Adjustable length shaft and adjustable mass for golf club

Abstract

To improve adjustability of a shaft length without substantially affecting total weight, swing weight or appearance of a golf club.SOLUTION: There is provided a golf club, including: a first shaft 22 coupled to a club head; a second shaft 120 configured to slidably engage a portion of the first shaft; a grip 34 coupled to the second shaft; and an adjustable length shaft assembly 800; wherein the adjustable length shaft assembly is received by the second shaft and configured to allow a portion of the first shaft to slide in relation to the second shaft in a first configuration, and to restrict a portion of the first shaft from sliding in relation to the second shaft in a second configuration. The grip is restricted from rotation about the first shaft or the second shaft as the first shaft slides in relation to the second shaft.SELECTED DRAWING: Figure 35

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application is a continuation-in-part of U.S. Nonprovisional Patent Application No. 15 / 165,889, filed May 26, 2016, which claims the benefit of U.S. Provisional Patent Application No. 62 / 167,833, filed May 28, 2015, U.S. Provisional Patent Application No. 62 / 220,013, filed September 17, 2015, U.S. Provisional Patent Application No. 62 / 258,837, filed November 23, 2015, and U.S. Provisional Patent Application No. 62 / 303,429, filed May 4, 2016. This application also claims the benefit of U.S. Provisional Patent Application No. 62 / 718,298, filed August 13, 2018. The contents of all of the above disclosures are incorporated herein in their entirety by reference.

[0002] This disclosure relates to golf clubs, and more particularly to golf clubs having variable length shafts that allow for selective lengthening or shortening of the club. Additionally, this disclosure relates to adjustable mass within a golf club shaft that allows for selective adjustment of the club's swing weight and moment of inertia while maintaining the overall weight of the club. [Background technology]

[0003] Golf clubs come in a variety of forms, such as woods, hybrids, irons, wedges, or putters, and these clubs generally differ in head shape and design (e.g., the difference between woods and irons), club head material, shaft material, club length, and club loft.

[0004] Typically, when assembling a known golf club, the shaft is cut or trimmed to a desired length. Woods and hybrids generally have longer shafts than irons, wedges, and putters, with putters generally having the shortest shaft lengths. After the shaft is trimmed to the desired length, it is attached to the golf club head by a hosel. The shaft is typically attached to the golf club head by epoxy or other adhesive. However, in some golf clubs, the shaft is coupled to an adapter, which engages a removable threaded member in the hosel to secure the shaft to the golf club head. A grip is then installed on the shaft.

[0005] After assembly of these known golf clubs, it is difficult to adjust the shaft length. The first option is to remove the original shaft and replace it with a new shaft of a different length. Unfortunately, this option results in the added cost of a new shaft. The second option is to remove the grip and shorten the shaft by cutting off a portion of the butt end of the shaft (e.g., the end of the shaft opposite the golf club head) or by installing a shaft extension into the butt end of the shaft to lengthen the shaft, and then install a new grip. Not only do these options incur the added cost associated with a new grip, but adjusting the shaft length at the butt end can change the swing weight of the golf club (specifically, shortening decreases swing weight, while lengthening increases swing weight), change the total weight of the golf club (shortening decreases total weight, while lengthening increases total weight), and change shaft stiffness (shortening generally increases shaft stiffness, while lengthening generally decreases shaft stiffness). Neither option is desirable to the average golfer due to the added expense, time required to repair or adjust the golf club, and / or deleterious changes to the total weight of the golf club, the swing weight of the golf club, and / or the stiffness of the shaft.

[0006] While these are known options for adjusting golf club shafts, there is a need for improved shaft length adjustability without substantially affecting the total weight, swing weight, or aesthetics of the golf club. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an elevational view of an embodiment of a golf club having a variable length shaft assembly in a first shaft length configuration. [Figure 2] 2 is an elevational view of the golf club of FIG. 1 with a variable length shaft assembly having a second shaft length configuration that is shorter than the first shaft length configuration. [Figure 3] FIG. 2 is a perspective view of a first embodiment of an adjustable length shaft assembly for use with the golf club of FIG. [Figure 4] FIG. 4 is a perspective view of the first embodiment of the adjustable length shaft assembly of FIG. 3 with the grip removed. [Figure 5] FIG. 5 is a perspective view of a portion of the variable length shaft assembly of FIG. 3 with the grip removed, as detailed in box 5-5 of FIG. 4. [Figure 6] FIG. 4 is a perspective view of a portion of the variable length shaft assembly of FIG. 3 with the grip and outer shaft removed to illustrate the inner shaft carrying the insert. [Figure 7] 7 is a cross-sectional view of a portion of the variable length shaft assembly of FIG. 3 taken along line 7-7 of FIG. 3. [Figure 8] FIG. 4 is a perspective view of an embodiment of a torque limiting tool for use with the adjustable length shaft assembly of FIG. [Figure 9] FIG. 2 is a perspective view of a second embodiment of an adjustable length shaft assembly for use with the golf club of FIG. 1; [Figure 10]FIG. 10 is a perspective view of a second embodiment of the adjustable length shaft assembly of FIG. 9 with the grip removed. [Figure 11] 11 is a cross-sectional view of a portion of the variable length shaft assembly of FIG. 9 taken along line 11-11 of FIG. 9. [Figure 12] 12 is a partial cross-sectional view of a portion of the variable length shaft assembly of FIG. 9 as detailed in box 12-12 of FIG. 11 and with the grip removed. [Figure 13] 13 is a partial cross-sectional view of a portion of the variable length shaft assembly of FIG. 9 as detailed in box 13-13 of FIG. 11 and with the grip removed. [Figure 14] FIG. 2 is a perspective view of a third embodiment of an adjustable length shaft assembly for use with the golf club of FIG. 1; [Figure 15] FIG. 15 is a perspective view of the third embodiment of the adjustable length shaft assembly of FIG. 14 with the grip removed. [Figure 16] 16 is a cross-sectional view of a portion of the variable length shaft assembly of FIG. 14 taken along line 16-16 of FIG. 14. [Figure 17] FIG. 17 is a perspective view of a portion of the adjustable length shaft assembly of FIG. 14, as detailed in box 17-17 of FIG. 15, illustrating a portion of the cam lock assembly in an unlocked position. [Figure 18] 18 is a perspective view of a portion of the variable length shaft assembly of FIG. 14 taken along line 18-18 of FIG. 16, illustrating a portion of the cam lock assembly in an unlocked position. [Figure 19] FIG. 19 is a perspective view of a portion of the cam lock assembly of FIG. 18 illustrating a portion of the cam lock assembly in a locked position. [Figure 20] FIG. 2 is a cross-sectional view of a portion of an adjustable mass assembly for use with the golf club of FIG. 1; [Figure 21]FIG. 2 is a cross-sectional view of a portion of an alternative embodiment of an adjustable mass assembly for use with the golf club of FIG. 1. [Figure 22] 1 is a flowchart of a method of manufacturing an adjustable length shaft assembly. [Figure 23] 1 is a flowchart of a method of fabricating an adjustable mass assembly. [Figure 24] FIG. 2 is a perspective view of a fourth embodiment of an adjustable length shaft assembly for use with the golf club of FIG. 1; [Figure 25] FIG. 25 is a perspective view of the fourth embodiment of the adjustable length shaft assembly of FIG. 24 with the grip removed. [Figure 26] FIG. 25 is a perspective view of the fourth embodiment of the adjustable length shaft assembly of FIG. 24 with the grip and second shaft removed. [Figure 27] FIG. 25 is a cross-sectional view of the second shaft of the fourth embodiment of the variable length shaft assembly of FIG. [Figure 28] FIG. 25 is a cutaway side view of an alternative to the fourth embodiment of the adjustable length shaft assembly of FIG. 24 with the grip removed. [Figure 29] FIG. 15 is a partial cross-sectional view of a portion of the third embodiment of the adjustable length shaft assembly of FIG. 14 with the grip removed. [Figure 30] FIG. 10 is a perspective view of a fifth embodiment of an adjustable length shaft assembly for use with the golf club of FIG. [Figure 31] FIG. 31 is a perspective view of a fifth embodiment of the adjustable length shaft assembly of FIG. 30 with the grip removed. [Figure 32] FIG. 31 is a perspective view of a retainer of the fifth embodiment of the variable length shaft assembly of FIG. [Figure 33] FIG. 31 is a cross-sectional view of the second shaft of the fifth embodiment of the adjustable length shaft assembly of FIG. 30 with the grip removed. [Figure 34]FIG. 21 is a perspective view of a fifth embodiment of the variable length shaft assembly of FIG. 20 with the grip and second shaft removed. [Figure 35] 35 is a cross-sectional view of a portion of the variable length shaft assembly of FIG. 30 taken along line 35-35 of FIG. 30. [Figure 36] 35 is a partial cross-sectional view of a portion of the variable length shaft assembly of FIG. 30 as shown in the detail circle of FIG. 35. [Figure 37] 35 is a partial cross-sectional view of a portion of the variable length shaft assembly of FIG. 30 as shown in the detail circle of FIG. 35. [Figure 38] FIG. 31 is a bottom view of the insert of the fifth embodiment of the variable length shaft assembly of FIG. 30. DETAILED DESCRIPTION OF THE INVENTION

[0008] The embodiments of the present invention discussed below are directed to a golf club having a first shaft coupled to a club head, a second shaft configured to slidably engage a portion of the first shaft, a grip coupled to the second shaft, and a variable-length shaft assembly configured to be received by the second shaft and allow a portion of the first shaft to slide relative to the second shaft. The variable-length shaft assembly further includes an insert coupled to an axial end face of the first shaft with a threaded screw that is engaged with the threaded screw. The threaded screw is configured to rotate, and the insert and the first shaft are configured to translate together along the threaded screw to adjust the length of the golf club. The insert further includes a nub-like protrusion positioned on an outer surface of the insert and a rib positioned on an inner surface of the insert to minimize side-to-side or radial movement between the first shaft and the second shaft during operation of the variable-length shaft assembly.

[0009] In one embodiment, a golf club includes a first shaft coupled to a club head, a second shaft configured to slidably engage a portion of the first shaft, a grip coupled to the second shaft, and an adjustable-length shaft assembly configured to be received on the second shaft and to allow a portion of the first shaft to slide relative to the second shaft in a first configuration and to limit the portion of the first shaft from sliding relative to the second shaft in a second configuration, and the grip is limited from rotating about either the first shaft or the second shaft when the first shaft slides relative to the second shaft.

[0010] In another embodiment, a golf club includes a shaft coupled to a club head, a grip coupled to a first shaft, and an adjustable mass assembly received by the shaft, the adjustable mass assembly having a mass configured to move within the shaft between the club head and the grip.

[0011] A method of manufacturing an adjustable length golf club includes the steps of connecting a first shaft to a club head, connecting a retainer to the first shaft, connecting an adjustable length shaft assembly to a second shaft, and connecting the first shaft to the second shaft, wherein the retainer engages the adjustable length shaft assembly.

[0012] Other features and aspects will become apparent by consideration of the following detailed description and the accompanying drawings. Before any embodiment of the present disclosure is described in detail, it should be understood that the disclosure is not limited in its application to the details or the construction and arrangement of components as set forth in the following description or illustrated in the drawings. The present disclosure is capable of supporting other embodiments and may be practiced or carried out in various ways. It should be understood that the description of a particular embodiment is not intended to limit the disclosure, since it covers all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. Also, it should be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0013] Terms such as "first," "second," "third," and "fourth" in the detailed description and claims, when used, are used to distinguish between like elements and not necessarily to describe a particular sequential or chronological order. It should be understood that such terms are interchangeable under appropriate circumstances, and that the embodiments described herein are capable of operating in sequences other than those illustrated or otherwise described herein. Moreover, the terms "comprise" 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 can include other elements not expressly listed or inherent in such process, method, system, article, device, or apparatus.

[0014] Terms such as "left," "right," "front," "rear," "top," "bottom," "above," and "below," when used in the detailed description and claims, are used for descriptive purposes and are not necessarily used to describe permanent relative positions. It should be understood that the terms so used are interchangeable under appropriate circumstances, and that embodiments of the apparatus, methods, and / or articles of manufacture described herein are capable of operation, for example, in other orientations than those illustrated or otherwise described herein.

[0015] Terms such as "couple," "coupled," "connection," and "coupled" should be understood broadly and refer to connecting two or more elements, mechanically or otherwise. The connection (mechanical or otherwise) can be for any length of time, for example, permanently or semi-permanently, or only momentarily.

[0016] For ease of discussion and understanding, and for purposes of illustration only, the following detailed description illustrates golf club 10 as a putter. It should be appreciated that a putter is provided for illustrative purposes of a variable length shaft assembly that increases or decreases the shaft length of a golf club, and an adjustable mass assembly that adjusts the swing weight and moment of inertia while maintaining the total weight of the golf club. The disclosed variable length shaft assemblies and / or adjustable mass assemblies may be used in connection with any desired driver, fairway wood, general wood, hybrid, iron, wedge, putter, or other golf club.

