US20040138015A1

US20040138015A1 - Racket frame

Info

Publication number: US20040138015A1
Application number: US10/385,494
Authority: US
Inventors: Kuo-Pin Yu
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-01-09
Filing date: 2003-03-12
Publication date: 2004-07-15
Also published as: TW200412623A; FR2853555B3; FR2853555A3; TW578218B

Abstract

A racket frame is constructed to include a body, the body having an endless head and a shaft extended from the endless head for the mounting of a grip, and two wooden strips fastened to the endless head of the body at two sides, the wooden strips taking about 5%˜70% of the volume of the racket frame.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to sports apparatus and, more specifically, to a racket frame, which achieves a good striking effect, has a good outer appearance quality, and is easy to manufacture.

2. Description of the Related Art

A racket for tennis or squash generally comprises a head adapted to accommodate a striking face (gut), a grip for holding by the user, and a throat connected between the handle and the head. Except the grip and the strings for the striking face, the frame of the racket is made from pure wood, aluminum alloy, or fiber-reinforced plastics. Conventional racket frames of either material have drawbacks as outlined hereinafter.

1. A wooden racket frame achieves a better striking effect, however, it is less strong, and tends to break when striking or to curve under a wet environment.

2. A metal or fiber-reinforced plastic racket has a better structural strength, however, it cannot effectively absorb shocks produced when hitting the ball. The major part of vibrating force produced upon the striking of the racket against the ball is directly transmitted to the grip, affecting the performance of the player. When a player frequently receives vibrating force from the grip, an athletic injury may occur.

3. A metal or fiber-reinforced plastic racket has a hard, cold, unfriendly outer appearance, affecting the player's touch and visual sense.

It is therefore desirable to have a racket frame that eliminates the aforesaid drawbacks.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a racket frame, which achieves a good striking effect and has a good outer appearance quality. It is another object of the present invention to provide a racket frame, which effectively absorb shocks when striking the ball. It is still another object of the present invention to provide a racket frame, which is easy to manufacture.

To achieve these and other objects of the present invention, the racket frame comprises a body, the body having an endless head and a shaft extended from the endless head for the mounting of the grip, and a wooden strip fastened to the endless head of the body at one side. The wooden strip preferably takes about 5%˜70% of the volume of the racket frame. The racket frame is made by putting an elongated wooden strip in a cavity of a die, and at the same time preparing multiple layers of resin-immersed fiber cloth and winding the multiple layers of rein-immersed fiber cloth into a tubular member having an axially extended receiving chamber and then putting the tubular member in the cavity of the die, and then applying a fluid into the receiving chamber of the tubular member by a predetermined pressure to expand the tubular member and to force the periphery of the tubular member into close contact with a periphery of the cavity, causing the tubular member to be formed into a racket frame body having an endless head and a shaft, which racket frame body joins the wooden strip and forms with the wooden strip the desired racket frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a racket frame according to the first embodiment of the present invention. [0011]
FIG. 2 is a sectional view in an enlarged scale taken along line [0012] 2-2 of FIG. 1.
FIG. 3 is a schematic drawing explaining the fabrication of the racket frame according to the present invention (I). [0013]
FIG. 4 is a schematic drawing explaining the fabrication of the racket frame according to the present invention (II). [0014]
FIG. 5 is a perspective view of a racket frame according to the second embodiment of the present invention. [0015]
FIG. 6 is an exploded view of a racket frame according to the third embodiment of the present invention. [0016]
FIG. 7 is a perspective view of a racket frame according to the fourth embodiment of the present invention. [0017]
FIG. 8 is a sectional view of a racket frame according to the fifth embodiment of the present invention.[0018]

