IP Library Granted Patent US 6,857,972
Granted Patent B2
US 6,857,972 · App. 10/645,505 · Granted Feb 22, 2005

Golf club shaft

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 6,857,972
App. No.
10/645,505
Granted
Feb 22, 2005
Kind
B2
Abstract

A golf club shaft 1 has a prepreg ( 15 ) consisting of an intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet having a tensile modulus of elasticity of 30 ton/mm 2 to 33 ton/mm 2 and a tensile strength of not less than 5000 MPa and a prepreg ( 16 ) consisting of a low-elasticity carbon fiber reinforced resinous sheet having a tensile modulus of elasticity of 5 ton/mm 2 to 10 ton/mm 2 and compressive breaking strain of not less than 2.0%. The prepregs ( 15 ) and the prepregs ( 16 ) are used to reinforce a tip side of the golf club shaft.

Claims (17)

1. A golf club shaft comprising:

an intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet having a tensile modulus of elasticity of 30 ton/mm 2 to 33 ton/mm 2 and a tensile strength of not less than 5000 MPa; and

a low-elasticity carbon fiber reinforced resinous sheet having a tensile modulus of elasticity of 5 ton/mm 2 to 10 ton/mm 2 and compressive breaking strain of not less than 2.0%,

each of said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet and said low-elasticity carbon fiber reinforced resinous sheet being used to reinforce a tip side of said golf club shaft, wherein each of said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet and said low-elasticity carbon fiber reinforced resinous sheet is disposed from said tip to a position located at not more than 20% of an overall length of said golf club shaft.

2. The golf club shaft according to claim 1 , wherein each of said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet and said low-elasticity carbon fiber reinforced resinous sheet has a length not less than 8% nor more than 15% of an overall length of said golf club shaft and is disposed from said tip of said golf club shaft toward a butt thereof.

3. The golf club shaft according to claim 2 , wherein a weight M1 of said intermediate-elasticity and high-strength carbon fiber and a weight M2 of said low-elasticity carbon fiber satisfy a relationship of:

0.5≦a ratio of said weight M1 to said weight M2≦3.0.

4. The golf club shaft according to claim 3 , wherein said low-elasticity carbon fiber reinforced resinous sheet is disposed outward from said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet; and

said low-elasticity carbon fiber reinforced resinous sheet has the same configuration as that of said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet or is larger than said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet.

5. The golf club shaft according to claim 2 , wherein said low-elasticity carbon fiber reinforced resinous sheet is disposed outward from said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet; and

said low-elasticity carbon fiber reinforced resinous sheet has the same configuration as that of said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet or is larger than said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet.

6. The golf club shaft according to claim 1 , wherein a weight M1 of said intermediate-elasticity and high-strength carbon fiber and a weight M2 of said low-elasticity carbon fiber satisfy a relationship of:

0.5≦a ratio of said weight M1 to said weight M2≦3.0.

7. The golf club shaft according to claim 6 , wherein said low-elasticity carbon fiber reinforced resinous sheet is disposed outward from said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet; and

said low-elasticity carbon fiber reinforced resinous sheet has the same configuration as that of said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet or is larger than said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet.

8. The golf club shaft according to claim 1 , wherein said low-elasticity carbon fiber reinforced resinous sheet is disposed outward from said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet; and

said low-elasticity carbon fiber reinforced resinous sheet has the same configuration as that of said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet or is larger than said intermediate-elasticity and high-strength carbon fiber reinforced resinous sheet.

Assignments (4)
MERGER Recorded Apr 17, 2018
From: DUNLOP SPORTS CO. LTD.
To: SUMITOMO RUBBER INDUSTRIES, LTD.
Reel/Frame 045959/0204 →
CHANGE OF NAME Recorded Apr 12, 2018
From: SRI SPORTS LIMITED
To: DUNLOP SPORTS CO. LTD.
Reel/Frame 045932/0024 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 16, 2005
From: SUMITOMO RUBBER INDUSTRIES, LTD.
To: SRI SPORTS LIMITED
Reel/Frame 016561/0471 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 22, 2003
From: KUMAMOTO, TOMIO
To: SUMITOMO RUBBER INDUSTRIES, LTD.
Reel/Frame 014424/0940 →