Method for making a wrench

Abstract

A method for manufacturing a wrench having a hollow handle includes preparing a head having an engaging portion, necking an end of a metal tubular member, closing another end of the metal tubular member, and fusing the end of the metal tubular member and the head together, forming a wrench having a hollow handle. The step of fusing may be performed before the step of closing. The method may further include a step of proceeding at least one of grinding, patching, and polishing an outer periphery of the hollow handle. Next, the hollow handle may be heat processed to improve the strength and hardness of the tubular member. Then, the surface of the tubular member may be finished.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for making a wrench.

2. Description of the Related Art

Ratchet wrenches have been widely used for tightening/loosening fasteners with or without the use of sockets. The handle of a typical ratchet wrench is formed by means of carrying out a “forge hot” process on a solid iron raw material, resulting in a solid weighty structure that is a burden to the user, which is particularly true for a large size handle. Further, stress concentration occurs easily during the forging process of the solid handle of iron, providing a weaker structure incapable of withstanding higher bending moment. Further, the manufacture cost of the solid handle requiring a large amount of material is relatively high, and the stock cost is expensive, as at least twenty thousands of pieces are required for each mold for forging the solid handles.

An example of forming a solid handle of a ratchet wrench is disclosed in, e.g., Taiwan Patent Publication No. 153538, in which a plate is process to form a wrench having a solid handle, a head with a hole, and a necked portion. Another conventional method for manufacturing a wrench includes directly forging a wrench having a solid handle and a head. As mentioned above, the cost is increased, and the overall weight is relatively large, causing a burden to the user. Further, it was found that the maximum torque-bearing capacity of a solid rod is smaller than that for a hollow tube. Thus, the present invention is intended to provide a method for manufacturing a wrench having a hollow handle for mitigating/obviating the above problems.

SUMMARY OF THE INVENTION

A method for manufacturing a wrench having a hollow handle in accordance with the present invention generally includes preparing a head having an engaging portion, necking an end of a metal tubular member, closing another end of the metal tubular member, and fusing the end of the metal tubular member and the head together, forming a wrench having a hollow handle.

The step of fusing may be performed before the step of closing. The step of necking is preferably performed before the step of closing and the step of fusing. The method may further include a step of proceeding at least one of grinding, patching, and polishing an outer periphery of the hollow handle. Next, the hollow handle may be heat processed to improve the strength and hardness of the tubular member. Then, the surface of the tubular member may be finished.

The overall weight of the wrench thus manufactured is relatively small when compared with a wrench having a solid handle. The burden to the user operating the wrench for a relatively long period of time is greatly reduced, and the working efficiency is improved. Further, the impact-resistance, toughness, and strength of the wrench having a hollow handle are improved.

Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating a method for manufacturing a wrench in accordance with the present invention.

FIGS. 2A through 2E are views illustrating manufacture of a wrench by the method shown in FIG. 1.

FIG. 3 is a perspective view of a wrench manufactured by the method in accordance with the present invention.

FIG. 4 is a flowchart illustrating a modified embodiment of the method for manufacturing a wrench in accordance with the present invention.

FIGS. 5A through 5E are views illustrating manufacture of a wrench by the method shown in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A method for manufacturing a wrench in accordance with the present invention generally comprises: preparing a head having an engaging portion, necking an end of a metal tubular member, closing the other end of the metal tubular member, fusing the end of the metal tubular member and the head together. The step of closing and the step of fusing can be exchanged, namely, the step of fusing can be performed before the step of closing.

Referring to FIGS. 1 and 2A-2E, in an embodiment of the invention, a method for manufacturing a wrench in accordance with the present invention comprises: preparing a head 20 having an engaging portion 21 (step 100 and FIG. 2A), necking an end 11 of a metal tubular member 10 that has a hollow interior 13 (step 102 and FIG. 2B), closing the other end 12 of the metal tubular member 10 (step 104 and FIG. 2C), fusing the end 11 of the metal tubular member 10 and the head 20 together (step 106 and FIG. 2D), grinding, patching, and polishing an outer periphery of the tubular member 10 to provide a smooth surface (step 108), heat processing the tubular member 10 to realign inner molecules of the tubular member 10, rendering a uniform hardness in the bending portions, joint portions, and the remaining portions of the tubular member 10 and thus providing improved strength and hardness for the tubular member 10 (step 110), and surface finishing the tubular member 10 (step 112 and FIG. 2E). The surface finishing process includes oscillation, sanding, blackening, and/or electro deposition.

