CN1329095C

CN1329095C - Badminton racket

Info

Publication number: CN1329095C
Application number: CNB031274102A
Authority: CN
Inventors: 米山稔
Original assignee: Yonex KK
Current assignee: Yonex KK
Priority date: 2002-08-09
Filing date: 2003-08-06
Publication date: 2007-08-01
Anticipated expiration: 2023-08-06
Also published as: CN1488415A; EP1388354A1; DE60300605D1; DE60300605T2; JP2004065862A; ATE294620T1; EP1388354B1; DK1388354T3

Abstract

A badminton racket comprises an oval-shaped frame and a hollow shaft joined together by a T-joint coated with adhesive. A vertical stem of the T-joint is provided with a plurality of ribs extending axially on the external surface thereof. The ribs are formed such that, when the T-joint is inserted into an upper open end of the shaft, top edges of the ribs are brought into close contact with inner surface of the shaft.

Description

Racket

The cross reference of related application

It is the priority of the Japanese patent application N0.2002-233275 on August 9th, 2002 that present patent application requires the applying date.

Technical field

The present invention relates to a kind of racket, this racket comprises oval frame and hollow stem, and they link together by the T junction that is coated with bonding agent.The vertical rod that this T junction has horizontal arm and extends downwards from the core of this horizontal arm.This horizontal arm inserts the opposite end of framework, and this vertical rod inserts in the upper, open end of hollow stem.

Background technology

By Japanese utility model application No.2-19163 a kind of the type racket of prior art as can be known.The racket of the prior art is by the following steps manufacturing: at first make T junction be coated with for example liquid epoxies of bonding agent; The vertical rod of this T junction is inserted in the open upper end of hollow stem; Two horizontal arms of this T junction are inserted in the relative hollow end of oval frame; The FRP band is wrapped on the joint of bar and framework, is used for strengthening; Such blank area that is connected of framework and bar is placed in the mould; And under predetermined temperature, close this mould scheduled time.

The vertical rod of general T-shaped joint form the external diameter that makes it than the internal diameter little about 0.2 at the upper, open end place of hollow stem to 0.3mm, so that this T junction can be inserted in the open upper end of this bar at an easy rate, and bonding agent can fully expansion between T junction and bar.Therefore, in assembling process, the relative pine of T junction with the engagement of bar.Therefore, after in the open upper end of the vertical rod insertion rod of T junction, when the blank area with framework and bar placed mould, the very little external force that the direction that the edge makes bar draw back from T junction applies also can make this bar leave T junction a little sometimes and depart from (for example several millimeter).When use is departing from the racket of making under the situation, stress occurs in the office, vertical rod upper end of the T junction that skids off the bar upper end a little and concentrate, this causes producing fracture at this part place of T junction sometimes.

And, when T junction is coated with for example epoxy resin of high viscosity bonding agent, so that in the time of in the open upper end of insertion axle, the vertical rod of the T junction opening with respect to bar accurately may be inserted with one heart hardly, this inserts common off-centre and carries out, and therefore, the bonding agent that is coated on the outer surface of T junction is wiped off in the termination of eccentric side by bar, this causes adhesive strength to reduce, thereby causes the problem of this bar with respect to the torsional strength reduction of framework.

The present invention considers the problems referred to above, the purpose of this invention is to provide a kind of racket, this racket is by reducing to produce the possibility that departs between T junction and bar, thereby can after their engagements, reduce the occurrence rate of faulty item, and improve the adhesive strength between T junction and bar.

Summary of the invention

To achieve these goals, the invention provides a kind of racket, this racket comprises oval frame and hollow stem, and they link together by the T junction that is coated with bonding agent.The vertical rod that this T junction has horizontal arm and extends downwards from the core of this horizontal arm.This horizontal arm inserts the opposite end of framework, and this vertical rod inserts in the upper, open end of hollow stem.

The vertical rod of T junction provides a plurality of axially extended ribs on its outer surface.Above-mentioned rib is sized to like this: when in the upper, open end of T junction insertion rod, the top edge of this rib closely contacts with the inner surface of this bar.

Therefore, in the opening of T junction insertion rod after, the less external force that is applied on this bar along direction that bar is drawn back from T junction can not make this bar depart from respect to T junction.Therefore, can reduce owing to departing between T junction and the bar and have flaw product.

And, a plurality of ribs can make the vertical rod of T junction accurately insert with one heart with respect to the open upper end of bar, therefore, the bonding agent that is coated on the T junction can not wiped off by the open upper end of bar, this makes bonding agent evenly expand around the outer surface of the vertical rod of T junction, does not reduce adhesive strength thereby can not resemble the prior art.

