GB2282974A

GB2282974A - Badminton racket.

Info

Publication number: GB2282974A
Application number: GB9321891A
Authority: GB
Inventors: Chin-San You
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-10-23
Filing date: 1993-10-23
Publication date: 1995-04-26
Anticipated expiration: 2013-10-23
Also published as: FR2711925A3; FR2711925B3; GB2282974B; GB9321891D0

Abstract

A badminton racket has an oval frame 12, a tubular shaft 14, a T-shaped joint 16 connecting the frame 12 to the shaft 14, and an outer plastics shell 18 covering a junction area between the frame 12 and the shaft 14. The frame 12 has two opposite side end portions 20 of hollow construction. The T-shaped joint 16 has two horizontal extension portions 26 which are inserted into the two side end portions 20 of the frame 12. The shaft 14 has an upper end 24 which is inserted into a vertical extension portion 28 of the T-shaped joint 16. The outer shell 18 is used to cover entirely the two opposite side end portions 20 of the frame 12 and the outer surface of the vertical extension portion 28 of the T-shaped joint 16. The shell 18 may be formed from a polymer or a fibre-reinforced plastic material. In addition, there may be a bridging layer (60 fig 7) around the frame/shaft junction. <IMAGE>

Description

BADMINTON RACKET FIELD OF THE INVENTION The present invention relates generally to a game racket, and more particularly to a badminton racket.

BACKGROUND OF THE INVENTION The conventional badminton racket is generally composed of a shaft, a frame, and a T-shaped neck connecting the shaft and the frame. The frame has two opposite ends which are inserted into the T-shaped neck. The top end of the shaft is also inserted into the T-shaped neck. In order to accommodate the two opposite ends of the frame as well as the top end of the shaft, the T-shaped neck must have an outer diameter greater than the outer diameters of the frame and the shaft. As a result, the dimension of the T-shaped neck is increased. Such an increase in the dimension of the T-shaped neck brings about a greater resistance to air. In addition, the T-shaped neck forms a pivotal portion of the badminton racket as well as a load center at the time when the badminton racket is swung.Any attempt to reduce the dimension and the thickness of the T-shaped neck is impractical in view of the fact that such attempt will undermine the structural strength of the T-shaped neck. On the other hand, it is equally impractical to increase the dimension of the T-shaped neck so as to enhance the structural strength of the T-shaped neck, because an oversize T-shaped neck does enhance the structural strength of the T-shaped neck at the expense of the resilience of both opposite ends of the frame. The T-shaped neck is different in resilience and rigidity from the junction areas where the T-shaped neck is joined respectively with the frame and the shaft. As a result, the junction areas are vulnerable to a phenomenon known as a material fatigue.Such material fatigue of the junction areas is caused by the concentration of impact loads which take place at the time when the badminton racket hits a shuttlecock. In other words, the junction areas of the prior art badminton racket are vulnerable to breakage or fracture.

SUMMARY OF THE INVENTION It is therefore the primary objective of the present invention to provide an improved badminton racket with a joint having a relatively smaller dimension and capable of reducing its resistance to air.

A further objective of the present invention is to provide an improved badminton racket with an appropriate strength and an appropriate resilience.

A still further objective of the present invention is to provide an improved badminton racket with a joint which is less subject to impact loads at the time when the badminton racket hits a shuttlecock.

The foregoing objectives of the present invention is attained by an improved badminton racket, which comprises a frame of oval construction, a tubular shaft, a T-shaped joint connecting the frame and the shaft, and an outer shell covering the junction area between the frame and the shaft.

The frame has two opposite ends of hollow construction and having an opening. The joint has a pair of horizontal extension portions and a vertical extension portion. The two horizontal extension portions of the joint are inserted securely and respectively into the hollow opposite ends of the frame. The vertical extension portion is of hollow construction and provided with a hollow end into which the top end of the shaft is inserted. The improved badminton racket of the present invention is further characterized in that the junction area between the frame and the shaft is reinforced by the outer shell of a polymer consisting of giant molecules.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a plan view of a first preferred embodiment of the present invention FIG. 2 shows a sectional view of a portion taken along the line 2-2 as shown in FIG. 1.

