GB2028665A - Racket - Google Patents

Abstract

A racket has a tubular frame (6), and a T-piece (1) which has a medial securing rib or plate (5) engaging in slots or grooves in the frame (6). <IMAGE>

Description

SPECIFICATION Racket This invention relates to rackets and has particular but not necessarily exclusive reference to badminton rackets or the like. The junction or joint between a handle shaft and a frame part to be strung for use has presented problems in obtaining the required strength together with desired use of fabrication and low weight.

Heretofore, such joints have been proposed as tubular "T" pieces for connecting between frame and handle shaft ends.

However in using such a T-piece joint problems have arisen in obtaining uniformity and integrity of fitting to both ends of the frame and adequate location against rocking of the frame relative to the handle shaft. In order to achieve these two objects two compositions have been needed, for example pinning through the T-piece cross tube and frame ends therein. By contrast this invention provides a structure enabling to achieve these two objects at a time by only one structure and set of operations.

According to this invention, a racket is formed with a T-piece joint with cross-tube able to accept end parts of a bent tubular frame from opposite ends of the cross tube, the stem-tube part accepting a racket shaft, and the cross-tube part having a securing member or members fixed to its interior and extending along a medial part of the length of the cross tube in the direction thereof to engage corresponding formations of the frame end parts over a length and form to mate on the securing member or members within the cross tube.

Embodiments of the invention will now be specifically described, by way of example, with reference to accompanying drawings, in which: Figure 1 shows a face view of a racket; Figure 2 is a cross-section through the racket of Figure 1 at the position of the handle-to-frame joint Figure 3 is a section at right angles to that of Figure 2 but of the T-piece alone; Figures 4 and 7 are sections similar to Figure 3 but of variants; and Figures 5, Sand 8 show of frame end parts for the embodiments of Figures 4 and 7, respectively.

In Figures 1,2,3 and 5, numeral 1 indicates a jointing piece in the form of a letter "T" comprising a stem-tube 2 and a curving cross-tube 3 extending to each side of the upper end of the stem-tube.

Numeral 4 indicates a through-bore of the cross-tube 3 with a securing plate 5 of a suitable length L at a central part thereof and generally following the direction of the central line of the through-bore 4.

The shape of the through bore 4 in section may follow a circular, elliptical, angular or other suitable form, though elliptical will be described.

The securing plate 5 is shown extending perpendicular to the direction of the stem-tube axis but may have any other desired and suitable direction, for example at right angles to that shown. It is preferably of a length at least equal to the diameter of the through-bore 4 and follows the central line thereof.

The securing plate 5 is preferably provided symmetrically and centrally of an extended central line of the stem tube 2, but need not be if racket frame forms so dictate or allow. Numeral 6 indicates a racket head frame formed by bending a tube body and provided with a sufficient number of throughholes (not shown) to permit desired stringing 7.

The frame 6 is formed in a shape such that its end parts correspond to that of the through-bore 4. Both ends 8 have securing slots 9 to mate with the securing plate 5. The securing slots 9 are each half the length of the securing plate 5 when the securing plate 5 is provided at the centre of the through-bore 4. If the securing plate is asymmetrically disposed, the slots 9 may differ in length in a corresponding way. Numeral 10 indicates a handle shaft having a grip 11 provided at the lower end thereof and having the upper end thereof fixed into the stem-tube 2, if desired by screwing, bonding, or force fit.

When assembling the racket, both ends 88 of the frame 6 are fitted into the through-bore 4 of the cross-tube 3 of the T-piece joint from the left and right sides.

Both ends 8 of the frame 6 described above are formed so as to correspond both to the curving of the through-bore 4, and to its cross-section, should that not be circular. As an end 8 of the frame 6 reaches the central part of the through-bore 4, its slots 9 will engage on the securing plate 5 with mutual guidance to the bottom of the securing slot 9, which will present further relative movement in the same direction.

It is convenient to taper both of the securing plate 5 and securing slot 9 so as to facilitate fitting of the securing slot 9 onto the securing plate 5. Both ends 8 of the frame 6 are fitted into the through-bore 4from the opposite ends thereof simultaneously or sequentially and are securely located relative to the crosstube by the integral securing plate 5. Of course, there could be a clearance between the two ends 8 of frame 6 in the cross-tube 4 depending on the length of the securing plate 5 and the depth of the securing slots 9.

When the frame 6 is so fitted into the through-bore 4 more permanent securement between them can be made by bonding or rivetting. Then, a racket can be completed by stringing the frame 6 before, after or during insertinglyfixing the shaft 10 into the stem tube 2.

Figures 4 and 6 show an embodiment with a securing plate 5' extending only part way across the through-bore 4 and a single corresponding slot 9 in the frame end 8.

Figures 7 and 8 show another embodiment with two ribs 5" extending from the inner wall of the through-bore 4 and inset grooves 13 in the frame end 8 to mate therewith. Although shown as only two in number and diametrically opposed, the ribs 5" and slots 13 may be of any desired number and location so long as they correspond one with the other.

For all embodiments, numeral 12 indicates a blind bore of the stem tube 2 to take the handle shaft 10.

Thus the embodiments as described above provide for a racket where end parts of a frame formed by bending a tube body are fitted from both ends thereof, that is, the left and right, into a through-bore of the cross-tube of a T-piece joint and the end of a handle shaft is fitted into its stem-bore, the crosstube through-bore having a securing plate or rib of a suitable length extending medially of the throughbore to engage securing formations of the frame end parts on the securing plate or rib when fittingly connecting a frame, the length and form of such formations corresponding to the securing plate, whereby rotation of the frame in the T-piece joint is surely prevented by the engagement of the securing formations and fixed plate or rib, the fitting insertion of the frame ends also being limited thereby when the frame is fittingly inserted in the cross tube through-bore of the T-piece joint.

Moreover, the accurate and secure location is achieved in one operation with a very simple construction to give a racket that is most convenient in use with its simple structure leading to easy production, and high strength.

Claims (7)

1. A racket having a "T" piece joint, a cross-tube of which has a through-bore and accommodates end parts of a frame of bent tubular form, and a stem-tube which has a bore accommodating an end of a handle shaft, wherein a securing member or members fixed to the interior of said through-bore and extending over a medial part of the length thereof engage corresponding formations of the end parts of the frame having a length and form to mate on the securing member or members within the cross-tube.

2. A racket as claimed in claim 1,wherein the or each said securing member extends from the through-bore of the cross-tube of the T-piece joint.

3. A racket as claimed in claim 2, wherein one said securing member comprises a plate extending across the through-bore of the cross-tube of the T-piece joint and is secured to the through-bore wall at both of the plate's sides, and the frame end part formations are slots two in each part.

4. A racket as claimed in claim 2, wherein one said securing member comprises a plate extending from one side of the through-bore but free at its other side, and the frame end part formations are slots one in each part.

5. A racket as claimed in claim 2, wherein the securing members comprise two ribs spaced from each other over the interior of the through-bore and the frame end part formations are grooves.

6. A racket according to any preceding claim, wherein the securing member or members and the frame end part formations cooperate to limitinser- tions of the frame ends into the T-piece joint.

7. A racket substantially as herein described with reference to and as shown in Figures 1,2,3 and 5 or Figures 4 and 6, or Figures 7 and 8 of the drawings.