Golf club with added bond area ferrule

Abstract

A ferrule for an iron-type golf club has multiple, discrete bonding areas to more securely join a shaft of the club to a hosel of a club head. The ferrule includes at least two discrete bonding areas for joining with the hosel, and a third, discrete bonding area for joining with the shaft. Further, the ferrule includes three shaft-bonding areas that provides a large total shaft-bonding area. The ferrule includes a body section, between an insertion section and extension section, that comprises a transition from the ferrule body to the extension section. The transition may have a steady taper or an abrupt rounding.

Description

GOLF CLUB WITH ADDED BOND AREA FERRULECROSS REFERENCE TO RELATED APPLICATIONS

[0001] This is a continuation-in-part of U.S. Non-Provisional Patent Appl. No. 18 / 470,414, filed September 19, 2023, the entire contents of which are incorporated herein by reference.FIELD OF INVENTION

[0002] This invention generally relates to golf equipment, and more particularly, to ferrules used to join iron-type golf club heads to shafts.BACKGROUND

[0003] A ferrule connects a hosel of an iron-type club head to a shaft to provide a seamless transition between the two. The shaft and the hosel typically have different sized outside diameters, and therefore an exterior of the ferrule may include a transition area that smoothly tapers from the shaft to the hosel to provide an aesthetically pleasing appearance. Additionally, surfaces on the ferrule contact portions of both the hosel and the shaft to provide areas for securing the club head to the shaft. As a player executes a swing, the connection point between the iron-type club head and the shaft can experience significant stresses, and therefore it is important for the ferrule to reliably couple the iron-type club head to the shaft. The overall length of a ferrule is typically short for aesthetics, and therefore there is only a limited amount of area available on the ferrule to bond to the shaft and hosel. Limited bonding area can result in an unreliable connection and can increase the possibility of the club head detaching from the shaft. Therefore, there is a need in the art for a ferrule that more securely joins the club head to the shaft while still maintaining an aesthetically pleasing appearance.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 illustrates a close-up view of conventional, prior art ferrule.

[0005] FIG. 2 illustrates a close-up view of a ferrule according to the present disclosure.

[0006] FIG. 3 illustrates a golf club having a club head connected to a shaft by the ferrule of FIG. 2.

[0007] FIG. 4 illustrates an enlarged detail of the golf club of FIG. 3.

[0008] FIG. 5 illustrates a perspective view of the ferrule of FIG. 2.

[0009] FIG. 6 illustrates an enlarged perspective view of the golf club head of FIG. 3.

[0010] FIG. 7A illustrates an enlarged side view, in cross-section, a golf club head with a golf club connection assembly that includes the ferrule of FIG. 2 and a tip weight.

[0011] FIG. 7B illustrates an enlarged side view, in cross-section, of the golf club of FIG. 3.

[0012] FIG. 8 illustrates a further enlarged side view, in cross-section, of the golf club ofFIG. 3.

[0013] FIG. 9 illustrates a side elevation view, in cross-section, of the ferrule of FIG. 5.

[0014] FIG. 10 illustrates another side elevation view, in cross-section, of the ferrule of FIG.5.

[0015] FIG. 11 illustrates a horizontal microgroove pattern on a shaft exterior surface.

[0016] FIG. 12 illustrates a vertical microgroove pattern on a shaft exterior surface.

[0017] FIG. 13 A illustrates an embodiment of a multi-component ferrule.

[0018] FIG. 13B illustrates another embodiment of the multi-component ferrule.

[0019] FIG. 14A is a perspective view of a ferrule according to the present disclosure.

[0020] FIG. 14B is a side view, in cross-section, of the ferrule of FIG. 14A, connected to a shaft and a hosel.

[0021] FIG. 14C is a side view, in cross-section, of the ferrule of FIG. 14A.

[0022] FIG. 15A is a perspective view of a ferrule according to the present disclosure.

[0023] FIG. 15B is a side view, in cross-section, of the ferrule of FIG. 15A, connected to a shaft and a hosel.

[0024] FIG. 15C is a side view, in cross-section, of the ferrule of FIG. 15 A.

[0025] For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. The same reference numerals in different figures denote the same elements.

[0026] The terms "include," and "have," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises 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.

[0027] The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises 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.

[0028] The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

[0029] The terms “couple,” “coupled,” “couples,” “coupling,” and the like should be broadly understood and refer to connecting two or more elements or signals, electrically, mechanically and / or otherwise.

[0030] The term “bonding strength” as used herein can be the strength of epoxy material at the head-shaft connection or grip-shaft connection. The bonding strength can be quantified by the energy required to break the bonds between the bonding surface and the hosel inner surface or between the bonding surface and the hosel exterior surface or between the bonding surface and the shaft exterior surface.

[0031] The term “epoxy” as used herein can be any adhesive or resin mixture used to bond the shaft to the club head or grip. The epoxy may be applied to the shaft-bonding area and used as means to secure the connection. The epoxy may form bonds between the shaft-bonding area and the hosel inner surface or between the shaft-bonding area and the hosel exterior surface or between the shaft -bonding area and the shaft exterior surface.

[0032] The term “hosel connection juncture” as used herein can be the connection between the hosel and the ferrule. The connection can be used interchangeably with the “connection juncture”.

[0033] The term “tip weight” as used herein can be a cylindrical weighting component that can be inserted into the hosel and held into place with an epoxy material. The tip weight can be formed from a high-density material.

[0034] “Longitudinal axis” as used herein can be the axis extending from a geometric center of the shaft top end to a geometric center of the shaft bottom end. The shaft can be a symmetrical cylinder that is bisected by the longitudinal axis.

[0035] “Normal force” as used herein can be a pulling force applied normal or perpendicular to the cross-sectional area of the shaft. In other words, the normal force can be applied parallel to the shaft longitudinal axis. The normal force may be used interchangeably with the “pushing force” or “pulling force”. The normal force may be applied to a shaft and cause a uniform normal stress over the object’s cross-sectional area.

[0036] Torsional force” as used herein can be a twisting force applied parallel or tangent to the cross-sectional area of the shaft. In other words, the torsional force can be applied perpendicular to the shaft longitudinal axis. The torsional force may mean be used interchangeably with the torque or twisting force. The torsional force may be applied to a shaft and cause a distribution of shear stress over the shaft’s cross-sectional area.

[0037] The term “iron,” as used herein, can, in some embodiments, refer to an iron-type golf club head having a loft angle that is less than approximately 62 degrees, less than approximately 61 degrees, less than approximately 60 degrees, less than approximately 59 degrees, less than approximately 58 degrees, less than approximately 57 degrees, less than approximately 56 degrees, less than approximately 55 degrees, less than approximately 54 degrees, less than approximately 53 degrees, or less than approximately 52 degrees. Further, in many embodiments, the loft angle of the club head is greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, greater than approximately 20 degrees, greater than approximately 21 degrees, greater than approximately 22 degrees, greater than approximately 23 degrees, greater than approximately 24 degrees, or greater than approximately 25 degrees.

[0038] The volume of the iron can be greater than or equal to 20 cubic centimeters (cc) and less than or equal to 80 cubic centimeters (cc). In some embodiments, the volume of the iron can range from 20 to 50 cc, or 50 to 80 cc. In other embodiments, the volume of the iron can rangefrom 20 to 60 cc, 30 to 70 cc, or 40 to 80 cc. For example, the volume of the iron can be 20, 30, 40, 50, 60, 70, or 80 cc.

[0039] In some embodiments, the iron can comprise a total mass ranging between 180 grams and 260 grams, 190 grams and 240 grams, 200 grams and 230 grams, 210 grams and 220 grams, or 215 grams and 220 grams. In some embodiments, the total mass of the club head is 215 grams, 216 grams, 217 grams, 218 grams, 219 grams, or 220 grams.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials similar or equivalent to those described herein can be used in practice or testing of the present invention. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.DETAILED DESCRIPTION

[0041] Described herein are various embodiments of a ferrule for an iron-type golf club which can increase the bonding strength between the hosel, the iron-type golf club head (hereafter also known as “golf club head”), and the shaft. More specifically, the ferrules described herein have increased bonding areas for joining the hosel to the shaft to provide a durable, longer lasting golf club while still maintaining a pleasing sight line.

[0042] The durable connection of the iron-type golf club head is achieved by providing a combination of interacting surfaces between the hosel and the ferrule. These surfaces of the hosel and the ferrule are complementary and provide greater bonding surface interaction, as described below. The ferrule comprises a collar that reaches over and interacts with the surface of the hosel to provide a strong, durable connection.

[0043] An exemplary iron-type golf club 200 is illustrated in FIG. 3. The golf club 200 includes a shaft 220 having a connection end 221 and a grip end. A club head 240 is coupled to the connection end 221, and comprises a body 201, a sole 202, a top 203 opposite the sole 202, atoe 204, a heel 205 opposite the toe, and a hosel 210. The hosel 210 defines a hosel bore 216 and a hosel connection section 219, to which the shaft 220 is coupled by a ferrule 230.

[0044] The hosel can be positioned at the heel of the golf club head and located near the hosel connection juncture. The hosel can comprise an hosel interior surface and a hosel exterior surface. Further, the hosel can comprise a hosel connection section, located on the hosel exterior surface near the top of the hosel, which can provide a first hosel-bonding area between the hosel and the ferrule. A second hosel-bonding area can be provided between the hosel interior surface and an exterior surface of a ferrule inner wall. Additionally, there is a shaft-bonding area between the shaft and the ferrule. A shaft exterior surface and an interior surface of a ferrule inner wall provide the shaft -bonding area. As described in greater detail below, these surfaces are complimentary to one another and can be used to strengthen the bond between the hosel and the ferrule. The seamless transition between the ferrule 230 and the hosel 210 improves aesthetics of the club and reduces air drag around the hosel connection juncture 206 during use.

[0045] Referring to FIGS. 5 and 7B the ferrule 230 can be located at the hosel connection juncture 206, connecting the hosel 210 and the shaft 220 together. The ferrule 230 can comprise a transition section 231 and an insertion section 232. The insertion section 232 can comprise an inner wall 234 and an outer wall 235, with a receptacle 233 defined therebetween. The ferrule has three bonding areas. Two of the bonding areas can be located on either side of the inner wall234 of the ferrule. The inner wall 234 can comprise an exterior surface 236 creating a first hosel- bonding area 246, and an interior surface 237 creating a shaft-bonding area 247. The outer wall235 of the ferrule can provide the third bonding area. The outer wall 235 can comprise an interior surface 239 creating a second hosel-bonding area 248 and an exterior surface 238. The hosel 210 can be connected to the ferrule 230 at the first hosel-bonding area 246 and the second hosel- bonding area 248. The shaft 220 can be connected to the ferrule 230 at the shaft-bonding area 247. The use of these three bonding areas can reduce the likelihood of the shaft detaching from the hosel through impact and prevent misaligning the ferrule for a poor sight line.

[0046] The outer wall 235 of the ferrule can extend straight down from a notch 250 and is sufficiently spaced from the inner wall 234 so that the receptacle 233 is large enough to receivethe hosel connection section 219. The notch 250 acts as a stress reliever to allow the insertion section 232 of the ferrule 230 to flex as it is inserted over the hosel connection section 219. Reducing the flexural stress on the ferrule 230 allows the ferrule 230 and hosel 210 to have a more durable connection. Referring to FIG. 5, the notch 250 can comprise a generally semicircle shape. The notch 250 can define a notch diameter 256 of between 0.40 inch to 0.60 inch. In some embodiment, the notch diameter 256 256 can be 0.40 inch to 0.42 inch, 0.42 inch to 0.44 inch, 0.44 inch to 0.46 inch, 0.46 inch to 0.48 inch, 0.48 inch to 050 inch, 0.50 inch to 0.52 inch, 0.52 inch to 0.54 inch, 0.54 inch to 0.56 inch, 0.56 inch to 0.58 inch, or 0.58 inch to 0.60 inch. In one exemplary embodiment, the notch diameter 256 is 0.49 inch. In other embodiments, the notch 250 can comprise a triangular, rectangular, polygonal or any other suitable shape.

