AU635417B2

AU635417B2 - A sports racket frame

Info

Publication number: AU635417B2
Application number: AU75397/91A
Authority: AU
Inventors: Chin-San You
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-04-24
Filing date: 1991-04-24
Publication date: 1993-03-18
Anticipated expiration: 2011-04-24
Also published as: AU7539791A; EP0512163A1

Description

6354 17 S F Ref: 161759 FORM COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int Class a a' ma. Complete Specification Lodged: Accepted: Published: Priority: Related Art: Name and Address of Applicant: Address for Service: a a..

Chin-San You No. 3, Lane 1029, Feng-Shyn Road Feng Yuan City Taichung Hsien TAIWAN R.O.C.

Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia a.

Ca I a a Complete Specification for the invention entitled: A Sports Racket Frame The following statement is a full description of this invention, including the best method of performing it known to me/us 5845/3 A SPORTS RACKET FRAME BACKGROUND OF THE INVENTION The present invention relates to a tennis racket, a squash racket, and a badminton racket, and more particularly to a sports racket made of a fiber reinforced composite material capable of minimizing the shock exerting on the hand of a player using the sports racket.

Generally speaking, a sports racket of conventional type made of a fiber reinforced composite material comprises an outer envelope of a fiber reinforced plastic. In the process of making such a sports racket as mentioned above, the outer envelope is formed by means of placing the intertwined fabric boards S" containing long fibers and thermosetting resin into a mold. As a result, the head portion and the handle portion of the racket are similar in terms of their crosssectional structures. In view of a shock-transmitting system, the structural uniformity of the head portion and the handle portion, which are made into a unitized body, is responsible for an easy transmission of shock with a minimum of obstruction. It is readily apparent that the shock generated by an impact of a ball on the ball-hitting surface of the racket described above is subject to transmitting easily from the head portion to the handle portion and then on to the hand which holds the racket.

In order to find a solution to the problem described above, a number of inventions have been developed and disclosed. For example, the inventor of raiwan Patent No. 78201997 discloses a sports racket having means to prevent the shock of striking a ball from transmitting to the handle. However, the constructional complexity of this invention makes it impractical from the standpoint of manufacture thereof and also results in a great deal of compromise of shock-absorbing effect thereof.

A sports racket having a shock-absorbing means of elastic sponge is V° suggested by the inventor of Taiwan Patent No. 75210508. This disclosure emphasizes the use of spongy pieces of a high elasticity, which are inserted into S. the strings forming the ball-hitting surface so as to absorb the shock generated on the strings. However, the arrangement as such does not serve to mitigate the

V.

S° °shock exerting on the racket frame.

The Taiwan Patent No. 78210299 discloses a sports racket having a frame oo°.0 S: structure capable of obstructing the transmission of shock, in which a plurality of 0009 grooves are constructed on the handle portion of the racket. Each of the grooves is covered with a shock-absorbing strap, whikh serves to hinder the shock wave. In fact, the transmission of the shock wave from the head frame to the grip portion can not be effectively averted by means of a structure of such design as disclosed in this invention.

S.

Additionally, the Taiwan Patent No. 78211558 discloses an improved structure for use in absorbing the shock exerting on a sports racket, which is characterized in that the edge of inner circumference of the head frame comprises a plurality of grooves, which are made into a unitized body of the head frame. A shock-absorbing rib bar is embedded in each of the grooves. It must be 2 -3pointed out that the shock generated on the strings traversing the shock-absorbing rib bar can be effectively absorbed. However, the shock generated on those strings which do not traverse the shock-absorbing rib bar is not effectively mitigated. In addition, the inventor of this disclosure ignores the fact that the structural design as suggested results in a technical difficulty of stretching the strings across the head frame of the racket.

As far as a sports racket having an outer envelope of fiber-reinforced plastic material is concerned, an effective method used to obstruct the transmission of the shock wave from the hear frame to the handle portion of the racket has not been introduced so far.

SUMMARY OF THE INVENTION S"Accordingly, the invention provides a sports racket frame having a head portion, a handle portion and a throat portion connecting the head 15 portion to the handle portion, the frame including a multi-ply outer shell of resin-impregnated fibrous fabric with a part of said shell encasing one end of the handle portion which is adjacent the throat portion, said part of the shell being severed by a plurality of slits cutting through fibers of the shell for inhibiting the transmission of S 20 shock waves from the head portion of the frame to the handle portion of the frame, the number of fibers cut by the slits comprising from 5% to of the total number of fibers in said part of the shell.

