GB2107224A

GB2107224A - Cold pressure butt-welding of wire or strips

Info

Publication number: GB2107224A
Application number: GB08130404A
Authority: GB
Inventors: Bernd Hoppe
Original assignee: Siemens AG; Siemens Corp
Current assignee: Siemens AG; Siemens Corp
Priority date: 1981-10-08
Filing date: 1981-10-08
Publication date: 1983-04-27

Abstract

The cold pressure butt-welding of wires (8, 9) or strips is effected by one or more upsetting operations using oppositely-located pairs of clamping jaws (10, 20). After welding, the burr formed is sheared-off at cutting edges (11, 21) formed on the opposed faces of the pairs of jaws (10, 20) by shifting the welded wire or strip in one longitudinal direction. For this purpose, each pair of jaws is provided with a respective locking means independently operable to prevent locking of one or other of the pairs of jaws. <IMAGE>

Description

SPECIFICATION Cold pressure butt-welding of wires or strips The present invention relates to a method of cold pressure butt-welding of wires or strips by a single or repeated upsetting of the ends of the wires or strips to be joined, using two oppositely located pairs of clamping jaws, and to apparatus for carrying out the method.

During such cold pressure welding, because of the method used, a burr is formed which extends around the welding point. This burr arises from the compression of the material of the wires or strips and is generally harder than the initial material of the wires or strips to be welded. In order to remove such burrs, it has previously been necessary to remove the welded article from the welding machine and to remove the burr by the use of auxiliary means. In order to remove such burrs in the welding machine itself, it has also been proposed to insert the welded article into another groove in the welding tool used, which groove corresponds in its cross-section to the profile of the welded article and to de-burr the welded article in this special groove.

It is an object of the present invention to provide a method of cold pressure butt-welding wires or strips, in which after the cold pressure welding step, the welded wire or strip can be deburred without removing it from the welding machine, or moving it significantly from the welding position.

According to the invention, there is provided a method of cold pressure butt-welding of wires or strips, comprising the steps of carrying out one or more upsetting operations on abutting ends of two wires or strips to be joined, using two oppositely-located pairs of clamping jaws to hold and move the respective ends of the wires or strips to be joined, and thereafter removing the burr formed at the junction point of the wires or strips by the upsetting operation or operations, by shearing-off the burr at cutting edges provided by movement of the joined wire or strip in one longitudinal direction thereof.

Since the parts to be welded form a single article after the welding step, the article formed can be shifted laterally, so that cutting edges preferably provided at the opposing end faces of the clamping jaws, effect shearing-off of the welding burr.

Apparatus for carrying out the method of the invention comprises two oppositely-located pairs of clamping jaws, the opposed faces of each said pair having co-operating grooves therein to accommodate one wire or strip to be welded, the opposed faces of the two pairs being provided with cutting edges immediately surrounding said grooves and respective blocking means assigned to each pair of jaws and independently operable to prevent locking of the pair of jaws to which is assigned on said wire or strip. The cutting edges act in the longitudinal direction of the welded wire or strip to shear off the burr. It is thus possible to effect the shifting of the welded wire or strip in one axial direction and thus causing cutting-off of the burr formed at the cutting on the end faces of the pairs of jaws, by cancelling the locking action of one pair of clamping jaws.

The invention will now be further described with reference to the drawing, in which:~ Figures 1 to 5 are similar schematic side views of apparatus for carrying out the method of the invention in successive operating positions; and Figures 2a and 4a are schematic end views of one of a pair of clamping jaws in positions corresponding to Figures 2 and 4 respectively.

The appratus used in carrying out the cold pressure butt-welding of wires or strips by the method of the invention can be designed, for example, in the same way as similar apparatus already on sale. Figures 1 to 5 illustrate the most essential process steps in the use of such apparatus.

The appratus illustrated comprises two pairs of clamping jaws 10 and 20, each provided with cutting edges 1 1 and 21 on their opposing end faces. In order to avoid reversing the pressing together of the parts to be welded, e.g. the abutting ends of wires 8 and 9 in the example illustrated, during the movement apart of the pairs of clamping jaws in readiness for a succeeding upsetting step, locking mechanisms 12 and 22 which can operate independently, are arranged behind the clamping jaws 10 and 20 respectively.

Moreover, one pair of clamping jaws 10 is provided with a blocking means 15 which allows the clamping effect of this pair of clamping jaws to be overridden. The blocking means 15 is so designed that the effect of the respective locking mechanism 12 is likewise similarly overridden.

Thus with such an arrangement the following sequence of operating steps can be carried out.

The materials to be welded, in this case the two ends of the wires 8 and 9, are inserted into the pairs of open clamping jaws 10 and 20 (Fig. 1).

The wire are then held by the jaws with a force P, and the wire ends are pressed against one another with a force P2 (Fig. 2) so as to upset the ends. The clamping jaws are then opened and retracted in readiness for the next upsetting step, so that the wire can be regripped for the next upsetting step. In order to avoid neutralising the upsetting force P2, the locking mechanisms 12, 22 are closed with a force P3 during this upsetting step (Fig. 3).

When a sufficient number of upsetting and welding steps have been carried out, the locking effect is cancelled by pivoting the blocking means 1 5 between the two clamping jaws of the pair 10 and thus the movement of the welded ends of the wires 8, 9 isin one longitudinal direction, rendered possible (Fig. 4). By such movement effected by means of the clamping jaws 20, the welding burr 17 is cut-off by the cutting edges 11,21 (Fig. 5).

