Golf Shaft Flex Connection

Abstract

A shaft insert (or external connecting segment) with greater flexibility than the substrate shaft allowing for a more flexible zone in an area of separation between two separated portions of the substrate shaft. The flexible connection is intended to be installed between two segments of the separated substrate shaft primarily on a golf putter with the flexible connection within 5 inches of the base of the club in total compliance with USGA (United States Golf Association) Rule 2, Appendix II. 2. b. requiring any change from the continuous shaft be within 5 inches of the club base. The shaft flex connection is designed to be symmetrical around its cross section with equal flexibility and torsional displacement in all directions in compliance with USGA Rule 2, Appendix 2. c. requiring golf shafts to be equally flexible with equal torsional displacement in all directions. The preferred embodiment of the invention utilizes a flexible tube for which the outside diameter is slightly smaller than the inside diameter of the substrate shaft. The substrate shaft is separated at the top of the hosel of the club and joined by fixing the tube (with epoxy or other adhesive) in each section of the separated sections of the substrate shaft whereby the separation is maintained at a fixed distance by installing an O ring or other spacer over the insert tube and between the two segments of the substrate shaft.

Claims

1-8. (canceled)

9. Golf club comprising upper shaft (12) and separate lower shaft (11) and club head (18) with fastening hole (17) with elastic cylindrical insert (13) with outside diameter essentially corresponding to the inside diameter of upper shaft (12) and lower shaft (11) fixed with adhesive (14) to both upper shaft (12) and lower shaft (11) with lower shaft (11) terminating at the top of fastening hole (17) and elastic ring (15) filling gap (16) between lower shaft (11) and upper shaft (12).

10. Golf club according to claim 9 where lower shaft section (11) terminates at the top of fixed collar (20) with insert (13) joining upper shaft (12) with lower shaft (11) separated from upper shaft (12) by elastic ring (15) filling gap (16) between lower shaft (11) and upper shaft (12).

11. Golf club according to any of the preceding claims, where elastic ring (15) has an inside diameter essentially corresponding to the outside diameter of cylindrical insert (13) and outer diameter equal to or greater than outer diameter of lower shaft (11) and upper shaft (12).

12. Golf club according to any of the preceding claims where cylindrical insert (13) is composed of braided cable.

13. Golf club according to any of the preceding claims where elastic ring (15) is replaced with coil spring (37) and washers (36) where washers (36) have an inside diameter corresponding to the outer diameter of cylindrical insert (13) and where washers (36) have an outer diameter equal or greater than the outer diameter of coil spring (37).

14. Golf club according to any of the preceding claims where elastic ring (15) is replaced with disk spring stack (35).

15. Golf club where elastic cylindrical insert (21) with outside diameter essentially corresponding to inside diameter of lower shaft (11) and upper shaft (12) and where elastic integrated spacer (22) joins lower shaft (11) to upper shaft (12) with insert (21) fixed to lower shaft (11) with adhesive (14) and insert (21) fixed to upper shaft (12) with adhesive (14).

16. Golf club where cap (23) with integral divider section (24) is fixed to lower shaft (11) with adhesive (14) and fixed to upper shaft (12) with adhesive (14).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0017] Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout, and in which:

[0018] FIG. 1 is a sectional view of the conventional golf shaft with separation between the parts with insert and O ring installed.

[0019] FIG. 2 is a sectional view of the rigid fitment of the lower portion of the shaft to the putter hosel with separation and O ring spacer just above the rigid fitment. The insert is also shown bridging the lower and upper portions of the separated shaft.

[0020] FIG. 3 is a sectional view of the shaft and insert installation in the body of a putter without a hosel.

[0021] FIG. 4 is a view of the shaft and insert installation in a putter head without hosel and with flex point above the putter body.

[0022] FIG. 5 is a view of an alternate single piece flexible connection between two separated portions of a shaft.

[0023] FIG. 6 is a sectional view of a flexible collar over the shaft sections providing the same functions as the insert

[0024] FIG. 7 is a view of an alternate putter stem insert providing toe same putter face reaction as the shaft insert

[0025] FIG. 8 is an amplified view of the preferred embodiment shown in FIG. 1 showing a more detailed view of the shaft sections as well as the epoxy or adhesive location. The O ring is not shown on one side of the gap between shaft sections for clarity.

