral portion 360 respectively increases the MOI. The toe mass 341 and the heel mass 343 can be integrally formed from a second material that is denser than the first material.

[0102] The toe mass 341 and the heel mass 343 provide two functions such that the toe mass 341 and the heel mass 343 not only increase the MOI of the putter 300, but also provide additional surfaces for the upper portion 304 to join to the lower portion 308. Thus, the toe mass 341 can also be referred to as the front toe bonding portion 341, and the heel mass 343 can also be referred to as the front heel bonding portion 343.

[0103] In some embodiments, the lower surface 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 lower surface of the toe end 312 towards the crown 342, but does not reach 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.

[0104] In some embodiments, the lower surface 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 lower surface of the heel end 316 towards the crown 342, but does not reach 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.

[0105] The first and second cavities can include any desired geometric shape. However, in most embodiments, the first and second cavities have a geometric shape similar or identical to the geometric shape of the corresponding toe mass 341 or heel mass 343. Further, when the upper portion 304 is fixed to the lower portion 308, the first cavity is arranged such that the first cavity surrounds the toe mass 341, and the second cavity is arranged such that the second cavity surrounds the heel mass 343.

[0106] The combination of the upper portion 304 of the low-density first material and the lower portion 308 of the high-density second material produces a high MOI putter 300 without producing an extremely heavy putter. The large opening 364 formed by the rear wall 332, the rear perimeter 352, the toe-side perimeter 356, and the heel-side perimeter 360 of the lower portion 308 forms 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 (50 cc to 75 cc) and mass (340 grams to 385 grams).

[0107] In most embodiments, the lower portion 308 constitutes less than 38% of the volume of the putter 300. In some embodiments, the lower portion 308 is 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.

[0108] Although the lower portion 308 constitutes less than half of the volume of the putter 300, the lower portion 308 constitutes at least 45% of the total mass of the putter 300. In some embodiments, the lower portion 308 is 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.

[0109] A beneficial shift of mass around the putter head 300 increases the MOI of the putter 300 more than 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).

[0110] (c. Semi-circular embodiment) In one embodiment, the putter-type golf club head can be a semi-circular putter head 400. Referring 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 of a first material having a first density, and the lower portion 408 is made of 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 are combined to produce a high MOI putter head 400 (5000 g·cm2 - 6500 g·cm2) while maintaining a desired volume and mass.

[0111] As described above, the lower part 408 is composed of a high-density material (i.e., the second material). The lower part 408 includes a front edge 448, a rear periphery 452, a toe-side span 456, and a heel-side span 460. The lower part 408 and the lower surface of the upper part 404 are combined to form a sole 468. The front edge 448 is adjacent to the toe-side span 456 and the heel-side span 460 and is opposite to the rear periphery 452. The toe-side span 456 is adjacent to the front edge 448 and the rear periphery 452 and is on the opposite side of the heel-side span 460. Also, the heel-side span 460 is adjacent to the front edge 448 and the rear periphery 452 but is opposite to the toe-side span 456. The toe-side span 456 and the heel-side span 460 extend beyond the rear periphery 448 of the upper part 404. In some embodiments, the heel-side span 460 and the toe-side span 456 can be parallel, but in some embodiments, the heel-side span 460 and the toe-side span 456 are not parallel. In some embodiments, the rear periphery 452 and the front edge 448 can be parallel, but in some embodiments, the rear periphery 452 and the front edge 448 are not parallel. In this embodiment, the rear periphery 452 is substantially semi-circular, and thus, the rear periphery 452 and the front edge 448 are not parallel.

[0112] In most embodiments, the toe-side span 456 extends perpendicularly from the front edge 448 such that a right angle (90° angle) is formed at the junction of the toe-side span 456 and the front edge 448. However, in other embodiments, the toe-side span 456 can extend in any direction from the front edge 448 such that any angle (0° to 180) can be formed at the junction of the toe-side span 456 and the front edge 448. Further, in most embodiments, the heel-side span 460 extends perpendicularly from the front edge 448 such that a right angle (90° angle) is formed at the junction of the heel-side span 460 and the front edge 448. However, in other embodiments, the heel-side span 460 can extend in any direction from the front edge 448 such that any angle (0° to 180) can be formed at the junction of the heel-side span 460 and the front edge 448.

[0113] The front edge 448, the toe-side span 456, and the heel-side span 460 form a gap 464. The gap 464 is bounded by the front edge 448, the toe-side span 456, and the heel-side span 460. The gap 464 formed by the front edge 448, the toe-side span 456, and the heel-side span 460 moves most of the volume and mass of the putter to the end of the lower portion 408. The gap 464 can include any shape, but in one embodiment, the gap is substantially rectangular. In other embodiments, the gap 464 can be circular, curved, triangular, trapezoidal, parabolic, golf ball shaped, square, or any other desired geometric shape.

[0114] The upper portion 404 of the club 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 a bottom surface (not shown). The toe end 412 is on the opposite side of the heel end 416. The striking face 420 extends from the toe end 412 to the heel end 416 and is on the opposite side of the rear wall 432. The rear wall 432 is opposite and substantially parallel to the striking face 420. The crown 442 extends away from the striking face 420 to the back edge 434 of the upper portion 404. Further, the bottom surface is opposite the crown 442 and spans from the striking face 420 to the back edge 434.

[0115] 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 beyond the front edge 448 of the lower portion 408 to the back edge 434 of the upper portion 404. The crown 442, in most embodiments, extends from the toe side span 456 to approximately the inner 25% of the full club head 400 width and from the heel side span 460 to approximately the inner 25% of the full club head 400 width. In other embodiments, the crown 442 can extend continuously or discontinuously across the full width of the entire club head 400 from heel to toe. In some embodiments, the crown 442 can extend less than 90% of the full width of the club head 400, less than 90% of the full width of the club head 400, less than 80% of the full width of the club head 400, less than 70% of the full width of the club head 400, less than 60% of the full width of the club head 400, less than 50% of the full width of the club head 400, less than 40% of the full width of the club head 400, or less than 30% of the full 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, curved, parabolic, sine wave, or polynomial function.

[0116] 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 to the rear wall 432 and is substantially 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 the toe end 412. In most embodiments, the alignment trough 455 is approximately equal to the width of a golf ball (about 4.27 cm) and provides a viewer with a visual alignment field that widens the width of the golf ball.

[0117] Furthermore, the upper portion 404 of the putter head 400 can include one or more alignment mechanisms 444 on the crown 442. The alignment mechanism 444 can be a line, a series of lines, a milled trough, a circle, a dashed line, a triangle, a channel, or any one or combination of any other desired alignment mechanisms 444. The alignment mechanism 444 can be evenly spaced across the entire crown 442, a portion of the crown 442, or on the alignment trough 455. The alignment mechanism 444 extending along the alignment trough 455 functions to provide a viewer with a visual alignment field that extends the width of the golf ball from the rear wall 432 to the back edge 434 of the putter 400. The purpose is to align the entire putter 400 with the golf ball using these alignment mechanisms 444 along the crown 442 and / or the alignment trough 455.

[0118] Referring to FIG. 4C, the upper portion 404 is secured to the lower portion 408 such that the upper portion 404 is further away from the ground plane 472 than the lower portion 408. Here, the ground plane 472 contacts the lower portion 408 when the putter head 400 is in the address position where it strikes the golf ball.

[0119] Furthermore, the striking face 420 of the putter head 400 includes a striking face center point 476 and a loft face 480. The striking face center point 476 is equidistant from the crown 442 and the lower surface of the upper portion 404, and is similarly equidistant from the heel end 416 and the toe end 412 of the putter head 400. The loft face 480 is in contact with the striking face 420 of the putter head 400. Further, the midplane 484 intersects the striking face center point 476 and is perpendicular to the loft face 480. Further, the y-axis 488 intersects the midplane 484 and is perpendicular to the ground plane 472.

[0120] When the upper portion 404 and the lower portion 408 are joined, the heel end 416 comes to overlap at least a part of the toe side span 456. Further, when the upper portion 404 and the lower portion 408 are joined, the toe end 412 comes to overlap at least a part of the heel side span 460. Further, when the upper portion 404 and the lower portion 408 are joined, the striking face 420 comes to overlap at least a part 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 part of the rear periphery 452.

[0121] The rear periphery 452 may be a curve extending from the heel side 416 to the toe side 416. The rear periphery 452 includes a curve length measured along the rear periphery 452 from the joint between the heel side 416 and the rear periphery 452 to the joint between the toe side 416 and the rear periphery 452. In some embodiments, the curve length of the rear periphery 452 can be from 4.5 inches to 8.0 inches. In some embodiments, the curve length of the rear periphery 452 can be 4.5 inches - 4.75 inches, 4.75 inches - 5.0 inches, 5.25 inches - 5.5 inches, 5.75 inches - 6.0 inches, 6.25 inches - 6.5 inches, 6.5 inches - 6.75 inches, 6.75 inches - 7.0 inches, 7.25 inches - 7.50 inches, or 7.75 inches - 8.0 inches.

[0122] The front edge 448, rear periphery 452, toe-side span 456, and heel-side span 460 of the lower portion 408 combine with the upper portion 404 to form the sole 468. The sole 468 is perpendicular to the ground plane 472, and when the putter head 400 is in the address position for striking a golf ball, the ground plane 472 contacts the sole 468. 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.

[0123] In most embodiments, the sole 468 of the putter head 400 can be completely flat. In some embodiments, the sole 468 of the putter head 400 can have a slight arch in the direction from the heel 416 to the toe 412, and the slight arch can be a linear or polynomial function. In some embodiments, the sole 468 of the putter head 400 can have a strong arch in the direction from the heel 416 to the toe 412, and the strong arch can 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.

[0124] Referring to FIG. 4A, in one embodiment, the lower portion 408 can further include a front toe mass 441 and a front heel mass 443. The front toe mass 441 and the front heel mass 443 are integrated with 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 toward the upper portion 404. These mass portions provide means for positioning and aligning the upper portion 404 with the lower portion 408 of the putter head 400. Further, these mass portions (i.e., the front toe mass 441 and the front heel mass 443) provide additional means for adding weight to the periphery to increase the MOI of the putter 400 compared to a putter without these mass functions. These mass functions can have weights in the range of 2 to 5 grams, 3 to 7 grams, or 1 to 6 grams. The mass functions can all have the same weight or can have different weights within the above ranges. The mass functions 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, semi-circular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0125] In FIG. 4A, the front toe mass 441 and the front heel mass 443 are disposed away from the rear periphery 452. Here, the front toe mass 441 and the front heel mass 443 do not contact or intersect the rear periphery 452. However, referring to FIGS. 5A - 5C, a modified semi-circular putter 500 is shown. The putter 500 has the same characteristics as the putter 400, but the front toe mass 541 and the front heel mass 543 of the putter 500 are disposed on the rear periphery 552. The front toe mass 541 and the front heel mass 543 are integral with and intersect the rear periphery 452.