[0017] Referring now to the figures, FIGS. 1-2 illustrate an embodiment of a golf club 10 incorporating a variable-length shaft assembly. The golf club 10 includes a club head 14 with a hosel 18. A first shaft 22 is attached to the hosel 18 at a first end or tip 26, while a second end or butt 30 (shown in FIG. 6) of the shaft 22 is received by a grip 34. The shaft 22 extends along an axis A. In FIG. 1, the shaft 22 is illustrated in a first shaft length configuration having a first club length L1, and the shaft 22 has a first balance point 38. In FIG. 2, the shaft 22 is illustrated in a second shaft length configuration having a second club length L2, and the shaft 22 has a second balance point 42. The second club length L2 is less than the first club length L1. Due to the shorter club length L2, the second balance point 42 of the shaft 22 is closer to the club head 14 than the first balance point 38 of the shaft 22 associated with the longer club length L1. The variable length shaft assembly is contained within the shaft 22 and grip 34 and is generally not visible from the exterior of the golf club 10.

[0018] In various embodiments, the club length of golf club 10 can be any suitable or desired club length. For example, the club length can be 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 inches or greater. An adjustable length shaft assembly as disclosed herein can adjust the club length between any suitable or desired club length range. For example, an adjustable length shaft assembly can adjust the club length by approximately 0 to 15 inches, 0 to 14 inches, 0 to 13 inches, 0 to 12 inches, 0 to 11 inches, 0 to 10 inches, 0 to 9 inches, 0 to 8 inches, 0 to 7 inches, 0 to 6 inches, 0 to 5 inches, 0 to 4 inches, 0 to 3 inches, 0 to 2 inches, 0 to 1 inch, or any other suitable range of adjustment of club length.

[0019] As a non-limiting example with respect to a putter, the variable length shaft assembly may adjust the club length from a first club length L1 of approximately 36 inches to a second club length L2 of approximately 30 inches. It should be appreciated that the first club length L1 and the second club length L2 may be any suitable or desired respective club lengths, including the exemplary club lengths disclosed herein.

[0020] In this example, the club length is adjustable between 0 and 6 inches. In other examples, the variable length shaft assembly may adjust the club length by approximately 0 to 15 inches, 0 to 14 inches, 0 to 13 inches, 0 to 12 inches, 0 to 11 inches, 0 to 10 inches, 0 to 9 inches, 0 to 8 inches, 0 to 7 inches, 0 to 5 inches, 0 to 4 inches, 0 to 3 inches, 0 to 2 inches, 0 to 1 inch, or any other suitable range of adjustment of the club length.

[0021] As a non-limiting example with respect to a driver, the variable length shaft assembly may adjust the club length from a first club length L1 of approximately 48 inches to a second club length L2 of approximately 44 inches. It should be appreciated that the first club length L1 and the second club length L2 may be any suitable or desired respective club lengths, including any of the exemplary club lengths disclosed herein. In this example, the club length may be adjustable between 0 and 4 inches. In other examples, the variable length shaft assembly may adjust the club length by approximately 0 to 15 inches, 0 to 14 inches, 0 to 13 inches, 0 to 12 inches, 0 to 11 inches, 0 to 10 inches, 0 to 9 inches, 0 to 8 inches, 0 to 7 inches, 0 to 6 inches, 0 to 5 inches, 0 to 3 inches, 0 to 2 inches, 0 to 1 inch, or any other suitable range of adjustment of the club length.

[0022] As a non-limiting example with respect to a fairway wood, the variable length shaft assembly may adjust the club length from a first club length L1 of approximately 44 inches to a second club length L2 of approximately 38 inches. It should be appreciated that the first club length L1 and the second club length L2 may be any suitable or desired respective club lengths, including any of the exemplary club lengths disclosed herein. In this example, the club length may be adjustable between 0 and 6 inches. In other examples, the variable length shaft assembly may adjust the club length by approximately 0 to 15 inches, 0 to 14 inches, 0 to 13 inches, 0 to 12 inches, 0 to 11 inches, 0 to 10 inches, 0 to 9 inches, 0 to 8 inches, 0 to 7 inches, 0 to 5 inches, 0 to 4 inches, 0 to 3 inches, 0 to 2 inches, 0 to 1 inch, or any other suitable range of adjustment of the club length.

[0023] As a non-limiting example for a hybrid, the variable length shaft assembly may adjust the club length from a first club length L1 of approximately 42 inches to a second club length L2 of approximately 35 inches. It should be appreciated that the first club length L1 and the second club length L2 may be any suitable or desired respective club lengths, including any of the exemplary club lengths disclosed herein. In this example, the club length may be adjustable between 0 and 7 inches. In other examples, the variable length shaft assembly may adjust the club length by approximately 0 to 15 inches, 0 to 14 inches, 0 to 13 inches, 0 to 12 inches, 0 to 11 inches, 0 to 10 inches, 0 to 9 inches, 0 to 8 inches, 0 to 6 inches, 0 to 5 inches, 0 to 4 inches, 0 to 3 inches, 0 to 2 inches, 0 to 1 inch, or any other suitable range of adjustment of the club length.

[0024] As a non-limiting example with respect to one or more irons or wedges, the variable length shaft assembly may adjust the club length from a first club length L1 of approximately 42 inches to a second club length L2 of approximately 35 inches. It should be appreciated that the first club length L1 and the second club length L2 may be any suitable or desired respective club lengths, including any of the exemplary club lengths disclosed herein.

[0025] It should be appreciated that the adjustment of club length by the variable length shaft assembly as described herein is not discrete. Rather, the variable length shaft assembly as described herein allows for adjustment of club length to any length or position between a first club length L1 and a second club length L2.

[0026] FIGS. 3-7 illustrate a first embodiment of an adjustable-length shaft assembly 100. The first embodiment of the assembly 100 generally employs a threaded screw 140, disclosed in additional detail below, to selectively adjust and maintain the length of the golf club 10. Referring to FIG. 3, the grip 34 defines an aperture 46 in the end surface 50. The aperture 46 provides access to a rotating screw head 104 having a polygonal socket 108, shown in FIGS. 4-5. The aperture 46 in the grip 34 can be a vent hole in the grip 34. However, in other embodiments, the aperture 46 can be a specially designed or custom hole through the grip to provide sufficient access to the socket 108. By way of non-limiting example, the aperture 46 can be a hole larger than a typical vent hole and sized sufficiently to receive a torque wrench and facilitate engagement of the torque wrench with the socket 108. Although socket 108 is illustrated as a star-shaped socket, in other embodiments, socket 108 can be any suitable shape, such as triangular, square, slotted, Phillips®, Torx®, POSIDRIV®, SUPADRIVE®, pentagonal, hexagonal, or any other suitable polygonal or other shape that secures to a corresponding torque wrench or adjustment tool.

[0027] 4-5, the screw head 104 is received by a retainer 112, which is stationary relative to a second shaft 120 but allows rotation of the screw head 104. The retainer 112 is itself received by a second or butt end 116 of the second shaft 120. The second shaft 120 includes a slot or cutout 124 that extends along an axis A (shown in FIG. 4) from the second end 116 in a direction toward the club head 14. In the illustrated embodiment, the slot 124 is approximately 5 inches long. However, in other embodiments, slot 124 can have a length ranging from approximately 1 inch to approximately 9 inches, more specifically ranging from approximately 2 inches to approximately 8 inches, more specifically ranging from approximately 3 inches to approximately 7 inches, more specifically ranging from approximately 4 inches to approximately 6 inches, or any suitable or desired length that can correspond to the length of adjustability of golf club 10. In addition, while slot 124 is illustrated as an open slot (i.e., extending through second shaft 120), in other embodiments, slot 124 can be a closed slot, such as, but not limited to, a channel or guide channel. Furthermore, while slot 124 is illustrated as extending through second shaft 120 at second end 116, in other embodiments, slot 124 need not extend through second end 116 but can be positioned or otherwise provided anywhere along second shaft 120.

[0028] 5-6 show an insert 128 that is received within the second end 30 of the first shaft 22. The insert 128 has a protrusion 132 that extends beyond the outer periphery of the first shaft 22. The protrusion 132 is secured to be received by the slot 124. The insert 128 also defines a threaded aperture 136.

[0029] 7, the threaded aperture 136 receives a correspondingly threaded screw 140 extending away from the screw head 104. Additionally, the grip 34 is attached to the second shaft 120 and not to the first shaft 22. The first shaft 22 is received by the second shaft 120, allowing the first and second shafts 22, 120 to move axially relative to one another.

[0030] As shown in FIG. 7 , the second shaft 120 is made from graphite, while the insert 128 is made from aluminum. These materials are lightweight and minimize the impact of the variable length shaft assembly 100 on the swing weight and total weight of the golf club 10. In other embodiments, the retainer 112, second shaft 120, and insert 128 may be made from any suitable or desired material, including, but not limited to, aluminum, steel, titanium, graphite, other metals, composites, metal alloys, polymers, polyurethane, thermoplastic polyurethane, thermoplastic elastomers, reinforced polyurethane, polyethylene, polypropylene, polytetrafluoroethylene, polyisobutylene, polyvinyl chloride, polyamide, nylon 66, or any other material. Furthermore, the retainer 112, second shaft 120, and insert 128 may be made from the same material, or the retainer 112, second shaft 120, and insert 128 may be made from different materials. In one example, the second shaft 120 and the insert 128 may be made from nylon-66.

[0031] In other embodiments, the retainer 112, the second shaft 120, or the insert 128 may be made from the materials described above and may further include a filler material. The filler material may be glass, carbon fiber, metal, or any other suitable filler material. The material of the retainer 112, the second shaft 120, or the insert 128 may include a volume percentage of a filler material. In some embodiments, the material of the retainer 112, the second shaft 120, or the insert 128 may include 0-90% filler volume. In some embodiments, the material of the retainer 112, the second shaft 120, or the insert 128 may include 0-50% or 50-90% filler volume. In some embodiments, the material of the retainer 112, the second shaft 120, or the insert 128 can include a filler volume of 0-40%, 10-50%, 20-60%, 30-70%, 40-80%, 50-90%, or 60-100%. For example, the material of the retainer 112, the second shaft 120, or the insert 128 can include a filler volume of 0%, 10%, 20%, 30%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 90%. As a further example, the insert 128 can be made from nylon 66 with a 30% carbon fiber filler volume. As a further example, the insert 128 can be made from nylon 66 with a 50% glass filler volume. As a further example, the retainer 112 may be made from nylon 66 with a 50% glass fill volume. As a further example, the second shaft 120 may be made from nylon 66 with a 30% carbon fiber fill volume.

[0032] In operation of the adjustable-length shaft assembly 100, a user inserts a portion of a torque wrench into the aperture 46 defined by the grip 34 and engages the torque wrench with the socket 108 of the screw head 104. To increase the club length of the golf club 10, the user rotates the torque wrench in a first direction to rotate the screw head 104 and associated screw 140 within the retainer 112. The threads of the screw 140 engage with the threads of the aperture 136 in the insert 128. The protrusion 132 fixes the rotational position of the insert 128 relative to the second shaft 120, such that rotation of the screw 140 drives the insert 128 axially along the slot 124. As the screw 140 rotates in a first direction, the protrusion 132 translates within the slot 124, moving the insert 128 away from the second end 116 and the first shaft 22 away from the second shaft 120. The insert 128 and first shaft 22 move together and away from the second end 116 as the screw 140 rotates in the first direction. The insert 128 is positioned away from the second end 116 in an extended, or expanded, configuration. The protrusion 132 within the slot 124 also limits rotation of the second shaft 120 relative to the first shaft 22, maintaining the orientation of the grip 34 relative to the club head 14 (or stated another way, the protrusion 132 limits rotation of the grip 34 about the first shaft 22). This is advantageous for certain clubs, such as putters with a paddle grip 34 (i.e., a flat surface on the grip 34), because the paddle maintains its orientation with the club head 14 as the club length increases (or decreases). Once the desired club length is obtained, the user removes the torque wrench from the screw head 104, temporarily locking the variable-length shaft assembly at the desired club length.

[0033] Similarly, to decrease the club length of the golf club 10, a user engages a torque wrench with the socket 108 of the screw head 104 and rotates the torque wrench in a second direction opposite the first direction. As the screw 140 rotates in the second direction, the insert 128 moves toward the second end 116 and the first shaft 22 moves toward the second shaft 120. The insert 128 and the first shaft 22 move together toward the second end 116 as the screw 140 rotates in the second direction. The insert 128 can abut or abut the retainer 112 in the fully retracted configuration. The protrusion 132 in the slot 124 again limits rotation of the second shaft 120 relative to the first shaft 22, maintaining the orientation of the grip 34 relative to the club head 14 (or limiting rotation of the grip 34 about the first shaft 22). Once the desired club length is achieved, the user removes the torque wrench from screw head 104, temporarily locking the adjustable length shaft assembly at the desired club length.