[0047] The connection of the ferrule 230 to the hosel connection section 219 can provide extra surface area for bonding the ferrule 230 to the hosel 210. The outer wall 235 can comprise an outer wall length 265. In some embodiments, the outer wall length 265 can be between 0.30 inch to 1.00 inch. In some embodiments, the outer wall length 265 can be between 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, 0.50 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0.70 inch to 0.80 inch, 0.80 inch to 0.90 inch or 0.90 inch to 1.00 inch. In one exemplary embodiment, the outer wall length 265 is 0.46 inch. As the outer wall length increase so does the available surface area for bonding.

[0048] The outer wall 235 can comprise an outer wall diameter 270. The outer wall diameter 270 can be larger than the first hosel connection section diameter 268 to ensure that the outer wall 235 can smoothly slide over the hosel connection section 219. In some embodiments, the outer wall diameter 270 can be between 0.40 inch and 0.60 inch. In some embodiments, the outer wall diameter 270 can be between 0.40 inch to 0.42 inch, 0.42 inch to 0.44 inch, 0.44 inch to 0.46 inch, 0.46 inch to 0.48 inch, 0.48 inch to 050 inch, 0.50 inch to 0.52 inch, 0.52 inch to 0.54 inch, 0.54 inch to 0.56 inch, 0.56 inch to 0.58 inch, or 0.58 inch to 0.60 inch. The outer wall diameter 270 is designed to complement the second hosel connection section diameter 269 to provide a seamless connection and an aesthetically pleasing golf club.

[0049] The transition section 231 extends away from the ferrule insertion section 232 to provide a seamless and aesthetically pleasing transition between the shaft 220, ferrule 230, and the hosel 210. The transition section 231 can comprise a transition section length 261. In some embodiments, the transition section length 261 can be between 0.5 inch to 1.0 inch. In some embodiments, the transition section length 261 may be between 0.5 inch to 0.6 inch, 0.6 inch to 0.7 inch, 0.7 inch to 0.8 inch, 0.8 inch to 0.9 inch, or 0.9 inch to 1.0 inch. In one exemplary embodiment, the transition section length 261 is 0.7 inch.

[0050] Further to FIG. 9, the ferrule 230 can comprise a transition section outer diameter 241. In some embodiments, the transition section outer diameter 241 can be between 0.20 inch and 1.00 inch. In some embodiments, the transition section outer diameter 241 can be between 0.20 inch to 0.30 inch, 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, 0.50 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0.70 inch to 0.80 inch, 0.80 inch to 0.90 inch, or 0.90 inch to 1.00 inch. In one exemplary embodiment, the transition section outer diameter 241 is 0.53 inch. In another exemplary embodiment, the transition section outer diameter varies between 0.30 inch and 0.55 inch. The transition section 231 can comprise a varying tapered outer diameter 241 to allow both a smooth transition between the shaft, ferrule 230 and hosel, and to allow the ferrule 230 to overlap the hosel.

[0051] The transition section 231 can comprise a transition angle 242 that extends the transition section length 261. In some embodiments, the transition angle 242 can be between 4 degrees and 24 degrees. In some embodiments, the transition angle 242 can be between 4 degrees to 7 degrees, 7 degrees to 10 degrees, 10 degrees to 13 degrees, 13 degrees to 16 degrees, 16 degrees to 19 degrees, 19 degrees to 21 degrees, or 21 degrees to 24 degrees. In one exemplary embodiment, the transition angle 242 is 9 degrees. The transition angle 242 can be constant along the transition section 231 or varying. The transition angle 242 can provide a visually seamless transition between the shaft 220 and the hosel 210.

[0052] A ferrule bore 243 extends through the transition section 231 and into the insertion section 232 for receiving the connection end 221 of the shaft 220. In some embodiments, the ferrule bore 243 stops before the bottom of the insertion section 232 and is not a through hole,but instead a cap extends across the end of the inner wall 234. Further, the ferrule bore 243 can comprise a ferrule bore diameter. In some embodiments, the ferrule bore diameter 244 can be between 0.20 inch and 0.60 inch. In some embodiments, the ferrule bore diameter 244 can be between 0.20 inch to 0.30 inch, 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, or 0.50 inch to 0.60 inch. In one exemplary embodiment, the ferrule bore diameter 244 is 0.30 inches.

[0053] With continued reference to FIG. 9, the ferrule inner wall 234 has an outer diameter 240 sized for insertion into the hosel connection section 219. In some embodiments, the insertion section outer diameter 240 can be between 0.20 inch and 0.60 inch. In some embodiments, the insertion section outer diameter 240 can be between 0.20 inch to 0.30 inch, 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, or 0.50 inch to 0.60 inch. In one exemplary embodiment, the insertion section outer diameter 240 is 0.35 inches. In some embodiments, the insertion section 232 comprises a constant insertion section outer diameter 240. A constant insertion section outer diameter 240 means that the insertion end 231 can easily be fitted within the hosel bore, allowing for a tight seal and an increased likelihood that the insertion end 231 can create an even dispersion of epoxy across the inner wall exterior surface.

[0054] The hosel bore 216 can extend along the hosel axis 215 and is configured to receive the ferrule 230 and the shaft 220. The hosel bore 216 can be recessed into the hosel 210, starting at the hosel connection section 219 and continuing downwards towards the hosel base end 224. A diameter of the hosel bore 216 can be constant from the hosel connection section 219 to the hosel base end 224, or, alternatively, the diameter can vary. The hosel bore 216 can comprise a bore top end 217 and a bore bottom end 218. The bore top end 217 can comprise an open end and the bore bottom end 218 can comprise a closed end. The hosel bore 216 can provide a means of joining the golf club head to the shaft 220 and ferrule 230. Additionally, the hosel bore 216 can comprise the key juncture where the epoxy, the tip weight, and the ferrule all interact.

[0055] The hosel bore 216 can further comprise a hosel bore length, defined herein as the distance from the top end 217 to the bottom end 218 of the bore. In some embodiments, the hosel bore length can be between 0.80 inch to 1.60 inches. In some embodiments, the hosel bore length can be between 0.80 inch to 0.90 inch, 0.90 inch to 1.00 inch, 1.00 inch to 1.10 inches, 1.10inches to 1.20 inches, 1.20 inches to 1.30 inches, 1.30 inches to 1.40 inches, 1.40 inches to 1.50 inches, or 1.50 inches to 1.60 inches. In one exemplary embodiment, the hosel bore length is 1.07 inches. The length of the hosel bore 216 can determine how much of the ferrule inner wall exterior surface 236 surface can act as a bonding area. A long hosel bore can allow for greater bonding area, however, it should be balanced with the overall mass of the club head as creating too long of a hosel bore generates more mass which can affect performance characteristics of the club head, such as center of gravity and moment of inertia of the club head.

[0056] As illustrated in FIG. 6 the hosel connection section 219 is configured to provide a smooth transition with the ferrule 230. The hosel connection end 219 can comprise an annular shoulder 227 joining a first hosel connection outer surface to a second hosel connection outer surface 228. The annular shoulder 227 provides a better, smoother transition from the ferrule to the hosel. Additionally, the annular shoulder 227 acts as a guide when assembling the golf club. The first hosel connection outer surface has a smaller diameter than the second hosel connection outer surface 228 to provide an outer hosel bonding surface for receiving a portion of the ferrule 230, as discussed in greater detail below. The reduced diameter of the first hosel connection outer surface receives a portion of the ferrule 230 to avoid an overhang of the ferrule 230 on top of the hosel 210, as well as to create a large and well-defined bonding area to improve adhesion between the hosel 210 and the ferrule 230. The first hosel connection outer surface can further comprise a hosel connection section length extending from an end of the hosel connection section 219 and the annular shoulder 227. In some embodiments, the hosel connection section length can be between 0.10 inch to 1.00 inch. In some embodiments, the hosel connection section length can be between 0.10 inch to 0.20 inch, 0.20 inch to 0.30 inch, 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, 0.50 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0.70 inch to 0.80 inch, 0.80 inch to 0.90 inch, or 0.90 inch to 1.00 inch. In one exemplary embodiment, the hosel connection section length is 0.41 inch. The hosel connection section length provides a set of surface interactions. The hosel connection section length interacts with both the receptacle, and the ferrule. A long hosel connection section can allow for greater bonding area, however, it should be balanced with the overall mass of the club head as creating too long of a hoselconnection end generates more mass which can affect performance characteristics of the club head, such as center of gravity and moment of inertia of the club head.

[0057] The hosel 210 further can comprise a first hosel thickness, which is the distance between the external surface 214 and the internal surface 213 of the hosel. In some embodiments, the first hosel thickness can be between 0.01 inch and 0.20 inch. In some embodiments, the first hosel thickness can be between 0.01 inch to 0.04 inch, 0.04 inch to 0.07 inch, 0.07 inch to 0.10 inch, 0.10 inch to 0.13 inch, 0.13 inch to 0.16 inch, or 0.16 inch to 0.20 inch. In one exemplary embodiment, the first hosel thickness is 0.06. The first hosel thickness may be constant.

[0058] Additionally, the hosel connection section outer surface can define a second hosel thickness that is less than the first hosel thickness. In some embodiments, the second hosel thickness can be between 0.01 inch to 0.20 inch. In some embodiments, the second hosel thickness can be between 0.01 inch to 0.04 inch, 0.04 inch to 0.07 inch, 0.07 inch to 0.10 inch, 0.10 inch to 0.13 inch, 0.13 inch to 0.16 inch, or 0.16 inch to 0.20 inch. In one exemplary embodiment, the second hosel thickness is 0.02 inches. The hosel connection section thickness is complimentary to the receptacle thickness to ensure a seamless transition between the ferrule and the hosel. The hosel connection section thickness must be thick enough to ensure that the hosel can withstand impact stresses, but also thin enough to ensure the receptacle can be placed over the hosel connection section. As described above, the hosel connection section 219 is thinner than the rest of the hosel 210 due to a reduction in material to fit the receptacle 233. The reduction of material at the hosel connection section 219 can increase discretionary mass.

[0059] This discretionary mass can either be redistributed to another area of the golf club body or can be used to create the ferrule 230 out of a stronger material. In some embodiments, the hosel connection section 219 can have mass savings of between 2.50 grams to 5.50 grams of weight. In some embodiments, the hosel connection section region mass savings can be between 2.50 grams to 2.75 grams, 2.75 grams to 3.00 grams, 3.25 grams to 3.50 grams, 3.50 grams to 3.75 grams, 3.75 grams to 4.00 grams, 4.00 grams to 4.25 grams, 4.25 grams to 4.50 grams, 4.50 grams to 4.75 grams, 4.75 grams to 5.00 grams, 5.00 grams to 5.25 grams, 5.25 grams to 5.75grams, or between 3.75 grams to 4.00 grams. In one exemplary embodiment, the hosel connection section mass savings can be 4.00 grams. The mass savings can lead to a more durable club through the use of a different material, or could be placed back into the club head to alter performance characteristics such as center of gravity and moment of inertia.