[0126] In one embodiment, the front toe mass 441 is disposed on the front edge 448, which is the junction of the toe side span 456 and the front edge 448. However, in other embodiments, the front toe mass 441 can be disposed at any location along the toe side span 456. In one embodiment, the front heel mass 443 is disposed on the front edge 448, which is the junction of the heel side span 460 and the front edge 448. However, in other embodiments, the front heel mass 443 can be disposed at any location along the heel side span 460.

[0127] 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. Since each mass 441, 443 is away from the center of gravity of the putter 400, placing each mass 441, 443 on the front edge 448 and the spans 456, 460 increases the MOI. Each mass 441, 443 on the perimeter 448 and the spans 456, 460 is integrally formed from a second material that is denser than the first material.

[0128] The front toe mass 441 and the front heel mass 443 provide two functions such that not only do the front toe mass 441 and the front heel mass 443 increase the MOI of the putter 400, but also provide an additional surface for the upper portion 404 to join to the lower portion 408. Thus, the front toe mass 441 can also be referred to as the front toe bonding portion 441, and the front heel mass 443 can also be referred to as the front heel bonding portion 443.

[0129] In some embodiments, the lower surface 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 lower surface of the toe end 412 towards the crown 442 but does not reach 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 the front toe mass 441 of the lower portion 408.

[0130] In some embodiments, the lower surface 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 lower surface of the heel end 416 towards the crown 442 but does not reach 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.

[0131] The first and second cavities can include any desired geometric shape, but in most embodiments, the first and second cavities include a geometric shape similar or identical to the geometric shape of the front toe mass 441 and the front heel mass 443. Further, when the upper portion 704 is fixed to the lower portion 408, the first cavity is arranged such that the first cavity surrounds the front toe mass 441, and the second cavity is arranged such that the second cavity surrounds the front heel mass 443.

[0132] The combination of the upper portion 404 of the low-density first material and the lower portion 408 of the high-density second material creates a high MOI pattern 400 without creating an extremely heavy pattern. The large gaps 464 formed by the spans 456, 460 of the rear perimeter 452 and the lower portion 408 form a high-density but low-volume portion that increases the MOI of the pattern (compared to a pattern milled from a single material). A single-material pattern cannot allocate high-density material to the perimeter while maintaining the desired volume (75 cc to 100 cc) and mass (340 grams to 385 grams).

[0133] In most embodiments, the lower portion 408 constitutes less than 38% of the volume of the pattern 400. In some embodiments, the lower portion 408 is less than 37% of the total volume of the pattern 400, less than 36% of the total volume of the pattern 400, less than 35% of the total volume of the pattern 400, less than 34% of the total volume of the pattern 400, less than 33% of the total volume of the pattern 400, less than 32% of the total volume of the pattern 400, less than 31% of the total volume of the pattern 400, less than 30% of the total volume of the pattern 400, less than 29% of the total volume of the pattern 400, less than 28% of the total volume of the pattern 400, or less than 27% of the total volume of the pattern 400.

[0134] Although the lower portion 408 constitutes less than half of the volume of the pattern 400, the lower portion 408 constitutes at least 45% of the total mass of the pattern 400. In some embodiments, the lower portion 408 is at least 46% of the mass of the pattern 400, at least 46% of the mass of the pattern 400, at least 47% of the mass of the pattern 400, at least 48% of the mass of the pattern 400, at least 49% of the mass of the pattern 400, at least 50% of the mass of the pattern 400, at least 51% of the mass of the pattern 400, at least 52% of the mass of the pattern 400, at least 53% of the mass of the pattern 400, at least 54% of the mass of the pattern 400, or at least 55% of the mass of the pattern 400.

[0135] A beneficial shift of mass around the putter head 400 increases the MOI of the putter 400 more than a putter having the same volume, mass, and single material structure (i.e., a putter milled from a single stainless steel block or a single material putter investment casting) through the use of a high density, low volume lower portion 408.

[0136] (d. Wing-shaped embodiment) In one embodiment, the putter-type golf club head can be a wing-shaped putter head having a peripheral span 600. Referring 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 of a first material having a first density, and the lower portion 608 is made of 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 are combined to produce a high MOI putter head 600 (5000 g·cm2 - 6500 g·cm2) while maintaining a desired volume and mass.

[0137] As described above, the lower part 608 is composed of a high-density material (i.e., the second material). The lower part 608 includes a front peripheral part 648, a sole 668, a rear peripheral part 652, a toe-side wing 656, and a heel-side wing 660. As will be described later, FIG. 6C shows that the front peripheral part 648, the rear peripheral part 652, the toe-side wing 656, and the heel-side wing 660 of the lower part 608 combine with the upper part 604 to generate the sole 668. The front peripheral part 648 is adjacent to the toe-side peripheral part 656 and the heel-side peripheral part 660 and is on the opposite side of the rear peripheral part 652. The toe-side wing 656 is adjacent to the front peripheral part 648 and the rear peripheral part 652 and is opposite to the heel-side wing 660. Also, the heel-side wing 660 is adjacent to the front peripheral part 648 and the rear peripheral part 652 but is opposite to the toe-side wing 656. The toe-side wing 656 and the heel-side wing 660 extend beyond the rear peripheral part 648 of the upper part 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 embodiments, the rear peripheral part 652 and the front peripheral part 648 may be parallel, while in some embodiments, the rear peripheral part 652 and the front peripheral part 648 are not parallel.

[0138] In most embodiments, the toe-side wing 656 extends perpendicularly from the rear peripheral portion 652 such that a right angle (90° angle) is formed at the junction of the toe-side wing 656 and the rear peripheral portion 652. However, in other embodiments, the toe-side wing 656 can extend in any direction from the rear peripheral portion 652 such that any angle (0° to 180°) can be formed at the junction of the toe-side wing 656 and the rear peripheral portion 652. Further, in most embodiments, the heel-side wing 660 extends perpendicularly from the rear peripheral portion 652 such that a right angle (90° angle) is formed at the junction of the heel-side wing 660 and the rear peripheral portion 652. However, in other embodiments, the heel-side wing 660 can extend in any direction from the rear peripheral portion 652 such that any angle (0° to 180°) can be formed at the junction of the heel-side wing 660 and the rear peripheral portion 652.

[0139] The front peripheral portion 648 of the lower part 608 has a front width. The front width is measured from the junction of the toe-side wing 656 and the front peripheral portion 648 to the junction of the heel-side wing 660 and the front peripheral portion 648. Further, the lower part 608 has a rear width. The rear width is measured from the tip 657 of the toe-side wing 656 and the tip 661 of the heel-side wing 660. Here, the tip 657 is the point of the toe-side wing 656 that is farthest from the front peripheral portion 648, and the tip 661 is the point of the heel-side wing 660 that is farthest from the front peripheral portion 648. 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.

[0140] The rear peripheral portion 652, the toe-side wing 656, and the heel-side wing 660 form a gap 664. The gap 664 is bounded by the rear peripheral portion 652, the toe-side wing 656, and the heel-side wing 660. The gap 664 formed by the rear peripheral portion 652, the toe-side wing 656, and the heel-side wing 660 moves most of the volume and mass of the putter to the end of the lower portion 608. The gap 664 can include any shape, but in one embodiment, the gap is substantially rectangular. In other embodiments, the gap 664 may be circular, curved, triangular, trapezoidal, parabolic, golf ball-shaped, square, or any other desired geometric shape.

[0141] The upper portion 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 a bottom surface (not shown). The toe end 612 is on the opposite side of the heel end 616. The striking face 620 extends from the toe end 612 to the heel end 616 and is on the opposite side of the rear wall 632. The rear wall 632 is opposite and substantially parallel to the striking face 620. The crown 642 extends away from the striking face 620 to the back edge 634 of the upper portion 604. Further, the bottom surface is opposite the crown 642 and spans from the striking face 620 to the back edge 634.

[0142] The crown 642 further descends from the hitting face 620 to the back edge 634. Additionally, the crown 642 extends away from the hitting face 620, beyond 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, extends to approximately the inner 25% of the full clubhead 600 width from the toe side wing 656 and to approximately the inner 25% of the full clubhead 600 width from the heel side wing 660. In other embodiments, the crown 642 can extend continuously or discontinuously across the full width of the entire clubhead 600 from heel to toe. In some embodiments, the crown 642 can extend to less than 90% of the full width of the clubhead 600, less than 90% of the full width of the clubhead 600, less than 80% of the full width of the clubhead 600, less than 70% of the full width of the clubhead 600, less than 60% of the full width of the clubhead 600, less than 50% of the full width of the clubhead 600, less than 40% of the full width of the clubhead 600, or less than 30% of the full width of the clubhead 600. Further, in some embodiments, the crown 642 can be substantially flat from the hitting face 620 to the back edge 634 or can rise from the hitting face 620 to the back edge 634. In most embodiments, the rise or fall of the crown 642 can be a linear, curved, parabolic, sine wave, or polynomial function.

[0143] 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 to the rear wall 632 and is substantially perpendicular to the hitting 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 the toe end 612. In most embodiments, the alignment trough is approximately equal to the width of a golf ball (about 4.27 cm), providing a viewer with a visual alignment field that widens the width of the golf ball.

[0144] Further, the upper portion 604 of the putter head 600 can include one or more alignment mechanisms 644 on the crown 642. The alignment mechanism 644 can be a line, a series of lines, a milling trough, a circle, a dashed line, a triangle, a channel, or any one or combination of any other desired alignment mechanisms 644. The alignment mechanism 644 can be evenly spaced across the entire crown 642, a portion of the crown 642, or on the alignment trough 655. The alignment mechanism 644 extending along the alignment trough 655 functions to provide a viewer with a visual alignment field that extends the width of the golf ball from the rear wall 632 to the back edge 634 of the putter 600. The purpose is to align the entire putter 600 with the golf ball using these alignment mechanisms 644 along the crown 642 and / or the alignment trough 655.

