GB2197208A

GB2197208A - Repairing games racquets

Info

Publication number: GB2197208A
Application number: GB08621489A
Authority: GB
Inventors: Paul Anthony Belger
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-09-05
Filing date: 1986-09-05
Publication date: 1988-05-18
Anticipated expiration: 2006-09-05
Also published as: GB2197208B; GB8621489D0

Abstract

A strung games racquet having a head (10) with a frame which is hollow or has a removable filling and which is cracked or broken is repaired by inserting within the frame of the unstrung racquet in the region of the crack or break (14) an elongate strengthening member (16) having holes (20) therethrough whose spacing corresponds to the stringing holes of the frame. The racquet is then restrung with the strengthening member in place, passing the strings through aligned holes of the frame and of the strengthening member. A strengthening layer (24) of fiber-reinforced resin or the like may be formed around the strengthening member, and the repair may be further reinforced by means of a grommet (26) or an outer covering. <IMAGE>

Description

SPECIFICATION Method of repairing games racquets This invention relates to a method of repairing strung racquets such as squash racquets, of the type wherein the head has a hollow frame or a tubular frame filled with foam or the like.

There has in recent years been a considerable increase in the use of squash racquets with frames made from graphite or carbon fibre-reinforced plastics. Such racquets generally have a head with a hollow or foam-filled frame. Squash racquets generally are easily broken since they have to be of lightweight construction and often strike the walls of the court at high speed during play. Graphite and carbon fibre racquets become virtually unusable if they are even cracked, and they are very expensive to replace. There is therefore a need for a method of repairing such racquets at a cost substantially less than the cost of a new racquet.

The present invention consists in a method of repairing a strung games racquet having a head with a frame which is hollow or has a removable filling, the frame being cracked or broken, which comprises the steps of: inserting within the hollow frame of the unstrung racquet in the region of the crack or break, an elongate strengthening member having holes therethrough with a spacing between them corresponding to that of the stringing holes of the frame, aligning the holes in the frame with those of the strengthening member, and restringing the racquet with strings passing through the holes in the strengthening member.

The strengthening member preferably has at least four holes, two to be positioned on each side of the site of the break. The strengthening member is preferably made from aluminium, but other materials such as titanium, brass, steel or even some plastics may be used.

Further strengthening may be provided by winding around the strengthening member a strip of woven glass fibre or the like. This acts as a packing within the hollow frame and also imparts greater tensile strength. A bonding resin can be applied to the strip as it is wound on.

In a preferred method according to the invention the frame, and optionally any packing around the strengthening member, is abraded or pared down on either side of the break so as to taper inwardly from each side to provide a waisted region around the strengthening member. The frame can then be made up back to its original shape by applying around the waisted region further reinforced plastics material, preferably similar to that of which the frame is made. For example graphite fibres in the form of a tape can be wound around the site, a bonding resin being applied to each turn of the tape as it is wound. The resin sets; bonding the ends together rigidly. A substantially invisible mend can be obtained in this way.

Preferred embodiments of the invention will now be described with reference to the accompanying drawings wherein: Figure 1 is a partial perspective view showing how a repair is effected in accordance with a first embodiment of the invention, Figure 2 is a partial cross-section in the plane of a racquet head, showing a repair made in accordance with a second embodiment, Figure 3 is a partial cross-section, in the plane of a racquet head, showing how a repair is made in accordance with a third embodiment of the invention and Figure 4 is a cross-section along the line IV-IV in Fig. 3.

Referring first to Fig. 1, part of a tubular frame of a racquet head is indicated by 10 and has regularly spaced holes 12 for stringing of the racquet. Th frame has a break in a region indicated by 14.

An elongate stiffening member 16, made of a rigid but relatively lightweight material such as aluminium, is inserted in the hollow centre 18 of the frame, bridging the break 14. The stiffening member is of rectangular cross-section and slightly arcuate to conform to the curvature of the passage '8. It has four holes 20 whose spacing corresponds to that of the holes 12 of the racquet frame. The four holes of the strengthening member are aligned with four holes of the frame, two on each side of the break.

A close fitting outer sleeve 22 of resilient plastics or rubber is fitted around the outside of the frame to cover the repair, this sleeve having been slid onto the frame over one of the broken ends before insertion of the strengthening member. Holes 23 are formed through both sides of the sleeve, aligned with the holes 12 of the frame. These holes can conveniently be formed in situ when the sleeve has been located.

The racquet can then be restrung, passing strings through the aligned holes of the frame, the strengthening member and the sleeve. The racquet may have a rubber or plastics grommet to be fitted around the outside of the frame prior to stringing, to protect the strings from wear by friction with the frame edges.

