Fabrication of a hollow composite-material shaft having an integral collar

• US 5,943,758 A
• Filed: 09/30/1997
• Issued: 08/31/1999
• Est. Priority Date: 09/30/1997
• Status: Expired due to Term

• Current Assignee: True Temper Sports, Inc. (New True Temper Holdings Corp., Inc.)
• Original Assignee: Grafalloy Corporation
• Inventors: Haas, Neal
• Primary Examiner(s): Hughes, S. Thomas
• Assistant Examiner(s): Preta, John
• Application Number:
  US08/940,935
• Time in Patent Office: 700 Days
• Field of Search: 473/318, 473/319, 473/320, 473/321, 29/516, 29/515, 264/257, 264/258, 156/172
• US Class Current: 29/516
• CPC Class Codes: A63B 2209/02 with reinforcing fibres, e.g. carbon, polyamide fibres
• CPC Class Codes: A63B 53/10 Non-metallic shafts
• CPC Class Codes: A63B 60/06 Handles
• CPC Class Codes: A63B 60/08 characterised by the material
• CPC Class Codes: A63B 60/10 with means for indicating correct holding positions A63B60/12 takes precedence
• CPC Class Codes: A63B 60/54 with means for damping vibrations
• CPC Class Codes: B29C 53/56 Winding and joining, e.g. winding spirally winding in general B65H
• CPC Class Codes: B29C 61/006 the force created by the liberation of the internal stresses being used for compression moulding or for pressing preformed material
• CPC Class Codes: B29C 70/32 on a rotating mould, former or core
• CPC Class Codes: Y10T 29/49927 Hollow body is axially joined cup or tube

Abstract

A hollow golf club shaft is prepared by flag rolling a base layer of composite material pieces over a mandrel having a larger-diameter region and a reduced-diameter region. The base layer is optionally precompacted. A collar is slid along he length of the mandrel having the reduced-diameter region and base layer to lie adjacent to the larger-diameter region, and at least one overlayer composite material piece is flag rolled overlying the base-layer composite material pieces onto that portion of the mandrel having the reduced diameter. The overlayer piece is compacted, preferably along with the base pieces, and all of the composite material is cured

Claims

1. A method for manufacturing a hollow shaft, comprising the steps of:

providing a shaft mandrel having a first size over a first length and a second size over a second length, the second size being smaller than the first size;

providing a collar having an inner diameter;

providing composite material including

at least one base-layer piece of a composite-material, and

at least one overlayer piece of a composite-material;

thereafter

applying the at least one base-layer piece overlying the first length and the second-length of the shaft mandrel;

thereafter

sliding the collar along the second length of the shaft mandrel and the at least one base-layer piece to a position adjacent to the first length;

thereafter

applying the at least one overlayer piece overlying the at least one base-layer piece at a location overlying at least a portion of the second length and laterally adjacent to the collar;

thereafter

compacting the at least one overlayer piece; and

curing the at least one base-layer piece and the at least one overlayer piece.

2. The method of claim 1, including an additional step, after the step of applying the at least one base layer and before the step of sliding, of

precompacting the at least one base-layer piece.

3. The method of claim 2, wherein the step of precomputing the at least one base-layer piece includes the step of

applying compaction tape overlying the at least one base-layer piece, and

heating the compaction tape and the at least one base-layer piece.

4. The method of claim 1, wherein the step of providing composite material includes the step of

providing the at least one base-layer piece and the at least one overlayer piece as prepregs of carbon fibers in a thermosetting material matrix.

5. The method of claim 1, wherein the step of applying the at least one base-layer piece includes the step of

flag rolling the at least one base-layer piece.

6. The method of claim 1, wherein the step of compacting the at least one overlayer piece includes the step of

applying compaction tape overlying the at least one overlayer piece, and

heating the compaction tape and the at least one overlayer piece.

7. The method of claim 1, wherein the step of compacting the at least one overlayer piece and the step of curing are preformed simultaneously.

8. The method of claim 1, wherein the step of providing a collar includes the step of

providing a collar made of a material selected from the group consisting of a metal, ceramic, plastic, and a composite material.