[0034] The threaded screw 140 can be a single-start screw having a single thread, or the threaded screw 140 can be a multi-start screw having two or more threads. The threads of the threaded screw 140 can be continuous along the length of the threaded screw 140. In other embodiments, the threads of the threaded screw 140 can be discontinuous along the length of the threaded screw 140. For example, the threaded screw 140 can have one, two, three, four, five, or any other number of threads. In embodiments where the threaded screw 140 is a multi-start screw, length adjustment can be achieved with fewer torque wrench turns than with a single-start screw. Thus, a multi-start screw can allow for faster length adjustment of a golf club 10 having an adjustable-length shaft assembly 100. The threaded screw 140 can have at least one channel running along the length of the threaded screw 140 to facilitate the molding process (not shown). Channels running along the length of the threaded screw 140 can divide the threads into one or more threaded regions. The one or more threaded regions can be interspersed with unthreaded regions along the length of the threaded screw 140 (not shown). Stated another way, the one or more threaded regions can be separated by unthreaded regions along the length of the threaded screw 140 (not shown). In one embodiment, the threaded screw 140 can have at least one channel, two channels, three channels, or four channels running along the length of the threaded screw. In another embodiment, the threaded screw 140 can have two channels cut into the threads on either side of the threaded screw 140 to facilitate the molding process. The channels can run partway or all of the way along the length of the threaded screw 140 (not shown).

[0035] To prevent a user from applying excessive torque to the screw head 104 when increasing or decreasing the length of the golf club 10, the torque wrench can be a torque-limiting tool 150. FIG. 8 illustrates an example embodiment of the torque-limiting tool 150. The tool 150 includes a handle 154 attached to a tip 158 by a torque-limiting joint 162. When a user applies more than a predetermined torque to the handle 154, the joint 162 can slip or ratchet, preventing the transmission of excessive torque to the tip 158 and potential damage to components of the adjustable-length shaft assembly 100.

[0036] In the illustrated embodiment, the second shaft includes a slot and the insert includes a protrusion. In other embodiments, the second shaft can include two or more slots and the insert can include two or more protrusions. The second shaft can have any number of slots, such as one, two, three, four, five, or any other number of slots. The insert can have any number of protrusions corresponding to the number of slots, such as one, two, three, four, five, or any other number of protrusions. For example, the second shaft can include three slots corresponding to three protrusions on the insert, or the second shaft can include four slots corresponding to four protrusions on the insert. In some embodiments, the slots can be positioned equidistantly or asymmetrically around the second shaft. Furthermore, the protrusions can be positioned equidistantly or asymmetrically around the insert.

[0037] In still other embodiments, the second shaft can include one or more protrusions and the insert can include one or more slots. In these or other embodiments, the second shaft can have any number of protrusions, such as one, two, three, four, five, or any other number of protrusions. In these or other embodiments, the insert can have any number of slots corresponding to the number of protrusions, such as one, two, three, four, five, or any other number of slots. For example, the second shaft can include three protrusions corresponding to three slots on the insert, or the second shaft can include four protrusions corresponding to four slots on the insert. In some embodiments, the protrusions can be positioned equidistantly or asymmetrically around the second shaft. Furthermore, the slots can be positioned equidistantly or asymmetrically around the insert.

[0038] 9-13 illustrate a second embodiment of an adjustable length shaft assembly 200. Assembly 200 has elements in common with assembly 100, which are given the same reference numerals. Second embodiment assembly 200 includes a compression assembly 204, which generally employs a resilient compression member, disclosed in additional detail below, to selectively adjust and maintain the length of golf club 10.

[0039] 9, grip 34 defines aperture 46 at second end 50. Aperture 46 provides access to compression assembly 204 (shown in FIGS. 11-12), and more specifically, to adjustment member 208 (shown in FIGS. 11-12) that carries socket 108 (shown in FIG. 12). Grip 34 is attached to second shaft 120 (shown in FIG. 10) but not to first shaft 22.

[0040] As shown in FIGS. 10-11 , the first shaft 22 is received by the second shaft 120, allowing the first and second shafts 22, 120 to move axially relative to one another. An insert 128 is secured to the second end 30 of the first shaft 22 (shown in FIG. 11 ). The insert 128 also includes a protrusion 132 that extends beyond the outer periphery of the first shaft 22. The second shaft 120 includes a slot 124 that extends axially along the second shaft 120 from the second end 116 toward the club head 14. The protrusion 132 is secured to be received by the slot 124.

[0041] 11-12, compression assembly 204 includes an adjustment member 208 and a retainer 212. Adjustment member 208 includes a head or head portion 216 connected to a member or shaft portion 220. Member 220 extends into second shaft 120 away from head 216. In the illustrated embodiment, head 216 has a diameter that is generally larger than the diameter of member 220. However, in other embodiments, head 216 can have a diameter that is approximately the same size as the diameter of member 220 or a diameter that is generally smaller than the diameter of member 220.

[0042] The retainer 212 includes a well 224 that defines a recess connected to a tubular portion 228. The tubular portion 228 extends into the second shaft 120 away from the well 224. The tubular portion 228 also defines an opening or open end 230 (shown in FIGS. 11 and 13 ) at the end of the tubular portion 228 opposite the well 224. The retainer 212 is received by the second shaft 120 through the second end 116. Additionally, the retainer 212, and more specifically, the well 224, is attached to the second shaft 120 at the second end 116. The retainer 212 does not rotate or otherwise move independently of the second shaft 120. Instead, the retainer 212 moves with the second shaft 120. In the illustrated embodiment, the well 224 has a diameter that is larger than the diameter of the generally tubular portion 228. However, in other embodiments, the well 224 can have a diameter that is approximately the same size as the diameter of the tubular portion 228 or a diameter that is smaller than the diameter of the generally tubular portion 228.

[0043] The retainer 212 slidably receives the adjustment member 208 such that the adjustment member 208 slides within the retainer 212. The well 224 slidably receives the head 216, while the tubular portion 228 slidably receives the member 220, which extends through the tubular portion 228 and out an open end 230. To facilitate slidable movement of the adjustment member 208 within the retainer 212, the tubular portion 228 has an inner diameter complementary to the outer diameter of the member 220. Similarly, the well 224 has an inner diameter complementary to the outer diameter of the head 216. The complementary sizes allow the adjustment member 208 to slide relative to the retainer 212 in an axial direction, or a direction generally parallel to the first and second shafts 22, 120.

[0044] The adjustment member 208 is resiliently connected to the retainer 212 by a biasing member or spring 232. In the illustrated embodiment, the biasing member 232 is coupled to the adjustment member 208, and more specifically, to the head 216 of the adjustment member 208. The biasing member 232 is also received by the well 224 of the retainer 212.

[0045] 11 , the insert 128 defines an aperture 236. The aperture 236 receives the retainer 212, and more specifically, the tubular portion 228 of the retainer 212. The aperture 236 has an inner diameter complementary to the outer diameter of the retainer 212, allowing the insert 128 to slide along the retainer 212. In the illustrated embodiment, the insert 128 slides along the tubular portion 228 of the retainer 212 during adjustment of the shaft length of the golf club.

[0046] 11 and 13, the compression assembly 204 includes a deformable or resilient member or stopper 240. The resilient member 240 provides a selective expansion force between the first shaft 22 and the tubular portion 228 to selectively retain the compression assembly 204, and the attached second shaft 120, by the first shaft 22. The selective expansion force limits movement between the first shaft 22 and the second shaft 120. In the illustrated embodiment, the resilient member 240 is retained by the compression assembly 204 between the adjustment member 208 and the retainer 212.

[0047] In the illustrated embodiment, the resilient member 240 has a generally cylindrical shape and includes a central channel 244 that receives the compression assembly 204, and more specifically, the retainer 212 that carries the adjustment member 208. The adjustment member 208 preferably extends completely through the resilient member 240. To assist in retaining the resilient member 240, the retainer 212 includes a first compression member retainer 248, while the adjustment member 208 includes a second compression member retainer 252. The first compression member retainer 248 can be a plurality of fins or an annular ring-shaped member that protrudes away from the tubular portion 228 of the retainer 212. The first compression member retainer 248 can be integrally formed with the retainer 212, or in other embodiments, can be attached to or otherwise connected to the retainer 248. Preferably, the first compression member retainer 248 has a diameter or circumference that is greater than the diameter or circumference of the tubular portion 228 of the retainer 212 but less than the inner diameter or circumference of the first shaft 22 .

[0048] The second compression member retainer 252 can be an annular ring-shaped member that protrudes away from the member 220 of the adjustment member 208. The second compression member retainer 252 can receive the member 220 and form a connection with a threaded, screw-like interconnection. In other embodiments, the second compression member retainer 252 can be integrally formed with the member 220 or can be otherwise connected to the member 220. Preferably, the second compression member retainer 252 has a diameter or circumference that is larger than the diameter or circumference of the member 220 but smaller than the inner diameter or circumference of the first shaft 22.

[0049] The adjustment member 208 is held in place relative to the retainer 212 by the second compression member retainer 252, so that the biasing member 232 applies tension between the adjustment member 208 and the retainer 212. When the biasing member 232 applies a biasing force, the second compression member retainer 252 contacts the retainer 212 and / or the resilient member 240, counteracting the biasing force and creating tension. In other embodiments of the compression assembly 204, the biasing member 232 can apply tension between any suitable portion of the adjustment member 208 and any suitable portion of the retainer 212. For example, the biasing member 232 can be positioned within the second shaft 120 between the adjustment member 208 and the retainer 212. In this example, adjustment member 208 and retainer 212 can each include a protrusion that contacts an opposite end of biasing member 232 to facilitate applying tension between adjustment member 208 and retainer 212. Additionally, in other embodiments, biasing member 232 may or may not be connected to one or both of adjustment member 208 and / or retainer 212.

[0050] The relative sizing of the first and second compression member retainers 248, 252 with respect to the other components provides retention of the resilient member 240 while also providing for axial sliding of the compression assembly 204 (and attached second shaft 120) relative to the first shaft 22. The relative sizing is provided for illustrative purposes. In other embodiments, the resilient member 240 and compression member retainers 248, 252 can be of any suitable size, shape, or positioning relative to one another to enable the compression assembly 204 to selectively apply a compressive force between the first shaft 22 and the compression assembly 204, and selectively retain the compression assembly 204 and attached second shaft 120 with the first shaft 22.

[0051] The compression assembly 204 is adjustable between a first configuration and a second configuration, wherein in the first configuration, as shown in FIGS. 11-13 , the compression assembly 204 applies a selective compressive force to the resilient member 240, and in the second configuration (not shown), the compression assembly 204 does not apply a selective compressive force to the resilient member 240. Specifically, the resilient member 240 has a larger outer diameter in the first configuration than in the second configuration. More specifically, when the compression assembly 204 applies a compressive force to the resilient member 240 in the first configuration, the resilient member 240 expands radially outward from the axial direction of the first and second shafts 22, 120 and engages the first shaft 22. In the second configuration, the compressive force is removed from the resilient member 240, and the resilient member 240 contracts radially inward, returning to a relaxed or normal state. In a relaxed state, the resilient member 240 is sized to permit axial movement within the first shaft 22, or movement in a direction generally parallel to the axis A (shown in FIGS. 1-2), by the compression assembly 204.

[0052] As shown in FIG. 11 , the adjustable-length shaft assembly 200 is provided in a first configuration. The biasing member 232 applies a biasing force against the head 216 of the adjustment member 208 in a first direction 256, away from the club head 14. The biasing force pulls the second compression member retainer 252 toward the first compression member retainer 248, decreasing the distance between the first compression member retainer 248 and the second compression member retainer 252. The second compression member retainer 252 then applies a compressive force to the resilient member 240, causing the resilient member 240 to expand radially outward from the compression assembly 204 (and radially outward from the axial direction of the first and second shafts 22, 120) and engage the first shaft 22. When the elastic member 240 expands radially outward between the first shaft 22 and the tubular portion 228 of the retainer 212, the elastic member 240 limits axial movement of the retainer 212 relative to the first shaft 22. And, because the second shaft 120 is attached to the retainer 212, the elastic member 240 limits movement of the second shaft 120 relative to the first shaft 22, and therefore the club length of the golf club 10 cannot be adjusted.

[0053] To adjust the club length of golf club 10, a user inserts a torque wrench into aperture 46 defined by grip 34 and engages the torque wrench with socket 108 of head 216. The user then applies force with the torque wrench in a direction 260 opposite biasing force direction 256, sufficiently overcoming the biasing force, i.e., it compresses biasing member 232. As biasing member 232 compresses, adjustment member 208 slides within retainer 212, and more specifically, slides in second direction 260 toward club head 14. Head 216 slides within well 224 in second direction 260 toward club head 14, while second compression member retainer 252 moves away from first compression member retainer 248, increasing the distance between first compression member retainer 248 and second compression member retainer 252.

