GB2081592A - Racquets - Google Patents

Abstract

A badminton racquet, comprises a generally toroidal, extruded aluminium frame, and a handle which is secured to the frame by a V-shaped securing member. The inclined limbs of the V-shaped member have respective transversely extending, substantially aligned, tubular portions, at their ends, which tubular portions receive and closely fit around two spaced apart portions of the frame. The base of the member is also tubular, with its axis bisecting the angle between the limbs, and receives the handle. The inner end of the handle extends between the limbs, into a socket or hole in the frame, in which it is secured. The internal profile of the extrusion is shaped to locate two steel pins 54, which extend between the abutting opposite ends of the extrusion. The pins 54 engage in respective grooves 56 in the inner end 36 of the handle 20, so as to lock the handle in the hole 38. <IMAGE>

Description

SPECIFICATION Racquets This invention relates to racquets, and is more par ticularly but not exclusively concerned with badmin ton racquets.

One known type of badminton racquet comprises a generallytoroidal frame made from a suitably bent length of tubular material, and a substantially radially extending handle secured to the frame by means of a T-shaped joining member. The cross piece of the T-shaped member is hollow, and receives the two ends of the length of material mak ing up the frame, while the upright portion of the T-shaped member serves as a socket for the handle.

This type of badminton racquet has met consider able success, since it is both light and aesthetically pleasing, but it nevertheless has a number of disad vantages and inconveniences. Thus the head of the racquet can pivot or flex to a significant extent about respective axes perpendicular to the plane ofthe frame and coaxial with the cross-piece and upright of the T-shaped member. This flexing can lead inter alia to fracturing of the frame at the points where it enters the cross-piece of the T-shaped member.

Additionally, it is usually necessary for the stringing of the racquet to pass through one or more holes extending radially through the cross-piece of the T-shaped member, so that these holes require spe cial grommets, i.e. grommets whose length is grea ter than that of the normal grommets which pass only through the frame.

It is therefore an object of the present invention to provide a racquet in which the abovementioned dis advantages and inconveniences of the known type of racquet are alleviated.

According to the present invention, there is pro vided a racquet comprising: a generallytoroidal frame made by suitably bending a length of a hollow extrusion until its opposite ends are adjacent one another; stringing secured to the frame; a handle securing member having a first tubular portion extending substantially radially outwardly from the frame and at least one second tubular portion receiv ing and surrounding the ends of said extrusion; and a handle secured within said first tubular portion; wherein said extrusion has an internal profile shaped to locate at least one pin which projects from one of said opposite ends into the corresponding portion of the internal profile of the other of said opposite ends.

The invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a somewhat diagrammatic representa- Alon of part of one embodiment of a badminton rac quet in accordance with the present invention; Figure 2 is a somewhat diagrammatic sectional view of the frame of the racquet of Figure 1; and Figure 3 is a sectional view of another embodi ment of a badminton racquet in accordance with the present invention.

The badminton racquet of Figures 1 and 2 is indicated generally at 10, and comprises a generally toroidal frame 12 which is slightly oval in shape and made from a single length of extruded aluminium tubing 14 bent, e.g. around a former, to produce the oval shape of the frame. The opposite ends 16, 18 of the tubing 14 abut each other, and are welded or otherwise bonded together, e.g. with suitable adhesive.

A slim tubular steel handle 20 extends substantially radially of the frame 12 and carries at the end remote from the frame a hand-grip (not shown) of wood or plastics. The handle 20 is typically of circular cross-section, and its diameter may either be uniform or increase slightly with increasing distance from the frame 12.

The handle 20 is secured to the frame 12 by means of an aluminium V-shaped member 24, having at the upper extremities of its two inclined limbs 26, 28 respective transversely extending tubular portions 30,32. The tubular portions 30, 32 are substantially axially aligned with each other, and they are a close fit around respective spaced-apart portions of the frame 12 selected such that the ends 16, 18 of the tubing 14 are disposed inside one of the tubular portions 30,32, e.g. the tubular portion 30 as shown in Figure 1.