9. The method of claim 1, wherein the steps of providing a shaft mandrel, providing a collar, providing composite material, applying the at least one base-layer piece, applying the at least one overlayer piece, compacting the at least one overlayer piece, and curing are cooperatively selected so that a final surface of shaft comprises the collar flush with cured composite material on each side of the collar.

10. The method of claim 1, wherein the step of providing a shaft mandrel includes the step of

providing a shaft mandrel sized such that the shaft is operable as a golf club shaft.

11. The method of claim 1, further including an additional step, after the step of applying the at least one base-layer piece and before the step of applying the at least one overlayer piece, of

sliding an O-ring along the shaft mandrel, the O-ring being positioned at a location selected from the group consisting of ahead of the collar and behind the collar.

12. A method for manufacturing a hollow shaft, comprising the steps of:

providing a shaft mandrel having a first diameter over a length and a second diameter over a second length, the second diameter being smaller than the first diameter;

providing a collar having an inner diameter;

providing composite material including

a plurality of base-layer pieces of a composite-material prepreg, and

at least one overlayer piece of a composite-material prepreg;

thereafter

applying the plurality of base-layer pieces overlying the shaft mandrel;

thereafter

precompacting the plurality of base-layer pieces;

thereafter

sliding the collar along the second length of the shaft mandrel and its overlying precompacted plurality of base-layer pieces to a position adjacent to the first length;

thereafter

applying the at least one overlayer piece overlying at least some of the plurality of base-layer pieces at a location overlying at least a portion of the second length and laterally adjacent to the collar;

thereafter

compacting the at least one overlayer piece; and

curing the plurality of base-layer pieces and the at least one overlayer piece.

13. The method of claim 12, wherein the step of pre compacting includes the step of precompacting the plurality of base-layer pieces to a diameter of about that of an inner diameter of the collar.

14. The method of claim 12, wherein the step of providing composite material includes the step of

providing the plurality of base-layer pieces and the at least one overlayer piece as prepregs of carbon fibers in a thermosetting material matrix.

15. The method of claim 12, wherein the step of applying the plurality of base-layer pieces includes the step of

flag rolling the plurality of base-layer pieces sequentially.

16. The method of claim 12, wherein the step of compacting the at least one ovelayer piece and the step of curing are preformed simultaneously.

17. The method of claim 12, wherein the steps of providing a shaft mandrel providing a collar, providing composite material, applying the plurality of base-layer pieces, precompacting, applying the at least one overlayer piece, compacting the at least one overlayer piece, and curing are cooperatively selected so that a final surface of the shaft comprises the collar flush with cured composite material on each side of the collar.

18. The method of claim 12, wherein the step of providing a shaft mandrel includes the step of

providing a shaft mandrel sized such that the shaft is operable as a golf club shaft.

19. The method of claim 12, further including an additional step, after the step of applying the at least one base-layer piece and before the step of applying the at least one overlayer piece, of

sliding an O-ring along the shaft mandrel, the O-ring being positioned at a location selected from the group consisting of ahead of the collar and behind the collar.

20. A method for manufacturing hollow shaft comprising the steps of:

providing a shaft mandrel having a diameter over a first length and a second diameter over a second length, the second diameter being smaller than the first diameter, the total of the first length and the second length of the shaft mandrel being selected such that the shaft is operable as a golf club shaft;

providing a collar having an inner diameter;

providing composite material including

a plurality of base-layer pieces of a composite-material prepreg, and

at least one overlayer piece of a composite-material prepreg;

thereafter

applying the plurality of base-layer pieces overlying the shaft mandrel;

thereafter

precompacting the plurality of base-layer pieces;

thereafter

sliding the collar along the second length of the shaft mandrel and its overlying precompacted plurality of base-layer pieces to a position adjacent to the first length;

thereafter

applying the at least one overlayer piece overlying at least some of the plurality of base-layer pieces at a location overlying at least a portion of the second length and laterally adjacent to the collar;

thereafter

compacting the at least one overlayer piece; and

simultaneously

curing the plurality of base-layer pieces and the at least one overlayer piece.