ZZ-1 oTR e• K -4- Preferably, the sports racket frame embodied In the present invention further comprises a covering layer encasing the area of outer envelope where fibrous cleavages are constructed. The covering layer is preferably of a polymeric material or a fiber-reinforced plastic material so as to absorb the residue of shock wave.

The sports racket frame embodied in the present invention preferably further comprises a certain number of inlays embedded in the area wherein the fibrous cleavages are constructed. The inlays, which can be made of metal, wood, elastic plastic, fiber-reinforced plastic, etc., are used to absorb the shock and to reinforce the strength of the area wherein they are lodged.

The sports racket frame embodiment in the present Invention i preferably further comprises a certain number of receiving slots constructed in the area of outer envelope wherein the fibrous cleavages 15 are arranged. The receiving slots can be used to accommodate the inlays securely in place.

An advantage of the present invention is that the sports racket is capable of effectively obstructing the shock wave transmission from the ball-hitting surface of the racket to the hand of a player using the racket.

A further advantage of the present invention is that the rigidity and elasticity of the frame can be adjusted, in accordance with requirements of players, during the process of manufacture thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a three-dimensional view of a sports racket frame embodiment in the present invention.

FIG. 2 shows a three-dimensional view of a portion of the first preferred embodiment of the present invention.

S

SS

rhi~/0882E FIG. 3 shows a cross-sectional view of the second preferred embodiment of the present invention.

FIG. 4 shows a three-dimensional view of a portion of the third preferred embodiment of the present invention.

FIG. 5 shows an exploded view of a portion of the third preferred embodiment of the present invention.

FIG. 6 shows a cut-away view of a portion taken along line 6-6 as shown in FIG. 4.

o FIG. 7 shows a cut-away view of a portion taken along line 7-7 as shown in a: o. FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the sports racket frame 10 embodied in the present invention is shown comprising an oval head portion 12, a throat portion 14 including two branch arms 141 and 142 and a throat bottom 143. The handle portion 16 is coupled with the throat bottom 143.

The racket frame 10 embodied in the present invention further comprises an outer envelope 30, which is formed by heating and molding a plurality of the pre-oriented and intertwined cloths of carbonaceous fiber pre-soaked in the epoxy resin. The outer envelope 30 encases a foam core 32.

6 As shown in FIG. 2 illustrating the first embodiment of the present invention, the outer envelope 30 includes a concave area 34 constructed in the handle portion 16. The concave area 34 is octagonal in cross section thereof and is therefore composed of eight rectangular surfaces 36, 38, 40, 42, 44, 46, 48, and Located on each of first, third, fifth, and seventh rectangular surfaces 36, 44, and 48 is a fibrous cleavage 52 perpendicular to the axial center of the throat portion 14. These four fibrous cleavages 52 so constructed are not situated on the same plane. As far as the first embodiment of the present invention is concerned, the sum of ;ibrous number of all fibrous cleavages 52 is about 50% of the total fibrous number of the concave area 34. The shock wave, which is generated on Soo* the ball-hitting surface 22 and is subsequently transmitted along the head portion 0°b 12 and the throat portion 14, is effectively obstructed and mitigated in the concave area 34 before reaching the handle portion 16. As a result, the shock exerting on the hand holding the handle portion 16 is effectively minimized. In addition, the sports racket frame 10 of the first embodiiment of the present invention comprises a covering layer 54, which is made of polymer and is used to encase the concave area 34 so as to absorb the residual shock wave and to ooo reinforce the strength of the concave area 34.

0000 Now referring to FIG. 3, the second preferred embodiment of the present invention is shown comprising a circular recess 53 with eight rectangular surfaces 55 therearound. Located on each of the first, the third, the fifth and the seventh rectangular surfaces is a fibrous cleavage 57, wherein an inlay rod 56 is lodged.

The inlay rod 56 is encased with a covering layer 59 in order to give the circular recess 53 an added rigidity. The inlay rod 56 may be made of a fiber-reinforced plastic material, a metal, a wood, an elastic plastic, or a ceramic material.