The strengthening member 16, assisted by the sleeve 22, enables the frame to be held firmly together by the strings so that the repaired part may even be stronger than the rest of the frame.

Fig. 2 shows a completed repair in accordance with a second embodiment of the invention. The repair is similar to that of Fig. 1 except that the outer sleeve is omitted and a packing layer 24 of glass fibre reinforced resin is formed around the strengthening member 16. This is formed by winding around the strengthening member a woven strip or sheet of glass fibre or other fibrous reinforcing material, impregnating the strip or sheet with a liquid thermosetting resin by applying the resin to each layer as it is wound on. The strengthening member, with the packing layer 24 around it, is inserted in position to allow the resin to cure in situ, bonding the insert rigidly to the inner surface of the frame to repair the break.

When the strengthening member is inerted, rods or the like can be pushed through the holes 12 of the frame to locate the strengthening member correctly and to form passages through the fibre reinforced resin for the racquet strings 28 and for the tubular projections 27 of a protective grommet 26 which is fitted around the periphery of the frame and through which the strings 28 are passed.

The embodiment shown in Figs. 3 and 4 is a further refinement of that shown in Fig. 2, the strengthening member 16 being surrounded by a layer 24 of fibre-reinforced resin. The site of the original break is indicated at 14' by broken lines, but the broken ends have been pared down, by cutting or abrading (for example with a file) to form surfaces 30 which taper inwardly from each side towards the site of the original break. The reinforced resin packing 24 is also cut or abraded down to form continuous tapering surfaces 32 which meet one another at the outer surface of the strenthening member 16, in the region of the original break. There is thus formed a waisted region 34 extending around the frame.

The repair is completed filling the waisted region 34 with a fibre-reinforced resin, preferably of a type similar to that of which the racquet frame is made. This can be done for example by winding a graphite tape around the tapering surfaces 30, 32, applying liquid resin to each layer as in the case of the layer 24. The outer layer of resin can be shaped, as it cures, to conform to the shape of the racquet frame. The resin bonds firmly to the frame so that a virtually invisible mend can be made in this way. The grommet 26 is then replaced and the racquet restrung as in the embodiment of Fig. 2.

The method of the invention can be used to repair not only graphite and carbon fibre type racquets but also other racquets having hollow or foam-filled frames such as those made of glass fibre reinforced plastics and those made of plastics compositions reinforced with aramid fibres such as Kevlar (registered Trademark).

Claims

1. A method of repairing a strung games racquet having a head with a frame which is hollow or has a removable filling, the frame being cracked or broken, which comprises the steps of: inserting within the hollow frame of the unstrung racquet in the region of the crack or break, an elongate strengthening member having holes therethrough with a spacing between them corresponding to that of the stringing holes of the frame, aligning the holes in the frame with those of the strengthening member, and restringing the racquet with strings passing through the holes in the strengthening member.

2. A method according to claim 1 wherein the strengthening member has at least four holes therethrough, two said holes being positioned on each side of the site of the break.

3. A method according to claim 1 or claim 2 wherein the strengthening member is made from aluminium.

4. A method according to any preceding claim wherein a strip of strengthening material is wound around the strengthening member to impart increased tensile strength.

5. A method according to claim 4 wherein the strengthening material comprises woven glass fibre.

6. A method according to claim 4 or claim 5 wherin a bonding resin is applied to a strip as it is wound around the strengthening member.

7. A method according to any preceding claim wherein after insertion of the strengthening member and before restringing of the racquet a grommet is fitted around the racquet head at least in the area of the break, the grommet comprising a strip fitting around the outer periphery of the racquet with tubular projections therefrom extending through the holes in the racquet head and the strengthening member.

8. A method according to any preceding claim wherein an outer covering is fitted around the repaired portion of the racquet head prior to restringing.

9. A method according to claim 8 wherein the outer covering comprises a rubber sleeve which is slid over one of the broken ends of the racquet head prior to insertion of the strengthening member and slid into position over the repaired joint prior to restringing, the racquet then be restrung by passing strings through'holes in the sleeve aligned with the holes in the racquet head and strengthening member.

10. A method according to claim 8 wherein the outer covering is formed by applying a tape of reinforcing material around the repair site.

11. A method according to claim 10 wherein an outer covering of reinforced plastics material is formed by winding a graphite fibre tape around the repair site and applying a bonded resin to each turn of the tape as it is wound.

12. A method according to claim 11 wherein the frame, and optionally any packing around the strengthening member, is abraded or pared down on either side of the break so as to taper inwardly from each side to provide a waisted region around the strengthening member, the frame then being made up back to its original shape with the reinforced plastics material covering.

13. A method of repairing a strung games racquet substantially as herein described with reference to Fig. 1, Fig. 2 or Figs. 3 and 4 of the accompanying drawings.