DETAILED DESCRIPTION OF THE INVENTION

Referring to Referring to FIGS. 1 and 2, a [0019] racket frame 10 in accordance with a first embodiment of the present invention is shown. The racket frame 10 is mounted with a grip 12 and a striking face (not shown), forming a ball game racket 14. The racket frame 10 is comprised of a body 20 and two wooden strips 30.
The [0020] body 20 comprises an endless head 21, and a shaft 22 extended from one end of the endless head 21 and mounted with the grip 12. The shaft 22 has a throat formed of two ribs 23. The ribs 23 each have one end terminating in the endless head 21 and the other end merged in each other and end covered with the grip 12. The body 20 is formed of multiple layers of resin-immersed fiber cloth 24 by winding.
The two [0021] wooden strips 30 are made from wood or bamboo, and respectively located on the outer surface 211 and inner surface 212 of the endless head 21 of the body 20. The thickness of the wooden strips 30 is determined subject to actual requirements, for example, 3˜5 mm or the like.
When striking the [0022] racket 14 against the ball, shock waves are transmitted from the racket frame 10 to the grip 12 through two different materials, i.e., the body 20 and the wooden strips 30. Because these two materials transfer shock waves at different speeds and amplitudes, shock waves set off one another, enabling the racket frame 10 to absorb vibrations. Further, because the volume of the wooden strips 30 takes a predetermined percentage of the whole volume of the racket frame 10, for example, 5%˜70% or 10%˜50%, the racket 14 has the advantage of wooden material's good striking effect and the advantage of fiber-reinforced plastics' structural toughness. Further, the user can adjust the volume ratio of the wooden strips 30 in the whole racket frame 10 subject to individual favorite. Further, the racket 14 eliminates the drawbacks of cold and hard quality features of conventional metal or fiber-reinforced plastic racket frames.
The fabrication of the [0023] racket frame 10 is outlined hereinafter:
As illustrated in FIG. 3, two elongated [0024] wooden strips 30 are prepared and put in the cavity 42 of a die 40 and located on two opposite lateral sides. The presence of crevices between the cavity 42 and the wooden strips 30 at this time can be ignored. At the same time, multiple layers of resin-immersed fiber cloth 24 are prepared. The resin used for the rein-immersed fiber cloth 24 can be thermoplastic resin or thermosetting resin. The fibers used for the rein-immersed fiber cloth 24 can be carbon fibers, glass fibers, boron fibers, or Kevlar fibers. The multiple layers of rein-immersed fiber cloth 24 are wound into a tubular member 44 having an axially extended receiving chamber 46. The tubular member 44 thus obtained is then put in the cavity 42. Thereafter, a flow of, for example, air is forced into the receiving chamber 46 of the tubular member 44 by a predetermined pressure to expand the tubular member 44 and to force the periphery of the tubular member 44 into close contact with the inside wall of the cavity 42. At the same time, as shown in FIG. 4, the system temperature is controlled within a proper range. A certain length of time after the application of the flow of air to the receiving chamber 46 of the tubular member 44, the tubular member 44 is formed into a racket frame body 20 having an endless head 21 and a shaft 22, which racket frame body 20 joins the wooden strips 30, forming the aforesaid racket frame 10. At final, the wooden strips 30 are trimmed and polished, and thus the desired finished product is obtained. This racket frame manufacturing process is simple and economic, practical for mass production.
FIG. 5 shows a [0025] racket frame 50 constructed according to a second embodiment of the present invention. During actual fabrication, only one wooden strip 55 is used and fastened to the outer surface 54 of the endless head 53 of the body 52, and the inner surface 56 of the endless head 53 is not mounted with a wooden strip.
FIG. 6 shows a [0026] racket frame 60 constructed according to a third embodiment of the present invention. According to this embodiment, two sections of wooden strip 62 are bilaterally fastened to the outer surface of the endless head 64 of the body 63 and extended to the shaft 65, and an elastic protective strip 66 is fastened to the front side of the endless head 64 and connected between the wooden strips 62. The thickness of the elastic protective strip 66 is equal to the wooden strips 62. When installed, the elastic protective strip 66 and the wooden strips 62 are maintained in a flush manner, causing a sense of beauty.
Actually, only the inner surface or outer surface of the endless head is mounted with a wooden strip or wooden strips, it is within the scope of the claims of the present invention. The covering of a wooden strip on a part of one side of the endless head of the body of the racket frame should also be included in the scope of the claims of the present invention. [0027]
The spirit of the present invention can be employed to any of a variety of rackets including tennis rackets and squash rackets. FIG. 7 shows a [0028] racket frame 70 for a squash racket according to the present invention.
FIG. 8 is a sectional view of a [0029] racket frame 80 according to a fifth embodiment of the present invention. According to this embodiment, two set of wooden strips 84 are respectively fastened to the body 82 of the racket frame 80 at two sides, each set of wooden strips 84 including four wooden strips fixedly arranged in a stack. The thickness of the wooden strips according to this embodiment is relatively thinner than the wooden strips used in the aforesaid other embodiments of the present invention. Due to relatively thinner thickness, the wooden strips can easily curved in the cavity of the die to facilitate the fabrication of the racket frame.
A prototype of racket frame has been constructed with the features of FIGS. [0030] 1˜7. The racket frame functions smoothly to provide all of the features discussed earlier.
Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. [0031]