[0145] The upper portion 604 is affixed to the lower portion 608 such that the upper portion 604 is further 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 the address position where it contacts the golf ball.

[0146] Further, the striking face 620 of the putter head 600 includes 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 lower surface of the upper portion 604, and similarly, is equidistant from the heel end 616 and the toe end 612 of the putter head 600. The loft plane 680 is in contact with the striking face 620 of the putter head 600. Further, the midplane 684 intersects the striking face center point 676 and is perpendicular to the loft plane 680. Further, the y-axis 688 intersects the midplane 684 and is perpendicular to the ground plane 672.

[0147] When the upper portion 604 and the lower portion 608 are joined, the heel end 616 will overlap at least a portion of the toe side wing 656. Further, when the upper portion 604 and the lower portion 608 are joined, the toe end 612 will overlap at least a portion of the heel side wing 660. Further, when the upper portion 604 and the lower portion 608 are joined, the striking face 620 will overlap at least a portion of the front periphery 648. Finally, the upper portion 604 and the lower portion 608 are joined such that the back edge 634 overlaps at least a portion of the rear periphery 652.

[0148] Referring to FIG. 6C, the front periphery 648, rear periphery 652, toe side wing 656, and heel side wing 660 of the lower portion 608 are combined with the upper portion 604 to produce a sole 668. The sole 668 is perpendicular to the ground plane 672. The ground plane 672 is in contact with the sole 668 when the putter head 600 is at the address position where it strikes the golf ball. The sole 668 of the putter head 600 extends from the toe end 612 of the putter head 600 to the heel end 616 of the putter head 600.

[0149] 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 can have a slight arch in the direction from the heel 616 to the toe 612, and the slight arch can be a linear or polynomial function. In some embodiments, the sole 668 of the putter head 600 can have a strong arch in the direction from the heel 616 to the toe 612, and the strong arch can be a linear or polynomial function. The sole 668 functions to provide a surface for resting the putter head 600 on the ground plane 672.

[0150] Referring to FIG. 6A, in one embodiment, the lower portion 608 can further include 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 with 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 toward the upper portion 604. These mass portions provide means for positioning and aligning the upper portion 604 with the lower portion 608 of the putter head 600. Further, these mass portions (i.e., the front toe mass 641, the front heel mass 643, the toe wing mass 645, and the heel wing mass 647) provide additional means for adding weight to the perimeter to increase the MOI of the putter 600 compared to a putter without these mass functions. These mass functions can have weights in the range of 2 to 5 grams, 3 to 7 grams, or 1 to 6 grams. The mass functions can all have the same weight or can have different weights within the above ranges. The mass functions can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front toe mass 641, the front heel mass 643, the toe wing mass 645, and the heel wing mass 647 can each be of any one or combination of rectangular, triangular, pyramidal, spherical, semi-circular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0151] In one embodiment, the front toe mass 641 is disposed on the front peripheral portion 648 at the junction of the toe-side wing 656 and the front peripheral portion 648. However, in other embodiments, the front toe mass 641 can be disposed at any location along the front peripheral portion 648. In one embodiment, the front heel mass 643 is disposed on the front peripheral portion 648 at the junction of the heel wing 660 and the front peripheral portion 648. However, in other embodiments, the front heel mass 643 can be disposed at any location along the front peripheral portion 648. In one embodiment, the toe wing mass 645 can be disposed on a portion of the toe-side wing 656, but in other embodiments, the toe wing mass 645 can be disposed at any location along a portion or the entire length of the toe-side wing 656. In one embodiment, the heel wing mass 647 can be disposed on a portion of the heel-side wing 660, but in other embodiments, the heel wing mass 647 can be disposed along a portion or the entire length of the heel-side wing 660.

[0152] 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 of the masses 641, 643, 645, and 647 functions to increase the moment of inertia of the pickhead 600. Disposing each of the masses 641, 643, 645, and 647 on the peripheral portion 648 and the wings 656, 660 causes each of the masses 641, 643, 645, and 647 to be farther from the center of gravity of the pick 600, thereby increasing the MOI. Each of the masses 641, 643, 645, 647 on the peripheral portion 648 and the wings 656, 660 is integrally formed from a second material that is denser than the first material.

[0153] The front toe mass 641 and the front heel mass 643 provide two functions such that 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 join with the lower portion 608. Thus, the front toe mass 641 can also be referred to as the front toe bonding portion 641, and the front heel mass 643 can also be referred to as the front heel bonding portion 643.

[0154] In some embodiments, the lower surface 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 lower surface on the toe end 612 towards the crown 642, but does not reach 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.

[0155] In some embodiments, the lower surface 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 lower surface on the heel end 616 towards the crown 642, but does not reach 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.

[0156] The first and second cavities can include any desired geometric shape, but in most embodiments, the first and second cavities include a geometric shape that is similar or identical to the geometric shape of the front toe mass 641 and the front heel mass 643. Further, when the upper portion 604 is fixed to the lower portion 608, the first cavity is arranged such that the first cavity surrounds the front toe mass 641, and the second cavity is arranged such that the second cavity surrounds the front heel mass 643.

[0157] The combination of the upper portion 604 of the low-density first material and the lower portion 608 of the high-density second material creates a high MOI pattern 600 without creating an extremely heavy pattern. The large gap 664 formed by the rear perimeter 652 and the wings 656, 660 of the lower portion 608 forms a high-density but low-volume portion that increases the MOI of the pattern (compared to a pattern milled from a single material). A single-material pattern cannot allocate high-density material to the perimeter while maintaining the desired volume (75 cc to 100 cc) and mass (340 grams to 385 grams).

[0158] The lower portion 608 constitutes less than 38% of the total volume of the pattern 600 in most embodiments. In some embodiments, the lower portion 608 comprises less than 37% of the total volume of the pattern 600, less than 36% of the total volume of the pattern 600, less than 35% of the total volume of the pattern 600, less than 34% of the total volume of the pattern 600, less than 33% of the total volume of the pattern 600, less than 32% of the total volume of the pattern 600, less than 31% of the total volume of the pattern 600, less than 30% of the total volume of the pattern 600, less than 29% of the total volume of the pattern 600, less than 28% of the total volume of the pattern 600, or less than 27% of the total volume of the pattern 600.

[0159] The lower portion 608 constitutes less than half of the volume of the pattern 600, but the lower portion 608 constitutes at least 45% of the total mass of the pattern 600. In some embodiments, the lower portion 608 comprises at least 46% of the total mass of the pattern 600, at least 46% of the total mass of the pattern 600, at least 47% of the total mass of the pattern 600, at least 48% of the total mass of the pattern 600, at least 49% of the total mass of the pattern 600, at least 50% of the total mass of the pattern 600, at least 51% of the total mass of the pattern 600, at least 52% of the total mass of the pattern 600, at least 53% of the total mass of the pattern 600, at least 54% of the total mass of the pattern 600, or at least 55% of the total mass of the pattern 600.

[0160] The beneficial shift of mass around the putter head 600 by using the high-density, low-volume lower portion 608 increases the MOI of the putter 600 more than a putter having the same volume, mass, and single-material structure (i.e., a single stainless steel block milled or a single-material investment cast putter).

[0161] (e. Spade Embodiment) In one embodiment, the putter-type golf club head can be a spade-shaped putter head having a peripheral span 700. Referring 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 of a first material having a first density, and the lower portion 708 is made of 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 are combined to produce a high-MOI putter head 700 (5000 g·cm2 - 6500 g·cm2) while maintaining a desired volume and mass.

[0162] As described above, the lower portion 708 is composed of a high-density material (i.e., the first material), thereby lowering the mass below the midline 784. The lower portion 708 includes a front peripheral portion 748, a rear peripheral portion 752, a toe-side peripheral portion 756, and a heel-side peripheral portion 760. The front peripheral portion 748 is adjacent to the toe-side peripheral portion 756 and the heel-side peripheral portion 760 and is on the opposite side of the rear peripheral portion 752. The toe-side peripheral portion 756 is adjacent to the front peripheral portion 748 and the rear peripheral portion 752 and is on the opposite side and the opposite side of the heel-side peripheral portion 760. The heel-side peripheral portion 760 is also adjacent to the front peripheral portion 748 and the rear peripheral portion 752 but is on the opposite side of the toe-side peripheral portion 756. In some embodiments, the heel-side peripheral portion 760 and the toe-side peripheral portion 756 can be parallel, but in some embodiments, the heel-side peripheral portion 760 and the toe-side peripheral portion 756 are not parallel. In some embodiments, the rear peripheral portion 752 and the front peripheral portion 748 can be parallel, but in some embodiments, the rear peripheral portion 752 and the front peripheral portion 748 are not parallel.

[0163] The front peripheral portion 748 of the lower part 708 has a front width. The front width is measured from the joint between the toe-side peripheral portion 756 and the front peripheral portion 748 to the joint between the heel-side peripheral portion 760 and the front peripheral portion 748. Also, the rear peripheral portion 752 of the lower part 708 has a rear width. The rear width is measured from the joint between the toe-side peripheral portion 756 and the rear peripheral portion 752 to the joint between the heel-side peripheral portion 760 and the rear peripheral portion 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.

[0164] The front peripheral portion 748, the rear peripheral portion 752, the toe-side peripheral portion 756, and the heel-side peripheral portion 760 are joined to form an opening 764. Here, the opening 764 is bounded by four peripheral portions (front 748, rear 752, toe-side 756, and heel-side 760). The four peripheral portions 756, 752, 756, 760 form a peripheral portion around the opening 764. The central opening 764 formed by the peripheral portions 756, 752, 756, 760 of the lower part 708 moves most of the volume and mass of the putter to the end of the lower part 708.

[0165] The upper part 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 bottom surface (not shown). The toe end 712 is on the opposite side of the heel end 716. The striking face 720 extends from the toe end 712 to the heel end 716 and is on the opposite side of the rear wall 732. The rear wall 732 is opposite and substantially parallel to the striking face 720. The crown 742 extends away from the striking face 720, covers at least a portion of the rear wall 732, and extends to the back edge 734 of the upper part 704. Further, the bottom surface is on the opposite side of the crown 742 and extends from the striking face 720 to the back edge 734.