And because provide rib, T junction is bigger without any the bond area of the prior art T junction of rib with respect to the bond area ratio of bar, and therefore, their adhesive strength is bigger than the adhesive strength of prior art.

Preferably, at the number of the rib that axially forms on the vertical rod in 2 to 8 scope.Therefore, the possibility that occurs departing between T junction and bar further reduces, and the bonding region of vertical rod can increase, so that improve cementability.

And preferably rib forms width and height reduces gradually along downward direction, so that at an easy rate in the upper, open end with the vertical rod insertion rod of T junction.

And preferably cross rib is formed on the upper surface of horizontal arm of T junction.Also preferably, form a plurality of cross ribs.Like this, because same as described above, the bond area between the horizontal arm of T junction and the hollow end of framework increases, so that make the adhesive strength between them bigger.

And preferably, the height of rib is in 0.1 to 1.0mm scope.The height of rib is arranged in value higher a little in this scope, like this, when the upper end of T junction insertion rod, the engagement of the inner surface of the open upper end of this rib and bar.Therefore, because the engagement of rib and in conjunction with the cementability of above-mentioned raising, the bonding strength between T junction and the bar increases greatly.

And preferably, the boundary of the vertical rod of T junction upper end and horizontal arm partly provides conical surface, and the open upper end of hollow stem provides countersunk, and this countersunk has essentially identical conical surface.Preferably, the radius of curvature of the conical surface of boundary part is in 0.5mm arrives the scope of 5.0mm.

Therefore, the intensity of T junction self increases, and the open upper end of bar closely contacts with T junction, so that strengthen the bonding strength between them more.

Introduce the preferred embodiments of the present invention below with reference to the accompanying drawings.

Description of drawings

In order to understand the present invention and its advantage more completely, describe below in conjunction with accompanying drawing,

In the accompanying drawing:

Fig. 1 is the front view of racket of the present invention;

Fig. 2 is the cutaway view of the major part of racket of the present invention, has represented the joint of framework and bar;

Fig. 3 is the front view of the T junction of racket of the present invention; And

Fig. 4 is the upward view of the T junction shown in Fig. 3.

The specific embodiment

As shown in Figure 1, racket of the present invention generally includes framework 1, bar 2 and handle 3.

Shown in Fig. 2 and 3, framework 1 and bar 2 improve T junction 4 and link together, and this T junction 4 is in the inside of framework and bar.

Framework 1 and bar 2 are tubular structure, and they are made by FRP, and FRP is mainly made by carbon fiber.T junction 4 by metal for example aluminium alloy make.

T junction 4 comprises the arm 5 of approximate horizontal and the vertical rod 6 that extends from the center of this arm downwards.Horizontal arm 5 has elliptic cross-section as framework 1, and vertical rod has circular cross-section as bar 2.

Rib (little protuberance bar) 7 forms along the core of the upper surface of horizontal arm 5, and extends on the whole length on this surface.Preferably, the height of this rib reduces gradually towards its two ends, and like this, arm can be easy to insert in the relative openend of framework, and this will introduce in the back.The termination of arm forms the tapering point 8 than minor diameter respectively, so that insert each hollow end of this framework easily.

Form four ribs (less protuberance bar) 9 on the outer surface of vertical rod 6, these four ribs equidistantly separate, and extend axially.The bottom of vertical rod 6 forms the tapering point 10 than minor diameter.At the height of the rib 9 of rib on the arm 7 and vertical rod 6 respectively in 0.1 to 1.0mm scope.This size determines according to the aperture of bar 2, under any circumstance, all must at the vertical rod 6 of T junction when this bar is inserted in the upper end of bar vertical rod 6 be closely cooperated by four ribs 9 and hollow stem.Therefore, when the aperture of hollow stem was constant, when the height increase of rib, the diameter of the main body cylindrical section of the vertical rod of T junction should reduce.Therefore, when the height of rib surpassed 1.0mm, the diameter of the main body cylindrical section of the vertical rod of T junction reduced too much, so that there is not enough intensity.Therefore, the limitation in height of rib is below the 1.0mm.On the contrary, when the height of rib is lower than 0.1mm, provide rib can't produce ideal effect, this will introduce in the back.

Preferably, the bottom towards it reduces gradually from the top of vertical rod for the width of the rib 9 on the vertical rod 6 of T junction and height.Therefore, the vertical rod 6 of T junction is at an easy rate in the open upper end of insertion rod 2.

The boundary part 11 of the vertical rod of T junction 4 and horizontal arm provides conical surface.Simultaneously, the inner surface 12 of the open upper end of hollow stem 2 provides countersunk, and this countersunk has the conical surface identical with the conical surface of this boundary part 11.Therefore, when the vertical rod 6 of T junction 4 inserted in the open upper end of hollow stems 2, the conical surface of boundary part 11 closely contacted with conical surface at the countersunk 12 of the upper end of hollow stem.And the intensity of T junction 4 self also strengthens by the conical surface of boundary part 11.

