# US 4,393,024 A · Method of producing a racket frame

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- Number: US 4,393,024 A
- Document ID: US4393024A
- Status: Granted
- Kind: A
- Application number: 06/332,312
- Filed: 1981-12-18
- Granted: 1983-07-12
- Earliest claimed: 1981-12-18
- Inventors: Chin-San You
- Web page: https://patentgrep.com/patent/US4393024A

## CPC

- B29D 99/0003: {Producing profiled members, e.g. beams}
- A63B 49/10: made of non-metallic materials, other than wood
- A63B 60/00: Details or accessories of golf clubs, bats, rackets or the like
- B29C 33/0011: {thin-walled moulds}
- B29C 70/30: Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
- B29C 53/00: Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor (B29C61/10 takes precedence)
- B29K 2101/10: Thermosetting resins
- B29L 2031/5245: {Rackets}
- B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00)
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

A racket frame is made by molding a thermosetting resin composition together with reinforcing fibers. Molds are made of flexible strip members, such as plastics, wood pulp, paper pulp, wood, bamboo, etc., which are bent to form a racket frame in a fitting, thereby reducing the production cost incurred in fabrication of expensive molds. The formed racket frame has no shell and core structure.

## Claims

### Claim 1

A method for making a racket frame comprising the steps of preparing two elongated strip members each including two racket handle portions and a racket head portion intermediate said racket handle portions and defining an elongated mold cavity section extending throughout its length, placing a thermosetting resin composition and fibres for reinforcing into the mold cavity sections, bringing said two strip members together in face-to-face relation with the mold cavity sections thereof in opposing relation to each other to form a structural member defining an elongated mold cavity containing said thermosetting resin composition and fibres, bending said strip members to form a shape of a racket frame, curing said thermosetting resin composition, and removing the strip members which comprise said structural member after curing.

### Claim 2 (depends on 1)

A method of making a racket frame as claimed in claim 1, wherein said structural member has its cross section in I-shape.

### Claim 3 (depends on 1)

A method making a racket frame as claimed in claim 1, wherein said structural member has its cross section in concave lens-shape.

### Claim 4 (depends on 1)

A method of making a racket frame as claimed in claim 1, wherein said structural member has its crosssection having a notch like part.

### Claim 5 (depends on 1)

A method of making a racket frame as claimed in claim 1, wherein the fibers are selected from the group consisting of carbon fiber, glass fiber and boron fiber.

### Claim 6 (depends on 1)

A method of making a racket frame as claimed in claim 1, wherein the removal of strip members is done by grinding.

### Claim 7 (depends on 1)

A method of making a racket frame as claimed in claim 1, wherein the removal of strip members is done by means of a mold releasing agent.

### Claim 8 (depends on 1)

A method for making a racket frame as claimed in claim 1 wherein said strip members comprise flexible members and said method includes the additional step of placing the structural member in a fitting.