[0060] The hosel 210, the ferrule 230, and the shaft 220 can comprise three separate bonding surfaces to increase the bonding area and strength between the hosel 210 and the shaft 220. A first hosel-bonding area 246 is formed between the inner wall exterior surface 236 and the hosel inner surface 213. A second hosel-bonding area 248 is formed between the outer wall interior surface 239 and the hosel connection section 219. A shaft-bonding area 247 is formed between the inner wall interior surface 237 and the shaft 220. The ferrule 230 with two bonding areas for the hosel increases the bonding strength, thereby providing a longer lasting and more durable hosel / ferrule connection. Additionally, the longer inner wall 234 increases the bonding area between the ferrule 230 and the shaft 220. Still further, the ferrule 230 engages both the shaft 220 with the hosel 210. Specifically, the inner and outer walls 234, 235 are complementary to the hosel connection section 219, thereby to more positively position the ferrule 230 within the hosel 210. Additionally, the extended length of the ferrule inner wall 234 better aligns the ferrule 230 with the shaft 220. Further, the addition of an extra bonding area can give a visually pleasing appearance of a seamless transition between the shaft, ferrule, and hosel. The bonding areas decrease the likelihood of an offset arising between the shaft and the ferrule, as well as decreasing the likelihood that the shaft and / or hosel will detach from the ferrule during a golf swing.

[0061] The shaft-bonding area 247 can define a shaft-bonding area length 277 from the top of shaft-bonding area to the bottom of shaft-bonding area. In some embodiments, shaft-bonding area length 277 can be between 1.02 inches to 1.12 inches. In some embodiments, the shaftbonding area length 277 can be between 1.02 inches and 1.03 inches, 1.03 inches and 1.04 inches, 1.04 inches and 1.05 inches, 1.05 inches and 1.06 inches, 1.06 inches and 1.07 inches, 1.07 inches and 1.08 inches, 1.08 inches and 1.09 inches, 1.09 inches and 1.10 inches, 1.10 inches and 1.11 inches or between 1.11 inches and 1.12 inches. In one exemplary embodiment, the shaft-bonding area length 277 is 1.07 inches.

[0062] The first hosel-bonding area 246 can define a first hosel -bonding area length 276 from the top of the first hosel-bonding area to the bottom of first hosel-bonding area. In some embodiments, the first hosel-bonding area length 276 can be between 0.45 inch to 1.25 inch. In some embodiments, the first hosel-bonding area length 276 can be between 0.45 inch and 0.55 inch, 0.55 inch and 0.65 inch, 0.65 inch and 0.75 inch, 0.75 inch and 0.85 inch, 0.85 inch and 0.95 inch, 0.95 inch and 1.05 inch, 1.05 inch and 1.15 inch, or between 1.15 inch and 1.25 inch. In one exemplary embodiment, the first hosel-bonding area length 276 is 0.75 inch. Increased surface area for the epoxy provides a stronger bond between the golf club head 200 and the ferrule 230 and shaft 220 combination to reduce the chance of the club head coming loose through typical use.

[0063] The second hosel-bonding area 248 can define a second hosel-bonding area length 278 from the top of the second hosel-bonding area to the bottom of the second hosel-bonding area. In some embodiments, the second hosel-bonding area length 278 can be between 0.30 inch to 1.00 inch. In some embodiments, the second hosel-bonding area length 278 can be between 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, 0.50 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0.70 inch to 0.80 inch, 0.80 inch to 0.90 inch or 0.90 inch to 1.00 inch. In one exemplary embodiment, the second hosel-bonding area length 278 is 0.47 inch. The second hosel-bonding area 248 is an additional area of adhesion that is not utilized in other ferrules. Increased surface area for the epoxy provides a stronger bond between the golf club head 200 and the ferrule 230 and shaft 220 combination to reduce the chance of the club head coming loose through typical use.

[0064] The second hosel-bonding area length 278 can be approximately half the first hosel- bonding area length 276. In one embodiment, the second hosel-bonding area length 278 can be the same as the first hosel-bonding area length 276. In other embodiments, the second hosel- bonding area length 278 can be longer than the first hosel-bonding area length 276. The second hosel-bonding area length 278 can be constant or varying around the circumference of the ferrule 230. The first hosel-bonding area length 276 can be constant or varying around the circumference of the ferrule 230. Varying the first hosel-bonding area length and second hosel- bonding area length allows for different hosel designs and concentrating the bonding effects of the epoxy.

[0065] Combining the first hosel-bonding area length with the second hosel-bonding area length can lead to the total hosel bonding area length. The total hosel bonding area length can be greater than 0.5 inch. In some embodiments, the total hosel bonding area length can be greater than 0.5 inch, greater than 0.6 inch, greater than 0.7 inch, greater than 0.8 inch, greater than 0.9 inch, greater than 1.0 inch, greater than 1.1 inches, or greater than 1.2 inches. In an exemplary embodiment, the total hosel bonding area length can be greater than 1.1 inches.

[0066] Epoxy is used to bond the hosel to the ferrule, and the shaft to the ferrule. Epoxy can be applied to the first hosel-bonding area 246, shaft-bonding area 247, and second hosel-bonding area 248 to secure the ferrule 230, the hosel 210, and the shaft 220 together. Small gaps are formed between the ferrule 230 and hosel 210, and the ferrule 230 and shaft 220. The gaps ensure that each bond surface has enough room for epoxy to be applied. The ferrule bore diameter and the hosel bore diameter are slightly larger than the shaft diameter and the ferrule inner wall diameter, respectively, to ensure that a small gap is left for epoxy to be applied.

[0067] In some embodiments, the shaft-bonding area 247 can create a shaft bond gap 252, comprising a shaft bond gap width that can be between 0.0070 inch to 0.0100 inch. A shaft bond gap width is provided to ensure that epoxy can be applied between the shaft exterior surface and the ferrule inner wall interior surface. In some embodiments, the shaft bond gap width can be between 0.0070 inch and 0.0075 inch, 0.0075 inch and 0.0080 inch, 0.0080 inch and 0.0085 inch, 0.0085 inch and 0.0090 inch, 0.0090 inch and 0.0095 inch, or 0.0095 inch and 0.0100 inch. In one exemplary embodiment, the shaft bond gap width is 0.0085 inch. The ability for epoxy to be applied between the external surface of the shaft and the ferrule inner wall interior surface can provide a stronger bond through a larger bonding surface. The ability to have a stronger bond can provide a more durable club.

[0068] In some embodiments, the first hosel-bonding area can create a first hosel bond gap 251, comprising a first hosel bond gap width that can be between 0.0070 inch to 0.0100 inch. A first hosel bond gap width is provided to ensure that epoxy can be applied between the hosel interior surface and the ferrule inner wall exterior surface. In some embodiments, the first hosel bond gap width can be between 0.0070 inch and 0.0075 inch, 0.0075 inch and 0.0080 inch,0.0080 inch and 0.0085 inch, 0.0085 inch and 0.0090 inch, 0.0090 inch and 0.0095 inch, or 0.0095 inch and 0.0100 inch. In one exemplary embodiment, the first hosel bond gap width is 0.0085 inch. The ability to bond the interior surface of the hosel with the ferrule inner wall exterior surface can provide a stronger bond through a larger bonding surface. The ability to have a stronger bond can provide a more durable connection of the ferrule 230, to the hosel 210, to the club head 200.

[0069] In some embodiments, the second hosel -bonding area 248 can create a second hosel bond gap 253, comprising a second hosel bond gap width that can be between 0.0070 inch to 0.0100 inch. A second hosel bond gap width is provided to ensure that epoxy can be applied between the hosel connection section and the ferrule outer wall interior surface. In some embodiments, the second hosel bond gap width can be between 0.0070 inch and 0.0075 inch, 0.0075 inch and 0.0080 inch, 0.0080 inch and 0.0085 inch, 0.0085 inch and 0.0090 inch, 0.0090 inch and 0.0095 inch, or 0.0095 inch and 0.0100 inch. In one exemplary embodiment, the second hosel bond gap width is 0.0085 inch. Second hosel bond gap 253 provides an additional bonding option for the ferrule, allowing for a stronger connection and decreasing the likelihood that the ferrule and hosel will separate from impact stresses.

[0070] First hosel bond gap 251, shaft bond gap 252, and second hosel bond gap 253 can comprise the same width. In one embodiment, the first hosel bond gap 251 can comprise a larger width than shaft bond gap 252 and second hosel bond gap 253. In other embodiments, shaft bond gap 252 can comprise a larger width than first hosel bond gap 251 and second hosel bond gap 253. In other embodiments, first hosel bond gap 251 can comprise a constant or varying width around the circumference of the ferrule 230. Shaft bond gap 252 can comprise a constant or varying width around the circumference of the ferrule 230. Second hosel bond gap 253 can comprise a constant or varying width around the circumference of the ferrule 230.

[0071] Referring to FIG. 4, the ferrule 230 can bond with both the hosel 210 and the shaft 220 to provide a secure, strong bond. In some embodiments, the ferrule 230 can see an increase in bond strength between 30% to 60%. In some embodiments, the ferrule 230 bond strength increase can be between 30% - 35%, 35% - 40%, 40% - 45%, 45% - 50%, 50% - 55%, or 55% -60%. In one exemplary embodiment, the ferrule 230 can see an increase in the strength of the hosel connection juncture 206 by 50%.

[0072] Additionally, the first hosel bonding area can comprise a first surface area, the second hosel bonding area can comprise a second surface area, and the shaft bonding area can comprise a third surface area. Combining all three surface areas can create a total surface area. The total surface area can be between 1.35 in2and 1.70 in2. In some embodiments, the total surface area can be between 1.35 in2to 1.40 in2, 1.40 in2to 1.45 in2, 1.45 in2to 1.50 in2, 1.50 in2to 1.55 in2, 1.55 in2to 1.60 in2, 1.60 in2to 1.65 in2, or 1.65 in2to 1.70 in2.

[0073] Further, the first hosel bonding area and the second hosel bonding area can comprise a yield force, wherein the hosel and the ferrule bond is disconnected. This yield is related to the strength of the epoxy bonding the ferrule and hosel. This yield force can be between 3,500 lbs and 5,500 lbs. In some embodiments, the yield force can be between 3,500 lbs to 3,700 lbs, 3,700 lbs to 3,900 lbs, 3,900 lbs to 4,100 lbs, 4,100 lbs to 4,300 lbs, 4,300 lbs to 4,500 lbs, 4,500 lbs to 4,700 lbs, 4,700 lbs to 4,900 lbs, 4,900 lbs to 5,100 lbs, 5,100 lbs to 5,300 lbs, or 5,300 lbs to 5,500 lbs.

[0074] The ferrule 230 can be made from various materials. In one embodiment, the material is a lightweight plastic acrylonitrile butadiene styrene. A lightweight material enables moving weight to other optimal positions for improved swing weighting, moment of inertia, and center of gravity location. Another embodiment utilizes aluminum, which is a lightweight metal. By utilizing the hosel connection section 219, the small amount of mass saved can be redistributed into either the body 201 or the ferrule 230. Should it be redistributed into the ferrule 230, then a different material, such as aluminum, can be used. The aluminum embodiment provides a stronger structure and thereby a stronger joint for the overall golf club. Further, the ferrule 230 may be fabricated using other metallic or plastic materials. In other embodiments, the ferrule 230 may consist of multiple materials.

[0075] An exemplary iron-type golf club 300 is illustrated in FIGS. 14A-14C. The golf club 300 includes a shaft 320 having a connection end and a grip end. A club head 300 is coupled to the connection end, and comprises a body, a sole, a top opposite the sole, a toe, a heel oppositethe toe, and a hosel 310. The hosel 310 defines a hosel bore 316 and a hosel connection section 319, to which the shaft 320 is coupled by a ferrule 330.