FIG. 3 shows an exploded view of the portion as shown in FIG. 2.

FIG. 4 shows a sectional view of a portion taken along the line 4-4 as shown in FIG. 3.

FIG. 5 shows a sectional view of a portion taken along the line 5-5 as shown in FIG. 3.

FIG. 6 shows a sectional view of a portion of a second preferred embodiment of the present invention, with the portion being taken in the direction similar to the line 2-2 as shown in FIG. 2.

FIG. 7 shows a sectional view of a portion of a third preferred embodiment of the present invention, with the portion being taken in the direction similar to the line 2-2 as shown in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION As shown in FIGS. 1-5, a badminton racket 10 of the first preferred embodiment of the present invention comprises a frame 12 of oval construction, a tubular shaft 14, a T-shaped joint 16 connecting the frame 12 and the shaft 14, and an outer shell 18 covering a junction area between the frame 12 and the shaft 14.

The frame 12 has two opposite side end portions 20-20 sealing the oval frame 12. Each of the side end portions 2020 has an oval section and an open end surface 22-22. The shaft 14 has an upper end 24 having an oval section. The frame 12 and the shaft 14 are made of stainless steel, aluminium alloy, fiber reinforced plastic, or other suitable material.

The T-shaped joint 16 has two horizontal extension portions 26-26 and one vertical extension portion 28. Each of the two horizontal extension portions 26-26 is of solid construction and provided with a section which is corresponding in location to the hollow interior of each of the two side end portions 20-20 and which has a uniform outer diameter throughout the section. The vertical extension portion 28 is of hollow construction and provided with an annular section and an open end surface 30. The Tshaped joint 16 is made of a lightweight material of great strength, such as an aluminium alloy or a fiber-reinforced plastic material.

In combination, the two horizontal extension portions 26-26 are inserted respectively from the open end surfaces 22-22 into the two opposite side end portions 20-20 of the frame 12, while the upper end 24 of the shaft 14 is inserted through the open end surface 30 into the vertical extension portion 28 of the T-shaped joint 16.

The frame 12 and the shaft 14 are connected by the Tshaped joint 16. The junction area is then arranged in a molding tool in which the junction area is covered with a reinforcing outer shell 18 of a polymer consisting of giant molecules. The outer shell 18 of an appropriate thickness is used to cover the two opposite side end portions 20-20 of the frame 12 and the external surface of the vertical extension portion 28 of the T-shaped joint 16. The outer shell 18 has two horizontal extension ends 40-40 of a thickness which is progressively thinner from an inner side thereof toward an outer side thereof. The outer shell 18 has a vertical extension end 42 having a thickness which is progressively thinner from the top thereof toward the bottom thereof.The vertical extension end 42 of the outer shell 18 covers preferably a junction between the upper end 24 of the shaft 14 and the vertical extension portion 28 of the Tshaped joint 16.

As shown in FIG. 6, the second preferred embodiment of the present invention is provided with an outer shell 50 covering the junction area between the frame 12 and the shaft 14. The outer shell 50 is formed of a plurality of fabric sheets of carbon fibers arranged in a predetermined orientation and preimpregnated with epoxy resin. It must be noted that the outer shell 50 is formed in a molding tool under heat and pressure. The third preferred embodiment of the present invention is provided with an outer shell 18 and a bridging layer 60, as shown in FIG. 7. The bridging layer 60 has two -horizontal covering portions 62-62 and one vertical covering portion 64. The horizontal covering portions 62-62 and the vertical covering portion 64 are made of a plurality of fabric sheets of long carbon fibers or long glass fibers, which are preimpregnated with thermosetting resin such as epoxy resin. The horizontal covering portions 62-62 are used to over the external surfaces of the two opposite side end portions 20-20 and the area between the two horizontal extension ends 40-40. The vertical covering portion 64 covers the external surface of the junction between the vertical extension portion 28 of the T-shaped joint 16 and the upper end 24 of the shaft 14 and the vertical extension 42 of the outer sheel 18.