Radius of curvature at the conical surface at the boundary of T junction 4 part 11 places should be in 0.5 to 5.0mm scope.When radius of curvature exceeds this scope, will become greatly at the countersunk end, that will be formed with corresponding radius of curvature of bar, this will make the intensity of rod end head reduce too much.On the other hand, when radius of curvature during less than 0.5mm, the tight contact between the boundary part 11 of the termination of bar and T junction 4 can not effectively improve intensity.

Below introduction is used to form the method for racket with above-mentioned T junction.As shown in Figure 3, the T junction that is formed by aluminium alloy immerses as in the fusion epoxy resin of bonding agent, like this, and on the outer surface of epoxy resin attached to T junction.Then, the vertical rod 6 of this joint 4 passes the open upper end of the hollow stem of being made by FRP and inserts, and contacts up to the countersunk 12 of the boundary of joint part 11 with the bar upper end.

Be sized to make this joint interference fit to pack in the hollow stem 2, four ribs 9 on the outer surface of vertical rod 6 closely contact or mesh with the inner surface of hollow stem 2 simultaneously.Therefore, less external force can not make joint 4 depart from respect to bar 2.

Then, the horizontal arm of T junction 45 inserts in the relative openend of hollow oval frame 1, and this framework 1 is formed by FRP, and this FRP is made up of carbon fiber.At this moment, the rib 7 that forms along the core of the upper surface of arm closely contacts with the inner surface of the openend of framework, thus make joint 4 can with the framework secure engagement, and can prevent that bonding agent from expanding unevenly, thereby guarantee suitable adhesive strength.Then, the pre-preg FRP of band shape is wrapped in framework 1 and bar 2, on the joint of T junction outer surface, and when keeping this state, T junction partly is arranged in mould inside, closed subsequently this mould, and at high temperature carry out molded operation, so that cured epoxy resin.

As shown in Figure 2, in the racket made from said method, framework 1 firmly is connected by T junction 4 with bar, and this joint is covered by FRP layer 13.

The present invention is not limited to the foregoing description, and the number that is formed at the rib 9 on the vertical rod can be any plural number, and preferably, this number is 8 or littler.And the number of the rib 7 on horizontal arm also is not limited to 1, and a plurality of ribs can be arranged.

Although described the preferred embodiments of the present invention in detail, should be known under the situation that does not break away from the spirit and scope of the present invention of determining by accessory claim, can carry out various variations, replacement and change.

Claims

1. a racket comprises oval frame (1) and hollow stem (2), and they link together by the T junction (4) that is coated with bonding agent;

The vertical rod (6) that described T junction (4) has horizontal arm (5) and extends downwards from the core of described horizontal arm (5);

Described horizontal arm (5) inserts the two ends of described framework (1), and described vertical rod (6) inserts in the upper, open end of described hollow stem (2);

Wherein, described vertical rod (6) provides a plurality of axially extended ribs (9) on its outer surface, described rib (9) forms like this: when described T junction (4) inserted in the described upper, open end of described hollow stem (2), the top edge of described rib (9) closely contacted with the inner surface of described hollow stem (2).

2. racket according to claim 1, wherein: go up the number of axially extended described rib (9) in 2 to 8 scope at described vertical rod (6).

3. racket according to claim 1, wherein: the width of each described rib (9) and highly reducing gradually from top to bottom.

4. racket according to claim 1, wherein: cross rib (7) is formed on the upper surface of described horizontal arm (5) of described T junction (4).

5. racket according to claim 4, wherein: be formed with a plurality of cross ribs (7).

6. according to arbitrary described racket among the claim 1-5, wherein: the height of the described rib (9) on described vertical rod (6) is in 0.1 to 1.0mm scope.

7. according to arbitrary described racket among the claim 1-5, wherein: described vertical rod (6) upper end of described T junction (4) and the boundary of described horizontal arm (5) partly provide conical surface (11), the upper end open of described hollow stem provides countersunk (12), and this countersunk (12) has essentially identical conical surface.

8. racket according to claim 6, wherein: described vertical rod (6) upper end of described T junction (4) and the boundary of described horizontal arm (5) partly provide conical surface (11), the upper end open of described hollow stem provides countersunk (12), and this countersunk (12) has essentially identical conical surface.

9. racket according to claim 7, wherein: the radius of curvature of the described conical surface (11) of the described part of having a common boundary is in 0.5mm arrives the scope of 5.0mm.

10. racket according to claim 8, wherein: the radius of curvature of the described conical surface (11) of the described part of having a common boundary is in 0.5mm arrives the scope of 5.0mm.