[0076] Referring to FIG. 14A, the ferrule 330 can be located at the hosel connection juncture, connecting the hosel 310 and the shaft 320 together. The ferrule 330 can comprise a body section (or the transition section) 331, an insertion section 332 and an extension section 380 projecting from the body section opposite the insertion section 332. The body section 331 can provide a seamless transition between the ferrule 330, the shaft 320 and the hosel 310 improving aesthetics of the club and reducing air drag around the hosel connection juncture during use.

[0077] As shown in FIG. 14C, the insertion section 332 extends between a first imaginary reference line Li and a second imaginary reference line L2. The body section 331 extends between the second imaginary reference line L2 and a third imaginary reference line L3. Lastly, the extension section 380 extends between the third imaginary reference line L3 and a fourth imaginary reference line L4.

[0078] The insertion section 332 can comprise an inner wall 334 and an outer wall 335, with a receptacle 333 defined therebetween. The extension section 380 can comprise an inner wall and an outer wall. The body section can comprise a body interior surface and a body exterior surface.

[0079] The transition section 331 extends away from the insertion section 332 to provide a seamless and aesthetically pleasing transition between the shaft 320, ferrule 330, and the hosel 310. The transition section 331 can comprise a transition section length. In some embodiments, the transition section length 261 can be between 0.5 inch to 1.0 inch. In some embodiments, the transition section length 261 may be between 0.5 inch to 0.6 inch, 0.6 inch to 0.7 inch, 0.7 inch to 0.8 inch, 0.8 inch to 0.9 inch, or 0.9 inch to 1.0 inch. In one exemplary embodiment, the transition section length is 0.7 inch.

[0080] Further to FIG. 14A, the ferrule 330 can comprise a transition section outer diameter. In some embodiments, the transition section outer diameter can be between 0.20 inch and 1.00 inch. In some embodiments, the transition section outer diameter can be between 0.20 inch to0.30 inch, 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, 0.50 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0.70 inch to 0.80 inch, 0.80 inch to 0.90 inch, or 0.90 inch to 1.00 inch. In one exemplary embodiment, the transition section outer diameter is 0.53 inch. In another exemplary embodiment, the transition section outer diameter varies between 0.30 inch and 0.55 inch. The transition section 231 can comprise a varying tapered outer diameter to allow both a smooth transition between the shaft, ferrule 330 and hosel, and to allow the ferrule 330 to overlap the hosel.

[0081] The transition section 331 can comprise a transition angle that extends the transition section length. In some embodiments, the transition angle can be between 4 degrees and 24 degrees. In some embodiments, the transition angle can be between 4 degrees to 7 degrees, 7 degrees to 10 degrees, 10 degrees to 13 degrees, 13 degrees to 16 degrees, 16 degrees to 19 degrees, 19 degrees to 21 degrees, or 21 degrees to 24 degrees. In one exemplary embodiment, the transition angle is 9 degrees. The transition angle can be constant along the transition section 331 or varying. The transition angle can provide a visually seamless transition between the shaft 320 and the hosel 310.

[0082] The hosel can be positioned at the heel of the golf club head and located near the hosel connection juncture. The hosel can comprise an hosel interior surface and a hosel exterior surface. Further, the hosel can comprise a hosel connection section, located on the hosel exterior surface near the top of the hosel, which can provide a first hosel-bonding area between the hosel and the ferrule. A second hosel-bonding area can be provided between the hosel interior surface and an exterior surface of a ferrule inner wall. Additionally, there can be multiple shaft-bonding areas between the shaft and the ferrule. A shaft exterior surface and an interior surface of a ferrule inner wall can provide the shaft-bonding areas. As described in greater detail below, these surfaces are complimentary to one another and can be used to strengthen the bond between the hosel and the ferrule. The use of these bonding areas can reduce the likelihood of the shaft detaching from the hosel through impact and prevent misaligning the ferrule for a poor sight line.

[0083] The connection of the ferrule 330 to the hosel connection section 319 can provide increased surface area for bonding the ferrule 330 to the hosel 310. The outer wall 335 cancomprise an outer wall length. In some embodiments, the outer wall length can be between 0.30 inch to 1.00 inch. In some embodiments, the outer wall length can be between 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, 0.50 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0.70 inch to 0.80 inch, 0.80 inch to 0.90 inch or 0.90 inch to 1.00 inch. In one exemplary embodiment, the outer wall length is 0.50 inch. As the outer wall length increases so does the available surface area for bonding.

[0084] The outer wall 335 can comprise an outer wall diameter. The outer wall diameter can be larger than the first hosel connection section diameter to ensure that the outer wall 335 can smoothly slide over the hosel connection section 319. In some embodiments, the outer wall diameter can be between 0.40 inch and 0.60 inch. In some embodiments, the outer wall diameter can be between 0.40 inch to 0.42 inch, 0.42 inch to 0.44 inch, 0.44 inch to 0.46 inch, 0.46 inch to 0.48 inch, 0.48 inch to 050 inch, 0.50 inch to 0.52 inch, 0.52 inch to 0.54 inch, 0.54 inch to 0.56 inch, 0.56 inch to 0.58 inch, or 0.58 inch to 0.60 inch. The outer wall diameter is designed to complement the second hosel connection section diameter to provide a seamless connection and an aesthetically pleasing golf club.

[0085] A ferrule bore extends through the body section 331, the insertion section 332 and the extension section 380 receiving the connection end of the shaft 320. In some embodiments, the ferrule bore stops before the bottom of the insertion section 332 and is not a through hole, but instead a cap extends across the end of the inner wall 334. Further, the ferrule bore can comprise a ferrule bore diameter. In some embodiments, the ferrule bore diameter can be between 0.20 inch and 0.60 inch. In some embodiments, the ferrule bore diameter can be between 0.20 inch to 0.30 inch, 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, or 0.50 inch to 0.60 inch. In one exemplary embodiment, the ferrule bore diameter is 0.30 inches.

[0086] Referring to FIG. 14A, the ferrule inner wall 334 has an outer diameter sized for insertion into the hosel connection section 319. In some embodiments, the insertion section outer diameter can be between 0.20 inch and 0.60 inch. In some embodiments, the insertion section outer diameter can be between 0.20 inch to 0.30 inch, 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, or 0.50 inch to 0.60 inch. In one exemplary embodiment, the insertion section outerdiameter is 0.35 inches. In some embodiments, the insertion section 332 comprises a constant insertion section outer diameter. A constant insertion section outer diameter means that the insertion end 331 can easily be fitted within the hosel bore, allowing for a tight seal and an increased likelihood that the insertion end 331 can create an even dispersion of epoxy across the inner wall exterior surface.

[0087] The hosel bore can extend along the hosel axis and is configured to receive the ferrule 330 and the shaft 320. The hosel bore can be recessed into the hosel 310, starting at the hosel connection section 319 and continuing downwards towards the hosel base end. A diameter of the hosel bore can be constant from the hosel connection section 319 to the hosel base end, or, alternatively, the diameter can vary. The hosel bore can comprise a bore top end and a bore bottom end. The bore top end can comprise an open end and the bore bottom end can comprise a closed end. The hosel bore can provide a means of joining the golf club head to the shaft 320 and ferrule 330. Additionally, the hosel bore can comprise the key juncture where the epoxy, the tip weight, and the ferrule all interact.

[0088] The hosel bore can further comprise a hosel bore length, defined herein as the distance from the top end to the bottom end of the bore. In some embodiments, the hosel bore length can be between 0.80 inch to 1 .60 inches. In some embodiments, the hosel bore length can be between 0.80 inch to 0.90 inch, 0.90 inch to 1.00 inch, 1.00 inch to 1.10 inches, 1.10 inches to 1.20 inches, 1.20 inches to 1.30 inches, 1.30 inches to 1.40 inches, 1.40 inches to 1.50 inches, or 1.50 inches to 1.60 inches. In one exemplary embodiment, the hosel bore length is 1.07 inches. The length of the hosel bore can determine how much of the ferrule inner wall exterior surface 336 surface can act as a bonding area. A long hosel bore can allow for greater bonding area, however, it should be balanced with the overall mass of the club head as creating too long of a hosel bore generates more mass which can affect performance characteristics of the club head, such as center of gravity and moment of inertia of the club head.

[0089] As illustrated in FIG. 14A the hosel connection section 319 is configured to provide a smooth transition with the ferrule 330. The hosel connection end 319 can comprise an annular shoulder 327 joining a first hosel connection outer surface to a second hosel connection outersurface. The annular shoulder 327 provides a better, smoother transition from the ferrule to the hosel. Additionally, the annular shoulder 327 acts as a guide when assembling the golf club. The first hosel connection outer surface has a smaller diameter than the second hosel connection outer surface to provide an outer hosel bonding surface for receiving a portion of the ferrule 330, as discussed in greater detail below. The reduced diameter of the first hosel connection outer surface receives a portion of the ferrule 330 to avoid an overhang of the ferrule 330 on top of the hosel 310, as well as to create a large and well-defined bonding area to improve adhesion between the hosel 310 and the ferrule 330. The first hosel connection outer surface can further comprise a hosel connection section length extending from an end of the hosel connection section 319 and the annular shoulder 327. In some embodiments, the hosel connection section length can be between 0.10 inch to 1.00 inch. In some embodiments, the hosel connection section length can be between 0.10 inch to 0.20 inch, 0.20 inch to 0.30 inch, 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, 0.50 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0.70 inch to 0.80 inch, 0.80 inch to 0.90 inch, or 0.90 inch to 1.00 inch. In one exemplary embodiment, the hosel connection section length is 0.41 inch. The hosel connection section length provides a set of surface interactions. The hosel connection section length interacts with both the receptacle, and the ferrule. A long hosel connection section can allow for greater bonding area, however, it should be balanced with the overall mass of the club head as creating too long of a hosel connection end generates more mass which can affect performance characteristics of the club head, such as center of gravity and moment of inertia of the club head.

[0090] The hosel 310 further can comprise a first hosel thickness, which is the distance between the external surface and the internal surface of the hosel. In some embodiments, the first hosel thickness can be between 0.01 inch and 0.20 inch. In some embodiments, the first hosel thickness can be between 0.01 inch to 0.04 inch, 0.04 inch to 0.07 inch, 0.07 inch to 0.10 inch, 0.10 inch to 0.13 inch, 0.13 inch to 0.16 inch, or 0.16 inch to 0.20 inch. In one exemplary embodiment, the first hosel thickness is 0.06. The first hosel thickness may be constant.

[0091] Additionally, the hosel connection section outer surface can define a second hosel thickness that is less than the first hosel thickness. In some embodiments, the second hosel thickness can be between 0.01 inch to 0.20 inch. In some embodiments, the second hoselthickness can be between 0.01 inch to 0.04 inch, 0.04 inch to 0.07 inch, 0.07 inch to 0.10 inch, 0.10 inch to 0.13 inch, 0.13 inch to 0.16 inch, or 0.16 inch to 0.20 inch. In one exemplary embodiment, the second hosel thickness is 0.02 inches. The hosel connection section thickness is complimentary to the receptacle thickness to ensure a seamless transition between the ferrule and the hosel. The hosel connection section thickness must be thick enough to ensure that the hosel can withstand impact stresses, but also thin enough to ensure the receptacle can be placed over the hosel connection section. As described above, the hosel connection section 319 is thinner than the rest of the hosel 310 due to a reduction in material to fit the receptacle 333. The reduction of material at the hosel connection section 319 can increase discretionary mass.