The junction area has a dimension which is substantially corresponding to other portions of the frame 12 in view of the fact that the two horizontal extension portions 26-26 are held securely in the two opposite side end portions 20-20. In addition, the junction area is completely integral in appearance with the frame 12 and the shaft 14, as shown in FIG. 1. As a result, the air resistance of the junction area of the present invention is relatively small as compared with the prior art badminton racket. In addition, the outer sheel 50, the bridging layer 60 and the T-shaped joint 16 work together to reinforce the fastening of the frame 12 with the shaft 14 without undermining the resilience of the frame 12. Furthermore, the impact loads of the badminton racket 10 hitting a shuttlecock will not be caused to concentrate on the junction area between the horizontal extension portions 2626 of the T-shaped joint 16 and the vertical extension portion 28 of the T-shaped joint 16 in view of the fact that the vertical extension portion 28 of the T-shaped joint 16 is fitted over the upper end 24 of the shaft 14. In other words, the stress concentration on the T-shaped joint 16 of the badminton racket 10 of the present invention is mitigated effectively.

Claims

1. A badminton racket comprising: a frame of oval construction and having two side end portions opposite to each other, with each of said two side end portions being of hollow construction and provided with an opening; a tubular shaft; and a T-shaped joint having two horizontal extension portions and one vertical extension portion, said two horizontal extension portion being connected with said two side end portions of said frame, said vertical extension portion being coupled with one end of said shaft; wherein each of said two horizontal extension portions of said T-shaped joint is inserted firmly into each of said two side end portions of said frame; wherein said vertical extension portion of said T-shaped joint is of hollow construction and provided with an opening dimensioned to fit over said one end of said shaft; and wherein said two side end portions of said frame and said vertical extension portion of said T-shaped joint are covered with an outer shell of a plastic material and serving as an outer connection of said two side end portions and said vertical extension portion.

2. The badminton racket of claim 1 wherein each of said two horizontal extension portions of said T-shaped joint has a uniform outer diameter from one end thereof to another end thereof.

3. The badminton racket of claim 1 wherein each of said two horizontal extension portions of said T-shaped joint is of solid construction.

4. The badminton racket of claim 1 wherein said outer shell has two horizontal extension ends and one vertical extension end, with each of said two horizontal extension ends covering an outer surface of each of said two side end portions of said frame such that a thickness of said each of said two horizontal extension ends decreases gradually from an inner side thereof toward an outer side thereof, said vertical extension end covering an outer surface of said vertical extension portion of said T-shaped joint in such a manner that a thickness of said vertical extension end decreases gradually from a top thereof toward a bottom thereof.

5. The badminton racket of claim 4 wherein said vertical extension end of said outer shell extends to cover an outer surface of a junction between said shaft and said vertical extension portion of said T-shaped joint.

6. The badminton racket of claim 1 wherein said outer shell is formed of a polymer consisting of giant molecules.

7. The badminton racket of claim 1 wherein said outer shell is made of a fiber -reinforced plastic material.

8. The badminton racket of claim 7 wherein said outer shell is made of a plurality of intertwined long fiber fabric sheets preimpregnated with thermosetting resin.

9. The badminton racket of claim 6 further comprising a bridging layer having two horizontal covering portions and one vertical covering portion, said each covering portion being made of a plurality of intertwined long fiber fabric sheets preimpregnated with thermosetting resin, with each of said two horizontal covering portions wrapping windingly between an outer surface of said two side end portions of said frame and said outer shell, and with said vertical covering portion wrapping windingly between an outer surface of a junction of said T-shaped joint and said shaft and said outer shell.

10. The badminton racket of claim 6 wherein said two horizontal covering portions have inner ends that are connected.

11. A badminton racket substantially as hereinbefore described with reference to Figures 1 to 5 or Figure 6 or Figure 7 of the accompanying drawings.