[0166] 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 of the lower portion 708, to the back edge 734 of the upper portion 704. The crown 742, in most embodiments, extends within the inner 25% of the total club head 700 width from the toe side perimeter 756 and the heel side perimeter 760. In this embodiment, the crown 742 extends over approximately 50% of the width of the club head 700. In other embodiments, the crown 742 can extend from heel to toe across the entire width of the entire club head 700. In some embodiments, the crown 742 can extend less than 90% of the total width of the club head 700, less than 90% of the total width of the club head 700, less than 80% of the total width of the club head 700, less than 70% of the total width of the club head 700, less than 60% of the total width of the club head 700, less than 50% of the total width of the club head 700, less than 40% of the total width of the club head 700, or less than 30% of the total 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, curved, parabolic, sine wave, or polynomial function.

[0167] Further, the upper portion 704 of the putter head 700 can include one or more alignment mechanisms 744 on the crown 742. The alignment mechanisms 744 can be a line, a series of lines, a milling trough, a circle, a dashed line, a triangle, a channel, or any other desired alignment mechanism 744 or combination thereof. The alignment mechanisms 744 are equally spaced across the entire crown 742, which is configured to be the width of a golf ball (about 4.27 cm). The alignment mechanisms 744 extending along the crown 742 function to provide a viewer with a visual alignment field that extends the width of the golf ball from the striking face 720 to the back edge 734 of the putter 700. The purpose is to align the entire putter 700 with the golf ball using these alignment mechanisms 744 along the crown 742.

[0168] Referring to FIG. 7C, the upper portion 704 is secured to the lower portion 708 such that the upper portion 704 is further away from the ground plane 772 than the lower portion 708. Here, the ground plane 772 is in contact with the lower portion 708 when the putter head 700 is in the address position where it strikes the golf ball.

[0169] Further, the striking face 720 of the putter head 700 includes a striking face center point 776 and a loft face 780. The striking face center point 776 is equidistant from both the heel end 716 and the toe end 712 of the putter head 700, as well as from the lower surfaces of the crown 742 and the upper portion 704. The loft face 780 is in contact with the striking face 720 of the putter head 700. Further, the mid-plane 784 intersects the striking face center point 776 and is perpendicular to the loft face 780. Further, the y-axis 788 intersects the mid-plane 784 and is perpendicular to the ground plane 772.

[0170] When the upper portion 704 and the lower portion 708 are joined, the heel end 716 will overlap at least a portion of the toe side peripheral portion 756. Further, when the upper portion 704 and the lower portion 708 are joined, the toe end 712 will overlap at least a portion of the heel side peripheral portion 760. Further, when the upper portion 704 and the lower portion 708 are joined, the striking face 720 will overlap at least a portion of the front peripheral portion 748. Finally, the upper portion 704 and the lower portion 708 are joined such that the back edge 734 overlaps at least a portion of the rear peripheral portion 752.

[0171] The four peripheral portions (front 748, rear 752, toe side 756, and heel side 760) of the lower portion 708 combine with the upper portion 704 to produce the sole 768. The sole 768 is perpendicular to the ground plane 772. The ground plane 772 contacts the sole 768 when the putter head 700 is at the address position where it strikes the golf ball. The sole 768 of the putter head 700 extends from the toe end 712 of the putter head 700 to the heel end 716 of the putter head 700.

[0172] 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 can have a slight arch in the direction from the heel 716 to the toe 712, and the slight arch can be a linear or polynomial function. In some embodiments, the sole 768 of the putter head 700 can have a strong arch in the direction from the heel 716 to the toe 712, and the strong arch can 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.

[0173] Referring to FIG. 7A, in one embodiment, the lower portion 708 can further include 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 with 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 toward the upper portion 704. These mass portions provide means for positioning and aligning the upper portion 704 with the lower portion 708 of the putter head 700. Further, these mass portions (i.e., the front mass 741, the rear mass 743, the toe mass 745, and the heel mass 747) provide additional means for adding weight to the perimeter to increase the MOI of the putter 700 over a putter that does not have these mass functions. These mass functions can have a weight in the range of 2 to 5 grams, 3 to 7 grams, or 1 to 6 grams. The mass functions can all have the same weight or can be different weights within the above ranges. The mass functions can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front mass 741, the rear mass 743, the toe mass 745, and the heel mass 747 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semi-circular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0174] In one embodiment, the front mass 741 is disposed on the front peripheral portion 748 and is equidistant from the toe side peripheral portion 756 and the heel side peripheral portion 760. However, in other embodiments, the front mass 741 can be disposed at any location along the front peripheral portion 748. In one embodiment, the rear mass 743 is disposed on the rear peripheral portion 752 and is equidistant from the toe side peripheral portion 756 and the heel side peripheral portion 760. However, in other embodiments, the rear mass 743 can be disposed at any location along the rear peripheral portion 752. In one embodiment, the toe mass 745 can be disposed at the junction of the toe side peripheral portion 756 and the rear peripheral portion 752. However, in other embodiments, the toe mass 745 can be disposed at any location along the toe side peripheral portion 756. In one embodiment, the heel mass 747 can be disposed at the junction of the heel side peripheral portion 760 and the rear peripheral portion 752. However, in other embodiments, the heel mass 747 can be disposed at any location along the heel side peripheral portion 760.

[0175] The front mass 741, the rear mass 743, the toe mass 745, and the 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 disposing each mass 741, 743, 745, and 747 on each of the masses 748, 752, 756, 760, the MOI increases because each mass 741, 743, 745, and 747 is away from the center of gravity of the putter 700. Each of the masses 741, 743, 745, 747 on the peripheral portions 748, 752, 756, 760 is integrally formed from a second material that is denser than the first material.

[0176] The front mass 741 and the rear mass 743 provide two functionalities such that the front mass 741 and the rear mass 743 not only increase the MOI of the putter 700 but also function to provide an additional surface for joining the upper portion 704 to the lower portion 708. Thus, the front mass 741 can also be referred to as the front bond 741 and the rear mass 743.

[0177] 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 towards the crown 742 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.

[0178] In some embodiments, the lower surface, the back edge 734, and the crown 742 form a second cavity (not shown). The second cavity extends inwardly from the lower surface towards 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 equidistantly 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.

[0179] The first and second cavities can include any desired geometric shape, but in most embodiments, the first and second cavities include a geometric shape that is similar or identical to the geometric shape of the front mass 741 and the rear mass 743. Further, when the upper portion 704 is fixed to the lower portion 708, the first cavity is arranged such that the first cavity surrounds the front mass 741, and the second cavity is arranged such that the second cavity surrounds the rear mass 743.

[0180] The combination of the low-density first material upper portion 704 and the high-density second material lower portion 708 produces a high MOI pattern 700 without creating an extremely heavy pattern. The large openings 764 formed by the peripheral portions 748, 752, 756, 760 of the lower portion 708 form high-density but low-volume portions that increase the MOI of the pattern (compared to a pattern milled from a single material). A single-material pattern cannot allocate high-density material to the periphery while maintaining the desired volume (75 cc to 100 cc) and mass (340 grams to 385 grams).

[0181] In most embodiments, the lower portion 708 constitutes less than 35% of the total volume of the pattern 700. In some embodiments, the lower portion 708 constitutes less than 34% of the total volume of the pattern 700, less than 33% of the total volume of the pattern 700, less than 32% of the total volume of the pattern 700, less than 31% of the total volume of the pattern 700, less than 30% of the total volume of the pattern 700, less than 29% of the total volume of the pattern 700, less than 28% of the total volume of the pattern 700, or less than 27% of the total volume of the pattern 700.

[0182] Although the lower portion 708 constitutes less than half of the volume of the pattern 700, the lower portion 708 constitutes at least 45% of the total mass of the pattern 700. In some embodiments, the lower portion 708 constitutes at least 46% of the mass of the pattern 700, at least 47% of the mass of the pattern 700, at least 48% of the mass of the pattern 700, at least 49% of the mass of the pattern 700, at least 50% of the mass of the pattern 700, at least 51% of the mass of the pattern 700, at least 52% of the mass of the pattern 700, at least 53% of the mass of the pattern 700, at least 54% of the mass of the pattern 700, or at least 55% of the mass of the pattern 700.

[0183] The beneficial shift of mass around the clubhead 700 increases the MOI of the pattern 700 relative to a pattern having the same volume, mass, and single-material structure (i.e., a pattern milled from a single stainless steel block or a single-material club investment casting) through the use of the high-density, low-volume lower portion 708.

[0184] (f. T-shaped embodiment with peripheral span) In one embodiment, the putter-type golf club head can be a T-shaped putter head having a peripheral span 800. Referring to FIGS. 8A and 8B, the T-shaped putter head having a peripheral span 800 has an upper portion 804 and a lower portion 808. The upper portion 804 is made of a first material having a first density, and the lower portion 808 is made of a second material having a second density. The first density is smaller than the second density. The upper portion 804 and the lower portion 808 are combined to produce a high MOI putter head 800 (5000 g·cm2 - 6500 g·cm2) while maintaining a desired volume and mass.

[0185] As described above, the lower portion 808 is composed of a high-density material (i.e., the second material), thereby reducing the mass below the midline 884. The lower portion 808 includes a front peripheral portion 848, a rear peripheral portion 852, a toe-side peripheral portion 856, and a heel-side peripheral portion 860. The front peripheral portion 848 is adjacent to the toe-side peripheral portion 856 and the heel-side peripheral portion 860 and is on the opposite side of the rear peripheral portion 852. The toe-side peripheral portion 856 is adjacent to the front peripheral portion 848 and the rear peripheral portion 852 and is on the opposite side of the heel-side peripheral portion 860. The heel-side peripheral portion 860 is also adjacent to the front peripheral portion 848 and the rear peripheral portion 852 but is on the opposite side of the toe-side peripheral portion 856. In some embodiments, the heel-side peripheral portion 860 and the toe-side peripheral portion 856 can be parallel, but in some embodiments, the heel-side peripheral portion 860 and the toe-side peripheral portion 856 are not parallel. In some embodiments, the rear peripheral portion 852 and the front peripheral portion 848 can be parallel, but in some embodiments, the rear peripheral portion 852 and the front peripheral portion 848 are not parallel.

[0186] The front peripheral portion 848 of the lower part 808 has a front width. The front width is measured from the joint between the toe-side peripheral portion 856 and the front peripheral portion 848 to the joint between the heel-side peripheral portion 860 and the front peripheral portion 848. Also, the rear peripheral portion 852 of the lower part 808 has a rear width. The rear width is measured from the joint between the toe-side peripheral portion 856 and the rear peripheral portion 852 to the joint between the heel-side peripheral portion 860 and the rear peripheral portion 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.

