GB1600869A

GB1600869A - Rackets and the like

Info

Publication number: GB1600869A
Application number: GB18148/77A
Authority: GB
Original assignee: Bigge T L
Current assignee: Bigge T L
Priority date: 1978-04-20
Filing date: 1978-04-20
Publication date: 1981-10-21

Description

(54) RACKETS AND THE LIKE (71) I, THOMAS LESLIE BIGGE, a British subject of Herton Farm, Lake, Barnstaple, North Devon, EX31 3HS, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to an improved racket which is provided with a shaft having a removable section which will break relatively easily and can be replaced thereby preventing serious damage to the remainder of the shaft or to the head of the racket.

The term "racket" where used throughout the present specification and claims is intended to include within its scope, any sporting implement used for striking a moving or stationary object, such as a squash racket, tennis racket, golf club, paddle tennis racket, bat or other club.

Rackets, particularly squash and tennis rackets have become increasingly expensive to manufacture as a result of rising raw material and labour costs. Because of the nature of the game, squash rackets are frequently broken when the head comes into contact with the wall or floor of the squash court during play. For this reason, the present invention is particularly advantageous when applied to a squash racket, but is not limited in its use only to squash rackets.

Rackets having relatively long shafts are also difficult to transport and there is therefore a need for a shaft which can be readily broken in two for transport and quickly and easily reassembled for use. Hitherto, problems have been encountered in de signing a breakable shaft which is sufficiently rigid in use, which can be properly aligned when reassembled and which is neither too heavy or out of balance.

In order to overcome these problems I provide a racket which has a shaft incor- porating a removable section which will break when subjected to a predetermined bending force, for instance, when the head of the racket strikes the wall or floor of the court or an opponent, and which can be quickly, cheaply and easily replaced thereby saving the remainder of the shaft or the head of the racket from serious damage.

In accordance with one aspect of the present invention, I provide a racket as hereinbefore defined comprising a handle, a head joined to the handle by a shaft which comprises a head portion and a handle portion and a breakable or bendable section in the shaft which is removably attached to the head portion and to the handle portion of the shaft, wherein the breakable or bendable section of the shaft is adapted to break or bend when subjected to a substantially smaller bending moment than that required to break or bend the remainder of the shaft.

Preferably the breakable or bendable section includes a flexible element which will hold the two ends of the breakable or bendable sections together if the section is broken in use.

The preferred material for the breakable or bendable section is zinc but other suitable materials such as fibre glass, cast iron, steel, carbon fibre reinforced plastics or various alloys may be used.

A preferred form of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a prospective view of a squash racket; Figure 2 is a longitudinal section through a part of the shaft of the racket shown in Figure 1; Figure 3 is an exploded, perspective view of the shaft assembly shown in Figure 2; and Figure 4 is a section taken on the line IV IV of Figure 2.

In Figure 1, a squash racket is indicated generally at 10 which comprises a head 11, a shaft 12 and a handle 13. The head 11 of the racket is a conventional laminated wood racket head and the shaft 12 is formed from tubular steel.

In a conventional steel shafted racket the steel shaft is unbroken from the handle to the head and of approximately constant diameter at either end though a taper often occurs in the middle of the shaft. However, in the racket 10 as can be seen from Figure 2, the shaft 12 is broken into a head portion 14 and a handle portion 15 and the ends 16 and 17 of the head portion 14 and handle portion 15 respectively are of increased diameter and are joined by a removable section in the form of a cylindrical spigot 18.

The spigot 18 preferably formed from zinc but may be made of any suitable materials such as fibre glass, nylon, any suitable alloy or a carbon fibre reinforced material.

Mid-way along the length of the spigot 18, the outer surface is formed with a circumferential groove 19 which defines a line of weakness or break point in the spigot and which divides the spigot into two end portions 20 and 21. An axial bore 22 is formed through the spigot from end to end and a flexible multi-filament metal cable 23 is housed in the bore 22. The ends of the cable 23 are clamped in position by transverse pins 24 and 25 respectively which extend through transverse holes 26 and 27 respectively in the end portions of the spigot.

The end portions 20 and 21 of the spigot are also provided with transverse threaded bores 28 and 29 respectively each of which houses a grub screw 30 and 31 respectively.

The enlarged ends 16 and 17 of the head portion and handle portion each house a similar sleeve 32 and 33 respectively. The sleeves 32 and 33 which are shown partially protruding from the short ends 16 and 17 in Figure 3 for clarity are preferably brazed into the ends of the shaft portions and their purpose is to provide an increased wall shaft thickness in the region of the joint between the shaft portions and this can be achieved in other ways if required.

When the sleeves are brazed into the shaft ends, holes 34 and 35 are formed in the shaft portions 14 and 15 respectively.

The holes 34 and 35 are circular and are adapted to give access to the grub screws 30 and 31 when the shaft is assembled together.