[0026] FIG. 9 is a modified free body diagram showing a right handed player side view of the preferred embodiment that shows the direction of displacement of the upper shaft section and resultant putter face displacement during the strike and resulting reaction of the golf ball.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0027] 1. Resumé

[0028] Pursuant to the preferred embodiment of the invention, a flexible shaft insert is composed of flexible nylon or other flexible tubing (or solid flexible shape) with an outside diameter matching or with clearance compared to the inside diameter of the substrate more rigid shaft. This insert is installed inside the shaft such that it bridges a separation between shaft portions which are separated by as little as 0.001 inch to any maximum distance that will provide the desired flexibility between the two portions of the substrate shaft. The separation in the substrate shaft is sized such that the lower portion of the shaft can be fixed inside the hosel or putter body with the separation occurring at the top of the hosel or putter body (depending on putter and shaft mounting design). At the top of the putter body or hosel, the O ring spacer or alternate spacers) with an inside diameter matching the outside diameter of the flexible insert covering the space between the substrate shaft sections and resting on the putter body or top of the hosel. All connections are made between; insert and shaft segments, shaft and putter head or hosel, O ring or O rings and flexible insert using conventional cementing adhesive commonly used for such connections.

[0029] 2. construction and Operation of a First Preferred Embodiment and Possible Alternates

[0030] Referring now to FIGS. 1-9 the exemplary putter illustrated in side view by FIG. 9 includes an upper shaft section 12, with lower section 11 inserted into hosel section 17 which is part of putter head 18 and shaft sections 11 and 12 connected by flexible shaft insert 13 with the fixed distance between shaft sections 11 and 12 fixed by flexible O ring (or alternate spacer) 15. The O ring 15 in FIG. 9 is shown in section but in fact is continuous around the circumference of the shaft and insert. The golfer holds and moves the putter at grip 33.

[0031] Although the present invention is not limited to any particular putter configuration or golf club for that matter, the exemplary club shown is a putter with raised hosel on putter stem 19. The present invention is, however equally applicable to any golf club or putter configuration and not limited to shaft design or shaft or insert material.

[0032] Turning to the insert assembly illustrated first by FIGS. 1 and 8, a golf shaft lower section 11 is separated from a golf shaft upper section 12 leaving a gap 16. Note that in FIG. 8 O ring 15 is not shown on one side for clarity to show gap 16. The shaft sections 11 and 12 are joined by flexible insert 13 and separated by O ring 15 installed over the gap 16. The flexible insert 13 is fixed to the shaft surface at points of contact by epoxy or other adhesive 14. The O ring 15 is also fixed to the exposed surface of the insert 13 at the controlled gap 16 with epoxy or other adhesive 14.

[0033] As illustrated by FIG. 2, the lower section of the golf shaft 11 is installed into the hosel 17 using adhesive 14 with O ring 15 resting on top of hosel 17.

[0034] As illustrated by FIG. 3, alternately the shaft lower section 11 is shown in putter body 18 using adhesive 14 with gap 16 coincident with O ring 15 resting on top of putter body 18 which is an illustrated connection method for putters without a raised hosel.

[0035] FIG. 4 shows an alternate for accommodating a third type of popular putter connection, with coincidental separation and O ring 15 and 16 oriented above putter head 18. The insert 13 and lower shaft section 11 can be installed over putter stem 30 which is either located within the putter head 18 or as an extension of the putter head 18. Optional non flexible collar 20 is fixed below O ring 15 end in contact with bottom of O ring 15 if additional stability in flex and torsional control is required. All points are secured with adhesive 14.

[0036] While many alternates to the preferred embodiment of the invention are possible, FIG. 5 illustrates a first alternate to the preferred embodiment of the invention shown by alternate insert 21 which is single molded piece integrating a collar 22 which replaces the O ring 15 of the first preferred embodiment. All portions are attached to lower shaft section 11 and upper shaft section 12 with adhesive 14. While the sectional view of alternate insert 21 shows the insert as solid it can also be hollow.

[0037] Another possible alternate to the preferred embodiment of the invention which retains the same principle of allowing added flexibility between shaft sections is shown by FIG. 6 demonstrating an outside flexible collar 23 with integrated or separate spacer 24 separating shaft lower section 11 and shaft upper section 12 with all surfaces in contact with shaft section 11 and shaft section 12 secured with epoxy or other adhesive 14.