[0187] The front peripheral portion 848, the rear peripheral portion 852, the toe-side peripheral portion 856, and the heel-side peripheral portion 860 are joined to form an opening 864. Here, the opening 864 is bounded by four peripheral portions (front 856, rear 852, toe-side 856, and heel-side 860). The four peripheral portions 856, 852, 856, 860 form a peripheral portion around the opening 864. The central opening 864 formed by the peripheral portions 856, 852, 856, 860 of the lower part 808 moves most of the volume and mass of the patter to the end of the lower part 808.

[0188] In some embodiments, the opening 864 formed by the front peripheral portion 848, the rear peripheral portion 852, the toe-side peripheral portion 856, and the heel-side peripheral portion 860 can be any one of the following shapes: rectangular, triangular, semi-circular, 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.

[0189] The upper portion 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 bottom surface (not shown). The toe end 812 is on the opposite side of the heel end 816. The striking face 820 extends from the toe end 812 to the heel end 816 and is on the opposite side of the rear wall 832. The rear wall 832 is opposite and substantially parallel to the striking face 820. The crown 842 extends away from the striking face 820, covers at least a portion of the rear wall 832, and extends to the back edge 834 of the upper portion 804. Further, the bottom surface is on the opposite side of the crown 842 and extends from the striking face 820 to the back edge 834.

[0190] The crown 842 further descends from the hitting face 820 to the back edge 834. Additionally, the crown 842 extends away from the hitting face 820, over at least a portion of the rear wall 832 and the opening 864 of the lower portion 808, to the back edge 834 of the upper portion 804. The crown 842, in most embodiments, extends within the inner 25% of the total club head 800 width from the toe side perimeter 856 and the heel side perimeter 860. In this embodiment, the crown 842 extends to about 50% of the width of the club head 800 and thus forms a "T shape" with the hitting face. In other embodiments, the crown 842 can extend from the heel to the toe across the entire width of the total club head 800. In some embodiments, the crown 842 can extend less than 90% of the total width of the club head 800, less than 90% of the total width of the club head 800, less than 80% of the total width of the club head 800, less than 70% of the total width of the club head 800, less than 60% of the total width of the club head 800, less than 50% of the total width of the club head 800, less than 40% of the total width of the club head 800, or less than 30% of the total width of the club head 800. Further, in some embodiments, the crown 842 can be substantially flat from the hitting face 820 to the back edge 834 or can rise from the hitting face 820 to the back edge 834. In most embodiments, the rise or fall of the crown 842 can be a linear, curved, parabolic, sine wave, or polynomial function.

[0191] Furthermore, the upper portion 804 of the putter head 800 can include one or more alignment mechanisms 844 on the crown 842. The alignment mechanisms 844 can be a line, a series of lines, a milled trough, a circle, a dashed line, a triangle, a channel, or any one or combination of any other desired alignment mechanisms 844. The alignment mechanisms 844 are equally spaced across the entire crown 842, which is configured to be the width of a golf ball (about 4.27 cm). The alignment mechanisms 844 extending along the crown 842 function to provide a viewer with a visual alignment field that extends the width of the golf ball from the striking face 820 to the back edge 834 of the putter 800. The purpose is to use these alignment mechanisms 844 along the crown 842 to align the entire putter 800 with the golf ball.

[0192] Referring to FIG. 8C, the upper portion 804 is secured to the lower portion 808 such that the upper portion 804 is farther from the ground plane 872 than the lower portion 808. Here, the ground plane 872 contacts the lower portion 808 when the putter head 800 is in the address position where it contacts the golf ball.

[0193] Furthermore, the striking face 820 of the putter head 800 includes a striking face center point 876 and a loft face 880. The striking face center point 876 is equidistant from the crown 842 and the lower surface of the upper portion 804, and similarly, is equidistant from the heel end 816 and the toe end 812 of the putter head 800. The loft face 880 is in contact with the striking face 820 of the putter head 800. Further, the mid-plane 884 intersects the striking face center point 876 and is perpendicular to the loft face 880. Further, the y-axis 888 intersects the mid-plane 884 and is perpendicular to the ground plane 872.

[0194] When the upper portion 804 and the lower portion 808 are joined, the heel end 816 will overlap at least a portion of the toe side peripheral portion 856. Further, when the upper portion 804 and the lower portion 808 are joined, the toe end 812 will overlap at least a portion of the heel side peripheral portion 860. Further, when the upper portion 804 and the lower portion 808 are joined, the striking face 820 will overlap at least a portion of the front peripheral portion 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 peripheral portion 852.

[0195] The four peripheral portions (front 848, rear 852, toe side 856, and heel side 860) of the lower portion 808 combine with the upper portion 804 to form the sole 868. The sole 868 is perpendicular to the ground plane 872. The ground plane 872 contacts the sole 868 when the putter head 800 is at the address position where it strikes the golf ball. The sole 868 of the putter head 800 extends from the toe end 812 of the putter head 800 to the heel end 816 of the putter head 800.

[0196] In most embodiments, the sole 868 of the putter head 800 can be completely flat. In some embodiments, the sole 868 of the putter head 800 can have a slight arch in the direction from the heel 816 to the toe 812, and the slight arch can be a linear or polynomial function. In some embodiments, the sole 868 of the putter head 800 can have a strong arch in the direction from the heel 816 to the toe 812, and the strong arch can 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.

[0197] Referring to FIG. 8A, in one embodiment, the lower portion 808 can further include 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 mass portions provide means for positioning and aligning the upper portion 804 with the lower portion 808 of the putter head 800. Further, these mass portions (i.e., the front mass 841, the rear mass 843, the toe mass 845, and the heel mass 847) provide additional means for adding weight to the perimeter to increase the MOI of the putter 800 compared to a putter without these mass functions. These mass functions can have weights in the range of 2 to 5 grams, 3 to 7 grams, or 1 to 6 grams. The mass functions can all have the same weight or can have different weights within the above ranges. The mass functions can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front mass 841, the rear mass 843, the toe mass 845, and the heel mass 847 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semi-circular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0198] In one embodiment, the front mass 841 is disposed on the front peripheral portion 848 and is equidistant from the toe-side peripheral portion 856 and the heel-side peripheral portion 860. However, in other embodiments, the front mass 841 can be disposed at any location along the front peripheral portion 848. In one embodiment, the rear mass 843 is disposed on the rear peripheral portion 852 and is equidistant from the toe-side peripheral portion 856 and the heel-side peripheral portion 860. However, in other embodiments, the rear mass 843 can be disposed at any location along the rear peripheral portion 852. In one embodiment, the toe mass 845 can be disposed at the junction of the toe-side peripheral portion 856 and the rear peripheral portion 852. However, in other embodiments, the toe mass 845 can be disposed at any location along the toe-side peripheral portion 856. In one embodiment, the heel mass 847 can be disposed at the junction of the heel-side peripheral portion 860 and the rear peripheral portion 852. However, in other embodiments, the heel mass 847 can be disposed at any location along the heel-side peripheral portion 860.

[0199] The front mass 841, the rear mass 843, the toe mass 845, and the heel mass 847 provide areas of concentrated mass such that each of the masses 841, 843, 845, and 847 functions to increase the moment of inertia of the putter head 800. The placement of each of the masses 841, 843, 845, and 847 on the peripheral portions 848, 852, 856, 860 increases the MOI since each of the masses 841, 843, 845, and 847 is far from the center of gravity of the putter 800. Each of the masses 841, 843, 845, 847 on the peripheral portions 848, 852, 856, 860 is integrally formed from a second material that is denser than the first material.

[0200] The front mass 841 and the rear mass 843 provide two functionalities such that the front mass 841 and the rear mass 843 not only increase the MOI of the putter 800 but also function to provide an additional surface for joining the upper 804 to the lower 808. Thus, the front mass 841 can also be referred to as the front adhesive portion 841 and the rear mass 843.

[0201] 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 towards the crown 842 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.

[0202] In some embodiments, the lower surface, the back edge 834, and the crown 842 form a second cavity (not shown). The second cavity extends inwardly from the lower surface towards 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 equidistantly 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.

[0203] The first and second cavities can include any desired geometric shape, but in most embodiments, the first and second cavities include a geometric shape similar or identical to the geometric shape of the front mass 841 and the rear mass 843. Further, when the upper portion 804 is fixed to the lower portion 808, the first cavity is arranged such that the first cavity surrounds the front mass 841, and the second cavity is arranged such that the second cavity surrounds the rear mass 843.

[0204] The combination of the upper portion 804 of the low-density first material and the lower portion 808 of the high-density second material produces a high MOI pattern 800 without creating an extremely heavy pattern. The large openings 864 formed by the peripheral portions 848, 852, 856, 860 of the lower portion 808 form high-density but low-volume portions that increase the MOI of the pattern (compared to a pattern milled from a single material). A single-material pattern cannot allocate high-density material peripherally while maintaining the desired volume (75 cc to 100 cc) and mass (340 grams to 385 grams).

[0205] The lower portion 808 constitutes less than 35% of the total volume of the pattern 800 in most embodiments. In some embodiments, the lower portion 908 constitutes less than 34% of the total volume of the pattern 800, less than 33% of the total volume of the pattern 800, less than 32% of the total volume of the pattern 800, less than 31% of the total volume of the pattern 800, less than 30% of the total volume of the pattern 800, less than 29% of the total volume of the pattern 800, less than 28% of the total volume of the pattern 800, or less than 27% of the total volume of the pattern 800.

[0206] The lower portion 808 constitutes less than half of the volume of the pattern 800, but the lower portion 808 constitutes at least 45% of the total mass of the pattern 800. In some embodiments, the lower portion 808 constitutes at least 46% of the mass of the pattern 800, at least 46% of the mass of the pattern 800, at least 46% of the mass of the pattern 800, at least 47% of the mass of the pattern 800, at least 48% of the mass of the pattern 800, at least 49% of the mass of the pattern 800, at least 50% of the mass of the pattern 800, at least 51% of the mass of the pattern 800, at least 52% of the mass of the pattern 800, at least 53% of the mass of the pattern 800, at least 54% of the mass of the pattern 800, or at least 55% of the mass of the pattern 800.

[0207] A beneficial shift of mass to the perimeter of the putter head 800 increases the MOI of the putter 800 relative to a putter having the same volume, mass, and single material construction (i.e., a milled putter from a single stainless steel block or a single material putter investment casting) through the use of a high density, low volume lower portion 808.