The base 34 of the V-shaped member 24 (i.e. the point where the limbs 26, 28 meet) is also tubular, with its axis (i.e. the axis of the tube constituted thereby) extending radially of the frame 12, and receives the inner end 36 of the handle 20. The end 36 of the handle 20 extends completely through the base 34, and projects between the limbs 26, 28 to engage in a hole 38 drilled in the radially outer surface oftheframe 12 midway between the tubular portions 30,32.

The V-shaped member 24 is initially made as a single piece by casting or die-stamping: the tubular portions 30,32 and the base 34 are initially solid, and are then renderened tubular by drilling. The tubing 14 is then bent to produce the desired oval shape of the frame 12, and the aligned tubular portions 30,32 are threaded onto one end of the tubing 14. The two ends of the tubing 14 are then joined together, as described above, and positioned inside the tubular portion 30. The end 36 of the handle 20 is passed through the tubular base 34 and into the hole 38 (previously drilled a predetermined distance from one end of the tubing 14), and is bonded into the hole 38 with a suitable bonding agent, e.g. ARAL DITE (Registered Trade Mark).Finally, the spaces between the frame 12 and the tubular portions 30, 32 and between the end 36 of the handle 20 and the tubular base 34 are filled with a suitable fillinglbond- ing agent, again typically ARALDITE (Registered Trade Mark), and the tubular portions 30,32 and the base 34 are crimped or pressed such that they conform to the external profile of the tubing 14 of the frame 12 orthe end 36 of the handle 20, as the case may be: excess fillinglbonding agent, squeezed out by the crimping or pressing operation, is removed before it hardens.

A plurality of holes, such as those indicated at 40, are drilled through the tubing 14 prior to its bending to form the frame 12, and thus extend approximately radially through the frame 12. Respective grommets 42, e.g. of nylon, are inserted through the holes 40, and the stringing of the racquet 10 is secured to the frame 12 by passing the strings through the grom mets 42 in the holes 40. It will be noted that the axial length of each of the tubular portions 30,32 is sufficiently small that it is not necessary to provide str inging holes extending therethrough: as a result, only one, standard, form of grommet 42 is necessary.

The racquet 10 has a numberof other advantages.

Thus the V-shape of the member 24 reduces the tendency of the head of the racquet 10 to twist about an axis extending coaxially of the handle 20, and about an axis extending perpendicular to the plane of the head ofthe racquet and passing through the frame 12 in the region of the hole 38. Further, the strength of the racquet 10 in the region of the connection between the handle 20 and the frame 12 is enhanced by the four-point fixing used to secure the handle 20 to the frame 12, these four points being at the tubular portions 30,32, at the tubular base 34 and at the hole 38.

A number of modifications can be made to the above described embodiment ofthe invention. For example, the end 36 of the handle 20 protruding from the base 34 of the V-shaped member 24 can be longitudinally split and bonded around the outside surface of the portion ofthe frame 12 between the tubing portions 30,32. Alternatively, the limbs 26,28 of the member 24 can be made hollow, in which case the end 36 can be longitudinally split and the split ends passed through the hollow limbs 26,28 respectively and secured to the frame 12 within the tubular portions 30,32 respectively. In orderto produce the member 24 with the limbs 26,28 hollow, the member 24 can be cast in two pieces which mate in a plane extending approximately diametrically of the tubular portions 30,32 and the tubular base 34.

However, by using a more sophisticated die for the die member 24, it can be cast with the portions 30,32 and the base 34 already tubular: in this case, the respective internal profiles of the tubular portions 30,32 and the tubular base 34 can be cast such that they substantially conform to the respective external profiles of the tubing 14 of the frame 12 and the end 36 of the handle 20.

Moreover, the tubular base 34 of the member 24 can be axially extended towards and/or away from the frame 12, the lattertending to renderthe member 24 somewhat V-shaped, and the limbs 30, 32 can be symmetrically concavely or convexly curved, the lattertending to renderthe member 24 somewhat U-shaped: however it is to be understood that the expression "V-shaped" as used in this specification is intended to embrace all of these possible shapes.

