GB2064384A

GB2064384A - Strip-joining apparatus

Info

Publication number: GB2064384A
Application number: GB8038878A
Authority: GB
Original assignee: Maschinenfabrik Weingarten AG
Current assignee: Maschinenfabrik Weingarten AG
Priority date: 1979-12-06
Filing date: 1980-12-04
Publication date: 1981-06-17
Also published as: DE2949095B1; GB2064384B; ES8200022A1; ES497352A0; FR2470647A1; SE8008560L

Abstract

A laser device is used for cutting- off the end region and starting region of material strips and the subsequent connection of the two strips in their cutting planes. The laser device is able to move at right angles to the longitudinal direction of the strip and is constructed to operate in cutting and welding modes. <IMAGE>

Description

SPECIFICATION Splicing apparatus The invention relates to a device for cutting-off the end region and starting region of material strips with subsequent connection of the two strips in their cutting planes.

For example, when processing material strips in presses, it is necessary to shorten the starting region and end region of these strips by a certain amount. The latter may be dirty parts caused during the production of the strips. It is known to use so called cropping shears for cutting-off these end regions. Furthermore, it is attempted to carry out the introduction of the next strip after processing of the preceding strip, as quickly as possible, in order to minimise the stoppage of the press for example. In this case, particularly with wide strips, it has been found that threading-in the beginning of the strip into the press frequently encountered great difficulties, particularly if the strips were relatively thin and the lateral end regions thereof hand down to a greater or lesser extent.

In order to remedy this, it is already known (applicant's construction) to provide welding installations preceding the press, which installations follow the cropping shears. In this known device, the end region of the previously processed strip and the starting region of the following strip are cut off, then their cutting planes are joined and the latter are then welded to each other for example electrically. However, in this case, relatively great stresses occur at the junction point of the two strips as well as projecting beads in the welding seam, which may once more lead to operating disturbances for example in a transfer press with follow-on tools. Furthermore, the parts punched-out in the region of the joint cannot be used as work pieces in the case of these known welding apparatus, which operate electrically and with a protective gas.

A further drawback of this known device consisted in that it comprised two completely separate apparatus which are then combined to form a unit, which required a relatively greater amount of space.

This is the basis of the present invention and the latter relates to a device for cutting off the end and starting regions of material strips with subsequent connection of the two strips in their cutting planes, the object of the invention being to construct the latter so that with this device it is possible to carry out exact cutting and then welding, in which case an exact welded seam is produced, which on the one hand does not project beyond the thickness of the metal sheet and on the other head in contrast to known welding methods causes considerably less stress in the connection region.

To achieve this object, a device is proposed according to the invention and of the aforedescribed construction, which is characterised by a laser apparatus able to move transversely with respect to the longitudinal direction of the strip, which is constructed on the one hand as a cutting apparatus and on the other hand as a welding apparatus.

There are several possibilities for changing from the cutting operation to the welding operation.

According to the invention, two are mentioned and in particular it is possible for example that the power supply necessary for the laser beam can be controlled and adjusted as desired depending on the "cutting" and "welding" stages of the operation. Another embodiment can be provided due to the fact that the speed at which the cutting nozzle moves transversely and longitudinally can be controlled and adjusted as desired depending on the "cutting" and "welding" stages of the operation.

Furthermore, it may be an advantage that a common laser arrangement is provided for "cutting" and "welding". However, it is also possible that a separate laser appliance is located in the common device for "cutting" and "welding".

The invention is described in detail hereafter with reference to a drawing which shows one embodiment partly diagrammatically.

Figure 1 shows a device in conjunction with a press in a diagrammatic side view, Figure 2 is a plan view of two end regions of material strips before the cutting operation, Figure 3 is a similar view to that of figure 2, in which after the cutting operation, the two cut surfaces are joined together at their junction point before the welding operation and Figure 4 shows the cutting nozzle in a diagrammatic side view before welding.

In figure 1 , the reference numeral 1 designates a double reel, the reference numeral 2 the device according to the invention for cutting-off the end and starting regions of the material strips with subsequent connection of the two strips in their cutting planes, reference numeral 3 an aligning device and the reference numeral 4 a press. The material strip is designated by the reference numeral 5.

The device 2 according to the invention operates as follows: when the strip 5 for example is withdrawn by its end region from the double reel 1 and introduced into the device 2, the press 4 is stopped. At the same time, the double reel 1 is rotated through 1 800 about a vertical axis, so that a second strip arrives in the starting position. This strip is indicated in figure 2 by the reference numeral 5a and is likewise drawn into the device 2 and in particular so far that the unsatisfactory starting region extends beyond the actual laser nozzle 6. The cut is now carried out by the laser nozzle 6 in the direction of arrow 7, in which case the respective end regions 8 of the strips 5 and 5a drop down and for example, as shown in figure 1, are discharged by way of slides 9 and 10 into a waste container 1 1. After the cutting operation, the two strips 5 and 5a are moved towards each other either by being moved transversely at one or both sides so that their cut surfaces abut against each other, as shown in figure 3. The actual welding now takes place with the same laser nozzle in the direction of arrow 12. The press may then be restarted. The control means etcetera necessary for changing from "cutting" to "welding" are not described and illustrated in detail.

Claims

1. A device for cutting-off the end region and starting region of material strips with subsequent connection of the two strips in their cutting planes, comprising a laser apparatus which is able to move at right angles to the longitudinal direction of the strip and is constructed on the one hand as a cutting apparatus and on the other hand as a welding apparatus.

2. A device as claimed in claim 1, wherein the power supply necessary for the laser beam can be controlled and adjusted as desired depending on the "cutting" and "welding" stages of the operation.

3. A device as claimed in claim 1 or 2, wherein the speed at which the cutting nozzle moves transversely and longitudinally can be controlled and adjusted as desired depending on the "cutting" and "welding" stages of the operation.

4. A device as claimed in any one of claims 1 to 3, wherein a common laser appliance is provided for "cutting" and "welding".

5. A device as claimed in any one of claims 1 to 3, wherein a separate laser appliance is provided in the common device for "cutting" and "welding" respectively.

6. A device for cutting-off the end region and starting region of material strips with subsequent connection of the two strips in their cutting planes, substantially as herein described with reference to and as illustrated in the accompanying drawings.