Claims

What is claimed is:

1. A racket frame for fastening with a grip to form a ball game racket, comprising:

a body, said body comprising an endless head and a shaft extended from said endless head for the mounting of the grip; and

a wooden strip fastened to one side of said endless head of said body,

the racket frame being made by:

putting an elongated wooden strip in a cavity of a die, and at the same time preparing multiple layers of resin-immersed fiber cloth and winding said multiple layers of rein-immersed fiber cloth into a tubular member having an axially extended receiving chamber and then putting said tubular member in the cavity of said die, and then applying a fluid into the receiving chamber of said tubular member by a predetermined pressure to expand said tubular member and to force the periphery of said tubular member into close contact with a periphery of said cavity, causing said tubular member to be formed into a racket frame body having an endless head and a shaft, which racket frame body joins the wooden strip and forms with the wooden strip the desired racket frame.

2. The racket frame as defined in claim 1, wherein said wooden strip fastened to an outer surface of the endless head of said body.

3. The racket frame as defined in claim 2, wherein said wooden strip includes two sections respectively fastened to the endless head of said body at two sides, the sections each having a rear end respectively extended to said shaft and a front end spaced from each other at a distance and connected to each other by a protective strip at a front side of the endless head of said body.

4. The racket frame as defined in claim 1, wherein said wooden strip is fastened to an inner surface of the endless head of said body.

5. The racket frame as defined in claim 1, wherein the wooden strip is polished after fastened to said body.

6. The racket frame as defined in claim 1, wherein the resin used for said multiple layers of rein-immersed fiber cloth is selected from a group of resins including thermoplastic resin and thermosetting resin.

7. The racket frame as defined in claim 1, wherein the fibers used for said rein-immersed fiber cloth is selected from a group of fibers including carbon fibers, glass fibers, boron fibers, and Kevlar fibers.

8. The racket frame as defined in claim 1 comprising a plurality of said wooden strips arranged into a stack fastened to the endless head of said body at one side.

9. The racket frame as defined in claim 1, wherein said shaft comprises two ribs, said ribs each having one end terminating in said endless head and an opposite end merged in each other and end covered with a grip.

10. The racket frame as defined in claim 1, wherein said wooden strip preferably takes about 5%˜70% of the volume of the racket frame.

11. The racket frame as defined in claim 1, wherein said wooden strip preferably takes about 10%˜50% of the volume of the racket frame.

12. The racket frame as defined in claim 1, wherein said wooden strip preferably has a thickness within 3˜5 mm.

13. A racket frame for fastening with a grip to form a ball game racket, comprising:

a wooden strip fastened to one side of said endless head of said body;

wherein said wooden strip takes about 5%˜70% of the volume of the racket frame.

14. The racket frame as defined in claim 13, wherein said wooden strip takes about 10%˜50% of the volume of the racket frame.

15. The racket frame as defined in claim 13, wherein said wooden strip is fastened to an outer surface of the endless head of said body.

16. The racket frame as defined in claim 14, wherein said wooden strip includes two sections respectively fastened to the endless head of said body at two sides, the sections each having a rear end respectively extended to said shaft and a front end spaced from each other at a distance and connected to each other by a protective strip at a front side of the endless head of said body.

17. The racket frame as defined in claim 13, wherein said wooden strip is fastened to an inner surface of the endless head of said body.

18. The racket frame as defined in claim 13, wherein said body is made from multiple layers of resin-immersed fiber cloth by winding.

19. The racket frame as defined in claim 18, wherein the resin used for said multiple layers of rein-immersed fiber cloth is selected from a group of resins including thermoplastic resin and thermosetting resin.

20. The racket frame as defined in claim 18, wherein the fibers used for said rein-immersed fiber cloth is selected from a group of fibers including carbon fibers, glass fibers, boron fibers, and Kevlar fibers.

21. The racket frame as defined in claim 13 comprising a plurality of said wooden strips arranged into a stack fastened to the endless head of said body at one side.

22. The racket frame as defined in claim 13, wherein said wooden strip preferably has a thickness within 3˜5 mm.