The third preferred embodiment of the present invention is illustrated in FIGS. 4-7. A circular recess 60 is constructed in the portion of outer envelope located at the junction between the throat bottom 143 and the handle portion 16.

The circular recess 60 has an octagonal cross section having eight adjacent rectangular surfaces 62, 64, 66, 68, 70, 72, 74, and 76. Located in each of the first, the third, the fifth, and the seventh rectangular surfaces 62, 66, 70, and 74 is a receiving slot 78 of a predetermined depth parallel to the axial center of the throat portion 14. In addition, each of the rectangular surfaces 62, 66, 70, and 74 comprises therein a fibrous cleavage 80 of a predetermined length. It must be noted that fibrous cleavages 80 of rectangular surfaces 62, 66, 70, and 74 are of different lenths and are arranged randomly on the different planes, The sum of fibrous number of the fibrous cleavages 80 is preferably about 40% of the total S fibrous number of the circular recesses 60. In addition, a shock-absorbing rod 82 made of an elastic plastic is embedded in each receiving slot 78 of the first and the fifth rectangular surfaces 62 and 70. A reinforced rod 84 made of a fiber- 0** reinforced plastic is lodged in each receiving slot 78 of the third and the seventh rectangular surfaces 66 and 74. Finally, the outer envelope 30, which has been so constructed as described above, is placed in an injection mold wherein a composite material containing short fibers and epoxy resin is used to form covering layers 86 encasing the circular recesses As a result, about 40% of fibers forming the outer envelope 30 located at oo o the front end portion of the handle portion 16 have been cleaved so as to obstruct 0. 0 S" effectively the transmission of the shock wave originating from the ball-hitting surface 22 upon an impact by a ball. The residual shock wave is absorbed by shock-absorbing rods 82 and covering layers 86. Therefore, the shock wave exerting on the hand of a player is effectively reduced to a minimum.

Furthermore, the rigidity of the sports racket frame 10 is further enhanced by 8 means of two reinforced rods 84 embedded in circular recesses 60 thereof so as to increase the striking force of the racket against the ball.

S.

S

4S*

S*S

S S S. S 4* 4 4 *4 4

S

a.

5 5.55.5

S

4.

**S

*SS.

S

*4S S. 5 4

Claims

2. A sports racket frame according to claim 1, wherein the slits m* are oriented substantialiiy transversely to a longitudinal axis of said handle portion. 15 3. A sports racket frame according to claim 1, wherein said slits are dlsposed in different transverse planes.
4. A sports racket frame according to claim I, wherein said part of the shell includes an annular recess containing the slits.
5. A sports racket frame according the claim 4, wherein said part 20 of the shell is encased by an elastic covering layer,
6. A soorts racket frame according to claim 5, wherein the covering layer comprises a polymeric material.
7. A sports racket frame according to claim 1, wherein said part of the frame is encased by an elastic covering layer and a pluralty of shock-absorbing inlay pieces are disposed between said part of the shell and said covering layer.
8. A sports racket frame according to claim 7, wherein the inlay pieces are received in axially extending slots formed in said part of the shell
9. A sports racket frame according to claim 7, wherein the inlay pieces comprise a plastic material. A sports racket frame according to claim 7, wherein the inlay pieces comprise a metal material. S.L /0a 11 11 A sports racket frame according to claim 7, wherein the inlay pieces comprise a wood material.
12. A sports racket frame substantially as hereinbefore described with reference to the drawings. DATED this THIRTY-FIRST day of DECEMBER 1992 Chin-San You Patent Attorneys for the Applicant **w C. S. S S S S S I C 'C S SPRUSON FERGUSON *4 55 S C *CSS S tq OSSS* .5 9 9 S S N 'I ~hi~IO882E A SPORTS RACKET FRAME ABSTRACT A sports racket frame comprises thereon an outer evvelope made of a fiber- reinforced composite. Located at a predetermined area of the outer envelope encasing the handle portion are fibrous cleavages, in which a plurality of strength- reinforcing and shock-absorbing inlay pieces are embedded so as to reduce S effectively the shock wave originating from the ball-hitting surface to a minimum S and to give the racket frame an added elasticity and rigidity. ee S *5 *a a