[0208] (g. Dual rail embodiments) In another embodiment, the putter-type golf club head can be a dual rail putter head 900. Referring 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 are combined to produce a high MOI putter head 900 (5000 g·cm2 - 6500 g·cm2) while maintaining a desired volume and mass.

[0209] As described above, the lower portion 908 is constructed of a high density material (i.e., the second material), thereby lowering the mass below the midline 984. The lower portion 908 includes 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 on the opposite side of the rear perimeter 952. The toe side perimeter 956 is adjacent to the front perimeter 948 and the rear perimeter 952 and is on the opposite side of 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 on the opposite side of 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 may be parallel, while in some embodiments, the rear perimeter 952 and the front perimeter 948 are not parallel.

[0210] The front peripheral portion 948 of the lower part 908 has a front width. The front width is measured from the joint of the toe side peripheral portion 956 and the front peripheral portion 948 to the joint of the heel side peripheral portion 960 and the front peripheral portion 948. Further, the rear peripheral portion 952 of the lower part 908 has a rear width. The rear width is measured from the joint of the toe side peripheral portion 956 and the rear peripheral portion 952 to the joint of the heel side peripheral portion 960 and the rear peripheral portion 952. In most embodiments, the front width is larger than the rear width, but in some embodiments, the front width can be less than or equal to the rear width.

[0211] The front peripheral portion 948, the rear peripheral portion 952, the toe side peripheral portion 956, and the heel side peripheral portion 960 are joined to form an opening 964. Here, the opening 964 is bounded by four peripheral portions (front 948, rear 952, toe side 956, and heel side 960). The four peripheral portions 948, 952, 956, 960 form a peripheral portion around the opening 964. The central opening 964 formed by the peripheral portions 948, 952, 956, 960 of the lower part 908 moves most of the volume and mass of the pattern to the end of the lower part 908.

[0212] In some embodiments, the opening 964 formed by the front peripheral portion 948, the rear peripheral portion 952, the toe side peripheral portion 956, and the heel side peripheral portion 960 can be any one of the following shapes: rectangular, triangular, semi - circular, 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.

[0213] The upper portion 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 bottom surface (not shown). The toe end 912 is on the opposite side of the heel end 916. The striking face 920 extends from the toe end 912 to the heel end 916 and is on the opposite side of the rear wall 932. The rear wall 932 is opposite and substantially parallel to the striking face 920. The crown 942 extends away from the striking face 920, covers at least a portion of the rear wall 932, and extends to the back edge 934 of the upper portion 904. Further, the bottom surface is on the opposite side of the crown 942 and extends from the striking face 920 to the back edge 934.

[0214] The crown 942 of the upper portion 904 further includes 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 substantially parallel and perpendicular to the striking face 920. Further, the toe end mid-rail 936 and the heel end mid-rail 940 do not contact the toe side peripheral portion 956 or the heel side peripheral portion 960. The toe end mid-rail 936 and the heel end mid-rail 940 are each located approximately 1 / 3 of the total club head width inward from the outer periphery of the toe side peripheral portion 956 and the heel side peripheral portion 960, respectively. However, in other embodiments, the toe end mid-rail 936 and the heel end mid-rail 940 can each be located more than 1 / 3 of the total club head width inward from the outer periphery of the toe side peripheral portion and the heel side peripheral portion, 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 the heel end mid-rail 940 are not parallel and not perpendicular to the striking face 920. In some embodiments, the toe end mid-rail 936 and the 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 can be linear, curved, parabolic, sinusoidal, or a polynomial function.

[0215] Furthermore, the upper portion 904 of the dual rail putter head 900 can include one or more alignment mechanisms 944 on the toe end mid rail 936 and the heel end mid rail 940. The alignment mechanisms 944 can be any one or combination of a line, a circle, a dashed line, a triangle, a channel, or any other desired alignment mechanism 944. The alignment mechanisms 944 are spaced on the rails 936, 940 to be the width of a golf ball (about 4.27 cm). The alignment mechanisms 944 extend along the rails and provide a viewer with a visual alignment field that extends from the golf ball striking face 920 across the entire putter 900. The purpose is to align the entire putter 900 with the golf ball using these alignment mechanisms 944 along the toe end mid rail 936 and the heel end mid rail 940.

[0216] The upper portion 904 is fixed to the lower portion 908 such that the upper portion 904 is farther 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 the address position where it contacts the golf ball.

[0217] Furthermore, the striking face 920 of the dual rail putter head 900 includes a striking face center point 976 and a loft face 980. The striking face center point 976 is equidistant from the crown 942 and the lower surface of the upper portion 904, and similarly, is equidistant from the heel end 916 and the toe end 912 of the dual rail putter head 900. The loft face 980 is in contact with the striking face 920 of the dual rail putter head 900. Furthermore, the mid plane 984 intersects the striking face center point 976 and is perpendicular to the loft face 980. Furthermore, the y-axis 988 intersects the mid plane 984 and is perpendicular to the ground plane 972.

[0218] When the upper portion 904 and the lower portion 908 are joined, the heel end 916 will overlap at least a portion of the toe side peripheral portion 956. Further, when the upper portion 904 and the lower portion 908 are joined, the toe end 912 will overlap at least a portion of the heel side peripheral portion 960. Further, when the upper portion 904 and the lower portion 908 are joined, the striking face 920 will overlap at least a portion of the front peripheral portion 948. Finally, the upper portion 904 and the lower portion 908 are joined such that the back edge 934 overlaps at least a portion of the rear peripheral portion 952.

[0219] Referring to FIG. 9C, the four peripheral portions (front 948, rear 952, toe side 956, and heel side 960) of the lower portion 908 are combined with the upper portion 904 to form the sole 968. The sole 968 is perpendicular to the ground plane 972. The ground plane 972 contacts the sole 968 when the dual rail putter head 900 is in the address position where it strikes the golf ball. The sole 968 of the dual rail putter head 900 extends from the toe end 912 of the dual rail putter head 900 to the heel end 916 of the dual rail putter head 900.

[0220] In most embodiments, the sole 968 of the dual rail putter head 900 can be completely flat. In some embodiments, the sole 968 of the putter head 900 can have a slight arch in the direction from heel to toe, and the slight arch can be a linear or polynomial function. In some embodiments, the sole 968 of the putter head 900 can have a strong arch in the heel-to-toe direction, and the strong arch can be a linear or polynomial function. The sole 968 functions to provide a surface for placing the dual rail putter head 900 on the ground plane 972.

[0221] Referring to FIG. 9A, in one embodiment, the lower portion 908 can further include 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 with 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 toward the upper portion 904. These mass portions provide means for positioning and aligning the upper portion below the dual-rail pattern head 900. Further, these mass portions (i.e., the front mass 941, the rear mass 943, the toe mass 945, and the heel mass 947) provide additional means for adding weight to the periphery to increase the MOI of the pattern over a pattern that does not have these mass functions. These mass functions can have weights in the range of 2 to 5 grams, 3 to 7 grams, or 1 to 6 grams. The mass functions can all have the same weight or can have different weights within the above ranges. The mass functions can be 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grams. The front mass 941, the rear mass 943, the toe mass 945, and the heel mass 947 can each be any one or combination of the following shapes: rectangular, triangular, pyramidal, spherical, semi-circular, square, cylindrical, oval, elliptical, trapezoidal, pentagonal, hexagonal, octagonal, or any other desired geometric or non-geometric shape.

[0222] In one embodiment, the front mass 941 is disposed on the front peripheral portion 948 and is equidistant from the toe side peripheral portion 956 and the heel side peripheral portion 960. However, in other embodiments, the front mass 941 can be disposed at any location along the front peripheral portion 948. In one embodiment, the rear mass 943 is disposed on the rear peripheral portion 952 that is equidistant from the toe side peripheral portion 956 and the heel side peripheral portion 960. However, in other embodiments, the rear mass 943 can be disposed at any location along the rear peripheral portion 952. In one embodiment, the toe mass 945 can be disposed at the junction of the toe side peripheral portion 956 and the rear peripheral portion 952. However, in other embodiments, the toe mass 945 can be disposed at any location along the toe side peripheral portion 956. In one embodiment, the heel mass 947 can be disposed at the junction of the heel side peripheral portion 960 and the rear peripheral portion 952. However, in other embodiments, the heel mass 947 can be disposed at any location along the heel side peripheral portion 960.

[0223] The front mass 941, the rear mass 943, the toe mass 945, and the 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. Since each mass is far from the center of gravity of the putter 900, disposing each mass 941, 943, 945, and 947 on the peripheral portions 948, 952, 956, 960 causes each mass 941, 943, 945, and 947 to increase the MOI. Each mass 941, 943, 945, 947 on the peripheral portions 948, 952, 956, 960 is integrally formed from a second material that is denser than the first material.

[0224] The front mass 941, rear mass 943, toe mass 945, and heel mass 947 provide two functions such that each of the masses 941, 943, 945, and 947 not only increases the MOI of the pattern 900 but also provides an additional surface for the upper 904 to join to the lower 908. Thus, the front mass 941 can also be referred to as the front bonding portion 941, the rear mass 943 can also be referred to as the rear bonding portion 943, the toe mass 945 can also be referred to as the toe bonding portion 945, and the heel mass 947 can also be referred to as the heel bonding portion 947.

[0225] Furthermore, 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 into 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 have the same geometric shape, but in some embodiments, the toe end cap 949 and the heel end cap 951 can have different geometric shapes.

[0226] In most embodiments, the toe end cap 949 and the heel end cap 951 of the crown 942 are larger than the toe mass 945 and the heel mass 947, respectively. As a result, the toe end cap 949 and the heel end cap 951 cover the toe mass 945 and the heel mass 947 when the upper 904 is fixed to the lower 908. Furthermore, when the upper 904 is fixed to the lower 908, the toe end cap 949 is arranged such that the toe end cap 949 overlaps at least a part of the toe side periphery 956 and the toe mass 945. Furthermore, when the upper 904 is fixed to the lower 908, the heel end cap 951 is arranged such that the heel end cap 951 covers at least a part of the heel side periphery 960 and the heel mass 960.

[0227] 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 towards the crown 942 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.

[0228] In some embodiments, the lower surface, the back edge 934, and the crown 942 form a second cavity (not shown). The second cavity extends inwardly from the lower surface towards 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 disposed equidistantly 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.

