Steel cable connector swaging method and machine thereof

Description

BACKGROUND OF THE INVENTION

(a) Technical Field of the Invention

The present invention generally relates to steel cables, and more particularly to a method and machine for swaging steel cable connectors.

(b) Description of the Prior Art

Connectors are often used to make steel cables into a noose or to connect them into a longer length. The connectors are usually swaged so as to clip the ends of steel cables tightly together by a swaging machine. As shown in FIG. 1, the connector 2 usually has a cylindrical shape. The steel cable 1 is usually made by twisting two or more steel wires into having a generally circular cross-section. In order to slip the steel cable 1 into the connector 2, the central hole 21 is also a round hole. A round central hole 21 is also easier to make with lower cost. After the steel cable 1 is slipped into the connector 2, the connector 2 is swaged into having a smaller cross-sectional diameter by a swaging machine using stamping, so as to fixedly clip the steel cable 1 inside the connector 2. The connector 2 would thereby have its length extended, as shown in FIG. 2. Conventionally, the swaging machine has a mold 3 composed of an upper die 31 and a lower die 32 so that, when closed together, the upper and lower dies 31 and 32 form a circular through hole at their sides. The operation of the swaging machine is as follows. The connector 2 having the steel cable 1 slipped through is placed on the semi-circular trough 321 of the lower die 32. The swaging machine is first operated to close the upper die 31 for only half of the course, as shown in FIG. 4. The upper die 31 is then lifted and the connector 2 is rotated for 45 degrees, as shown in FIG. 5. The swaging machine is again operated for a second swaging, in which the upper die 31 is closed for one fourth of the course, as shown in FIG. 6. Then the upper die 31 is lifted and the connector 2 is rotated for another 45 degrees, as shown in FIG. 7. Finally, the upper die 31 is fully closed with the lower die 32 for a complete course, as shown in FIG. 8. The connector 2 now remains to have a generally cylindrical shape but with a smaller cross-section diameter and a longer length, as shown in FIG. 2 and as compared to FIG. 1. The connector 2 thereby tightly clips the steel cable 1 inside.

As described above, the conventional steel cable connector swaging method requires three swaging operations and two connector rotations. This is a time consuming and, thereby, costly process. Especially, the three swaging operations requires the operator to close the upper die 31 for one half and one fourth of the course, which is very difficult for an operator of ordinary skill to precisely control the upper die 31's position. Furthermore, the conventional swaging machine is usually operated manually so as to adapt to different types of swaging process and connectors. Therefore, the foregoing process could only be operated by an experienced operator and the operator could only control the upper die 31's course simply based on experience and naked eyes.

In addition, every time when the connector 2 is rotated and swaged and when the upper die 31 is closed to press against the bulge part 22 of the connector 2, a side force would be generated, which would very likely to damage the mold 3 and shorten the operation life of the swaging machine. This is especially true when the connector 2 is made of a steel material having a high hardness. Further, for connectors having a cross-sectional diameter greater than 1⅛ inches, since the connector 2 would have a shape and cross-sectional diameter exceeding the limitation of the mold 3 after the first swaging, the mold 3 has to be replaced before continuing the second swaging. The replacement of mold not only further extends the operation time, increases the production cost, but also leads to a lower yield rate.

Besides, for the two swaging operations after the connector 2 is rotated, as shown in FIGS. 4 and 6, since the connector 2 is already deformed, the upper die 31's pressing against the bulge part 22 would leave dents on and cause a rough surface of the connector 2. The handsome outlook of the steel cable product is thereby comprised, and the rough surface also often gives the operator and user cutting wounds. The conventional approach therefore presents a hazard to the safety of the operators and users.

To simplify the swaging process, as shown in FIG. 9, another swaging method is developed. This method adopts a mold 4 whose upper and lower dies 41 and 42, when closed together, form a through hole having a nearly hexagonal cross-sectional shape at their sides. The troughs on the upper and lower dies 41 and 42 have curved surfaces 413 and 423, and planar surfaces 412 and 422 respectively. When the connector 2 is placed on the lower die 42's trough, the upper die 41 is closed completely with the lower die 41 so that the connector 2 would have a tube shape with a curved hexagonal cross-section, as shown in FIG. 10. The connector 2 is then rotated for 45 degrees, as shown in FIG. 11. The upper die 41 is closed completely again for a second swaging, as shown in FIG. 12. The connector 2 now has a tube shape with a hexagonal cross-section. The method requires only two swaging operations, and both the production time and cost are reduced. In addition, since the dies are closely completely and there is no need to estimate the course advance, operators with limited experience are capable of performing the staging operations.