[0092] This discretionary mass can either be redistributed to another area of the golf club body or can be used to create the ferrule 330 out of a stronger material. In some embodiments, the hosel connection section 319 can have mass savings of between 2.50 grams to 5.50 grams of weight. In some embodiments, the hosel connection section region mass savings can be between 2.50 grams to 2.75 grams, 2.75 grams to 3.00 grams, 3.25 grams to 3.50 grams, 3.50 grams to 3.75 grams, 3.75 grams to 4.00 grams, 4.00 grams to 4.25 grams, 4.25 grams to 4.50 grams, 4.50 grams to 4.75 grams, 4.75 grams to 5.00 grams, 5.00 grams to 5.25 grams, 5.25 grams to 5.75 grams, or between 3.75 grams to 4.00 grams. In one exemplary embodiment, the hosel connection section mass savings can be 4.00 grams. The mass savings can lead to a more durable club through the use of a different material, or could be placed back into the club head to alter performance characteristics such as center of gravity and moment of inertia.

[0093] J ? hosel 310, the ferrule 330, and the shaft 320 can comprise increased bonding area and strength between the hosel 310 and the shaft 320. A first hosel-bonding area 346 is formed by the inner wall exterior surface 336. A second hosel-bonding area 348 is formed by the outer wall interior surface 339. A first shaft-bonding area SBi, a second shaft-bonding area SB2, and a third shaft-bonding area SB3 can be formed by the inner wall interior surface. The first shaftbonding area can be formed by an interior surface of the body section. The second shaft -bonding area can be formed by an interior surface of the insertion section. The third shaft-bonding area can be formed by an interior surface of the extension surface. The ferrule 330 with two bonding areas for the hosel increases the bonding strength, thereby providing a longer lasting and moredurable hosel / ferrule connection. Additionally, the longer inner wall 334 increases the bonding area between the ferrule 330 and the shaft 320. Still further, the ferrule 330 engages both the shaft 320 with the hosel 310. Specifically, the inner and outer walls 334, 335 are complementary to the hosel connection section 319, thereby to more positively position the ferrule 330 within the hosel 310. Additionally, the extended length of the ferrule inner wall 334 better aligns the ferrule 330 with the shaft 320. Further, increasing the bonding area can give a visually pleasing appearance of a seamless transition between the shaft, ferrule, and hosel. The bonding areas decrease the likelihood of an offset arising between the shaft and the ferrule, as well as decreasing the likelihood that the shaft and / or hosel will detach from the ferrule during a golf swing.

[0094] The sum of the first shaft-bonding area SBi„ the second shaft-bonding area SB2,, and the third shaft bonding area SB3 creates total shaft-bonding area. This total shaft-bonding area allows for the shaft 320 to be coupled to the ferrule 330. Further, the total shaft-bonding area of embodiment 300 is larger than the total shaft-bonding area of embodiment 200. The total shaft bonding may be between 2.0 in2and 3.0 in2. In some embodiments, the total shaft bonding area may be between 2.0 in2and 2.1 in2, between 2.1 in2and 2.2 in2, between 2.2 in2and 2.3 in2, between 2.3 in2and 2.4 in2, between 2.4 in2and 2.5 in2, between 2.5 in2and 2.6 in2, between 2.6 in2and 2.7 in2, between 2.7 in2and 2.8 in2, between 2.8 in2and 2.9 in2, or between 2.9 in2and 3.0 in2.

[0095] The first shaft-bonding area SBi corresponds to the body section of the ferrule 330 that is coupled to the shaft 320. The first shaft-bonding area SBi comprises a bonding area between 0.55 in2and 0.95 in2. In some embodiments, the first shaft-bonding area may be between 0.55 in2and 0.65 in2, between 0.65 in2and 0.75 in2, between 0.75 in2and 0.85 in2, or between 0.85 in2and 0.95 in2.

[0096] The second shaft -bonding area SB2 corresponds to the insertion section of the ferrule 330 that is coupled to the shaft 320. This includes the closed base of the ferrule 330. The second shaft-bonding area SB2 comprises a bonding area between 0.55 in2and 1.05 in2. In some embodiments, the first shaft-bonding area may be between 0.55 in2and 0.65 in2, between 0.65in2and 0.75 in2, between 0.75 in2and 0.85 in2, between 0.85 in2and 0.95 in2, or between 0.95 in2and 1.05 in2.

[0097] The third shaft-bonding area SB3 corresponds to the extension section of the ferrule 330 that is coupled to the shaft 320. The third shaft-bonding area SB3 may vary based on the size of the taper in the body section. A smaller taper will yield a larger extension section and therefore a larger third shaft-bonding area SB3. The third shaft-bonding area SB3 comprises a bonding area between 0.70 in2and 1.1 in2. In some embodiments, the first shaft-bonding area may be between 0.70 in2and 0.80 in2, between 0.80 in2and 0.90 in2, between 0.90 in2and 1.00 in2, or between 1.00 in2and 1.10 in2. This area in particular provides additional bonding strength over a ferrule alone.

[0098] The shaft-bonding areas SBi, SB2, SB3 can define a total shaft-bonding area length extending in a direction along an axis of the ferrule bore. In some embodiments, total shaftbonding area length can be between 1.5 inches to 2.5 inches. In some embodiments, the total shaft-bonding area length can be between 1.5 inches and 1.6 inches, 1.6 inches and 1.7 inches, 1.7 inches and 1.8 inches, 1.8 inches and 1.9 inches, 1.9 inches and 2.0 inches, 2.0 inches and 2.1 inches, 2.1 inches and 2.2 inches, 2.2 inches and 2.3 inches, 2.3 inches and 2.4 inches or between 2.4 inches and 2.5 inches. In one exemplary embodiment, the total shaft-bonding area length is 2.0 inches.

[0099] The first hosel -bonding area 346 can define a first hosel-bonding area length from the top of the first hosel-bonding area to the bottom of first hosel-bonding area. In some embodiments, the first hosel-bonding area length can be between 0.45 inch to 1.25 inch. In some embodiments, the first hosel-bonding area length can be between 0.45 inch and 0.55 inch, 0.55 inch and 0.65 inch, 0.65 inch and 0.75 inch, 0.75 inch and 0.85 inch, 0.85 inch and 0.95 inch, 0.95 inch and 1.05 inch, 1.05 inch and 1.15 inch, or between 1.15 inch and 1.25 inch. In one exemplary embodiment, the first hosel-bonding area length is 0.75 inch. Increased surface area for the epoxy provides a stronger bond between the golf club head 300 and the ferrule 330 and shaft 320 combination to reduce the chance of the club head coming loose through typical use.

[0100] The second hosel-bonding area 348 can define a second hosel-bonding area length from the top of the second hosel-bonding area to the bottom of the second hosel-bonding area. In some embodiments, the second hosel-bonding area length can be between 0.30 inch to 1.00 inch. In some embodiments, the second hosel-bonding area length can be between 0.30 inch to 0.40 inch, 0.40 inch to 0.50 inch, 0.50 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0.70 inch to 0.80 inch, 0.80 inch to 0.90 inch or 0.90 inch to 1.00 inch. In one exemplary embodiment, the second hosel- bonding area length is 0.47 inch. The second hosel-bonding area 348 is an additional area of adhesion that is not utilized in other ferrules. Increased surface area for the epoxy provides a stronger bond between the golf club head 300 and the ferrule 330 and shaft 320 combination to reduce the chance of the club head coming loose through typical use.

[0101] The second hosel-bonding area length can be approximately half the first hosel- bonding area length. In one embodiment, the second hosel-bonding area length can be the same as the first hosel-bonding area length. In other embodiments, the second hosel-bonding area length can be longer than the first hosel-bonding area length. The second hosel-bonding area length can be constant or varying around the circumference of the ferrule 330. The first hosel- bonding area length can be constant or varying around the circumference of the ferrule 330. Varying the first hosel-bonding area length and second hosel-bonding area length allows for different hosel designs and concentrating the bonding effects of the epoxy.

[0102] Combining the first hosel-bonding area length with the second hosel-bonding area length can lead to the total hosel bonding area length. The total hosel bonding area length can be greater than 0.5 inch. In some embodiments, the total hosel bonding area length can be greater than 0.5 inch, greater than 0.6 inch, greater than 0.7 inch, greater than 0.8 inch, greater than 0.9 inch, greater than 1.0 inch, greater than 1.1 inches, or greater than 1.2 inches. In an exemplary embodiment, the total hosel bonding area length can be greater than 1.1 inches.

[0103] Epoxy is used to bond the hosel to the ferrule, and the shaft to the ferrule. Epoxy can be applied to the first hosel-bonding area 346, shaft-bonding areas SBi. SB2, SB3, and second hosel-bonding area 348 to secure the ferrule 330, the hosel 310, and the shaft 320 together. Small gaps are formed between the ferrule 330 and hosel 310, and the ferrule 330 and shaft 320. Thegaps ensure that each bond surface has enough room for epoxy to be applied. The ferrule bore diameter and the hosel bore diameter are slightly larger than the shaft diameter and the ferrule inner wall diameter, respectively, to ensure that a small gap is left for epoxy to be applied.

[0104] In some embodiments, the ferrule bore is sized to create a shaft bond gap, comprising a shaft bond gap width that can be between 0.0070 inch to 0.0100 inch. A shaft bond gap width is provided to ensure that epoxy can be applied between the shaft exterior surface and the ferrule inner wall interior surface. In some embodiments, the shaft bond gap width can be between 0.0070 inch and 0.0075 inch, 0.0075 inch and 0.0080 inch, 0.0080 inch and 0.0085 inch, 0.0085 inch and 0.0090 inch, 0.0090 inch and 0.0095 inch, or 0.0095 inch and 0.0100 inch. In one exemplary embodiment, the shaft bond gap width is 0.0085 inch. The ability for epoxy to be applied between the external surface of the shaft and the ferrule inner wall interior surface can provide a stronger bond through a larger bonding surface. The ability to have a stronger bond can provide a more durable club.

[0105] In some embodiments, the first hosel-bonding area can create a first hosel bond gap, comprising a first hosel bond gap width that can be between 0.0070 inch to 0.0100 inch. A first hosel bond gap width is provided to ensure that epoxy can be applied between the hosel interior surface and the ferrule inner wall exterior surface. In some embodiments, the first hosel bond gap width can be between 0.0070 inch and 0.0075 inch, 0.0075 inch and 0.0080 inch, 0.0080 inch and 0.0085 inch, 0.0085 inch and 0.0090 inch, 0.0090 inch and 0.0095 inch, or 0.0095 inch and 0.0100 inch. In one exemplary embodiment, the first hosel bond gap width is 0.0085 inch. The ability to bond the interior surface of the hosel with the ferrule inner wall exterior surface can provide a stronger bond through a larger bonding surface. The ability to have a stronger bond can provide a more durable connection of the ferrule 330, to the hosel 310, to the club head 300.

[0106] In some embodiments, the second hosel-bonding area 348 can create a second hosel bond gap, comprising a second hosel bond gap width that can be between 0.0070 inch to 0.0100 inch. A second hosel bond gap width is provided to ensure that epoxy can be applied between the hosel connection section and the ferrule outer wall interior surface. In some embodiments, the second hosel bond gap width can be between 0.0070 inch and 0.0075 inch, 0.0075 inch and0.0080 inch, 0.0080 inch and 0.0085 inch, 0.0085 inch and 0.0090 inch, 0.0090 inch and 0.0095 inch, or 0.0095 inch and 0.0100 inch. In one exemplary embodiment, the second hosel bond gap width is 0.0085 inch. Second hosel bond gap provides an additional bonding option for the ferrule, allowing for a stronger connection and decreasing the likelihood that the ferrule and hosel will separate from impact stresses.