[0229] The first and second cavities can include any desired geometric shape, but in most embodiments, the first and second cavities include a geometric shape similar or identical to the geometric shape of the front mass 941 and the rear mass 943. Further, when the upper portion 904 is fixed to the lower portion 908, the first cavity is disposed such that the first cavity surrounds the front mass 941, and the second cavity is disposed such that the second cavity surrounds the rear mass 943.

[0230] The combination of the upper portion 904 of the low-density first material and the lower portion 908 of the high-density second material produces a high MOI pattern 900 without creating an extremely heavy pattern. The large openings 964 formed by the peripheral portions 948, 952, 956, 960 of the lower portion 908 form high-density but low-volume portions that increase the MOI of the pattern (compared to a pattern milled from a single material). A single-material pattern cannot allocate high-density material peripherally while maintaining the desired volume (75 cc to 100 cc) and mass (340 grams to 385 grams).

[0231] In most embodiments, the lower portion 908 constitutes less than 35% of the total volume of the pattern 900. In some embodiments, the lower portion 908 constitutes less than 34% of the total volume of the pattern 900, less than 33% of the total volume of the pattern 900, less than 32% of the total volume of the pattern 900, less than 31% of the total volume of the pattern 900, less than 30% of the total volume of the pattern 900, less than 29% of the total volume of the pattern 900, less than 28% of the total volume of the pattern 900, or less than 27% of the total volume of the pattern 900.

[0232] The lower portion 908 constitutes less than half of the volume of the pattern 900, but the lower portion 908 constitutes at least 45% of the total mass of the pattern 900. In some embodiments, the lower portion 908 constitutes at least 46% of the mass of the pattern 900, at least 46% of the mass of the pattern 900, at least 46% of the pattern 900, at least 47% of the mass of the pattern 900, at least 48% of the pattern 900, at least 49% of the mass of the pattern 900, at least 50% of the pattern 900, at least 51% of the mass of the pattern 900, at least 52% of the pattern 900, at least 53% of the mass of the pattern 900, at least 54% of the mass of the pattern 900, or at least 55% of the mass of the pattern 900.

[0233] A beneficial shift of mass to the perimeter of the putter head 900 increases the MOI of the putter 900 relative to a putter having the same volume, mass, and single material structure (i.e., a putter milled from a single stainless steel block or a single material putter investment casting) through the use of a high density, low volume lower portion 908.

[0234] (h. Circular Embodiment) In another embodiment, the putter-type golf club head 1000 can be a circular putter head 1000. Referring 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 of a first material having a first density, and the upper portion 1004 is made of 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 are combined to produce a high MOI putter head 1000 (5000 g·cm2 - 6500 g·cm2) while maintaining a desired volume and mass.

[0235] As described above, the upper portion 1004 is composed of a high density material (i.e., the second material). The upper portion 1004 includes a toe end 1012, a heel end 1016, a striking face 1020, a rear wall 1032, and a bottom surface (not shown). The toe end 1012 is on the opposite side of the heel end 1016. The striking face 1020 extends from the toe end 1012 to the heel end 1016 and is on the opposite side of the rear wall 1032. The rear wall 1032 is opposite and substantially parallel to the striking face 1020.

[0236] The upper portion 1004 further includes a toe-side span 1056 and a heel-side span 1060. The toe-side span 1056 is adjacent to the toe end 1012 and is on the opposite side of the heel-side span 1060. The heel-side span 1060 is also adjacent to the heel end 1016 and is on the opposite side of the toe-side span 1056. In some embodiments, the heel-side span 1060 and the toe-side span 1056 can be parallel, but in some embodiments, the heel-side span 1060 and the toe-side span 1056 are not parallel. The toe-side span 1056 and the heel-side span 1060 extend away from the rear wall 1032 and the striking face 1020.

[0237] 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.

[0238] The rear wall 1032, the toe side span 1056, and the heel side span 1060 form a gap 1064. The gap 1064 is bounded by the rear wall 1032, the toe side span 1056, and the heel side span 1060. The gap 1064 formed by the rear wall 1032, the toe side span 1056, and the heel side span 1060 moves most of the volume and mass of the putter to the end of the upper portion 1008. The gap 1064 can include any shape, but in one embodiment, the gap is substantially rectangular. In other embodiments, the gap 1064 may be circular, curved, triangular, trapezoidal, parabolic, golf ball shaped, square, or any other desired geometric shape.

[0239] 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.

[0240] 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 (front 1041, rear 1034, toe 1043, heel 1045). The four edges 1041, 1034, 1043, 1045 form a perimeter around the opening 1065.

[0241] In some embodiments, the opening 1065 formed by the front edge 1041, rear edge 1034, toe edge 1043, and heel edge 1045 can be any one of the following shapes: rectangular, triangular, semi-circular, 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.

[0242] Referring to FIG. 10C, the lower portion 1008 is fixed to the upper portion 1004 such that a part of the upper portion 1004 and the lower portion 1008 intersects the ground plane 1072. The ground plane 1072 is in contact with the lower portion 1008 when the putter head 1000 is at the address position where it strikes the golf ball.

[0243] Furthermore, the striking face 1020 of the putter head 1000 includes a striking face center point 1076 and a loft face 1080. The striking face center point 1076 is equidistant from the upper rail 1050 of the upper portion 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 face 1080 is in contact with the striking face 1020 of the putter head 1000. Furthermore, the mid-plane 1084 intersects the striking face center point 1076 and is perpendicular to the loft face 1080. Furthermore, the y-axis 1088 intersects the mid-plane 1084 and is perpendicular to the ground plane 1072.

[0244] When the upper part 1004 and the lower part 1008 are joined, the toe-side span 1056 comes to overlap at least a part of the toe edge 1043. Further, when the upper part 1004 and the lower part 1008 are joined, the heel-side span 1060 comes to overlap at least a part of the heel edge 1045. Further, when the upper part 1004 and the lower part 1008 are joined, the striking face 1020 comes to overlap at least a part of the front edge 1048. Finally, when the upper part 1004 and the lower part 1008 are joined such that the lower part 1008 is fixed to a part of the striking face 1020, the toe-side span 1056, and the heel-side span 1060, at least a part of the gap 1064 formed by the rear wall 1032, the toe-side span 1056, and the heel-side span 1060 is filled thereby.

[0245] When the lower part 1008 is combined with the toe-side span 1056 and the heel-side span 1060 of the upper part 1004, the sole 1068 is formed. The sole 1068 is perpendicular to the ground plane 1072. Here, the ground plane 1072 contacts the sole 1068 when the putter head 1000 is in the address position where it hits 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.

[0246] In most embodiments, the sole 1068 of the putter head 1000 can be completely flat. In some embodiments, the sole 1068 of the putter head 1000 can have a slight arch in the direction from the heel 1016 to the toe 1012, and the slight arch can be a linear or polynomial function. In some embodiments, the sole 1068 of the putter head 1000 can have a strong arch in the direction from the heel 1016 to the toe 1012, and the strong arch can 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.

[0247] In some embodiments, the top 1004 can further include a crown (not shown). The crown extends from the striking face 1020 to the back edge 1034 of the bottom 1008. Further, the crown covers at least a portion of the lower opening 1065 and at least a portion of the rear wall 1032, extending from the striking face 1020 to the back edge 1034.

[0248] The crown can further descend from the striking face 1020 to the back edge 1034. In most embodiments, the crown extends from the toe side span 1056 to approximately the inner 25% of the full width of the entire clubhead 1000 and from the heel side span 1060 to approximately the inner 25% of the full width of the entire clubhead 1000. In other embodiments, the crown can extend continuously or discontinuously across the full width of the entire clubhead 1000 from heel to toe. In some embodiments, the crown can extend less than 90% of the full width of the clubhead 1000, less than 90% of the full width of the clubhead 1000, less than 80% of the full width of the clubhead 1000, less than 70% of the full width of the clubhead 1000, less than 60% of the full width of the clubhead 1000, less than 50% of the full width of the clubhead 1000, less than 40% of the full width of the clubhead 1000, or less than 30% of the full width of the clubhead 1000. Further, 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, curved, parabolic, sine wave, or polynomial function.

[0249] Furthermore, the upper portion 1004 of the putter head 1000 can include one or more alignment mechanisms 1044 on the toe side span 1065 and the heel side span 1060. The alignment mechanism 1044 can be a line, a series of lines, a milled trough, a circle, a dashed line, a triangle, a channel, or any one or combination of any other desired alignment mechanisms 1044. The alignment mechanisms 1044 can be evenly spaced across the entire toe side span 1065 and heel side span 1060, a portion of the crown, or the entire crown. The alignment mechanisms 1044 extending along the toe side span 1056 and the heel side span 1060 function to provide a viewer with a visual alignment field extending the width of the golf ball from the rear wall 1032 to the back edge 1034 of the putter 1000. The purpose is to align the entire putter 1000 with the golf ball using these alignment mechanisms 1044 along the toe side span 1056 and the heel side span 1060 and / or the crown.

[0250] The combination of the high-density first material upper portion 1004 and the low-density second material lower portion 1008 creates a high MOI putter 1000 without creating an extremely heavy putter. The large gap 1064 formed by the rear wall 1032 and the spans 1056, 1060 of the upper portion 1004 forms 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 (75 cc to 100 cc) and mass (340 grams to 385 grams).

[0251] The beneficial shift of mass around the putter head 1000 by using the high-density upper portion 1004 and the low-volume low-mass lower portion 1008 increases the MOI of the putter 1000 relative to 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).

[0252] The replacement of one or more claim elements constitutes a rearrangement and not a patch. Further, advantages over the problem, other advantages, and solutions have been described in connection with specific embodiments. However, an advantage over the problem, other advantages, and solutions, and any one or more elements that cause or make apparent any advantage, advantage, or solution, do not constitute a material, essential, or essential feature or element of any or all of the elements of the claims unless such advantage, advantage, solution, or element is expressly stated in such claims.

[0253] The rules for golf are sometimes changed (e.g., new rules may be applied by golf standard organizations and / or governing bodies such as the United States Golf Association (USGA), the Royal & Ancient Golf Club of St Andrews (R&A), etc., or old rules may be abolished or changed), so golf equipment related to the devices, methods, and products described herein may or may not conform to the rules of golf at any given time. Accordingly, golf equipment related to the devices, methods, and products described herein may be published, sold, and / or sold as conforming or non-conforming golf equipment. The devices, methods, and products described herein are not limited in this regard.

[0254] The above examples may be described in connection with the putter-type golf clubs, devices, methods, and manufactured articles described herein. On the other hand, the devices, methods, and products described herein may be applicable to other types of sports equipment such as hockey sticks, tennis rackets, fishing rods, ski stocks, etc.