The shaft is assembled by sliding one end 20 of the spigot 18 into the head portion 14 of the shaft until the groove 19 is flush with the end of the shaft. It will be seen that both ends of the spigot 18 are identical so that it can be reversed, eliminating any necessity to select the correct end for the assembly operation. The spigot 18 is then rotated until the head of the grub screw 30 is aligned with the hole 34, a key is inserted through the hole 34 into the head of the grub screw 30 and the grub screw is rotated so as to drive the leading end of the screw 30 against the sleeve 32 there by locking the end 20 of the spigot in the head portion 14 of the shaft. The projecting end portion 21 of the spigot is then inserted into the end of the handle portion 15 of the shaft and locked in position in a similar manner.

Finally, a flexible sleeve 36 is rolled over the enlarged ends 16 and 17 of the shaft portion to hide the joint. The position of the holes 34 and 35 in the shaft portions in relation to the transverse threaded bores 28 and 29 in the spigot is such that, when assembled the head of the racket is correctly aligned with the handle.

In use, when the head of the racket.

strikes the wall or floor of a squash court and the shaft is subjected to a bending force above a certain level the spigot 18 will break along the line of weakness formed by the groove 19 thereby ensuring that the head or the remainder of the shaft of the racket is not damaged. The loading which the spigot 18 can take before it breaks is determined by the thickness of the spigot at the line of weakness and thus by the depth of the groove 19. This can be determined initially by trial and error to give the required break characteristics.

When the spigot 18 breaks, the flexible cable 23 will bend, but will not break, thereby ensuring that the head of the racket cannot fly away from the handle end of the shaft.

When the spigot 18 has been broken during use, it is a simple operation to unscrew the grub screws 30 and 31, withdraw the end portions 20 and 21 of the spigot and fit a new unbroken spigot in place.

The racket 10 can thus be repaired and made ready for use again at a minimum cost.

The present invention lends itself parti- cularly to use in a conventional metal shafted racket but it is also possible to adapt a wooden shaft racket to take the breakable spigot 18. All that is necessary is to attach a projecting metal tubular boss to each of the two portions of a wooden shaft. Each boss may be threadedly attached or glued to the end of the wooden shaft and the spigot 18 can then be inserted into the tubular bosses and clamped in position in the same manner as that described above.

It will be appreciated that the breakable spigot 18 may take many forms and be manufactured from any suitable material. It should also be understood that the present invention lends itself to use in a racket having a metal head. Hitherto, a squash racket formed with a metal head has been unacceptable because of the risk of damage which the metal head may do to a player if he is struck by the head of the racket or court wall, in the case of a game played in a court.

By providing a breakable section in the shaft of such a racket, the maximum force which can be applied by the head of the racket can be kept at a level such that there is a diminished risk of real damage to walls or injury to a player and a metal headed squash racket becomes a practical commercial possibility.

It is also envisaged that the breakable spigot may be attached to the ends of the two portions of the shaft with the aid of an adhesive which can be released by the application of heat or the appropriate solvent.

It is not essential that the spigot 18 should break in use and it may be adapted to bend substantially rather than breaking completely into two parts.

WHAT I CLAIM IS: 1. A racket as hereinbefore defined comprising a handle, a head joined to the handle by a shaft which comprises a head portion and a handle portion and a breakable or bendable section in the shaft which is removably attached to the head portion and to the handle portion of the shaft, wherein the breakable or bendable section of the shaft is adapted to break or bend when subjected to a substantially smaller bending moment than that required to break or bend the remainder of the shaft.

2. A racket as claimed in claim 1, wherein the breakable section comprises a spigot having a line of weakness defined by a circumferential external groove.

3. A racket as claimed in claim 1 or claim 2, wherein the breakable section is formed from zinc.

4. A racket as claimed in claim 1 or 2, wherein the breakable section is formed from a fibre glass and resin material.

5. A racket as claimed in any preceding claim, wherein the breakable section comprises a spigot the ends of which are inserted into receiving bores in the head portion and handle portion of the shaft.

6. A racket as claimed in claim 5, wherein the ends of the spigot are clamped in position by threaded clamping elements.

7. A racket as claimed in any preceding claim, wherein the shaft is tubular and the wall of the shaft is enlarged and strengthened in the area of the junction between the head portion and the handle portion of the shaft.

8. A racket as claimed in any preceding claim, wherein the head portion and the handle portion of the shaft are joined by a flexible element which is adapted to tie the head portion to the handle portion when the breakable section is broken.

9. A racket as claimed in claim 8, wherein the ends of the flexible element are attached to the ends of the breakable section.

10. A racket as claimed in claim 9, wherein the flexible element is housed in a bore extending through the breakable section.

11. A racket as claimed in any of claims 8 to 10 wherein the flexible element comrises a multi-filament metal cable.

12. A racket substantially as described herein with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. squash racket becomes a practical commercial possibility. It is also envisaged that the breakable spigot may be attached to the ends of the two portions of the shaft with the aid of an adhesive which can be released by the application of heat or the appropriate solvent. It is not essential that the spigot 18 should break in use and it may be adapted to bend substantially rather than breaking completely into two parts. WHAT I CLAIM IS:

1. A racket as hereinbefore defined comprising a handle, a head joined to the handle by a shaft which comprises a head portion and a handle portion and a breakable or bendable section in the shaft which is removably attached to the head portion and to the handle portion of the shaft, wherein the breakable or bendable section of the shaft is adapted to break or bend when subjected to a substantially smaller bending moment than that required to break or bend the remainder of the shaft.