[0107] First hosel bond gap, shaft bond gap, and second hosel bond gap can comprise the same width. In one embodiment, the first hosel bond gap can comprise a larger width than shaft bond gap and second hosel bond gap. In other embodiments, shaft bond gap can comprise a larger width than first hosel bond gap and second hosel bond gap. In other embodiments, first hosel bond gap can comprise a constant or varying width around the circumference of the ferrule 330. Shaft bond gap can comprise a constant or varying width around the circumference of the ferrule 330. Second hosel bond gap can comprise a constant or varying width around the circumference of the ferrule 330.

[0108] Referring to FIGS. 14B and 15B, the ferrule 330 can bond with both the hosel 310 and the shaft 320 to provide a secure, strong bond. In some embodiments, the ferrule 330 can see an increase in bond strength between 20% to 40%. In some embodiments, the ferrule 330 bond strength increase can be between 20% - 25%, 25% - 30%, 30% - 35%, or 35% - 40%. In one exemplary embodiment, the ferrule 230 can see an increase in the strength of the hosel connection juncture by 26%.

[0109] Additionally, a sum of the multiple shaft bonding areas create a total surface area. The total surface area can be between 1.35 in2and 1.70 in2. In some embodiments, the total surface area can be between 1.35 in2to 1.40 in2, 1.40 in2to 1.45 in2, 1.45 in2to 1.50 in2, 1.50 in2to 1.55 in2, 1.55 in2to 1.60 in2, 1.60 in2to 1.65 in2, or 1.65 in2to 1.70 in2.

[0110] Further, the first hosel bonding area and the second hosel bonding area can comprise a yield force, wherein the hosel and the ferrule bond is disconnected. This yield is related to the strength of the epoxy bonding the ferrule and hosel. This yield force can be between 3,500 lbs and 5,500 lbs. In some embodiments, the yield force can be between 3,500 lbs to 3,700 lbs, 3,700 lbs to 3,900 lbs, 3,900 lbs to 4,100 lbs, 4,100 lbs to 4,300 lbs, 4,300 lbs to 4,500 lbs, 4,500 lbs to4,700 lbs, 4,700 lbs to 4,900 lbs, 4,900 lbs to 5,100 lbs, 5,100 lbs to 5,300 lbs, or 5,300 lbs to 5,500 lbs.[0U1] The ferrule 330 can be made from various materials. In one embodiment, the material is a lightweight plastic acrylonitrile butadiene styrene. A lightweight material enables moving weight to other optimal positions for improved swing weighting, moment of inertia, and center of gravity location. Another embodiment utilizes aluminum, which is a lightweight metal. By utilizing the hosel connection section 319, the small amount of mass saved can be redistributed into either the body or the ferrule 330. Should it be redistributed into the ferrule 330, then a different material, such as aluminum, can be used. The aluminum embodiment provides a stronger structure and thereby a stronger joint for the overall golf club. Further, the ferrule 330 may be fabricated using other metallic or plastic materials. In other embodiments, the ferrule 330 may consist of multiple materials.

[0112] Referring to FIG. 14A, the outer wall 335 of the ferrule can extend straight down from a notch 350 and is sufficiently spaced from the inner wall 334 so that the receptacle 333 is large enough to receive the hosel connection section 319. The notch 350 acts as a stress reliever to allow the insertion section 332 of the ferrule 330 to flex as it is inserted over the hosel connection section 319. Reducing the flexural stress on the ferrule 330 allows the ferrule 330 and hosel 310 to have a more durable connection. The notch 350 can comprise a generally semicircle shape. The notch 350 can define a notch diameter of between 0.40 inch to 0.60 inch. In some embodiments, the notch diameter can be 0.40 inch to 0.42 inch, 0.42 inch to 0.44 inch, 0.44 inch to 0.46 inch, 0.46 inch to 0.48 inch, 0.48 inch to 050 inch, 0.50 inch to 0.52 inch, 0.52 inch to 0.54 inch, 0.54 inch to 0.56 inch, 0.56 inch to 0.58 inch, or 0.58 inch to 0.60 inch. In one exemplary embodiment, the notch diameter is 0.49 inch. In other embodiments, the notch 350 can comprise a triangular, rectangular, polygonal or any other suitable shape.

[0113] In another embodiment, illustrated in FIGS. 15A-15C, the ferrule 430 comprises a body section that ends in an abrupt rounding, creating a shorter, cylindrical shape. This abrupt rounding permits a longer extension section than the previous ferrule 330. The ferrule 430 canotherwise be similar to the ferrule 330 described above, comprising a body section, an insertion section, and an extension section, with components increasing bond area.OTHER FEATURES

[0114] The embodiments described above can be combined with other features to further increase the surface area available for bonding, the bonding strength, or help adjust the overall performance of the club head.

[0115] The ferrule 230 can further comprise one or more relief ports 254. A relief port 254 provides a passageway for air and adhesive to flow through, as the ferrule 230 is inserted on the hosel connection end 219. The relief port 254 can extend from the receptacle 233 to the outer wall exterior surface and / or the transition section exterior surface. The one or more relief ports 254 can comprise a generally circular shape. In other embodiments, the one or more relief ports 254 can comprise a triangular, rectangular, polygonal or any other suitable shape.

[0116] The one or more relief ports 254 can comprise a relief port diameter. In some embodiments, the relief port diameter can be between 0.01 inch and 0.10 inch. In some embodiments, the relief port diameter can be between 0.01 inch to 0.02 inch, 0.02 inch to 0.03 inch, 0.03 inch to 0.04 inch, 0.04 inch to 0.05 inch, 0.05 inch to 0.06 inch, 0.06 inch to 0.07 inch, 0.07 inch to 0.08 inch, 0.08 inch to 0.09 inch, or 0.09 inch to 0.10 inch. In one exemplary embodiment, the relief port diameter is 0.05 inch. The relief port diameter can allow excess epoxy and air to escape in order to be fully set within the hosel bore 216. The one or more relief ports 254 serve as a pressure relief to ensure that the ferrule 230 fully seats onto the hosel 210. A complete ferrule / hosel connection results in a stronger bond.

[0117] In some embodiments, a tip weight 290 can be disposed within the hosel bore 216, between the ferrule 230 and the club head 210. The tip weight 290 can have a mass that can range between 0 grams to 18 grams. In some embodiments, the tip weight 290 mass can be 0 grams (in the embodiment where there is no tip weight), 1 gram, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, 7 grams, 8 grams, 9 grams, 10 grams, 11 grams, 12 grams, 13 grams, 14 grams, 15 grams, 16 grams, 17 grams, or 18 grams.

[0118] The tip weight 290 can comprise a material that is different from the material of the club head body 200, the shaft 220, and the ferrule 230. The tip weight 290 may comprise a high- density material, such as tungsten or any other suitable metal or metal alloy material. In some embodiments, the density of the material of the tip weight 290 can be between 1.1 g / cc and 19.6 g / cc. In some embodiments, the density of the tip weight 290 material can be 1.1 g / cc, 1.5 g / cc, 2.0 g / cc, 2.5 g / cc, 3.0 g / cc, 3.5 g / cc, 4.0 g / cc, 4.5 g / cc, 5.0 g / cc, 5.5 g / cc, 6.0 g / cc, 6.5 g / cc, 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, 15.8 g / cc, 16.0 g / cc, 16.2 g / cc, 16.4 g / cc, 16.6 g / cc, 16.8 g / cc, 17.0 g / cc, 17.2 g / cc, 17.4 g / cc, 17.6 g / cc, 17.8 g / cc, 18.0 g / cc, 18.2 g / cc, 18.4 g / cc, 18.6 g / cc, 18.8 g / cc, 19.0 g / cc, 19.2 g / cc, 19.4 g / cc, or 19.6 g / cc.

[0119] In other embodiments that include the shorter hosel 210, a tip weight 290 may not be inserted to allow for the shaft 220 to be pushed further into the hosel 210, thereby maximizing the surface area available for bonding. Further, removing the tip weight 290 can also lead to a redistribution of mass to either perimeter weighting on the club head 200 or to the ferrule 230. If the mass if redistributed to the ferrule 230, this can lead to a heavier, stronger material being used, which can further strengthen the bond at the hosel connection juncture 206.

[0120] Referring to FIGS. 11 and 12, the shaft 220 can comprise microgrooves 255. The microgrooves 255 can form pathways or channels that promote even epoxy flow around the shaft 220. Having an even epoxy flow can prevent pressure build ups and air pockets between the shaft 220 and the ferrule 230 resulting in a more durable hosel connection juncture 206. Further, microgrooves 255 can improve the bonding strength while keeping other golf club features, such as the ferrule 230, hosel size and tip weight 290, desirable. Additionally, the microgrooves 255 can also be located on the hosel 210.

[0121] The microgrooves 255 can be recessed into the shaft 220 to define a plurality of side walls. In some embodiments, the microgrooves can be discrete lines, discrete shapes, intersecting lines, or intersecting shapes. The microgrooves 255 can create pathways to distribute stress more evenly throughout the connection. The microgrooves 255 can extend circumferentially aroundthe shaft 210, or they can be formed in groups. The microgroove side walls can be smooth or jagged. The microgroove 255 side walls can be orientated in different directions to provide more surface area to increase the bond strength.

[0122] The microgroove 255 depth is between 0.0010 inch to 0.0050 inch. In some embodiments, the microgroove 255 depth is less than approximately 0.0010 inch, 0.0015 inch, 0.0020 inch, 0.0025, 0.0030 inch, 0.0035 inch, or 0.0040 inch. In some embodiments, the microgroove depth is between 0.0010 inch to 0.0025 inch, 0.0010 inch to 0.0050 inch, 0.0015 inch to 0.0030 inch, 0.0025 inch to 0.0040 inch, or 0.0035 inch to 0.0050 inch. In one exemplary embodiment, the microgroove 255 depth is 0.0030 inch. The microgrooves 255 can be applied to both graphite and steel shafts. In some graphite shafts, the microgrooves 255 are recessed into an outer resin layer of the shaft, but do not penetrate an inner composite layer.

[0123] In some embodiments, the microgroove 255 depth is constant throughout the microgrooves 255, while in other embodiments, the microgroove 255 depth varies throughout the microgrooves 255. In some embodiments, the microgroove 255 depth varies such that the microgrooves 255 are deeper near the shaft bottom end, and the microgrooves 255 become shallower towards the shaft top end. Conversely, in other embodiments, the microgroove 255 depth varies such that the microgrooves 255 are deeper near the shaft top end, and the microgrooves 255 become shallower towards the shaft bottom end. The microgroove 255 depth can vary in any pattern, or the microgroove 255 depth can vary randomly. Further, the depth can also vary within each individual microgroove 255 in any direction.

[0124] Each microgroove 255 defines a shape that can be the same or different than the rest of the microgrooves 255. The microgrooves 255 can be any combination of circles, lines, triangles, squares, rectangles, polygons, or any suitable shape. The microgrooves 255 can intersect, overlap, or be a discrete shape. The microgrooves 255 can be formed in groups of at least two microgrooves 255. However, each group can comprise one, two, three, four, five, six, seven, eight, nine, or ten or more microgrooves 255. Further, the microgrooves 255 can be formed in one, two, three, four, five, six, seven, eight, nine, or ten or more groups ofmicrogrooves 255. The microgrooves 255 can include other features such as ridges, cutouts, roughness zones, or any other feature that can increase the bond strength of the shaft 220.