[0054] The second compression member retainer 252 then releases the compression force on the resilient member 240, allowing the resilient member 240 to contract radially inwardly toward the axes of the first and second shafts 22, 120, releasing the first shaft 22. Once the resilient member 240 is released from the first shaft 22, the first and second shafts 22, 120 are free to move relative to one another, allowing the user to adjust the club length of the golf club 10. The compression assembly 204 is now in a second configuration, not shown.

[0055] More specifically, to adjust the club length of golf club 10, the user maintains the application of force in second direction 260 with the torque wrench and then slides first shaft 22 relative to second shaft 120. To increase the club length of golf club 10, the user slides first shaft 22 away from second shaft 120 (in first direction 256), withdrawing first shaft 22 from second shaft 120. To decrease the club length of golf club 10, the user slides first shaft 22 toward second shaft 120 (in second direction 260), inserting first shaft 22 into second shaft 120. As first shaft 22 moves axially (in either first direction 256 or second direction 260), attached insert 128 moves with first shaft 22. Thus, the insert 128 moves in both axial directions along the tubular portion 228 of the retainer 212, with the slot 124 retaining and guiding the protrusion 132 on the insert 128. This combination assists in adjusting the first shaft 22 relative to the second shaft 120 to increase or decrease the club length of the golf club 10, while limiting rotation of the second shaft 120 relative to the first shaft 22 to maintain the orientation of the grip 34 relative to the club head 14 (i.e., limiting rotation of the grip 34 about the first shaft 22). Adjusting the club length by sliding the first shaft 22 relative to the second shaft 120 is provided for illustrative purposes, and it should be recognized that either of the first and second shafts 22, 120 can slide relative to the other.

[0056] Once the user adjusts the first shaft 22 and / or the second shaft 120 to the desired club length of the golf club 10, the user removes the force applied by the torque wrench in the second direction 260, causing the compression assembly 204 to transition from the second configuration back to the first configuration. The biasing member 232 applies a biasing force in the first direction 256 to the head 216 of the adjustment member 208, pulling the second compression member retainer 252 toward the first compression member retainer 248. The second compression member retainer 252 then applies a compressive force to the resilient member 240, causing the resilient member 240 to expand radially outward and engage the first shaft 22, limiting axial movement of the retainer 212 relative to the first shaft 22 along axis A (see FIGS. 1-2 ). This in turn limits or minimizes the movement of the second shaft 120 relative to the first shaft 22, and therefore the club length of the golf club 10 cannot be adjusted.

[0057] In the illustrated embodiment, the second shaft includes a slot and the insert includes a protrusion. In other embodiments, the second shaft can include two or more slots and the insert can include two or more protrusions. The second shaft can have any number of slots, such as one, two, three, four, five, or any other number of slots. The insert can have any number of protrusions corresponding to the number of slots, such as one, two, three, four, five, or any other number of protrusions. For example, the second shaft can include three slots corresponding to three protrusions on the insert, or the second shaft can include four slots corresponding to four protrusions on the insert. In some embodiments, the slots can be positioned equidistantly or asymmetrically around the second shaft. Furthermore, the protrusions can be positioned equidistantly or asymmetrically around the insert.

[0058] In still other embodiments, the second shaft can include one or more protrusions and the insert can include one or more slots. In these or other embodiments, the second shaft can have any number of protrusions, such as one, two, three, four, five, or any other number of protrusions. In these or other embodiments, the insert can have any number of slots corresponding to the number of protrusions, such as one, two, three, four, five, or any other number of slots. For example, the second shaft can include three protrusions corresponding to three slots on the insert, or the second shaft can include four protrusions corresponding to four slots on the insert. In some embodiments, the protrusions can be positioned equidistantly or asymmetrically around the second shaft. Furthermore, the slots can be positioned equidistantly or asymmetrically around the insert.

[0059] 14-19 illustrate a third embodiment of an adjustable length shaft assembly 300. Assembly 300 has elements in common with assemblies 100 and 200, and the common elements are given the same reference numerals. Third embodiment assembly 300 includes a cam lock assembly 304, which is disclosed in additional detail below, for selectively adjusting and maintaining the length of golf club 10.

[0060] 14, grip 34 defines aperture 46 at second end 50. Aperture 46 provides access to cam lock assembly 304 (shown in FIGS. 15-17), and more specifically, to adjustment member 308 (shown in FIG. 16) that carries socket 108 (shown in FIGS. 15-17). Grip 34 is attached to second shaft 120 (shown in FIGS. 15-16) but not to first shaft 22.

[0061] As shown in FIGS. 15-16 , the first shaft 22 is received by the second shaft 120, allowing the first and second shafts 22, 120 to move axially relative to one another. An insert 128 is secured to the second end 30 of the first shaft 22 (shown in FIG. 16 ). The insert 128 also includes a protrusion 132 that extends beyond the outer periphery of the first shaft 22. The second shaft 120 includes a slot 124 (shown in FIG. 15 ), which extends axially along the second shaft 120 from the second end 116 (shown in FIG. 16 ) toward the club head 14. The protrusion 132 is secured to be received by the slot 124.

[0062] 16, the adjustable length shaft assembly 300 includes an adjustment member 308 and a retainer 312. The adjustment member 308 includes a head or head portion 316 connected to a member or shaft portion 320. The member 320 extends into the second shaft 120 away from the head 316. In the illustrated embodiment, the head 316 has a diameter that is generally larger than the diameter of the member 320. However, in other embodiments, the head 316 can have a diameter that is approximately the same size as the diameter of the member 320 or a diameter that is generally smaller than the diameter of the member 320.

[0063] The retainer 312 includes a well 324 that defines a recess that connects to a channel or aperture 328 provided through the retainer 312. The retainer 312 is received by the second shaft 120 through the second end 116. Additionally, the retainer 312, and more specifically, the well 324, is attached to the second shaft 120 at the second end 116. The retainer 312 does not rotate or otherwise move independently of the second shaft 120. Instead, the retainer 312 moves with the second shaft 120.

[0064] The retainer 312 slidably receives the adjustment member 308, such that the adjustment member 308 slides independently of the retainer 312. More specifically, the recess slidably receives the head 316, while the channel 328 slidably receives the member 320. To facilitate slidable movement of the adjustment member 308 within the retainer 312, the channel 328 has an inner diameter complementary to the outer diameter of the member 320. Similarly, the well 324 has an inner diameter complementary to the outer diameter of the head 316. The complementary sizes allow the adjustment member 308 to slide relative to the retainer 312 in an axial direction, or a direction generally parallel to the first and second shafts 22, 120.

[0065] The adjustment member 308 is resiliently connected to the retainer 312 by a biasing member or spring 332. In the illustrated embodiment, the biasing member 332 is coupled to the adjustment member 308, and more specifically, to the head 316 of the adjustment member 308. The biasing member 332 is also received by the well 324 of the retainer 312.

[0066] Insert 128 defines an aperture 336. Aperture 336 slidably receives adjustment member 308, and more specifically, member 320 of adjustment member 308. Aperture 336 has an inner diameter complementary to the outer diameter of member 320, allowing insert 128 to slide along member 320.

[0067] 17, the cam lock assembly 304 includes a cam member 340 that protrudes from the adjustment member 308. In the illustrated embodiment, the cam member 340 protrudes from the head 316. The cam member 340 is received by a slot 344 within the retainer 312. The slot 344 includes a first end 348 opposite a second end 352, the first end 348 being disposed at an angle relative to the axis A (shown in FIGS. 1-2), with the second end 352 positioned closer to the second shaft 120 than the first end 348. An offset locking portion or groove 356 communicates with the slot 344. In the illustrated embodiment, the locking portion 356 is disposed at an angle relative to the slot 344 at the second end 352 of the slot 344. Additionally, the locking portion 356 is located further away from the second shaft 120 than the second end 352 .

[0068] 16, 18, and 19, insert 128 also includes an extension 360 that extends toward club head 14. Insert 128 defines a channel 364 with extension 360 that receives adjustment member 308, and more specifically, member 320 forming cam portion 368. Channel 364 has a geometry that allows adjustment member 308 and associated cam portion 368 to slide within channel 364 when cam lock assembly 304 is in a first or unlocked configuration, but does not allow adjustment member 308 and associated cam portion 368 to slide within channel 364 when cam lock assembly 304 is in a second or locked configuration. Because adjustment member 308 is held in place relative to retainer 312 by cam portion 368, biasing member 332 applies tension between adjustment member 308 and retainer 312. When biasing member 332 applies a biasing force, cam portion 368 contacts channel 364 and / or insert 128, counteracting the biasing force and creating tension. In other embodiments of variable-length shaft assembly 300, biasing member 332 can apply tension between any appropriate portion of adjustment member 308 and any appropriate portion of retainer 312. In this example, adjustment member 308 and retainer 312 can each include a protrusion in second shaft 120 that contacts opposite ends of biasing member 332 and facilitates applying tension between adjustment member 308 and retainer 312. Additionally, in other embodiments, biasing member 332 may or may not be connected to one or both of adjustment member 308 and / or retainer 312.

[0069] 18 illustrates the adjustment member 308 and associated cam portion 368 in a first or unlocked configuration. The channel 364 has a complementary geometry to the cam portion 368, allowing the cam portion 368 to slide freely within the channel 364. The first and second shafts 22, 120 are then free to move relative to one another, allowing adjustment of the club length of the golf club 10.

[0070] 19 illustrates the adjustment member 308 and associated cam portion 368 in a second or locked configuration. As the cam portion 368 moves from the first configuration to the second configuration, the channel 364 has opposing cam surfaces 372 that respectively engage the cam portion 368, forming a friction fit, press fit, or interference fit. The friction fit holds the adjustment member 308 against the insert 128, which in turn locks the second shaft 120 (coupled to the adjustment member 308 by the retainer 312) to the first shaft 22 (coupled to the insert 128) and limits the club length adjustment of the golf club 10. Although the illustrated embodiment of channel 364 and cam portion 368 are shown with a generally oval cross-sectional shape, in other embodiments, channel 364 and cam portion 368 can have any suitable complementary geometric shape that allows sliding movement of cam portion 368 within channel 364 in an unlocked configuration and does not allow sliding movement of cam portion 368 within channel 364 in a locked configuration by forming a friction fit between cam portion 368 and one or more cam surfaces 372.

[0071] As shown in FIGS. 15-18 , the adjustable shaft assembly 300 is provided in a first or unlocked configuration. The cam lock assembly 304 is in the unlocked configuration, with the cam member 340 positioned in the slot 344 proximal to the first end 348. To help maintain the cam member 340 in the unlocked configuration, the biasing member 332 uses the well 324 to apply a biasing force against the head 316 of the adjustment member 308 in a first direction 376 (shown in FIG. 16 ), away from the club head 14. The cam portion 368 of the adjustment member is secured to or aligned with the channel 364 of the insert 128, allowing the cam portion 368 to slide within the channel 364. The second shaft 120 carries the adjustment member 308 by means of an attached retainer 312, and the second shaft 120 is movable relative to the first shaft 22, which carries the insert 128. Thus, in the unlocked configuration, the first and second shafts 22, 120 can be moved axially relative to one another to adjust the club length of the golf club 10.

[0072] To adjust the club length of the golf club 10, the user can slide the first shaft 22 axially relative to the second shaft 120. To decrease the club length of the golf club 10, the user slides the first shaft 22 toward the second shaft 120 (in a first direction 376), further inserting the first shaft 22 into the second shaft 120. To increase the club length of the golf club 10, the user slides the first shaft 22 away from the second shaft 120 (in a second direction 380 shown in FIG. 16 ), withdrawing the first shaft 22 from the second shaft 120. As the first shaft 22 moves axially (in either the first direction 376 or the second direction 380), the attached insert 128 moves with the first shaft 22. Thus, the insert 128 moves axially along the member 320 of the adjustment member 308 by the aperture 336, the cam portion 368 moves axially within the channel 364 defined by the insert 128, and the slot 124 in the second shaft 120 retains and guides the protrusion 132 on the insert 128. This combination assists in adjusting the first shaft 22 relative to the second shaft 120 to increase or decrease the club length of the golf club 10. The protrusion 132, which is slidably secured within the slot 124, limits rotation of the second shaft 120 relative to the first shaft 22 and maintains the orientation of the grip 34 relative to the club head 14.

[0073] Once the user adjusts the first shaft 22 and / or the second shaft 120 to the desired club length of the golf club 10, the user transitions the cam lock assembly 304 from the unlocked configuration to the locked configuration. The user inserts a torque wrench into the aperture 46 defined by the grip 34 and engages the torque wrench with the socket 108 of the head 316. The user then applies a rotational force with the torque wrench in a first rotational direction, which in the illustrated embodiment is clockwise. Rotation of the torque wrench in the first rotational direction rotates the head 316, the attached cam member 340, and the adjustment member 308 as a whole.

