Method of forming metal zipper teeth and forming device thereof

Abstract

A method for forming metal zipper teeth includes following steps: a step of forming embryonic teeth, a material wire being stamped and cut by way of an upper blank mold and a lower blank mold to form embryonic teeth detaching from the material wire; a step of corner cutting, redundant material at two outer ends on the open end of each of the embryonic teeth being removed by way of an upper corner cutting mold and a lower corner cutting mold so that almost finished zipper teeth can be obtained; and a step of forming, each of the almost finished zipper teeth being worked to have a tooth recess at the top thereof and a tooth jut at the bottom thereof by way of an upper forming mold and a lower forming mold and finished zipper teeth being complete.

Description

FIELD OF THE INVENTION

The present invention relates to technique of metal zipper and particularly to a method of forming metal zipper teeth and a device to carry out the method.

BACKGROUND OF THE INVENTION

Metal zippers are frequently seen in our daily lives and in fact, the metal zippers are developed much earlier than the nylon zippers and fiber reinforced plastic zippers. Usually, the metal zippers can be divided into aluminum zippers and copper zippers.

The principle of a metal zipper, as shown in FIG. 1, basically has two cloth strips a and a cord b is provided at the cloth strips respectively to face to each other. The respective cord b is clipped with a plurality of equidistantly arranged zipper teeth c and a gap between two adjacent teeth of one of the cords is the height of each zipper tooth c2 of the other cord so that the zipper teeth at the cords can be joined firmly to each other once the a zipper head is pulled upward. Therefore, each zipper tooth (c1, c2) has a tooth jut d extending in a direction and the backside of the zipper tooth corresponding to the tooth jut d is a tooth recess e. As a result, when the zipper teeth is in a state of being joined to each other, the tooth jut d at least at the front end thereof is received in the tooth recess e to constitute engagement as shown in FIG. 1.

Referring to FIGS. 2 and 3, in order to allow the zipper teeth (c1, c2) to clip the cord b of the cloth strip a, an upper mold set f and a lower mold set g are provided to form the zipper teeth c with stamping. The dash lines at left side of FIG. 2 indicate the metal wire w, which usually is aluminum or copper, and the metal wire is fed with the front end thereof entering the lower mold g and the upper mold f and the lower mold g provide tooth jut mold (h1, h2) corresponding to each other. Once the operation of stamping is performed, the metal wire is worked with the upper and lower mold sets f, g joining to each other such that each of the zipper teeth c can be formed the tooth jut d at the upper part thereof and the tooth recess e at the lower part thereof. Besides, the upper and lower mold sets f, g provides two cutting molds (k1, k2) extending inward for forming a neck part 1 during stamping and the neck part 1 can be worked by the forming molds (m1, m2) to form independent zipper teeth c. Meanwhile, the cord b of the cloth a passes through the openings of the zipper teeth c and the cord c is clipped by the zipper teeth c by way of left and right molds joining to each other. The operation is repeated to carry out the work of planting teeth on the cord b. It is known that the method and the device have been used for years and the entire process has been developed as automatic production. Although the convention way can reach the purpose of teeth planting, the deficiency is one time forming such that there are cutting clear scars on the zipper teeth resulting from stamping such as lateral cutting notches of the zipper teeth at the neck 1 and the cord b and even at intersections of lines. After the zipper teeth being formed, there is no change to trim or treat the surface of each zipper tooth so that it is coarse without a sense of good quality and sharp corners on the zipper teeth being not chamfered results in being not smooth zipper teeth engagement during the zipper being pulled up.

SUMMARY OF THE INVENTION

The crux of the present invention is to provide a method for forming metal zipper teeth includes following steps: a step of forming embryonic teeth, a material wire being stamped and cut by way of an upper blank mold and a lower blank mold to form embryonic teeth detaching from the material wire; a step of corner cutting, redundant material at two outer ends on the open end of each of the embryonic teeth being removed by way of an upper corner cutting mold and a lower corner cutting mold so that a most finished zipper teeth can be obtained; and a step of forming, each of the almost finished zipper teeth being worked to have a tooth recess at the top thereof and a tooth jut at the bottom thereof by way of an upper forming mold and a lower forming mold and finished zipper teeth being complete.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reference to the following description and accompanying drawings, in which:

FIG. 1 is a plan view of a metal zipper illustrating the construction thereof;

FIG. 2 is a perspective view illustrating teeth of the metal zipper being planted;

FIG. 3 is a plan view illustrating relation between the zipper teeth forming and the core; and

FIG. 4 is a perspective view illustrating a forming device of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 to 4, a method of forming metal zipper teeth of the present invention can be explained in company with a forming device for the metal zipper teeth. The forming device includes a blank mold 1, a corner cutting mold 2, one or more forming molds 3, a rotary mold seat 4 and/or a core holding device 5.