The badminton racquet shown in part in Figure 3 is basically similar to the racquet of Figures 1 and 2, so corresponding elements have been given the same references but with the suffix a. Thus Figure 3 is an enlarged section through the extruded aluminium tubing 14a forming the frame 12a of the racquet, art a point close to where the end 36a of the handle 20a is secured in the hole 38a in the frame 12a. The handle 20 is additionally secured to the frame by a V-shaped member corresponding to the V-shaped member 24 of Figure 1, but this has been omitted from Figure 3 for the sake of clarity.

The tubing 14a has a groove 50 in the external surface thereof which forms the radially outer surface of the frame 12a. This groove 50 is wider at its base than at its mouth, such that the radially outer heads of the grommets (not shown) corresponding to the grommets 42 of Figure 2 can lie wholly therein, and be retained ortrapped therein.

The internal profile of the tubing 14a is shaped to form two inwardly projecting locating or retaining lugs 52, which serve to receive and locate two steel pins 54 by trapping them against the internal surface of the portion of the tubing 1 4a forming the base of the groove 50.

During manufacture of the racquet, the steel pins 54 are inserted into the end of the bent tubing 14a corresponding to the end 18 of Figure 1. The pins 54 are inserted sufficiently far into the tubing 14a to engage respective tangential grooves 56 machine on diametrically opposite sides of the portion of the end 36a of the handle 20a actually in the hole 38a, and thus serve to lock the handle in the hole. The ends of the pins 54 projecting from the end of the tubing 14a are then inserted into the other end of the tubing, i.e.

the end corresponding to the end 16 of Figure 1, to join the two ends of the tubing together, this joining being effected by filling the spaces such as 56 around the pins 54 with a bonding agent such as ARALDITE (Registered Trade Mark).

It will be appreciated that the lugs 52, since they are formed as the tubing 14a is extruded, extend the whole length of the tubing, so that the pins 54 are received and located in both ends ofthe tubing.

However, the portions of the lugs 52 at the base of the hole 38a are machined away when the hole is formed, so that the end 36a of the handle 20a can bed against a flat internal wall of the tubing 14a.

In addition to locking the handle 20a in the hole 38a, the pins 54 considerably reinforce or strengthen the joints between the ends of the tubing 14a and between the handle 20a and the tubing 14a. Indeed, this strengthening is sufficient to permit the V-shaped member corresponding to the member 24 of Figure 1 to be replaced if desired by a T-shaped joining member of the general type discussed in the introduction, the joint between the ends of the tubing 14a being displaced within the crosspiece of the T-shaped member frorn the point where the handle 20a projects from the top of the upright portion of the T-shaped member into the hole 38a.

Although the invention has been described in relation to its application to badminton racquets, it can also be applied to other racquets, particularly squash racquets.

Attention is directed to my co-pending UK Patent Application No.79 22108, Serial No. 2,033,760, from which the present application has been divided.

Claims (3)

1. A racquet comprising: a generally toroidal frame made by suitably bending a length of a hollow extrusion until its opposite ends are adjacent one another; stringing secured to the frame; a handlesecuring member having a first tubular portion extending substantially radially outwardly from the frame and at least one second tubular portion receiving and surrounding the ends of said extrusion; and a handle secured within said first tubular portion; wherein said extrusion has an internal profile shaped to locate at least one pin which projects from one of said opposite ends into the corresponding portion of the internal profile of the other of said opposite ends.

2. A racquet as claimed in claim 1, wherein the frame is provided with a hole or socket in its radially outer surface and the end of the handle disposed in the first tubular portion extends therethrough and is secured in said hole, and wherein said pin engages the portion of the handle in said hole so as to lock the handle in the hole.

3. A racquet as claimed in claim 2, wherein said profile is shaped to locate two such pins symmetrically on each side of the mean plane of the stringing, each pin engaging a respective tangential groove in said portion of the handle.