[0074] During rotation, cam member 340 slides along slot 344, moving from first end 348 toward second end 352. Slot 344 converts the rotational force from the torque wrench into a linear force that overcomes the biasing force imparted by biasing member 332. This results in adjustment member 308 sliding relative to both retainer 312 and insert 128 in a second direction 380 (toward club head 14) along axis A (shown in FIGS. 1-2). Cam portion 368 simultaneously rotates within channel 364 from the unlocked configuration (shown in FIG. 18 ) to the locked configuration (shown in FIG. 19 ), and one or more cam surfaces 372 of channel 364 engage cam portion 368.

[0075] 17, when cam member 340 reaches second end 352 of slot 344, continued rotation of the torque wrench in a first rotational direction directs cam member 340 into locking portion 356, which is offset from slot 348. Once cam member 340 is received within locking portion 356, a user can no longer rotate adjustment member 308 by head 316. A biasing force applied by biasing member 332 relative to head 316 in a first direction 376 (shown in FIG. 16) maintains cam member 340 within locking portion 356. Cam lock assembly 308 is now in a locked configuration. Additionally, one or more cam surfaces 372 of channel 364 engage cam portion 368, forming a friction fit that locks adjustment member 308 (and attached second shaft 120) to channel 364 defined by insert 128 (and attached first shaft 22). In the locked configuration, relative movement of first shaft 22 and second shaft 120 is limited or minimized, and thus, the club length of golf club 10 cannot be adjusted. A user can freely withdraw the torque wrench from socket 108 of head 316.

[0076] To transition cam lock assembly 304 from the locked configuration to the unlocked configuration, a user inserts a torque wrench into socket 208 and applies a twisting and downward force in second direction 380 (or toward club head 14) to overcome the biasing force applied by biasing member 332 against head 316. While applying the downward force on head 316, the user rotates the torque wrench in a second rotational direction, which in the illustrated embodiment is counterclockwise. This disengages cam member 340 from locking portion 356 and moves cam member 340 toward second end 352 of slot 344. Continued rotation in the second rotational direction further rotates head 316 and moves cam member 340 along slot 344 from second end 352 to first end 348. It should be appreciated that the biasing force applied to head 316 by biasing member 332 contributes to moving cam member 340 toward first end 348 of slot 344. As head 316 rotates, cam portion 368 rotates about insert 124 within channel 364 from the locked configuration (shown in FIG. 19 ) toward the unlocked configuration (shown in FIG. 18 ), and one or more cam surfaces 372 of channel 364 disengage cam portion 368. Once cam member 340 reaches first end 348 of slot 344 (shown in FIG. 17 ), cam lock assembly 304 is in the unlocked configuration. In this unlocked configuration, the club length of golf club 10 may be freely adjusted, as previously described.

[0077] It should be appreciated that the geometry of cam lock assembly 304, and more specifically, the geometry of slot 344 and associated offset locking portion 356, is provided for illustrative purposes. In other embodiments, the geometry may be adjusted while maintaining the same functionality. For example, the geometry may be such that to rotate adjustment member 308 from an unlocked configuration to a locked configuration, a user rotates the torque wrench in a first rotational direction, the first rotational direction being a counterclockwise rotation of the torque wrench. Similarly, to rotate adjustment member 308 from a locked configuration to an unlocked configuration, a user rotates the torque wrench in a second rotational direction, the second rotational direction being a clockwise rotation of the torque wrench.

[0078] It should also be appreciated that in other embodiments, aspects of variable-length shaft assembly 300 may be modified, added, or removed while still selectively adjusting and maintaining the length of golf club 10. For example, in one embodiment of variable-length shaft assembly 300, cam lock assembly 304 does not include biasing member 332, cam member 340, or slot 344. Instead, cam lock assembly 304 includes cam portion 368, which rotates within channel 364 between an unlocked configuration (shown in FIG. 18 ) and a locked configuration (shown in FIG. 19 ), as otherwise previously described.

[0079] In another embodiment of adjustable-length shaft assembly 300, biasing member 332, cam member 340, and slot 344 of cam lock assembly 304 are replaced by a plurality of threads extending around the outer periphery or periphery of head 316 that mate with threads extending around the recess defined by well 324. Rotation of head 316 effects translational movement of adjustment member 308 in the axial direction.

[0080] In another embodiment of adjustable length shaft assembly 300, slot 344 is positioned perpendicular to axis A (shown in FIGS. 1-2) and defines a limit of travel for head 316. Thus, rotation of head 316 results in rotation of adjustment member 308, but not translation.

[0081] 24-27 illustrate a fourth embodiment of an adjustable length shaft assembly 500. Assembly 500 has elements in common with assembly 100, and the common elements have been given the same reference numerals.

[0082] 24-25, the screw head 104 is received by a retainer 112, which is stationary relative to a second shaft 120 but allows rotation of the screw head 104. The second shaft 120 includes an inner surface 122 that is configured to receive an outer surface 130 of an insert 128. Both the second shaft 120 and the insert are slot- and protrusion-free (see FIGS. 26-27).

[0083] 26-27 , the inner surface 122 of the second shaft 22 includes a substantially hexagonal cross-sectional shape. The outer surface 130 of the insert 128 includes a substantially hexagonal cross-sectional shape that corresponds to the inner surface 122 of the second shaft 120. The cross-sectional shape of the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 128 limit rotation of the second shaft 120 relative to the first shaft 22, similar to the slots 124 and protrusions 132 in the first embodiment of the variable length shaft assembly 100.

[0084] In the illustrated embodiment, the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 128 have a substantially hexagonal cross-sectional shape. In other embodiments, the cross-sectional shape of the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 128 can be any shape that can limit rotational movement between the second shaft 120 and the insert 128. For example, the cross-sectional shape of the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 128 can be a polygon or shape with at least one curved surface, such as a semicircle, a triangle, a square, a rectangle, a pentagon, a hexagon, or any other shape.

[0085] 25 , the second shaft 120 further includes one or more tabs 126. The tabs 126 are angled toward the first shaft 22 to provide a secure fit between the second shaft 120 and the first shaft 22. In the illustrated embodiment, the second shaft 120 includes three tabs 126. Each of the three tabs 126 is spaced equidistant from one another. In other embodiments, the second shaft 120 can include any number of tabs 126. For example, the second shaft 120 can include one, two, three, four, five, or any other number of tabs 126.

[0086] Additionally, in other embodiments, the second shaft 120 can include a gasket in addition to or instead of the tabs 126. The second shaft 120 can have one or more grooves (171) for receiving the gasket 170. The second shaft 120 can have one, two, three, or four grooves (171) for receiving the gasket 170. The gasket 170 can be made from rubber, polyurethane, a polymeric material, or any other material that can provide a tight fit between the first shaft 22 and the second shaft 120 ( FIG. 28 ). Furthermore, the second shaft 120 with the gasket 170 can travel the length of the threaded screw 140 but limit side-to-side movement between the first shaft 22 and the second shaft 120.

[0087] Additionally, in other embodiments, the second shaft 120 can include an overmolded section that provides a tight fit between the second shaft 120 and the first shaft 22 (not shown). The second shaft 120 can have an overmolded section within the bottom 0.5 inches, 1.0 inches, 1.5 inches, 2.0 inches, or 2.5 inches of the second shaft 120. This overmolded section can comprise a polymer material, rubber, a rubber-like material, or any other material that can provide a tight fit between the first shaft 22 and the second shaft 120 (not shown). Additionally, the second shaft 120 with the overmolded section can travel the length of the threaded screw 140, limiting side-to-side movement between the first shaft 22 and the second shaft 120.

[0088] The variable length shaft assembly 500 described herein may be operated in the same manner as the variable length shaft assembly 100 described above, with the restriction of rotational movement of the first shaft 22 relative to the second shaft 120 being achieved by the cross-sectional shape of the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 128 instead of by a slot and protrusion mechanism.

[0089] 30-38 show a fifth embodiment of an adjustable length shaft assembly 800. Assembly 800 has elements in common with assemblies 100 and 500, and the common elements are given the same reference numerals.

[0090] 31-34 , the screw head 104 is received by a retainer 812, which is stationary relative to the second shaft 120 but allows rotation of the screw head 104. The retainer 812 is itself received by the second or butt end 116 of the second shaft 120. The second shaft 120 further includes a first end 118 opposite the second end 116. The second shaft 120 includes an inner surface 122, which is configured to receive the outer surface 114 of the retainer 812.

[0091] In the illustrated embodiment, the retainer 812 includes two semicircular pieces. The two pieces of the retainer 812 snap-fit ​​within the second end 116 of the second shaft 120, improving the concentricity of the threaded screw 140 within the second shaft 120. The improved concentricity better aligns the first shaft 22 within the second shaft 120. To achieve the improved concentricity, the outer surface 114 of the retainer 812 further includes one or more pegs 818. The one or more pegs 818 extend outward from the outer surface 114 of the retainer 812 and are configured to be received by one or more apertures 820 disposed on the second shaft 120. The interlocking geometry between the pegs 818 and the apertures 820 allows the retainer 812 to remain stationary relative to the second shaft 120, while allowing the screw head 104 to rotate.

[0092] The inner surface 122 of the second shaft 120 includes a substantially hexagonal cross-sectional shape. The outer surface 114 of the retainer 812 includes a substantially hexagonal cross-sectional shape that corresponds to the inner surface 122 of the second shaft 120. The cross-sectional shapes of the inner surface 122 of the second shaft 120 and the outer surface 114 of the retainer 812 allow the retainer 812 to remain stationary within the second shaft 120 while still allowing the threaded screw 140 to rotate.

[0093] In other embodiments, the cross-sectional shape of the outer surface 114 of the retainer 812 can be any shape that can allow the retainer 812 to remain stationary within the second shaft 120. For example, the cross-sectional shape of the outer surface 114 of the retainer 812 can be a polygon or shape with at least one curved surface, such as a semicircle, a triangle, a square, a rectangle, a pentagon, a hexagon, or any other shape.

[0094] 32 and 34 , the outer surface 114 of the retainer 812 includes a plurality of nub-like protrusions 814. The nub-like protrusions 814 extend outward from the outer surface 114 of the retainer 812. The nub-like protrusions 814 can be point-like protrusions or projections extending outward from the outer surface 114 of the retainer 812. The nub-like protrusions 814 are configured to abut or press against the inner surface 122 of the second shaft 120. The nub-like protrusions 814 provide a secure fit between the retainer 112 and the second shaft 120. The nub-like protrusions 814 further improve the concentricity of the threaded screw 140 within the second shaft 120.

[0095] As shown in FIG. 34 , the retainer 812 includes an axial end surface 816. The axial end surface 816 of the retainer 812 is adjacent to the second end 116 of the second shaft 120. The retainer 812 further includes an axial length measured from the axial end surface 816 of the retainer in a direction from the second end 116 to the first end 118 of the second shaft 120. In some embodiments, the nub 814 can be located near the axial end surface 816 of the retainer. In other embodiments, the nub 814 can be located away from the axial end surface 816 of the retainer. The nub 814 of the retainer 812 can be positioned at least 25% of the axial length of the retainer 812. In other embodiments, the nub-like protrusions 814 of the retainer 812 may be positioned at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80% of the axial length of the retainer 812. In still other embodiments, the nub-like protrusions 814 of the retainer 812 may be positioned on at least one side of the hexagonal retainer 812. In other embodiments, the nub-like protrusions 814 of the retainer 812 may be positioned on one, two, three, four, five, or six sides of the hexagonal retainer 812.

[0096] The nub-like protrusion 814 can include a substantially spherical shape. In other embodiments, the nub-like protrusion 814 can be any shape that can abut or press against the inner surface 122 of the second shaft 120. For example, the shape of the nub-like protrusion 814 can be a semicircle or a shape with at least one curved surface, such as a hemisphere, a cylinder, a triangle, a square, a rectangle, a pentagon, a hexagon, a polygon, or any other shape.

[0097] In the illustrated embodiment, the outer surface 114 of the retainer 812 includes eight nub-like protrusions 814, where two nub-like protrusions 814 are positioned on the sides of the hexagonal retainer 812. In other embodiments, the retainer 812 can include any number of nub-like protrusions 814. For example, the retainer 812 can include 4 to 24, 4 to 18, or 4 to 12 nub-like protrusions 814. In other examples, the retainer 812 can include 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 nub-like protrusions 814.

[0098] 34-36 depict an insert 828 received within the second end 30 of the first shaft 22. The insert 828 also defines a threaded aperture 136 and an unthreaded tubular portion 836. The inner surface 122 of the second shaft 120 is configured to receive the outer surface 130 of the insert 828. The insert 128 is configured to be coupled, attached, or secured to the second end 30 of the first shaft 22. The outer surface 130 of the insert 828 is configured to be coupled, attached, or secured to the inner surface 24 of the first shaft 22 at the second end 30. In other words, the insert 828 is coupled, attached, or secured to the end or axial end face 32 of the first shaft 22. The insert 828 may be coupled, attached, or secured to the first shaft 22 by adhesive, epoxy, glue, or any other suitable adhesive. In some embodiments, the insert 828 is permanently coupled, attached, or secured to the axial end face 32 of the first shaft 22 .