[0255] Furthermore, the embodiments and limitations described herein are not provided to the public under the doctrine of disclosure if the embodiments and / or limitations are (1) not expressly claimed in the claims and (2) equivalent or potentially equivalent to the recited elements and / or limitations in the claims under the doctrine of equivalents.

[0256] Clause 1: A putter-type golf club head comprising an upper portion and a lower portion, wherein the upper portion is made of a first material having a first density, the lower portion is made of a second material having a second density, the first density is less than the second density, the lower portion includes a front peripheral portion, a toe-side peripheral portion, a heel-side peripheral portion, and a rear peripheral portion, the lower portion further includes an opening bounded by the front peripheral portion, the toe-side peripheral portion, the heel-side peripheral portion, and the rear peripheral portion, the upper portion includes a heel end, a toe end, a striking face, a rear wall, a back edge, a crown, and a bottom face, the toe end is on the opposite side of the heel end, the back edge is on the opposite side of the striking face, the crown extends from the striking face at least partially over the rear wall to the back edge, the bottom face is on the opposite side of the crown extending from the striking face to the back edge, the upper portion is fixed to the lower portion, the upper portion is farther from the ground plane than the lower portion, the heel end overlaps at least a part of the heel-side peripheral portion, the toe end overlaps at least a part of the toe-side peripheral portion, the striking face overlaps at least a part of the front peripheral portion, the crown extends from the striking face to the rear peripheral portion, the lower portion and the upper portion are joined to form a sole, when the golf club head is in the address position, the sole is in contact with the ground plane, the striking face is in contact with a loft face, a loft angle is formed between the loft face and the ground plane, the lower portion constitutes less than 30% of the volume of the golf club head, and the lower portion constitutes more than 50% of the mass of the golf club head, a putter-type golf club head.

[0257] Clause 2: The lower part further includes the toe mass at the joint of the toe side peripheral part and the rear peripheral part, the heel mass at the joint of the heel side peripheral part and the rear peripheral part, the rear mass located on the rear peripheral part and equidistant from the toe side peripheral part and the heel side peripheral part, and the front mass located on the front peripheral part and equidistant from the toe side peripheral part and the heel side peripheral part. The putter-type golf club head according to Clause 1.

[0258] Clause 3: The toe mass, the heel mass, the rear mass, and the front mass are integral with the lower part and extend from the lower part in a direction away from the ground plane and toward the upper part. The putter-type golf club head according to Clause 2.

[0259] Clause 4: The crown of the upper part further includes a toe end mid rail, a heel end mid rail, a toe end cap, and a heel end cap. The putter-type golf club head according to Clause 1.

[0260] Clause 5: The toe end cap is configured to fit with the toe mass, and the heel end cap is configured to fit with the heel mass. The putter-type golf club head according to Clause 4.

[0261] Clause 6: The upper part further includes a first cavity and a second cavity. The first cavity is formed on the lower surface between the striking face and the rear wall and extends in a direction toward the crown. The rear opening is formed on the lower surface adjacent to the back edge and is equidistant from the toe end cap and the heel end cap. The putter-type golf club head according to Clause 5.

[0262] Clause 7: The putter-type golf club head according to clause 6, wherein the first cavity is configured to fit with the front mass, and the second cavity is configured to fit with the rear mass.

[0263] Clause 8: The putter-type golf club head according to clause 4, wherein the toe end mid-rail and the heel end mid-rail descend from the hitting face to the rear peripheral portion.

[0264] Clause 9: The putter-type golf club head according to clause 4, wherein the heel end mid-rail and the toe end mid-rail are provided with one or more alignment mechanisms on the heel end mid-rail and the toe end mid-rail.

[0265] Clause 10: The putter-type golf club head according to clause 9, wherein the one or more alignment mechanisms can be at equal or unequal intervals from the hitting face to the rear peripheral portion.

[0266] Clause 11: The putter-type golf club head according to clause 1, wherein the lower front peripheral portion has a front width measured from the joint of the toe side peripheral portion and the front peripheral portion to the joint of the heel side peripheral portion and the front peripheral portion.

[0267] Clause 12: The putter-type golf club head according to clause 11, wherein the lower rear peripheral portion has a rear width measured from the joint of the toe side peripheral portion and the rear peripheral portion to the joint of the heel side peripheral portion and the rear peripheral portion.

[0268] Clause 13: The putter-type golf club head according to clause 12, wherein the front width is larger than the rear width.

[0269] Clause 14: The putter-type golf club head according to clause 1, wherein one or more alignment mechanisms are arranged on the crown.

[0270] Clause 15: The club head of the putter-type golf club according to Clause 1, wherein the first density of the first material is less than 6.0 g / cc.

[0271] Clause 16: The club head of the putter-type golf club according to Clause 1, wherein the second density of the second material is greater than 7.0 g / cc.

[0272] Clause 17: The club head of the putter-type golf club according to Clause 1, wherein the second density of the second material is at least twice as large as the first density of the first material.

[0273] Clause 18: The club head of the putter-type golf club according to Clause 1, wherein the first material can comprise any one or combination of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 303 stainless steel, 304 stainless steel, stainless steel alloy, tungsten, aluminum, aluminum alloy, ADC-12, or any metal suitable for making a golf club head.

[0274] Clause 19: The club head of the putter-type golf club according to Clause 1, wherein the second material can comprise any one or combination of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 303 stainless steel, 304 stainless steel, stainless steel alloy, tungsten, aluminum, aluminum alloy, ADC-12, or any metal suitable for making a golf club head.

[0275] Clause 20: The club head of the putter-type golf club according to Clause 1, wherein the first material is ADC-12 and the second material is 304 stainless steel.

Claims

1. A putter-type golf club head, It has an upper portion and a lower portion, the upper portion is made from a first material having a first density and the lower portion is made from a second material having a second density; the first density is less than the second density; The lower portion includes a front perimeter, a toe perimeter, a heel perimeter, and a rear perimeter; the lower portion further comprises an opening bounded by the front perimeter, the toe side perimeter, the heel side perimeter, and the rear perimeter; the upper portion includes a heel end, a toe end, a striking face, a rear wall, a back edge, a crown, and a lower surface; the toe end is opposite the heel end and the back edge is opposite the striking face; the crown extends from the striking face over at least a portion of the rear wall to the back edge; the lower surface is opposite a crown that extends from the striking face to the back edge; the upper portion is fixed to the lower portion, the upper portion being further from the ground plane than the lower portion; The heel end overlaps at least a portion of the heel side periphery, The toe end portion overlaps at least a portion of the toe side peripheral portion, the striking face overlies at least a portion of the front perimeter; the crown extends from the striking face to the rear periphery; The lower part and the upper part are joined to form a sole, When the golf club head is in an address position, the sole is in contact with the ground plane; the striking face is in contact with a loft surface, and a loft angle is formed between the loft surface and the ground plane; the lower portion comprises less than 30% of the volume of the golf club head; the lower portion comprises greater than 50% of the mass of the golf club head; Putter type golf club head.

2. The lower portion is a toe mass at a joint between the toe side peripheral portion and the rear peripheral portion; a heel mass at a joint between the heel side peripheral portion and the rear peripheral portion; a rear mass located on the rear perimeter and equidistant from the toe side perimeter and the heel side perimeter; a front mass located on the front periphery and equidistant from the toe side periphery and the heel side periphery; The putter-type golf club head of claim 1 further comprising:

3. 3. The putter-type golf club head of claim 2, wherein the toe mass, the heel mass, the rear mass, and the front mass are integral with the lower portion and extend from the lower portion in a direction away from the ground plane toward the upper portion.

4. 4. The putter-type golf club head of claim 3, wherein the crown of the upper portion further comprises a toe-end mid-rail, a heel-end mid-rail, a toe-end cap, and a heel-end cap.

5. the toe end cap is configured to mate with the toe mass; The putter-type golf club head of claim 4 , wherein the heel end cap is configured to mate with the heel mass.

6. the top further comprises a first cavity and a second cavity; the first cavity is formed in the lower surface between the striking face and the rear wall and extends in a direction toward the crown; 6. The putter-type golf club head of claim 5, wherein the rear opening is formed in the lower surface adjacent the back edge and is equidistant to the toe end cap and the heel end cap.

7. the first cavity is configured to mate with the front mass; The putter-type golf club head of claim 6 , wherein the second cavity is configured to mate with the rear mass.

8. 5. The putter-type golf club head of claim 4, wherein the toe-end mid-rail and the heel-end mid-rail descend from the striking face to the rear perimeter.

9. The putter-type golf club head of claim 4 , wherein the heel-end mid-rail and the toe-end mid-rail include one or more alignment features thereon.

10. The putter-type golf club head of claim 9 , wherein the one or more alignment features can be evenly or unevenly spaced from the striking face to the rear perimeter.

11. 2. The putter-type golf club head of claim 1, wherein the front perimeter of the lower portion comprises a front width measured from a junction of the toe side perimeter and the front perimeter to a junction of the heel side perimeter and the front perimeter.

12. 12. The putter-type golf club head of claim 11, wherein the rear perimeter of the lower portion comprises a rear width measured from the junction of the toe side perimeter and the rear perimeter to the junction of the heel side perimeter and the rear perimeter.

13. The putter-type golf club head of claim 12 , wherein the front width is greater than the rear width.

14. The putter-type golf club head of claim 1 , wherein the one or more alignment features are located on the crown.

15. 2. The putter-type golf club head of claim 1, wherein the first density of the first material is less than 6.0 g / cc.

16. The putter-type golf club head of claim 1 , wherein the second density of the second material is greater than 7.0 g / cc.

17. The putter-type golf club head of claim 1 , wherein the second density of the second material is at least two times greater than the first density of the first material.

18. 2. The putter type golf club head of claim 1, wherein the first material may comprise any one or combination of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 303 stainless steel, 304 stainless steel, stainless steel alloy, tungsten, aluminum, aluminum alloy, ADC-12, or any metal suitable for making a golf club head.

19. 2. The putter type golf club head of claim 1, wherein the second material may comprise any one or combination of 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 303 stainless steel, 304 stainless steel, stainless steel alloy, tungsten, aluminum, aluminum alloy, ADC-12, or any metal suitable for making a golf club head.

20. 2. The putter-type golf club head of claim 1, wherein the first material is ADC-12 and the second material is 304 stainless steel.

Images