US20030073522A1

US20030073522A1 - Method for manufacturing rackets with shock absorbing members

Info

Publication number: US20030073522A1
Application number: US09/977,321
Authority: US
Inventors: Young-chen Hsu
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-10-16
Filing date: 2001-10-16
Publication date: 2003-04-17

Abstract

A method for manufacturing racket with shock absorbing members includes step 1 to form a shaft having two extensions; step 2 to wrap two respective shock absorbing members on the two extensions; step 3 to form a head having two tubular portions extending therefrom, and steps 4 to securely insert the two extensions wrapped with the shock absorbing members in the two tubular portions.

Description

FIELD OF THE INVENTION

The present invention relates to a method for manufacturing a racket that has shock absorbing member inserted in the throat portion and/or shaft so as to reduce vibration on these parts.

BACKGROUND OF THE INVENTION

A conventional racket such as a tennis racket generally includes a head, a throat and a shaft. The throat is connected between the frame and the shaft. Strings are connected in the head so as to hit the ball. The impact that the head bears when the ball hits on the head can be huge that the user's hand cannot hold the handle properly. Therefore, manufacturers try to reduce the impact and vibration on the racket. Most of the manufacturers put shock absorbing material on the sides of the head or on the shaft, and that cannot be satisfied because the shock absorbing material does not located at accurate positions and the thickness and weight limit the performance of the shock absorbing material. U.S. Pat. No. 4,284,275 to Fletcher discloses a polyurethane gripping material which is mounted to the handle of rackets. The gripping material has a thickness limitation and absorbs limited vibration. U.S. Pat. No. 5,695,418 to Huang discloses a shock absorbing grip that has the same problems and limitations as U.S. Pat. No. 4,284,275.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, there is provided a method for manufacturing racket with shock absorbing members and the method comprises the following steps:

step 1: forming a shaft which has two extensions extending from one of two ends thereof;

step 2: wrapping two respective shock absorbing members on the two extensions;

step 3: forming a head which has two tubular portions extending therefrom, and

steps 4: securely inserting the two extensions wrapped with the shock absorbing members in the two tubular portions.

The primary object of the present invention is to provide a method for manufacturing a racket that has shock absorbing members located between the shaft and the throat portion so as to reduce the vibration of the racket.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart to illustrate a conventional way to manufacture a racket; [0010]
FIG. 2 is a cross sectional view to show the conventional racket is formed in molds; [0011]
FIG. 3 shows the conventional racket; [0012]
FIG. 4 is a flow chart to illustrate the steps of the method of the present invention to manufacture a racket; [0013]
FIGS. 5A and 5B is a cross sectional view to show the shaft of the racket made by the method of the present invention; [0014]
FIG. 6A shows two shock absorbing members are wrapped around the two extensions of the throat portion; [0015]
FIG. 6B shows the connection of the throat portion and the shaft of the racket made by the method of the present invention; [0016]
FIG. 7 shows another embodiment of the connection of the shock absorbing member and the extensions; [0017]
FIG. 8 shows the racket made by the method of the present invention; [0018]
FIG. 9 shows the connection of the connection tube, the shock absorbing member and the shaft, and [0019]
FIG. 10 shows a diagram to show the vibration difference between the conventional racket and the racket made by the method of the present invention.[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. [0021] 1 to 3, the conventional way to manufacture a racket 100 is to form a combination of the head 120 and the shaft 110 of the racket 100 in a mold “A-” by heating the material of the head 120 and the shaft 110 under pre-decided pressure. The racket 100 is then separated from the mold “A” and is applied with a sand-grinding process, a coating process and assembling accessory process.
Referring to FIGS. 4, 5A, [0022] 5B and 6, the method for manufacturing a racket 10 of the present invention comprises the following steps:
step 1: forming a [0023] shaft 11 in a mold “B” and the shaft having two extensions 13 extending from one of two ends thereof;
The [0024] shaft 11 is made by composite prepreg material and the composite prepreg material is heated under pre-decided pressure;
step 2: wrapping two respective [0025] shock absorbing members 20 on the two extensions 13;
The absorbing [0026] members 20 are made of rubber or silicone which has a fusion temperature higher than that of the composite prepreg material and has a Shore hardness number of 30 to 80.
step 3: forming a [0027] head 12 in a mold “C” and the head having two tubular portions 130 extending therefrom;
steps 4: securely inserting the two [0028] extensions 13 wrapped with the shock absorbing members 20 in the two tubular portions 130;
The connection of the [0029] extensions 13 and the tubular portions 130 is made by a secondary heating under pressure.
step 5: applying a sand-grinding process to the racket; [0030]
step 6: coating the racket; [0031]
step 7: assembling accessories to the racket. [0032]
The [0033] head 12 and the shaft 11 are made individually so that the size and/or the weight of the two items can be made according to needs so that the manufacturers can manufacture the rackets which meet requirements of attack type players and defense type players.
FIGS. 7 and 8 show that the distal ends of the two [0034] extensions 13 can be a close end and the shock absorbing members 20 are mounted onto the close ends of the extensions 13.
Referring to FIG. 9, another method for manufacturing racket with shock absorbing members of the present invention comprises the following steps: [0035]
step 1: forming a [0036] head 12 in a mold and the head having a throat portion 121 and a connection section 122 extending from the throat portion 121;
step 2: wrapping a [0037] shock absorbing member 20 on the connection section 122;
step 3: forming a [0038] shaft 11 in a mold and the shaft 11 having an opening defined in one of two ends thereof;
steps 4: securely inserting the [0039] connection section 122 wrapped with the shock absorbing member 20 in the opening of the shaft 11 and heating the connection part under pressure in a mold.
As shown in FIG. 10, taking a point “D” as shown in FIG. 7 to test the vibration of the conventional racket and the racket made by the method of the present invention, two different shock waves are illustrated and which show that the racket made by the method of the present invention dramatically reduces the vibration. [0040]
While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. [0041]

Claims

What is claimed is:

1. A method for manufacturing racket with shock absorbing members, comprising the following steps:

step 2: wrapping two respective shock absorbing members on said two extensions;

step 3: forming a head which has two tubular portions extending therefrom, and

steps 4: securely inserting said two extensions wrapped with said shock absorbing members in said two tubular portions.

2. The device as claimed in claim 1, wherein shaft in said step 1 is made by composite prepreg material and said composite prepreg material is heated under pressure.

3. The device as claimed in claim 1 wherein head in said step 3 is made by composite prepreg material and said composite prepreg material is heated under pressure.

4. The device as claimed in claim 1, wherein said shock absorbing members have a Shore hardness number of 30 to 80.

5. A method for manufacturing racket with shock absorbing members, comprising the following steps:

step 1: forming a head which has a throat portion and a connection section extending from said throat portion;

step 2: wrapping a shock absorbing member on said connection section;

step 3: forming a shaft which has an opening defined in one of two ends thereof, and

steps 4: securely inserting said connection section wrapped with said shock absorbing member in said opening of said shaft.

6. The device as claimed in claim 5, wherein head in said step 1 is made by composite prepreg material and said composite prepreg material is heated under pressure.

7. The device as claimed in claim 5, wherein shaft in said step 3 is made by composite prepreg material and said composite prepreg material is heated under pressure.

8. The device as claimed in claim 5, wherein said shock absorbing member has a Shore hardness number of 30 to 80.