[0099] The insert 828 defines a first axial end face 838 and a second axial end face 840. The first axial end face 838 is located near the second end 116 of the second shaft 120. The second axial end face 840 is located near the first end 118 of the second shaft 120. The insert 828 extends into a portion of the first shaft 22 and engages with the first shaft 22, where the second axial end face 840 is located within the first shaft 22. The engagement between the insert 828 and the first shaft 22 defines an engagement length. The engagement length is defined as the axial length between the axial end face 32 of the first shaft 32 and the second axial end face 840 of the insert 828. The engagement length between the insert 828 and the first shaft 22 improves the stiffness of the variable shaft length assembly 800, thereby limiting side-to-side or radial movement between the first shaft 22 and the second shaft 120 during operation of the variable shaft length assembly 800. The insert 828 engages a larger portion of the first shaft 22, which can improve alignment of the first shaft 22 within the second shaft 120. Good alignment of the first shaft 22 reduces misalignment, thereby allowing the first shaft 22 to translate freely without interfering with the second shaft 120.

[0100] In the illustrated embodiment, the engagement length between the insert 828 and the first shaft 22 is 5.0 inches. In other embodiments, the engagement length can be 2 to 10 inches. In other embodiments, the engagement length can be 2 to 5 or 5 to 10 inches. In still other embodiments, the engagement length can be 2 to 6, 3 to 7, 4 to 8, 5 to 9, or 6 to 10 inches. For example, the engagement length can be 2, 3, 4, 5, 6, 7, 8, 9, or 10 inches.

[0101] 33 , the outer surface 130 of the insert 828 includes a substantially hexagonal cross-sectional shape. As described above, the inner surface 122 of the second shaft 120 includes a hexagonal cross-sectional shape. The outer surface 130 of the insert 128 corresponds to the inner surface 122 of the second shaft 120. The cross-sectional shapes of the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 828 limit rotation of the second shaft 120 relative to the first shaft 22. Limiting rotation of the second shaft 120 relative to the first shaft 22 with the cross-sectional shape can be similar to how the slot 124 and protrusion 132 of the variable-length shaft assembly 100 limit rotation of the second shaft 120 relative to the first shaft 22.

[0102] In the illustrated embodiment, the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 828 have a substantially hexagonal cross-sectional shape. In other embodiments, the cross-sectional shape of the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert can be any shape that can limit rotational movement between the second shaft 120 and the insert 828. For example, the cross-sectional shape of the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 828 can be a polygon or shape with at least one curved surface, such as a semicircle, a triangle, a square, a rectangle, a pentagon, a hexagon, or any other shape.

[0103] 34 and 38 , the outer surface 130 of the insert 828 further includes a plurality of nub-like protrusions 832. The nub-like protrusions 832 of the insert 828 can be similar to the nub-like protrusions 814 of the retainer 812. The nub-like protrusions can be point-like protrusions or projections extending outward from the outer surface 130 of the insert 828. The nub-like protrusions 832 are configured to abut or press against the inner surface 122 of the second shaft 120. The nub-like protrusions 832 provide a secure fit between the insert 828 and the second shaft 120. Additionally, the nub-like protrusions 832 are configured to abut or press against the inner surface 24 of the first shaft 22. The nub-like protrusions 832 of the insert 828 provide good adhesion coverage by allowing adhesive to collect between the nub-like protrusions 832.

[0104] The nub-like protrusion 832 can include a substantially spherical shape. The nub-like protrusion 832 of the insert 828 can include a shape similar to the nub-like protrusion 814 of the retainer 812. In other embodiments, the nub-like protrusion 832 can be any shape that can abut or press against the inner surface 122 of the second shaft 120. For example, the shape of the nub-like protrusion 832 can be a semicircle, or a shape with at least one curved surface, such as a hemisphere, a cylinder, a triangle, a square, a rectangle, a pentagon, a hexagon, a polygon, or any other shape.

[0105] In the illustrated embodiment, the outer surface 130 of the insert 828 includes 60 nub-like protrusions 832, where 24 nub-like protrusions 832 press against or abut the inner surface 122 of the second shaft 120 and 36 nub-like protrusions 832 abut against or press against the inner surface 24 of the first shaft 22. In other embodiments, the insert 828 can include any number of nub-like protrusions 832. For example, the insert 828 can include 10 to 100, 10 to 90, 10 to 80, 10 to 70, or 10 to 60 nub-like protrusions 832. In other examples, the insert 828 can include 10 to 50, 20 to 60, 30 to 70, 40 to 80, 50 to 90, or 60 to 100 nub-like protrusions 832. In still other examples, the insert 828 can include 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 nub-like protrusions 832 .

[0106] Further, the nub-like protrusion 832 can include a height. The height of the nub-like protrusion 832 is measured in a direction perpendicular to the outer surface 130 of the insert 828 from the outer surface 130 of the insert 828 to the apex of the nub-like protrusion 832. The height of the nub-like protrusion 832 of the insert 828 and the height of the nub-like protrusion 814 of the retainer 812 can be similar. The height of the nub-like protrusion 832 can be in the range of 0.005 to 0.015 inches. In some embodiments, the height of the nub-like protrusion 832 can be in the range of 0.005 to 0.01 inches, or 0.01 to 0.015 inches. For example, the height of the nub protrusions 832 can be 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.011, 0.012, 0.013, 0.014, or 0.015 inches. In one example, the height of the nub protrusions 832 is 0.01 inches.

[0107] Referring to FIG. 38 , the insert 828 also includes an inner surface 138. The insert 828 may further include one or more ribs 834 positioned on the inner surface 138 of the insert 828. The one or more ribs 834 may be positioned on the inner surface 138 within the tubular portion 836 of the insert 828. The ribs 834 extend outward from the inner surface 138 of the insert 828. The ribs 834 extend along the tubular portion 836 in a direction from the first axial end face 838 to the second axial end face 840. The ribs 834 provide a secure fit between the threaded screw 140 and the insert 828. In the illustrated embodiment, the insert 828 includes three ribs 834. Each of the ribs 834 is spaced equidistant from one another. In other embodiments, the insert 828 may include any number of ribs 834. For example, the insert 828 can include one, two, three, four, five, six, seven, eight, nine, or ten ribs 834. As described in more detail below, the ribs 834 provide a secure fit between the threaded screw 140 and the insert 828. The threaded screw 140 is configured to weave into the ribs 834 and minimize side-to-side or radial movement between the first shaft 22 and the second shaft 120.

[0108] Additionally, the ribs 834 can include a height. The height of the ribs 834 is measured in a direction perpendicular to the inner surface 138 of the insert 828 from the inner surface 138 to the apex of the ribs 834. The height of the ribs 834 is measured radially inward from the inner surface 138 to a centerline extending through the threaded aperture 136 and tubular portion 836 of the insert 828. The height of the ribs 834 can be in the range of 0.001 to 0.01 inches. In some embodiments, the height of the ribs 834 can be in the range of 0.001 to 0.005 inches, or 0.005 to 0.01 inches. For example, the height of the ribs 834 can be 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, or 0.01 inches. In one example, the height of the ribs 834 is 0.005 inches.

[0109] 35 and 37 , the variable shaft length assembly 800 further includes an alignment member 844. The alignment member 844 is positioned on the first end 118 of the second shaft 120. The first end 118 is opposite the second end 116 of the second shaft 120. The alignment member 844 includes one or more protrusions 848. The one or more protrusions 848 extend away from the alignment member and are configured to be received by one or more apertures 820 disposed on the second shaft 120. The protrusions 848 are configured to mechanically interlock with the apertures 820. The protrusions 848 fix the position of the alignment member 844 within the second shaft 120. The alignment member 844 does not move or translate within the second shaft 120 during operation of the variable shaft length assembly 800. The alignment member 844 minimizes side-to-side or radial movement of the first shaft 22 within the second shaft 120 during operation of the variable shaft length assembly 800. The alignment member 844 minimizes misalignment of the first shaft within the second shaft 120, thereby allowing the first shaft 22 to translate freely without interfering with the second shaft 120 during operation of the variable shaft length assembly 800.

[0110] The threaded aperture 136 of the insert 828 receives the threaded screw 140. The threaded screw 140 is configured to have a mating engagement with the threaded aperture 136. As described above with respect to the variable shaft length assembly 100, the mating engagement between the threaded screw 140 and the threaded aperture 136 allows the first shaft 22 and the second shaft 120 to move axially relative to one another and temporarily lock the variable shaft length assembly axially when not in use.

[0111] During operation of the adjustable-length shaft assembly 800, the threads of the screw 140 interlock with the threads of the aperture 136 of the insert 828. As the insert 828 and first shaft 22 move toward the second end 116, the threaded screw 140 overlaps a portion of the tubular portion 836 of the insert 828. The threads of the screw 140 interlock with one or more ribs 834, providing a tight fit between the insert 828 and the threaded screw 140. The threads of the screw 140 weave into the one or more ribs 834. The wedging action between the threaded screw 140 and the ribs 834 is achieved by the diameter of the threaded screw 140 and the diameter of the opening between the one or more ribs 834.

[0112] In the illustrated embodiment, the diameter of the threaded screw 140 is larger than the diameter of the opening between the one or more ribs 834. In the illustrated embodiment, the diameter of the threaded screw 140 is 0.25 inches, and the diameter of the opening between the one or more ribs 834 is 0.242 inches. However, the diameter of the threaded screw 140 and the opening between the one or more ribs 834 is not limited and can be any diameter suitable for the threaded screw 140 to wedged into the one or more ribs 834. The wedging action between the threaded screw 140 and the one or more ribs 834 provides a tight fit by minimizing side-to-side or radial movement of the first shaft 22 within the second shaft 120.

[0113] The variable shaft length assembly 800 described herein may be operated in the same manner as variable shaft length assemblies 100 or 500, as described above, and the restriction of rotational movement of the first shaft 22 relative to the second shaft 120 is achieved by the cross-sectional shape of the inner surface 122 of the second shaft 120 and the outer surface 130 of the insert 128, as in variable length shaft assembly 500.

[0114] FIG. 20 illustrates an embodiment of an adjustable mass assembly 400. In the illustrated embodiment, the grip 34 is attached to the shaft 22, which contains a mass 404. The mass 404 is attached to an adjustment assembly 408, which provides axial movement of the mass 404 within or along the shaft 22 (or along axis A shown in FIG. 1 ) while also locking the mass 404 in a desired position. The adjustment assembly 408 can be any suitable assembly for moving the mass 404 within the shaft 22, as described further below.

[0115] Mass 404 is a single piece of weighted material, which may include rubber, metal, metal alloy, composite material, polyurethane, reinforced polyurethane, or any other suitable material or combination of materials. Mass 404 may be any suitable size, so long as mass 404 fits within shaft 22 and is movable within shaft 22. Mass 404 may be any suitable or desired weight, which may include, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more than 20 grams. Mass 404 may be removable from shaft 22 and replaceable with a second mass 404 having a different weight, size, shape, or combination thereof.

[0116] In one or more example embodiments, mass 404 may include multiple masses 404 having the same or different weights, sizes, shapes, or combinations thereof. For example, multiple masses 404 may be axially disposed or stacked within shaft 22. As another example, multiple masses 404 may be radially offset within shaft 22. In yet other embodiments, mass 404 may incorporate a flexible material that allows for axial movement of mass 404 within shafts 22 having different or variable shaft diameters, resulting in less impact on shaft stiffness.

[0117] In yet another embodiment, the mass 404 may be defined by multiple separate shaft sections that together define the shaft 22. One or more sections may be interchangeable or replaceable with sections having different masses (e.g., sections having larger or smaller masses). The sections may be coupled together to define the club shaft 22.

[0118] 21, there is illustrated an embodiment of an adjustable mass assembly 400. In an embodiment, the adjustment assembly 408 includes components of the variable length shaft assembly 100, with common elements being given the same reference numerals.

[0119] The adjustment assembly 408 includes a screw head 104 that is received by a retainer 112 and rests relative to the shaft 22. The retainer 112 is itself received by the second or butt end 30 of the shaft 22. The shaft 22 includes a slot or cutout 124 that extends axially along the axis A (shown in FIGS. 1-2 ) from the second end 30 toward the club head 14. The slot 124 may extend axially along any desired distance or length of the shaft 22.

[0120] The mass 404 is received within the shaft 22 and includes a protrusion 132 that projects away from the mass 404 and is secured to be received by the slot 124. The mass 404 also defines a threaded aperture 136 that receives a correspondingly threaded screw 140 that extends away from the screw head 104. The grip 34 is attached to the shaft 22.