Referring to FIGS. 4 and 5A-5E, in another embodiment of the invention, a method for manufacturing a wrench in accordance with the present invention comprises: preparing a head 20 having an engaging portion 21 (step 200 and FIG. 5A), necking an end 11 of a metal tubular member 10 that has a hollow interior 13 (step 202 and FIG. 5B), fusing the end 11 of the metal tubular member 10 and the head 20 together (step 204 and FIG. 2C), closing the other end 12 of the metal tubular member 10 (step 206 and FIG. 2D), grinding, patching, and polishing an outer periphery of the tubular member 10 to provide a smooth surface (step 208), heat processing the tubular member 10 to realign inner molecules of the tubular member 10, rendering a uniform hardness in the bending portions, joint portions, and the remaining portions of the tubular member 10 and thus providing improved strength and hardness for the tubular member 10 (step 210), and surface finishing the tubular member 10 (step 212 and FIG. 5E). The surface finishing process includes oscillation, sanding, blackening, and/or electro deposition.

FIG. 3 is a perspective view of the wrench manufactured in accordance with the method of the invention. The overall weight of the wrench is relatively small when compared with a wrench having a solid handle. The burden to the user operating the wrench for a relatively long period of time is greatly reduced, and the working efficiency is improved regardless of the age and sex of the user. Further, it was found that the impact-resistance, toughness, and strength of the wrench having a hollow handle were better than those of a wrench having a solid handle while reducing the manufacture cost of the wrench.

Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed.

Claims

1. A method for manufacturing a wrench having a hollow handle, comprising:

preparing a head having an engaging portion;

necking an end of a metal tubular member;

closing another end of the metal tubular member; and

fusing the end of the metal tubular member and the head together, forming a wrench having a hollow handle.

2. The method as claimed in claim 1, wherein the step of fusing is performed before the step of closing.

3. The method as claimed in claim 1, wherein the step of necking is performed before the step of closing and the step of fusing.

4. The method as claimed in claim 1, further including a step of proceeding at least one of grinding, patching, and polishing an outer periphery of the hollow handle.

5. The method as claimed in claim 4, further including a step of heat processing the hollow handle after the step proceeding at least one of grinding, patching, and polishing an outer periphery of the hollow handle.

6. The method as claimed in claim 5, further including a step of surface finishing the hollow handle after the step of heat processing.

7. The method as claimed in claim 6, wherein the step of surface finishing includes at least one of oscillation, sanding, blackening, and electro deposition.

8. The method as claimed in claim 2, further including a step of proceeding at least one of grinding, patching, and polishing an outer periphery of the hollow handle.

9. The method as claimed in claim 8, further including a step of heat processing the hollow handle after the step proceeding at least one of grinding, patching, and polishing an outer periphery of the hollow handle.

10. The method as claimed in claim 9, further including a step of surface finishing the hollow handle after the step of heat processing.

11. The method as claimed in claim 10, wherein the step of surface finishing includes at least one of oscillation, sanding, blackening, and electro deposition.

12. The method as claimed in claim 3, further including a step of proceeding at least one of grinding, patching, and polishing an outer periphery of the hollow handle.

13. The method as claimed in claim 12, further including a step of heat processing the hollow handle after the step proceeding at least one of grinding, patching, and polishing an outer periphery of the hollow handle.

14. The method as claimed in claim 13, further including a step of surface finishing the hollow handle after the step of heat processing.

15. The method as claimed in claim 14, wherein the step of surface finishing includes at least one of oscillation, sanding, blackening, and electro deposition.