Wherein, the blank mold 1 has an upper mold part 11 and a lower mold part 12 for the zipper teeth being formed with an approximate shape respectively and being separated from the original material wire A. Thus, once the material wire A enters the blank mold 1, the material wire A is stamped and cut and embryonic teeth B of the zipper can be obtained. The formed zipper teeth are delivered with the rotary mold seat 4.

The corner cutting mold 2 is composed of an upper cutting mold 21 and a lower cutting mold 22 (not shown) disposed on the rotary mold seat 4 for cutting residue material X at the outer end section on the open end of a holding core b to constitute unfinished and ready to be formed zipper teeth C. The ready to be formed zipper teeth C are provided with a flat shape respectively without the preceding tooth jut d and tooth recess.

One or more of the forming molds 3 are provided in the forming device and each of the forming molds 3 includes an upper forming mold 31 and a lower forming mold 41, which is attached to the rotary mold base 4. Only stamping is processed and no cutting is engaged at the stage of the forming molds. Each of the zipper teeth is formed with the tooth recess c at the upper part thereof and the tooth jut d at the bottom part thereof as shown in FIG. 4. There are four steps at the forming stages, i.e., upper forming molds 31, 31-1, 31-2, 31-3 and lower forming molds 41, 41-1, 41-2, 41-3 but, it still depends on the actual need. Basically, more steps get involved in the mold tool stamping process and softer product can be obtained so that the preceding scars, sharp corners, burrs and etc. can be eliminated.

The rotary mold base 4 provides one or more lower forming molds 41 for the lower cutting corner molds 22 so that the lower forming molds 41 can be disposed in a way of equiangular position along the outer edge of the mold base to rotate a preset angular motion by way of conventional automatic control for being capable of obtaining zipper teeth D4 available for being held to the cord b.

The cord holding device 5 is conventional device for and can be provided at formed zipper teeth D and the cord b can be held to the formed zipper teeth D while the cord b moves upward to pass through the cord holding device 5 so as to form a zipper strip with a lateral side thereof having zipper teeth. by way of automatic control with programming.

It is appreciated that the method of forming metal zipper teeth with forming device thereof has the following advantages:

1. The traditional material wire can be utilized in the method and device of the present invention without changing material source and habit using material.

2. The tooth jut and the tooth recess become delicate via multiple forming steps being joined to the mold design and it is helpful to enhance the quality thereof.

3. The outer walls of the zipper teeth become more smooth after multiple forming steps being performed so that it is helpful for the zipper being opened and shut easily with gentle sense of touch.

4. The tooth recess faces upward and it is different from the conventional way of forming so that it is different from successive design and utilization of the tooth recess.

5. The forming device is independent of the device for detaching from the material wire so that it is flexible to install, maintenance and repair.

While the invention has been described with reference to the a preferred embodiment thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims.

Claims

1. A forming device of metal zipper teeth, comprising:

a blank mold, providing an upper blank mold and a corresponding lower blank for stamping and cutting material wire as embryonic teeth with approximate shape of the zipper teeth;

a corner cutting mold, providing an upper corner cutting mold and a lower corner cutting mold for removing two front ends of an open end of each of the embryonic teeth;

a forming mold, providing at least an upper forming mold for stamping a tooth recess in each of the embryonic teeth and a lower forming mold corresponding to the upper forming mold for forming the tooth recess with the upper forming mold; and

a rotary mold base, being disposed with the lower corner cutting mold and the lower forming mold and being capable of turning a preset angular displacement.

2. The forming device of metal zipper teeth as defined in claim 1, further comprises a cord holding device for formed zipper teeth being joined to a cloth cord.

3. The forming device of metal zipper teeth as defined in claim 1, wherein the respective lower forming mold is disposed at an equiangular position on the outer edge of the rotary mold base.

4. The forming device of metal zipper teeth as defined in claim 1, wherein the lower corner cutting mold is disposed on the rotary mold base.

5. A method for forming metal zipper teeth, comprising following steps:

a step of forming embryonic teeth, a material wire being stamped and cut by way of an upper blank mold and a lower blank mold to form embryonic teeth detaching from the material wire;

a step of corner cutting, redundant material at two outer ends on the open end of each of the embryonic teeth being removed by way of an upper corner cutting mold and a lower corner cutting mold so that almost finished zipper teeth can be obtained; and

a step of forming, each of the almost finished zipper teeth being worked to have a tooth recess at the top thereof and a tooth jut at the bottom thereof by way of an upper forming mold and a lower forming mold and finished zipper teeth being complete.

6. The method for forming metal zipper teeth as defined in claim 5, further comprises a cord holding step to allow the finished zipper teeth at the respective open end thereof holding a cloth cord and form a zipper strip.

7. The method for forming metal zipper teeth as defined in claim 5, wherein the step of forming can be operated a plurality of times by way of the lower forming mold being disposed on a rotary mold base with an equiangular position to turn a preset angular displacement and the forming molds can be corresponding to each other and the zipper teeth are formed sequentially.

8. The method for forming metal zipper teeth as defined in claim 5, wherein the material wire is made of aluminum or copper.