[0121] During operation of the adjustable mass assembly 400, a user engages a torque wrench with the socket 108 of the screw head 104. To adjust the position of the mass 404 within the shaft 22, the user rotates the torque wrench in a first direction, rotating the screw head 104 and associated screw 140 within the retainer 112. The threads of the screw 140 engage the threads of the aperture 136 in the mass 404. The protrusion 132 fixes the rotational position of the mass 404 relative to the shaft 22, and rotation of the screw 140 drives the mass 404 axially along the slot 124. As the screw 140 rotates in the first direction, the mass 404 is driven away from the second end 30. Alternatively, the user rotates the torque wrench in a second direction opposite the first direction, moving the mass 404 within the shaft 22 toward the second end 30. Once the desired position of the mass 404 within the shaft 22 is achieved, the user removes the torque wrench from the screw head 104.

[0122] In another embodiment of adjustable mass assembly 400 (similar to FIG. 21 ), slot 124 is replaced with an axial rail on the interior of shaft 22 to increase the axial travel distance of mass 404 within shaft 22. Instead of protrusion 132, mass 404 may be secured to the rail. The rail fixes the rotational position of mass 404 relative to shaft 22 and drives mass 404 axially in response to rotation of screw 140. The rail can provide greater structural rigidity to shaft 22 than slot 124, while also extending axially along a greater length of shaft 22 and providing a greater adjustment distance for mass 404 within shaft 22.

[0123] 29 illustrates another embodiment of a golf club shaft having an adjustable mass assembly 400. In the illustrated embodiment, adjustable mass assembly 400 includes an adjustable mass 404, which is shown as an internal screw located at the butt end of shaft 22 or grip 34 end. Adjustable mass 404 includes a threaded body portion 410 and a screw head 412. Threaded body portion 410 is received within a screw nut 414.

[0124] The screw-nut 414 has inner surface threads that meshingly engage the threaded body portion 410 of the mass 404. The threads on the inner surface 416 of the screw-nut 414 guide the mass 404 for axial movement relative to the shaft 22 as the mass 404 is rotated. The screw-nut 414 further includes an outer surface 418 that is attached to the inner surface 416 of the shaft 22 at a fixed location along the shaft 22. The screw-nut 414 may be attached to the inner surface of the shaft 22 with an adhesive, such as epoxy, glue, or tape.

[0125] The screw head 412 of the mass 404 includes a socket 108 that is exposed in the aperture 46 at the butt of the shaft 22. A torque wrench 150 can be inserted through the aperture 46 and into the socket 108 of the screw head 412 to adjust the position of the mass 404 within the shaft 22. Rotating the torque wrench 150 in a clockwise motion shifts the mass 404 down the shaft 22 or closer to the club head. Similarly, rotating the torque wrench 150 in a counterclockwise motion shifts the mass 404 up the shaft 22 or closer to the butt. Shifting the mass 404 affects the moment of inertia and swing weight of the golf club 10. The distance and weight of the mass 404 shifted per rotation of the torque wrench 150 depends on the pitch of the threaded body 410. For example, for a mass 404 having a weight of 4 grams, rotating the torque wrench 150 five revolutions will shift the mass 404 by 1.25 inches, changing the swing weight by 0.1. In another example, for a mass 404 having a weight of 8 grams, rotating the torque wrench 150 two and a half revolutions will shift the mass 404 by 1.25 inches, changing the swing weight by 0.1.

[0126] In one example, mass 404 has a weight of 4 grams, with 2 grams of additional weight positioned in club head 14 to provide a counterbalance in golf club 10. The counterbalance for adjustable mass 404 in the butt of the shaft to club head 14 is approximately a 2:1 ratio, meaning that for every 2 grams of weight added to the butt of the shaft, an additional 1 gram must be added to club head 14. In another embodiment, adjustable mass 404 in the butt of shaft 22 can have a weight of 6 grams, and club head 14 can have a weight of 3 grams. This counterbalance ratio of 2:1 will help maintain the same swing weight of the golf club.

[0127] In other embodiments, adjustment assembly 408 can incorporate components and aspects of adjustable-length shaft assemblies 200, 300 to adjust the position and retain mass 404 within shaft 22. For example, mass 404 can be formed from or include a resilient material that can be deformed to retain mass 404 at a desired position within shaft 22. As another example, mass 404 can include cam portion 368 that rotates within channel 364 in the shaft, rotating between a position where mass 404 can be moved axially within shaft 22 and a different position where cam portion 368 engages one or more cam surfaces 372 to retain mass 404 at a desired position within shaft 22. In these example embodiments, the mass 404 may be fixed in the axial slot 134 or may be positioned at the end of the member 320, so that the distance that the mass 404 can be adjusted axially within the shaft 22 may be limited to be less than the overall length of the shaft 22.

[0128] In other embodiments, aspects of adjustable mass assembly 400 may be incorporated into golf club 10 in combination with the above-disclosed variable length shaft assemblies 100, 200, 300. For example, each variable length shaft assembly 100, 200, 300 may have nested screw assemblies that allow for independent adjustment of shaft length and mass 404 position within the shaft.

[0129] As an example, the screw head 104 and screw 140 of the variable-length shaft assembly 100 can receive a nested second screw (not shown). Rotating the screw 140 adjusts the club length, while rotating only the second screw adjusts the position of the mass 404 within the club shaft. Generally, the screw head 104 is received within the well 224, and a biasing member applies a biasing force to the screw head 104 in directions 256, 376 away from the retainer 112. When biased, the screw 140 and second screw rotate together, adjusting the club length. To adjust the position of the mass 404 within the club shaft, a user can apply a downward force in directions 260, 380 (see FIGS. 11 and 16 ), overcoming the biasing force and engaging the screw head 104 with the well 224. The well 224 can include a finger or aperture that interlocks with an associated aperture or finger provided on the screw head 104. The interlocking finger / aperture prevents rotation of the screw head 104 and associated screw 140 while allowing rotation of the secondary screw. Thus, application of a downward force and a rotational force causes the secondary screw to rotate to axially adjust the position of the mass 404 within the club shaft. In other embodiments, a telescoping secondary screw can be incorporated into the adjustment member 208, 308 of each variable-length shaft assembly 200, 300.

[0130] In embodiments of golf club 10 that include adjustable mass 404 of adjustable mass assembly 400, golf club 10 can include one or more removable or adjustable weights located within club head 14. Adjustable mass 404 and the adjustable weights within club head 14 can together adjust characteristics of golf club 10, such as moment of inertia, total weight, and swing weight.

[0131] In other embodiments of golf club 10 including adjustable mass 404, mass 404 can be moved within club shaft 22 (and / or 120) to adjust swing weight while maintaining the same total weight. For example, by moving adjustable mass 404 closer to grip end 50, swing weight can be decreased while maintaining the same total weight. By moving adjustable mass 404 closer to club head 14, swing weight can be increased while maintaining the same total weight.

[0132] In one or more other exemplary embodiments of the golf club 10 including the adjustable mass 404 of the adjustable mass assembly 400, the adjustable mass 404 can be moved within the club shaft 22 (and / or 120) to adjust the moment of inertia while maintaining the same total weight. Generally, by moving the adjustable mass 404 closer to the club head 14, the moment of inertia can be increased while maintaining the same total weight. By moving the adjustable mass 404 within the club shaft 22 (and / or 120), the moment of inertia can be adjusted or customized to a golfer's profile (e.g., swing style (upright, flat, etc.), strength, height, arm length, swing speed, swing tempo) to achieve a desired shot shape or dispersion pattern without substantially affecting the total weight.

[0133] It should be appreciated that adjustable mass 404 can be used to adjust the mass distribution relative to the center of rotation of an individual golfer's golf swing. By adjusting mass 404 closer to or farther from the center of rotation of a given golf swing, club delivery to the golf ball can be improved. For example, adjusting mass 404 can improve the consistency of attack angle, swing path, or swing direction toward the golf ball, which can result in more consistent contact between club head 14 and the golf ball.

[0134] Additionally, it should be appreciated that adjustable mass 404 can be used to adjust the launch angle and / or ball flight of the golf ball after contact with golf club 10. A golfer may desire to change the launch angle or golf ball trajectory based on changes to swing mechanics, weather conditions, and / or course conditions. For example, adjustable mass 404 can be moved to a first position within the club shaft to lower the launch angle or golf ball trajectory in windy weather conditions to reduce the effect of wind on the golf ball after contact. As another example, adjustable mass 404 can be used to lower the launch angle or golf ball trajectory on a links-style golf course or similar course conditions where the golfer benefits from a rolling golf ball at the end of its flight. Similarly, adjustable mass 404 can be moved to a second position within the club shaft to increase the launch angle or golf ball trajectory.

[0135] In other embodiments, the mass 404 may be used to locally change or increase shaft stiffness along the shaft 22 (and / or shaft 120). Shaft stiffness is measured by an instrument that vibrates the shaft and measures the frequency in cycles per minute (CPM). A shaft that bends less easily is considered to have a stiffer flex and a higher frequency, while a shaft that bends more easily is considered to have a softer flex and a lower frequency. By adjusting the position of the mass 404 within the shaft 22, 120 closer to the club head 14, the measured CPM is reduced, resulting in a softer or reduced shaft stiffness. Conversely, adjusting the position of the mass 404 within the shaft 22, 120 farther away from the club head 14 increases the measured CPM, resulting in a stiffer or increased shaft stiffness. Based on optimal shaft performance in terms of the golfer's profile (e.g., swing style (upright, flat, etc.), strength, height, arm length, swing speed, swing tempo), as well as based on changes to swing mechanics, weather conditions, and / or course conditions, a golfer may desire to change shaft stiffness.

[0136] It should be appreciated that adjustable mass 404 may be used in conjunction with one or more other adjustable aspects of golf club 10, in addition to the variable length shafts disclosed herein. For example, adjustable mass 404 may be used in conjunction with adjustable club loft at address (e.g., open, square, closed), adjustable club lie, adjustable face angle, and / or adjustable weight on club head 14 to improve customization for a golfer's profile (e.g., swing style (upright, flat, etc.), strength, height, arm length, swing speed, swing tempo).

[0137] 22 illustrates a method 600 of manufacturing a golf club 10 having an adjustable-length shaft assembly 100, 200, 300, 500. The method 600 includes providing a first shaft 22 (step 602), coupling the first shaft 22 to the club head 14 (step 604), engaging a retainer 112 with the first shaft 22 (step 606), coupling the adjustable-length shaft assembly 100, 200, 300, 500 to a second shaft 120 (step 608), coupling the first shaft 22 to the second shaft 120, where the retainer 112 is engaged with the adjustable-length shaft assembly 100, 200, 300, 500 (step 610), and attaching a grip 34 to the second shaft 120 (step 612).

[0138] 23 illustrates a method 700 of manufacturing a golf club 10 having an adjustable mass assembly 400. The method 700 includes providing a first shaft 22 (step 702), coupling the first shaft 22 to the club head 14 (step 704), coupling the adjustable mass assembly 400 to the first shaft 22 (step 706), and attaching a grip 34 to the first shaft 22 (step 708).

[0139] The methods for manufacturing golf club 10 described herein are merely exemplary and are not limited to the embodiments presented herein. The methods may be used in many different embodiments or examples not specifically shown or described herein. In some embodiments, the processes of the described methods may be performed in any suitable order. In other embodiments, one or more of the processes may be combined, separated, or skipped.

[0140] The variable length shaft assembly 100, 200, 300, 500 has certain advantages over the prior art. For example, the variable length shaft assembly 100, 200, 300, 500 is not visible from the exterior of the golf club. The grip 34 is attached to and substantially overlaps the second shaft 120, while the first shaft 22 is received by the second shaft 120. Because the variable length shaft assembly 100, 200, 300, 500 and the second shaft 120 are generally not visible from the exterior of the golf club 10, the golf club 10 is more visually appealing and appears more like a traditional golf club 10. Additionally, the variable length shaft assembly 100, 200, 300, 500 is lighter in weight, reducing the impact the assembly has on both the swing weight and the total weight of the golf club 10. Furthermore, the variable length shaft assemblies 100, 200, 300, 500 allow for adjustment of club length while maintaining the orientation of the grip 34 (i.e., it does not change the rotational position of the grip 34). The variable length shaft assemblies 100, 200, 300 also allow for adjustment of club length with a single tool, such as a torque wrench. The single tool can also be used to adjust other aspects of the golf club, such as the weight on the club head 14, club loft, club lie, club face angle, etc., and / or to replace the shaft 22. Additionally, the variable length shaft assemblies 100, 200, 300, 500 allow the shaft length of the golf club 10 to be customized to a golfer's profile, such as the golfer's height, arm length, and / or natural address position.

[0141] Variable-length shaft assembly 800 has advantages similar to those of variable-length shaft assemblies 100, 200, 300, and 500 described above, as well as additional advantages over the prior art. For example, variable-length shaft assembly 800 reduces side-to-side or radial movement between first shaft 22 and second shaft 120 by at least 70%. The nub-like protrusions on insert 828 and retainer 812 improve concentricity of first shaft 22 within second shaft 120. Additionally, the interleaving action between threaded screw 140 and rib 834 on insert 828 provides a tight fit between threaded screw 140 and insert 828, thereby reducing side-to-side or radial movement between first shaft 22 and second shaft 120. The alignment member 844 also provides an additional means of improving the concentricity of the first shaft 22 within the second shaft 120, minimizing misalignment and allowing the first shaft 22 to translate freely within the second shaft 120 during operation of the variable length shaft assembly 800.

