US 4,264,389 AGranted

Method of manufacturing a tennis racket

AssigneeStarwin Industries, Inc.

InventorsAnthony F. Staub, Norman T. Staub, John R. Erwin

Life of this patent

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Abstract

A tennis racket frame is constructed primarily of an elongated tubular member having a wall thereof consisting of a plurality of concentric layers of high tensile strength fibers impregnated and bonded together by binder resin to produce a hollow cored tennis racket. The method includes forming a plurality of string holes in the head portion of the racket, during or prior to the molding operation. The holes are formed by separating the fibers around the location of the hole by passing pointed penetrating tools through the frame in the area which will form the head portion thereof, and either retaining the tool in position in the holes during molding, or replacing the tools with positioning pins or grommets prior to the molding operation. If the pins are utilized they may be removed after molding of the racket is complete, and if grommets are utilized they become integrally attached to the racket and provide additional support for the strings.

Claims9

Dependent claims

A method of making a racket frame having a handle portion, a throat portion and a head portion, and for forming holes for positioning strings in at least said head portion of said racket, comprising the steps of:

forming a hollow-core flexible tubular member including plurality of fiber reinforced heat-curable resin-impregnated layers;
placing a pressurizable tube in said hollow-core of said tubular member, said tube providing a central region through which a hole forming penetrating means can pass without puncturing said pressurizable tube and extending along at least a portion of its length in an area of said tubular member where string holes are to be formed;
positioning said tubular member with said tube therein in a mold cavity for containing said tubular member in a predetermined transverse cross sectional shape having holes therethrough in positions for forming string holes in at least said head portion of said racket;
pressurizing said tube sufficiently to maintain said tubular member in conformity with said mold cavity;
heating said tubular member in at least the areas where said string holes are to be formed to soften said resin sufficiently to be penetrated by said hole forming penetrating means then;
passing said hole forming penetrating means completely through said holes in said mold cavity and through said tubular member in said central region of said tube to form said string holes in said tubular member;
and then
curing said tubular member in the shape of a racket to form said frame with said string holes therein.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/112,380Filed 15 Jan 1980 · continuation in part
Priority: 18 Jan 1971
Granted: 28 Apr 1981
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

A63B 49/10
Frames: made of non-metallic materials, other than wood
A63B 49/02
Stringed rackets, e.g. for tennis: frames
A63B 49/022
Frames: string guides on frames, e.g. grommets
A63B 51/14
Stringing tennis, badminton or like rackets; Strings therefor; Maintenance of racket strings: arrangements for stringing, e.g. for controlling the…

Family

Serial107,304Parent of this division · filed 18 Jan 1971
Serial332,130Parent of this continuation-in-part · filed 13 Feb 1973
Serial480,462Parent of this division · filed 18 Jun 1974
Serial827,670Parent of this continuation-in-part · filed 25 Aug 1977
US 4,183,776 AParent of this continuation-in-part
US 4,045,025 AParent of this division
3755037Parent of this division
US 4,264,389 AThis patent

From the US filing history. Foreign family members aren’t listed.