However, the rotation of connector 2 is still required after the first swaging operation. On the other hand, when performing the second swaging, as shown in FIG. 11, the two planar surfaces 411 and 421 of the upper and lower dies 41 and 42 respectively are pressed against the curved surfaces of the connector 2, a significant side force would be generated which, similar to the previous approach, would damage the mold and swaging machine, and reduce their operation lives. As the connector 2 has to be rotated for 45 degrees before the second swaging, the method is applicable to connectors having a diameter between ¼ and 1¾ inches. Larger connectors still have to rely on the previous swaging method. Also because of the connector 2 has to be rotated, the connector 2 would suffer dents and a rough surface as well, which are threats to the safety of the operators and users. Besides the foregoing approaches, there are other swaging methods being developed but all with various limitations on the size of the connectors.

SUMMARY OF THE INVENTION

The primary purpose of the present invention is to provide a swaging method and a swaging machine which has an external through hole and an internal through hole in the mold so that a connector could undergo two stages of swaging operations, all within the same mold for a speedy swaging process.

Another objective of the present invention is to provide a swaging method and a swaging machine so that connectors of various sizes could be swaged within a same mold, and production time and cost could thereby be saved.

Still another objective of the present invention is to provide a swaging method and a swaging machine so that the connectors would have smooth surfaces after being swaged, and the connectors' outlook and safe usage are enhanced.

A further objective of the present invention is to provide a swaging method and a swaging machine so that no side force would be generated during the swaging operations, and the mold and the swaging machine could be free from the damage of side force and would have longer operation lives.

The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective schematic view of a steel cable connector.

FIG. 2 is a perspective schematic view of a swaged steel cable connector.

FIGS. 3˜8 are schematic cross-sectional views showing the various stages of a conventional swaging method.

FIGS. 9˜12 are schematic cross-sectional views showing the various stages of another conventional swaging method.

FIG. 13 is a schematic cross-sectional view of a mold according to the present invention.

FIGS. 14˜16 are schematic cross-sectional views showing the various stages of the swaging method according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

In the following, detailed description along with the accompanied drawings is given to better explain preferred embodiments of the present invention.

Please refer to FIG. 13. As shown in FIG. 13, a mold 5 used in the swaging machine according to the present invention has an upper and lower dies 51 and 52, which would form rectangular external troughs 511 and 521 at their sides respectively. The external troughs 511 and 521 are shaped by right-angled planar surfaces 512 and 522 respectively. The upper and lower dies 51 and 52 also have semi-circular internal troughs 513 and 523 respectively, which would form a through hole in the middle of the mold 5 when the upper and lower dies 51 and 52 are closed together.

The swaging machine according to the present invention is operated as follows. First, the connector 2 is placed between the external troughs 511 and 521, as shown in FIG. 14. The upper and the lower dies 51 and 52 are closed completely to press the connector 2 into having an oval cross-sectional shape. The connector 2 is then moved into the internal troughs 513 and 523, as shown in FIG. 15. The upper and lower dies 51 and 52 are again closed completely together to press the connector 2 into having a circular cross-sectional shape and a longer length, as shown in FIG. 16. The swaging process of the steel cable connector 2 is completed.

According to the foregoing description, the present invention requires only two swaging operations, and the production time and cost are both reduced accordingly. In addition, an operator with limited experience could perform the swaging operations as the operator is not required to make precise estimation of the pressing course's advance. Further, there is no need to replace the mold 5 since connectors of various cross-sectional diameters could be swaged in the external and internal troughs of a single mold. In other words, the present invention poses no limitation on the size of the connectors. As the external troughs are located at the sides of the upper and lower dies 51 and 52, the connector 2 with a steel cable slipped through is very convenient to work on. Also, during the swaging operations, the connector 2 is either having a circular or having an oval cross-sectional shape, no side force would be generated during the swaging operations to damage the mold 5 and the swaging machine. Moreover, the swaged connector 2 has a smooth surface without any dent. The swaged connector 2 therefore has a handsome outlook and presents no threat to the safety of the operators.

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.