[0125] In an additional embodiment, the ferrule can be comprised of individual components that are assembled to provide a complete ferrule similar to that described above. The transition section, the insertion section, and / or the outer wall of the ferrule can be comprised of one or more components. Referring to FIGS. 13A and 13B, the ferrule can be comprised of two separate components. In an exemplary embodiment shown in FIG. 13A, a seam 258 separates the first component, comprised of the outer wall, from the second component, which is comprised of the transition section and the insertion section. In another exemplary embodiment shown in FIG. 13B, a seam 258 separates the first component, comprised of the transition section and outer wall, from the second component, which is comprised of the insertion section. In another exemplary embodiment (not shown), a seam separates the first component, comprised of the outer wall and the insertion section, from the second component, which is comprised of the transition section. In a further embodiment, a seam separates a first component, comprised of half of the outer wall, half of the transition section, and half of the insertion section, from the second component, which is comprised of half of the outer wall, half of the transition section, and half of the insertion section. Manufacturing the ferrule using one or more components can allow for tighter tolerances to ensure a snug fit between the hosel, shaft and ferrule. Additionally, creating the ferrule from one or more components can help ease the manufacturing process by allowing simpler sections to be machined before joining them together. The one or more components may be coupled through either brazing, welding, soldering, or adhesive bonding. Coupling the one or more components together creates the final structure.

[0126] While the invention has been described in connection with various aspects, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptation of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within the known and customary practice within the art to which the invention pertains.

[0127] Replacement of one or more claimed elements constitutes reconstruction and not repair. Additionally, benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims, unless such benefits, advantages, solutions, or elements are expressly stated in such claims.

[0128] As the rules to golf may change (e.g., new regulations may be adopted or old rules may be eliminated or modified by golf standard organizations and / or governing bodies such as the United States Golf Association (USGA), the Royal and Ancient Golf Club of St. Andrews (R&A), etc ), golf equipment related to the apparatus, methods, and articles of manufacture described herein may be deemed conforming or non-conforming to the rules of golf at any particular time. Accordingly, golf equipment related to the apparatus, methods, and articles of manufacture described herein may be advertised, offered for sale, and / or sold as conforming or non-conforming golf equipment. The apparatus, methods, and articles of manufacture described herein are not limited in this regard.

[0129] While the above examples may be described in connection with a iron-type golf club, the apparatus, methods, and articles of manufacture described herein may be applicable to other types of golf club such as a driver wood-type golf club, a fairway wood-type golf club, a hybridtype golf club, an iron-type golf club, a wedge-type golf club, or a putter-type golf club. Alternatively, the apparatus, methods, and articles of manufacture described herein may be applicable to other types of sports equipment such as a hockey stick, a tennis racket, a fishing pole, a ski pole, etc.

[0130] Moreover, embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and / or limitations: (1) are not expressly claimed in the claims; and (2) are or are potentially equivalents of express elements and / or limitations in the claims under the doctrine of equivalents.EXAMPLES

[0131] Example 1 : Finite Element Analysis

[0132] A finite element analysis (FEA) program was run to compare the force needed to disconnect a golf club head from a shaft / ferrule assembly. The FEA examined two different models: (1) a control sample, similar to golf club head 100, being an industry standard hosel 110, ferrule 130, and shaft 120 connection assembly; and (2) another test sample using a hosel 210, ferrule 230, and shaft 220 connection assembly similar to golf club head 200. The FEA models studied having the control sample and test sample connected without epoxy. The connection was held together through a frictional force to study how the increased surface area improves the connection strength.Table 1

[0133] Table 1 above reveals the increased strength of the test sample compared to the control sample. The FEA results showed the test sample required 84.0 Ibf of force to disconnect the ferrule 130 and shaft 120 connection from the hosel 110, while the control required 70.1 Ibf. This equates to a 19.8% increase in connection strength using solely friction. The addition of epoxy in the hosel connection juncture could further increase this connection strength. The FEA test showed that the test sample does provide a stronger hosel 210, ferrule 230, and shaft 220 connection when compared to the control sample.

[0134] Example 2: Pull Test Analysis

[0135] In another example, a pull test is conducted to study the strength of the hosel connection juncture. In this example, a hosel 210, ferrule 230, shaft 220 connection consistent with the test sample of Example 1 and the control sample of Example 1 are physicallyconstructed, using an epoxy as a bonding agent. Both samples are placed in a pull test machine to compare the force necessary to break the bond and disconnect the hosel 210 from the shaft 220 and ferrule 230. In this test, using an epoxy with a bond strength of 3,300 lbs / in2and assuming a pull force of 3,300 lbs / in2, the control sample was expected to yield between 3,500 lbs and 3,800 lbs of force, while the test sample was expected to yield between 4,500 lbs and 5,100 lbs of force. Therefore, the test sample is expected to provide between 25% and 40% increase in bond strength. This increase could be attributed to the increased surface area that the test sample provides and the increased surface for epoxy to interact and bond. The control sample has a connection surface area of between 1.10 in2and 1.20 in2, wherein the test sample has a connection surface area of between 1.45 in2and 1.58 in2. The increased connection surface area is attributed to the three bond areas in the test sample, compared to the two bond areas in the control sample.

[0136] The two samples are placed in a pull test machine and pulled until bond failure. The results show a 20% to 40% increase with the test sample over the control sample, depending on the epoxy used for bonding. The additional strength translates to a better bond for a golf club, further reducing the risk of a golf club head disconnecting through use.

[0137] Example 3: Pull Test Results

[0138] In another example, a pull test experiment was conducted to determine the bond strength of a control hosel connection assembly and a test hosel connection assembly. The control hosel connection assembly is similar to golf club head 100, while the test hosel connection assembly is similar to golf club head 400. The test hosel connection assembly included an extension section. The pull test machine applies a pulling force parallel to a shaft / hosel axis, such that there is no shaft / hosel bending. The stress is placed on the epoxy, which adheres the hosel to the shaft / ferrule. The test hosel connection assembly and the control hosel connection assembly used the same epoxy to join the hosel to the shaft / ferrule.

[0139] Table 2 illustrates the force at which the test and control hosel connections failed. The control hosel connection assembly yielded at 2769.9 Ibf of force, at which point the epoxy bond was broken, and the shaft / ferrule was pulled from the hosel. The test hosel connection assemblyyielded at a 3483.8 Ibf force, however, the system failed due to a weld breaking. The weld was necessary to couple a metal rod to the hosel connection assembly, which simulates a golf shaft. This isolated the strength of the hosel and ferrule bond, and reduced the risk of the golf shaft failing before the epoxy. Overall, the test hosel connection assembly improved the bond strength by 713.9 Ibf over the control hosel connection assembly. This equates to at least a 26% increase in bond strength. A bond strength increase of over 26% could be expected, as the failure was mechanical and not due to the epoxy.Table 2

[0140] Example 4: Shaft Pull Test Analysis

[0141] In another example, a pull test is conducted to study the strength of the shaft and ferrule connection. In this example, a shaft is adhered within a hosel and ferrule consistent with the control sample of Example 3 and another shaft is adhered within the ferrule consistent with the test sample of Example 3. Both samples are placed in a pull test machine to compare the force necessary to break the bond and disconnect the shaft from the hosel in the control sample and the shaft from the ferrule in the test sample. The control sample has a total shaft bonding area within the hosel between 1.50 in2and 1.60 in2, while the test sample has a total shaft bonding area between 2.40 in2and 2.50 in2. In this test, using an epoxy with a bond strength of 3,300 lbs / in2and assuming a pull force of 3,300 lbs / in2, the control sample was expected to yield between 4,900 lbs and 5,100 lbs of force, while the test sample was expected to yield between 7,900 lbs and 8,200 lbs of force. Therefore, the test sample is expected to provide between 50% and 70% increase in bond strength. This increase could be attributed to the increased surface area that the test sample provides, which increases surface for epoxy to interact and bond. Theincreased connection surface area is attributed to the longer ferrule inner wall in the test sample, compared to the shorter hosel depth in the control sample.

[0142] The two samples are placed in a pull test machine and pulled until bond failure. The results show a 50% to 70% increase with the test sample over the control sample, depending on the epoxy used for bonding. The additional strength translates to a better bond for a golf club, further reducing the risk of a golf club head disconnecting through use.

[0143] Various features and advantages of the disclosure are set forth in the following clauses and claims.CLAUSES

[0144] Clause 1 : A golf club, comprising a shaft having a shaft connection end and defining a shaft exterior surface; a club head comprising a body, a sole, a top opposite the sole, a toe, a heel opposite the toe, and a hosel, wherein the hosel comprises a hosel interior surface defining a hosel bore, a hosel exterior surface, and a hosel connection section; a ferrule for joining the hosel connection section to the shaft connection end, the ferrule comprising: a transition section having a transition exterior surface; an insertion section coupled to the transition section and comprising: an inner wall sized for insertion into the hosel bore, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive the shaft connection end and defining a shaft-bonding area facing the shaft exterior surface; and an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel-bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive the hosel connection section.

[0145] Clause 2: The golf club of clause 1, wherein: the outer wall has an outer wall length; and the inner wall has an inner wall length greater than the outer wall length.

[0146] Clause 3: The golf club of clause 1, wherein the inner wall comprises a distal end sized for insertion into the hosel bore, and a cap extends across the distal end of the inner wall.

[0147] Clause 4: The golf club of clause 1, wherein the transition exterior surface comprises a frustoconical shape.

[0148] Clause 5: The golf club of clause 4, wherein: the hosel connection section comprises an annular shoulder joining a first hosel connection section outer surface to a second hosel connection section outer surface; and the outer wall extends over the second hosel connection section outer surface.

[0149] Clause 6: The golf club of clause 1, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

[0150] Clause 7: The golf club of clause 1, wherein the ferrule comprises a ferrule material of acrylonitrile butadiene styrene or aluminum.

[0151] Clause 8: A ferrule for joining a shaft, comprising a shaft connection end and defining a shaft exterior surface, to a golf club head, comprising a hosel having a hosel interior surface defining a hosel bore, a hosel exterior surface, and a hosel connection section, the ferrule comprising: a transition section having a ferrule transition exterior surface; an insertion section coupled to the transition section and comprising: an inner wall sized for insertion into a hosel bore of the golf club head, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive a connection end of the shaft and defining a shaft-bonding area facing the shaft exterior surface; an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel-bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive a hosel connection section of the golf club head.

[0152] Clause 9: A golf club connection assembly for joining a shaft, comprising a shaft connection end and defining a shaft exterior surface, to a golf club head, comprising a hosel having a hosel interior surface defining a hosel bore, a hosel bore base, a hosel exterior surface, and a hosel connection end, the golf club connection assembly comprising: a ferrule, comprising; a transition section having a ferrule transition exterior surface; an insertion section coupled to thetransition section and comprising: an inner wall sized for insertion into a hosel bore of the golf club head, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive a connection end of the shaft and defining a shaft-bonding area facing the shaft exterior surface; and an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel-bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive a hosel connection section of the golf club head; and a tip weight disposed in the hosel bore and between the hosel bore base and the ferrule.

[0153] Clause 10: The golf club of clause 1, further comprising a tip weight disposed in the hosel bore and between the ferrule and the club head.

[0154] Clause 11 : The golf club of clause 1, wherein the ferrule comprises a notch formed between the transition section and the insertion section.

[0155] Clause 12: The golf club of clause 1, wherein the outer wall defines an outer wall length that is at least 0.40 inch.

[0156] Clause 13: The ferrule of clause 8, wherein: the outer wall has an outer wall length; and the inner wall has an inner wall length greater than the outer wall length.

[0157] Clause 14: The ferrule of clause 8, wherein the inner wall comprises a distal end sized for insertion into the hosel bore, and a cap extends across the distal end of the inner wall.

