# US 8,784,231 B2 · Golf club

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,784,231 B2
- Document ID: US8784231B2
- Status: Granted
- Kind: B2
- Application number: 13/541,415
- Filed: 2012-07-03
- Published: 2012-11-22
- Granted: 2014-07-22
- Earliest claimed: 2010-02-24
- Assignees: SRI Sports Limited
- Applicants: Dustin J. Brekke; Jeff D. Brunski; Matthew R. Daraskavich; Samuel G. Lacey; Nathaniel J. Radcliffe; Brian D. Schielke
- Inventors: Dustin J. Brekke; Jeff D. Brunski; Matthew R. Daraskavich; Samuel G. Lacey; Nathaniel J. Radcliffe; Brian D. Schielke
- Web page: https://patentgrep.com/patent/US8784231B2

## CPC

- A63B 53/00: Golf clubs
- A63B 53/0466: {wood-type}
- A63B 60/00: Details or accessories of golf clubs, bats, rackets or the like
- A63B 53/0408: {characterised by specific dimensions, e.g. thickness}
- A63B 53/0412: {Volume}
- A63B 53/0416: {Heads having an impact surface provided by a face insert}
- A63B 53/10: Non-metallic shafts
- A63B 53/14: Handles
- A63B 60/42: Devices for measuring, verifying, correcting or customising the inherent characteristics of golf clubs, bats, rackets or the like, e.g. measuring the maximum torque a batting shaft can withstand
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)

## Abstract

A golf club according to one or more aspects of the present invention may have a mass less than 300 g, a length greater than about 45 inches, a swing weight between D0 and D6, a head weighing less than about 200 g, a club-head volume of at least about 360 cm3, a grip weighing less than about 50 g, and a shaft having a tip end, a butt end, and a shaft balance point located no more than 24 inches from the butt end. The shaft may have a torsional displacement angle greater than about 5.5° and a mass less than about 50 g. A coordinate system having x-, y-, and z-axes may have its origin at the center of gravity of the club head. The golf club head may have a moment of inertia of at least about 4500 g·cm2 about the z-axis and a moment of inertia of at least about 3000 g·cm2 about the y-axis.

## Claims

### Claim 1

A golf club comprising:
a club head having a mass less than 200 g and a volume greater than about 360 cm3; and
a shaft attachable to the club head having a tip end and a butt end, the shaft having a shaft length, Ls, and a shaft balance point distance, BPs, as measured from the butt end,
wherein:
a mass of the golf club is less than 300 g;
the golf club has an overall club length, Lc, and a club balance point distance, BPc, as measured from the butt end, such that a ratio (BPc/Lc)/(BPs/Ls) is no less than 1.68; and
the shaft balance point is located no more than 19 inches from the butt end.

### Claim 2 (depends on 1)

The golf club of claim 1, further comprising an imaginary coordinate system having an origin located at a center of gravity of the club head, the coordinate system having an x-axis, a y-axis and a z-axis, and wherein the club head having a moment of inertia (MOI) about the z-axis of at least about 4000 g·cm2.

### Claim 3 (depends on 2)

The golf club of claim 2, wherein the MOI about the z-axis is about 4500 g·cm2.

### Claim 4 (depends on 1)

The golf club of claim 1, wherein the mass of the golf club is less than 295 g.

### Claim 5 (depends on 1)

The golf club of claim 1, wherein the mass of the golf club is between 285 g and 295 g.

### Claim 6 (depends on 1)

The golf club of claim 1, wherein the overall club length, Lc, is no less than 45 inches.

### Claim 7 (depends on 1)

The golf club of claim 1, wherein a ratio (BPc/Lc) is no less than 0.76.

### Claim 8 (depends on 1)

The golf club of claim 1, wherein a ratio of the mass of the club head to the club balance point distance, BPc, is no greater than 8.5 grams/inch.

### Claim 9 (depends on 1)

The golf club of claim 1, wherein the mass of the club head is between 190 g and 200 g.

### Claim 10 (depends on 1)

The golf club of claim 1, wherein the shaft length, Ls, is no less than 44 inches.