[0142] The adjustable mass assembly 400 has certain advantages over the prior art. For example, by adjusting the mass 404 within the club shaft 22 (and / or shaft 120), the club's swing weight can be adjusted while maintaining total weight, the moment of inertia can be adjusted while maintaining total weight, and / or shaft stiffness can be adjusted. In addition, after contact can be adjusted, golf ball trajectory can be adjusted, which may be desirable for different course conditions, weather conditions, or mechanical changes to the golfer's swing. Furthermore, adjusting the mass 404 within the club shaft 22 (and / or shaft 120) adjusts the mass distribution of the golf club 10 relative to the center of rotation of the golfer's golf swing, improving the consistency of the attack angle, swing path, and / or swing direction toward the golf ball, resulting in more consistent contact between the club head 14 and the golf ball.

[0143] It should be appreciated that the advantages are provided for purposes of example and are not intended to be comprehensive or limiting.

[0144] Replacement of one or more claimed elements constitutes a reconfiguration, not a repair. Additionally, benefits, other advantages, and solutions to problems have been described in connection with particular embodiments. However, the benefits, advantages, solutions to problems, and any one or more elements that may cause any benefit, advantage, or solution to occur or become more pronounced should not be construed as a critical, necessary, or essential feature or element of any or all of the claims unless such benefit, advantage, solution, or element is expressly recited in such claim.

[0145] Because the Rules of Golf may change from time to time (e.g., new Rules may be adopted, or old Rules may be eliminated or amended, by golf standards organizations and / or governing bodies such as the United States Golf Association (USGA), the Royal and American Golf Association (R&A), etc.), golf equipment related to the apparatus, methods, and articles of manufacture described herein may or may not comply with 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 either compliant or non-compliant golf equipment. The apparatus, methods, and articles of manufacture described herein are not limited in this respect.

[0146] The above examples may be described in connection with a wood-type golf club, a fairway wood-type golf club, a hybrid-type 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 hockey sticks, tennis rackets, fishing poles, ski poles, etc.

[0147] Moreover, embodiments and limitations disclosed herein are not available to the public under the doctrine of dedication if the embodiment and / or limitation (1) is not explicitly claimed in the claims and (2) is an equivalent or potential equivalent of an element and / or limitation in the claims under the doctrine of equivalents.

[0148] (Article 1) a first shaft coupled to a club head; a second shaft configured to slidably engage a portion of the first shaft; a grip coupled to the second shaft; and an adjustable-length shaft assembly positioned at least partially within the second shaft and configured to allow a portion of the first shaft to slide relative to the second shaft, the adjustable-length shaft assembly comprising: an insert coupled to an axial end face of the first shaft, the insert having a threaded aperture; and an adjustment member comprising a threaded screw configured to meshingly engage the threaded aperture of the insert, the adjustment member configured to rotate, and the insert configured to move along the adjustment member as the adjustment member rotates, allowing the first shaft to slide relative to the second shaft to adjust the length of the golf club; and the grip is limited to rotate about either the first shaft or the second shaft as the first shaft slides relative to the second shaft.

[0149] (Article 2) 10. The golf club of claim 1, wherein the adjustable length shaft assembly includes a socket configured to receive a tool.

[0150] (Article 3) 10. The golf club of claim 1, wherein the inner surface of the second shaft and the outer surface of the insert are provided with a shape capable of limiting rotational movement between the second shaft and the insert.

[0151] (Article 4) 4. The golf club of clause 3, wherein the inner surface of the second shaft and the outer surface of the insert comprise a hexagonal cross-sectional shape.

[0152] (Article 5) 10. The golf club of claim 1, wherein the outer surface of the insert comprises a plurality of nodular protrusions.

[0153] (Article 6) 10. The golf club of claim 1, wherein an inner surface of the insert comprises one or more ribs that engage the adjustment member.

[0154] (Article 7) Clause 6 golf club, wherein the diameter of the screw with the threaded portion is greater than the diameter of the opening between the one or more ribs.

[0155] (Article 8) 10. The golf club of claim 1, wherein the adjustment member is received by a retainer, the retainer being configured to be stationary relative to the second shaft and to allow rotation of the adjustment member.

[0156] (Article 9) 9. The golf club of clause 8, wherein the retainer comprises one or more pegs, the pegs configured to be received by one or more apertures disposed on the second shaft.

[0157] (Article 10) 10. The golf club of claim 1, wherein the first shaft is received by an alignment member, the alignment member being positioned near a first end of the second shaft and configured to improve concentricity of the first shaft within the second shaft.

[0158] (Article 11) A golf club comprising: a first shaft coupled to a club head; a second shaft configured to slidably engage a portion of the first shaft; a grip coupled to the second shaft; and an adjustable-length shaft assembly positioned at least partially within the second shaft and configured to allow a portion of the first shaft to slide relative to the second shaft, the adjustable-length shaft assembly including: an insert coupled to an axial end face of the first shaft, the insert including a threaded aperture; and an adjustment member including a threaded screw configured to matingly engage the threaded aperture of the insert, the adjustment member being configured to rotate. and a retainer coupled to a butt end of the second shaft and configured to receive the adjustment member, the retainer being stationary relative to the second shaft and allowing rotation of the adjustment member, wherein the insert is positioned away from the retainer in an extended configuration and the insert abuts against the retainer in a fully retracted configuration, and the grip is limited from rotating about either the first shaft or the second shaft as the first shaft slides relative to the second shaft.

[0159] (Article 12) 12. The golf club of clause 11, wherein the adjustable length shaft assembly includes a socket configured to receive a tool.

[0160] (Article 13) 12. The golf club of clause 11, wherein the inner surface of the second shaft and the outer surface of the insert are provided with a shape capable of limiting rotational movement between the second shaft and the insert.

[0161] (Article 14) 14. The golf club of clause 13, wherein an inner surface of the second shaft and an outer surface of the insert have a hexagonal cross-sectional shape.

[0162] (Article 15) 12. The golf club of claim 11, wherein the outer surface of the insert comprises a plurality of nodular protrusions.

[0163] (Article 16) 12. The golf club of claim 11, wherein an outer surface of the retainer comprises a plurality of knobby protrusions.

[0164] (Article 17) 12. The golf club of clause 11, wherein an inner surface of the insert comprises one or more ribs that engage the adjustment member.

[0165] (Article 18) 18. The golf club of clause 17, wherein the diameter of the adjustment member is greater than the diameter of the opening between the one or more ribs.

[0166] (Article 19) 12. The golf club of claim 11, wherein the first shaft is received by an alignment member, the alignment member being positioned near the first end of the second shaft and configured to improve concentricity of the first shaft within the second shaft.

[0167] (Article 20) 20. The golf club head of clause 19, wherein the alignment member comprises one or more pegs, the pegs configured to be received by one or more apertures disposed on the second shaft.

[0168] (Article 21) Clause 11. The golf club of clause 11, wherein the insert engages with a portion of the first shaft to define an engagement length, the engagement length being 5.0 inches.

[0169] (Article 22) 12. The golf club of claim 11, wherein an outer surface of the retainer comprises a plurality of knobby protrusions.

[0170] (Article 23) 12. The golf club of claim 11, wherein an outer surface of the retainer has a hexagonal cross-sectional shape.

[0171] (Article 24) The second shaft is formed from nylon 66 with 30% carbon fiber filler material, Article 11 golf club.

[0172] (Article 25) 12. The golf club of claim 11, wherein the insert and the first shaft move together when the adjustment member rotates.

[0173] (Article 26) 16. The golf club of claim 15, wherein the knobby protrusion of the insert abuts against an inner surface of the second shaft.

[0174] (Article 27) 23. The golf club of claim 22, wherein the knobby portion of the retainer abuts against an inner surface of the second shaft.

[0175] (Article 28) 18. The golf club of Clause 17, wherein the threaded screw includes a diameter and the one or more ribs define an opening diameter, and the threaded screw diameter is greater than the opening diameter between the one or more ribs.

[0176] (Article 29) Article 28 golf club, wherein the diameter of the screw with the threaded portion is 0.25 inch and the diameter of the opening between the rib or ribs is 0.242 inch.

[0177] (Article 30) 12. The golf club of claim 11, wherein the insert is permanently coupled to an axial end face of the first shaft.

[0178] (Article 31) 31. The golf club of claim 30, wherein the insert is coupled to the axial end face of the first shaft by an adhesive.

[0179] Various features and advantages of the disclosure are set forth in the following claims.

Claims

1. A golf club, a first shaft coupled to the club head; a second shaft configured to slidably engage a portion of the first shaft; a grip connected to the second shaft; an adjustable-length shaft assembly positioned at least partially within the second shaft and configured to allow a portion of the first shaft to slide relative to the second shaft; The variable length shaft assembly includes: an insert coupled to an axial end surface of the first shaft, the insert including a threaded aperture; an adjustment member comprising a threaded screw configured to matingly engage the threaded aperture of the insert, the adjustment member configured to rotate and the insert configured to move along the adjustment member as the adjustment member rotates, allowing the first shaft to slide relative to the second shaft to adjust the length of the golf club; the grip is restricted from rotating about the first shaft or the second shaft when the first shaft slides relative to the second shaft; The golf club, wherein the outer surface of the insert comprises a plurality of nub-like protrusions.

2. The golf club of claim 1 , wherein the variable length shaft assembly includes a socket configured to receive a tool.

3. The golf club of claim 1 , wherein an inner surface of the second shaft and an outer surface of the insert comprise a shape capable of limiting rotational movement between the second shaft and the insert.

4. The golf club of claim 3 , wherein the inner surface of the second shaft and the outer surface of the insert comprise a hexagonal cross-sectional shape.

5. The golf club of claim 1 , wherein the plurality of nub-like protrusions of the insert abut an inner surface of the second shaft.

6. The golf club of claim 1 , wherein the inner surface of the insert comprises one or more ribs that engage the adjustment member.

7. The golf club of claim 6 , wherein the diameter of the threaded screw is greater than the diameter of the opening between the one or more ribs.

8. the adjustment member is received by a retainer; The golf club of claim 1 , wherein the retainer is configured to be stationary relative to the second shaft and to allow the rotation of the adjustment member.

9. the retainer comprises one or more pegs; The golf club of claim 8 , wherein the peg is configured to be received by one or more apertures disposed on the second shaft.

10. the first shaft is received by the alignment member; 2. The golf club of claim 1, wherein the alignment member is positioned near a first end of the second shaft and is configured to improve concentricity of the first shaft within the second shaft.

11. A golf club, a first shaft coupled to the club head; a second shaft configured to slidably engage a portion of the first shaft; a grip connected to the second shaft; an adjustable-length shaft assembly positioned at least partially within the second shaft and configured to allow a portion of the first shaft to slide relative to the second shaft; The variable length shaft assembly includes: an insert coupled to an axial end surface of the first shaft, the insert including a threaded aperture; an adjustment member comprising a threaded screw configured to matingly engage the threaded aperture of the insert, the adjustment member configured to rotate and the insert configured to move along the adjustment member as the adjustment member rotates, allowing the first shaft to slide relative to the second shaft to adjust the length of the golf club; and a retainer coupled to a mating end of the second shaft and configured to receive the adjustment member, the retainer configured to be stationary relative to the second shaft and to allow the rotation of the adjustment member; the insert is positioned away from the retainer in an extended configuration, the insert abutting the retainer in a fully contracted configuration; the grip is restricted from rotating about the first shaft or the second shaft when the first shaft slides relative to the second shaft; The golf club, wherein the outer surface of the insert comprises a plurality of nub-like protrusions.

12. The golf club of claim 11 , wherein the variable length shaft assembly includes a socket configured to receive a tool.

13. The golf club of claim 11 , wherein an inner surface of the second shaft and an outer surface of the insert comprise a shape capable of limiting rotational movement between the second shaft and the insert.

14. The golf club of claim 13 , wherein the inner surface of the second shaft and the outer surface of the insert comprise a hexagonal cross-sectional shape.

15. The golf club of claim 11 , wherein the plurality of nub-like protrusions of the insert abut an inner surface of the second shaft.

16. The golf club of claim 11 , wherein the outer surface of the retainer comprises a plurality of nub-like protrusions.

17. The golf club of claim 11 , wherein the inner surface of the insert comprises one or more ribs that engage the adjustment member.

18. 18. The golf club of claim 17, wherein the diameter of the adjustment member is greater than the diameter of the opening between the one or more ribs.

19. the first shaft is received by the alignment member; 12. The golf club of claim 11, wherein the alignment member is positioned near a first end of the second shaft and is configured to improve concentricity of the first shaft within the second shaft.

20. the adjustment member comprises one or more pegs; 20. The golf club head of claim 19, wherein the peg is configured to be received by one or more apertures disposed on the second shaft.

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