[0158] Clause 15: The ferrule of clause 8, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

[0159] Clause 16: The ferrule of clause 8, wherein the ferrule comprises a ferrule material of acrylonitrile butadiene styrene or aluminum.

[0160] Clause 17: The ferrule of clause 8, further comprising a notch formed between the transition section and the insertion section.

[0161] Clause 18: The ferrule of clause 8, wherein the outer wall defines an outer wall length that is at least 0.40 inch.

[0162] Clause 19: The golf club connection assembly of clause 9, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

[0163] Clause 20: The golf club connection assembly of clause 9, wherein the ferrule comprises a notch formed between the transition section and the insertion section.

[0164] Clause 21 : A golf club, comprising a shaft having a shaft connection end and defining a shaft exterior surface; a club head comprising a body, a sole, a top opposite the sole, a toe, a heel opposite the toe, and a hosel, wherein the hosel comprises a hosel interior surface defining a hosel bore, a hosel exterior surface, and a hosel connection section; a ferrule for joining the hosel connection section to the shaft connection end, the ferrule comprising a body section having a body exterior surface and a body interior surface sized to receive the shaft and defining a first shaft-bonding area facing the shaft exterior surface; an insertion section coupled to the transition section and comprising an inner wall sized for insertion into the hosel bore, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive the shaft connection end and defining a second shaft-bonding area facing the shaft exterior surface; and an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel-bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive the hosel connection section; and an extension section projecting from the body section opposite the insertion section and having an extension section interior surface sized to receive the shaft and defining a third shaft-bonding area facing the shaft exterior surface; wherein a total shaftbonding area comprises a sum of the first shaft-bonding area, the second shaft-bonding area, and the third shaft-bonding area is and the total shaft bonding area is between 2.40 in2 and 2.50 in2.

[0165] Clause 22: The golf club of clause 21, wherein the outer wall has an outer wall length; and the inner wall has an inner wall length greater than the outer wall length.

[0166] Clause 23: The golf club of clause 21, wherein the inner wall comprises a distal end sized for insertion into the hosel bore, and a cap extends across the distal end of the inner wall.

[0167] Clause 24: The golf club of clause 21, wherein the transition exterior surface comprises a frustoconical shape or a cylindrical shape.

[0168] Clause 25: The golf club of clause 24, wherein the hosel connection section comprises an annular shoulder joining a first hosel connection section outer surface to a second hosel connection section outer surface; and the outer wall extends over the second hosel connection section outer surface.

[0169] Clause 26: The golf club of clause 21, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

[0170] Clause 27: The golf club of claim 21, wherein the ferrule comprises a ferrule material of acrylonitrile butadiene styrene or aluminum.

[0171] Clause 28: The golf club of claim 21, further comprising a tip weight disposed in the hosel bore and between the ferrule and the club head.

[0172] Clause 29: The golf club of claim 21, wherein the ferrule comprises a notch formed between the transition section and the insertion section.

[0173] Clause 30: The golf club of claim 21, wherein the outer wall defines an outer wall length that is at least 0.40 inch.

[0174] Clause 31 : A ferrule for joining a shaft, comprising a shaft connection end and defining a shaft exterior surface, to a golf club head, comprising a hosel having a hosel interior surface defining a hosel bore, a hosel exterior surface, and a hosel connection section, the ferrule comprising a body section having a body exterior surface and a body interior surface sized to receive the shaft and defining a first shaft-bonding area facing the shaft exterior surface; an insertion section coupled to the transition section and comprising an inner wall sized for insertioninto a hosel bore of the golf club head, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive a connection end of the shaft and defining a second shaft-bonding area facing the shaft exterior surface; an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel- bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive a hosel connection section of the golf club head; and an extension section projecting from the body section opposite the insertion section and having an extension section interior surface sized to receive the shaft and defining a third shaft-bonding area facing the shaft exterior surface; wherein a total shaft-bonding area comprises a sum of the first shaft-bonding area, the second shaft-bonding area, and the third shaft-bonding area is and the total shaft bonding area is between 2.40 in2 and 2.50 in2.

[0175] Clause 32: The ferrule of claim 31, wherein the outer wall has an outer wall length; and the inner wall has an inner wall length greater than the outer wall length.

[0176] Clause 33: The ferrule of claim 31, wherein the inner wall comprises a distal end sized for insertion into the hosel bore, and a cap extends across the distal end of the inner wall.

[0177] Clause 34: The ferrule of claim 31, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

[0178] Clause 35: The ferrule of claim 31, wherein the ferrule comprises a ferrule material of acrylonitrile butadiene styrene or aluminum.

[0179] Clause 36: The ferrule of claim 31, further comprising a notch formed between the transition section and the insertion section.

[0180] Clause 37: The ferrule of claim 31, wherein the outer wall defines an outer wall length that is at least 0.40 inch.

[0181] Clause 38: A golf club connection assembly for joining a shaft, comprising a shaft connection end and defining a shaft exterior surface, to a golf club head, comprising a hoselhaving a hosel interior surface defining a hosel bore, a hosel bore bottom end, a hosel exterior surface, and a hosel connection end, the golf club connection assembly comprising a ferrule, comprising; a body section having a body exterior surface and a body interior surface sized to receive the shaft and defining a first shaft-bonding area facing the shaft exterior surface; an insertion section coupled to the transition section and comprising an inner wall sized for insertion into a hosel bore of the golf club head, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive a connection end of the shaft and defining a second shaft-bonding area facing the shaft exterior surface; and an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel- bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive a hosel connection section of the golf club head; an extension section projecting from the body section opposite the insertion section and having an extension section interior surface sized to receive the shaft and defining a third shaft-bonding area facing the shaft exterior surface; wherein a total shaft-bonding area comprises a sum of the first shaft-bonding area, the second shaft-bonding area, and the third shaft-bonding area is and the total shaft bonding area is between 2.40 in2 and 2.50 in2; and a tip weight disposed in the hosel bore and between the hosel bore bottom end and the ferrule.

[0182] Clause 39: The golf club connection assembly of clause 38, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

[0183] Clause 40: The golf club connection assembly of clause 38, wherein the ferrule comprises a notch formed between the transition section and the insertion section.

Claims

CLAIMS1. A golf club, comprising: a shaft having a shaft connection end and defining a shaft exterior surface; a club head comprising a body, a sole, a top opposite the sole, a toe, a heel opposite the toe, and a hosel, wherein the hosel comprises a hosel interior surface defining a hosel bore, a hosel exterior surface, and a hosel connection section; a ferrule for joining the hosel connection section to the shaft connection end, the ferrule comprising: a body section having a body exterior surface and a body interior surface sized to receive the shaft and defining a first shaft-bonding area facing the shaft exterior surface; an insertion section coupled to the transition section and comprising: an inner wall sized for insertion into the hosel bore, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive the shaft connection end and defining a second shaft-bonding area facing the shaft exterior surface; and an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel-bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive the hosel connection section; and an extension section projecting from the body section opposite the insertion section and having an extension section interior surface sized to receive the shaft and defining a third shaft-bonding area facing the shaft exterior surface; wherein a total shaft-bonding area comprises a sum of the first shaftbonding area, the second shaft-bonding area, and the third shaft-bonding area is and the total shaft bonding area is between 2.40 in2and 2.50 in2.

2. The golf club of claim 1, wherein: the outer wall has an outer wall length; and the inner wall has an inner wall length greater than the outer wall length.

3. The golf club of claim 1, wherein the inner wall comprises a distal end sized for insertion into the hosel bore, and a cap extends across the distal end of the inner wall.

4. The golf club of claim 1, wherein the transition exterior surface comprises a frustoconical shape or a cylindrical shape.

5. The golf club of claim 4, wherein: the hosel connection section comprises an annular shoulder joining a first hosel connection section outer surface to a second hosel connection section outer surface; and the outer wall extends over the second hosel connection section outer surface.

6. The golf club of claim 1, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

7. The golf club of claim 1, wherein the ferrule comprises a ferrule material of acrylonitrile butadiene styrene or aluminum.

8. The golf club of claim 1, further comprising a tip weight disposed in the hosel bore and between the ferrule and the club head.

9. The golf club of claim 1, wherein the ferrule comprises a notch formed between the transition section and the insertion section.

10. The golf club of claim 1, wherein the outer wall defines an outer wall length that is at least 0.40 inch.

11. A ferrule for joining a shaft, comprising a shaft connection end and defining a shaft exterior surface, to a golf club head, comprising a hosel having a hosel interior surface defining a hosel bore, a hosel exterior surface, and a hosel connection section, the ferrule comprising: a body section having a body exterior surface and a body interior surface sized to receivethe shaft and defining a first shaft-bonding area facing the shaft exterior surface; an insertion section coupled to the transition section and comprising: an inner wall sized for insertion into a hosel bore of the golf club head, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive a connection end of the shaft and defining a second shaft-bonding area facing the shaft exterior surface; an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel-bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive a hosel connection section of the golf club head; and an extension section projecting from the body section opposite the insertion section and having an extension section interior surface sized to receive the shaft and defining a third shaftbonding area facing the shaft exterior surface; wherein a total shaft-bonding area comprises a sum of the first shaftbonding area, the second shaft-bonding area, and the third shaft-bonding area is and the total shaft bonding area is between 2.40 in2and 2.50 in2.

12. The ferrule of claim 11, wherein: the outer wall has an outer wall length; and the inner wall has an inner wall length greater than the outer wall length.

13. The ferrule of claim 11, wherein the inner wall comprises a distal end sized for insertion into the hosel bore, and a cap extends across the distal end of the inner wall.

14. The ferrule of claim 11, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

15. The ferrule of claim 11, wherein the ferrule comprises a ferrule material of acrylonitrile butadiene styrene or aluminum.

16. The ferrule of claim 11, further comprising a notch formed between the transition section and the insertion section.

17. The ferrule of claim 11, wherein the outer wall defines an outer wall length that is at least 0.40 inch.

18. A golf club connection assembly for joining a shaft, comprising a shaft connection end and defining a shaft exterior surface, to a golf club head, comprising a hosel having a hosel interior surface defining a hosel bore, a hosel bore bottom end, a hosel exterior surface, and a hosel connection end, the golf club connection assembly comprising: a ferrule, comprising; a body section having a body exterior surface and a body interior surface sized to receive the shaft and defining a first shaft-bonding area facing the shaft exterior surface; an insertion section coupled to the transition section and comprising: an inner wall sized for insertion into a hosel bore of the golf club head, the inner wall having an inner wall exterior surface defining a first hosel-bonding area facing the hosel interior surface, and an inner wall interior surface sized to receive a connection end of the shaft and defining a second shaft-bonding area facing the shaft exterior surface; and an outer wall spaced from and surrounding at least a portion of the inner wall, the outer wall having an outer wall interior surface defining a second hosel-bonding area facing the hosel exterior surface; wherein the outer wall interior surface and the inner wall exterior surface define a receptacle sized to receive a hosel connection section of the golf club head; an extension section projecting from the body section opposite the insertion section and having an extension section interior surface sized to receive the shaft and defining a third shaftbonding area facing the shaft exterior surface; wherein a total shaft-bonding area comprises a sum of the first shaftbonding area, the second shaft-bonding area, and the third shaft-bonding area is and the total shaft bonding area is between 2.40 in2and 2.50 in2; anda tip weight disposed in the hosel bore and between the hosel bore bottom end and the ferrule.

19. The golf club connection assembly of claim 18, further comprising a relief port extending through the ferrule from the receptacle to the outer wall exterior surface or the transition exterior surface.

20. The golf club connection assembly of claim 18, wherein the ferrule comprises a notch formed between the transition section and the insertion section.

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