1. A method of cold pressure butt-welding of wires or strips, comprising the steps of carrying

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Cold pressure butt-welding of wires or strips The present invention relates to a method of cold pressure butt-welding of wires or strips by a single or repeated upsetting of the ends of the wires or strips to be joined, using two oppositely located pairs of clamping jaws, and to apparatus for carrying out the method. During such cold pressure welding, because of the method used, a burr is formed which extends around the welding point. This burr arises from the compression of the material of the wires or strips and is generally harder than the initial material of the wires or strips to be welded. In order to remove such burrs, it has previously been necessary to remove the welded article from the welding machine and to remove the burr by the use of auxiliary means. In order to remove such burrs in the welding machine itself, it has also been proposed to insert the welded article into another groove in the welding tool used, which groove corresponds in its cross-section to the profile of the welded article and to de-burr the welded article in this special groove. It is an object of the present invention to provide a method of cold pressure butt-welding wires or strips, in which after the cold pressure welding step, the welded wire or strip can be deburred without removing it from the welding machine, or moving it significantly from the welding position. According to the invention, there is provided a method of cold pressure butt-welding of wires or strips, comprising the steps of carrying out one or more upsetting operations on abutting ends of two wires or strips to be joined, using two oppositely-located pairs of clamping jaws to hold and move the respective ends of the wires or strips to be joined, and thereafter removing the burr formed at the junction point of the wires or strips by the upsetting operation or operations, by shearing-off the burr at cutting edges provided by movement of the joined wire or strip in one longitudinal direction thereof. Since the parts to be welded form a single article after the welding step, the article formed can be shifted laterally, so that cutting edges preferably provided at the opposing end faces of the clamping jaws, effect shearing-off of the welding burr. Apparatus for carrying out the method of the invention comprises two oppositely-located pairs of clamping jaws, the opposed faces of each said pair having co-operating grooves therein to accommodate one wire or strip to be welded, the opposed faces of the two pairs being provided with cutting edges immediately surrounding said grooves and respective blocking means assigned to each pair of jaws and independently operable to prevent locking of the pair of jaws to which is assigned on said wire or strip. The cutting edges act in the longitudinal direction of the welded wire or strip to shear off the burr. It is thus possible to effect the shifting of the welded wire or strip in one axial direction and thus causing cutting-off of the burr formed at the cutting on the end faces of the pairs of jaws, by cancelling the locking action of one pair of clamping jaws. The invention will now be further described with reference to the drawing, in which:~ Figures 1 to 5 are similar schematic side views of apparatus for carrying out the method of the invention in successive operating positions; and Figures 2a and 4a are schematic end views of one of a pair of clamping jaws in positions corresponding to Figures 2 and 4 respectively. The appratus used in carrying out the cold pressure butt-welding of wires or strips by the method of the invention can be designed, for example, in the same way as similar apparatus already on sale. Figures 1 to 5 illustrate the most essential process steps in the use of such apparatus. The appratus illustrated comprises two pairs of clamping jaws 10 and 20, each provided with cutting edges 1 1 and 21 on their opposing end faces. In order to avoid reversing the pressing together of the parts to be welded, e.g. the abutting ends of wires 8 and 9 in the example illustrated, during the movement apart of the pairs of clamping jaws in readiness for a succeeding upsetting step, locking mechanisms 12 and 22 which can operate independently, are arranged behind the clamping jaws 10 and 20 respectively. Moreover, one pair of clamping jaws 10 is provided with a blocking means 15 which allows the clamping effect of this pair of clamping jaws to be overridden. The blocking means 15 is so designed that the effect of the respective locking mechanism 12 is likewise similarly overridden. Thus with such an arrangement the following sequence of operating steps can be carried out. The materials to be welded, in this case the two ends of the wires 8 and 9, are inserted into the pairs of open clamping jaws 10 and 20 (Fig. 1). The wire are then held by the jaws with a force P, and the wire ends are pressed against one another with a force P2 (Fig. 2) so as to upset the ends. The clamping jaws are then opened and retracted in readiness for the next upsetting step, so that the wire can be regripped for the next upsetting step. In order to avoid neutralising the upsetting force P2, the locking mechanisms 12, 22 are closed with a force P3 during this upsetting step (Fig. 3). When a sufficient number of upsetting and welding steps have been carried out, the locking effect is cancelled by pivoting the blocking means 1 5 between the two clamping jaws of the pair 10 and thus the movement of the welded ends of the wires 8, 9 isin one longitudinal direction, rendered possible (Fig. 4). By such movement effected by means of the clamping jaws 20, the welding burr 17 is cut-off by the cutting edges 11,21 (Fig. 5). CLAIMS

1. A method of cold pressure butt-welding of wires or strips, comprising the steps of carrying out one or more upsetting operations on abutting ends of two wires or strips to be joined, using two oppositely-located pairs of clamping jaws to hold and move the respective ends of the wires or strips to be joined, and thereafter removing the burr formed at the junction point of the wires or strips by the upsetting operation or operations, by shearing-off the burr at cutting edges provided by movement of the joined wire or strip in one longitudinal direction thereof.

2. A method as claimed in Claim 1, wherein said cutting edges are provided on the opposed faces of said pairs of clamping jaws.

3. A method of cold pressure butt-welding of wires or strips, substantially as hereinbefore described with reference to the drawing.

4. Apparatus for carrying out a method as claimed in Claim 1, comprising two oppositelylocated pairs of clamping jaws, the opposed faces of each said pair having co-operating grooves therein to accommodate one wire or strip to be welded, the opposed faces of the two pairs being provided with cutting edges immediately surrounding said grooves and respective blocking means assigned to each pair of jaws and independently operable to prevent locking of the pairs of jaws to which is assigned on said wire or strip.

5. Apparatus for carrying out a method as claimed in Claim 1 substantially as hereinbefore described with reference to and as shown in the drawing.