GB1577917A - Resistance welding apparatus - Google Patents

Description

(54) RESISTANCE WELDING APPARATUS (71) We, LUCAS INDUSTRIES LI MITED, of Great King Street, Birmingham, B19 2XF, a British Company, do hereby declare the invention for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to resistance welding apparatus.

Apparatus, according to the invention, includes in combination first and second welding electrodes, fluid pressure actuated means for imparting to the electrodes relative movement towards each other and for urging the electrodes against respective workpieces to be interconnected by resistance welding, and resilient means interposed between said fluid pressure actuated means and said electrodes so as to be stressed when said electrodes are, in use, urged against the workpieces, the combination of the electrodes, fluid pressure actuated means and resilient means being supported by a fixed carrier so as to be angularly movable, in use, about a vertical axis.

By virtue of the arrangement described above, when the electrodes are urged against the workpieces and welding current is passed between the electrodes, the stressed resilient means urges the electrodes to remain in pressure contact with the workpieces despite the sudden dimensional changes which can occur in the workpieces as a result of melting of the workpieces.

Preferably, said combination is supported by the fixed carrier so as also to be capable of linear movement along said vertical axis.

Preferably, said combination is suspended by a cable from said fixed carrier.

In the accompanying drawings, which illustrate one example of the invention; Figure I is a perspective view of apparatus for resistance welding the intercell connections of lead-acid batteries, and Figure 2 is a part-sectional plan view of part of the apparatus shown in Figure 1.

Referring to the drawings, the apparatus includes a fixed support 11 having a pair of ground-engaging feet 12 and a column 13 extending vertically from the feet 12. Projecting from the free end of the column 13 is a horizontal bar 14 which carries a rotatable drum 15 at its free end and a pulley 16 at its end connected to the column 13. Passing over the pulley 16 and drum 15 is a cable 17 which at one end is connected to the base of a generally U-shaped bracket 20. The limbs of the bracket 20 are secured to an electrode assembly 18 and at its other end the cable is connected to a device (not shown) for adjusting the vertical position of the assembly 18. It will of course be appreciated that, by virtue of being suspended by the cable 17, the assembly 18 is capable of angular movement about a vertical axis.

As shown in Figure 2, the assembly 18 includes a generally rectangular casing 19 having end walls to which the limbs respectively of the bracket 20 are secured and side walls which are formed internally with respective parallel guide channels 21. Slidably received in the channels 21 is an electrode carrier 22 which supports a first welding electrode 23 so that the electrode is movable with the carrier 22 towards and away from a second, fixed welding electrode 24. The electrodes 23, 24 extend parallel with each other and are arranged so that one end of each electrode projects through the base of the casing 19 remote from the cable 17. Associated with the electrode 23 is a piston and cylinder arrangement 25, the piston 26 of which acts on the electrode 23 by way of a stack of four Belleville disc springs 27 arranged so that adjacent springs are in the opposite orientation.

As previously stated, the apparatus is intended for resistance welding the intercell connections of lead-acid batteries. Thus in use, a battery to be processed is supported, such as for example on a conveyor, relative to the assembly 18 so that a pair of conductive members which are to form an intercell connection are located between said one ends of the electrodes 23, 24. The piston and cylinder arrangement 25 is then operated to initially move the electrode 23 to trap the conductive members against the electrode 24 and then urge the electrodes 23, 24 into pressure contact with the conductive members, whereby the springs 27 are compressed. An a.c. supply (not shown) connected to the electrodes 23, 24 is then energised to pass welding current between the electrodes so as to complete the required intercell connection. The stressed disc springs 27 ensure that the electrodes 23, 24 instantaneously follow any dimensional changes in, and hence remain in pressure contact with, the conductive members during the resistance welding operation.

The apparatus described above is intended to be hand operated and hence as shown in Figure 1, the limbs of the bracket 20 house respective handles 28 mounted thereon which, in use, are gripped by the operator of the apparatus. The handles 28 not only allow the operator to bring the electrodes 23, 24 into the required position to effect welding, but also are provided with manually operable buttons which control operation of the welding sequence.

In a modification (not shown) the electrode 23 is supported by a cylindrical carrier member which is received as a sliding fit in a hollow, cylindrical bearing member which forms part of the casing of the welding assembly 18.

WHAT WE CLAIM IS: 1. Resistance welding apparatus including in combination first and second welding electrodes, fluid pressure actuated means for imparting to the electrodes relative movement towards each other and for urging the electrodes against respective workpieces to be interconnected by resistance welding, and resilient means interposed between said fluid pressure actuated means and said electrodes so as to be stressed when said electrodes are, in use, urged against the workpieces, the combination of the electrodes, fluid pressure actuated means and resilient means being supported by a fixed carrier so as to be angularly movable, in use, about a vertical axis.

2. Apparatus as claimed in Claim 1, wherein said combination is supported by the fixed carrier so as also to be capable of linear movement along said vertical axis.

3. Apparatus as claimed in Claim 1 or Claim 2, wherein said combination is suspended by a cable from said fixed carrier.

4. Resistance welding apparatus comprising the combination and arrangement of parts substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

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

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. connections of lead-acid batteries. Thus in use, a battery to be processed is supported, such as for example on a conveyor, relative to the assembly 18 so that a pair of conductive members which are to form an intercell connection are located between said one ends of the electrodes 23, 24. The piston and cylinder arrangement 25 is then operated to initially move the electrode 23 to trap the conductive members against the electrode 24 and then urge the electrodes 23, 24 into pressure contact with the conductive members, whereby the springs 27 are compressed. An a.c. supply (not shown) connected to the electrodes 23, 24 is then energised to pass welding current between the electrodes so as to complete the required intercell connection. The stressed disc springs 27 ensure that the electrodes 23, 24 instantaneously follow any dimensional changes in, and hence remain in pressure contact with, the conductive members during the resistance welding operation. The apparatus described above is intended to be hand operated and hence as shown in Figure 1, the limbs of the bracket 20 house respective handles 28 mounted thereon which, in use, are gripped by the operator of the apparatus. The handles 28 not only allow the operator to bring the electrodes 23, 24 into the required position to effect welding, but also are provided with manually operable buttons which control operation of the welding sequence. In a modification (not shown) the electrode 23 is supported by a cylindrical carrier member which is received as a sliding fit in a hollow, cylindrical bearing member which forms part of the casing of the welding assembly 18. WHAT WE CLAIM IS:

1. Resistance welding apparatus including in combination first and second welding electrodes, fluid pressure actuated means for imparting to the electrodes relative movement towards each other and for urging the electrodes against respective workpieces to be interconnected by resistance welding, and resilient means interposed between said fluid pressure actuated means and said electrodes so as to be stressed when said electrodes are, in use, urged against the workpieces, the combination of the electrodes, fluid pressure actuated means and resilient means being supported by a fixed carrier so as to be angularly movable, in use, about a vertical axis.

2. Apparatus as claimed in Claim 1, wherein said combination is supported by the fixed carrier so as also to be capable of linear movement along said vertical axis.

3. Apparatus as claimed in Claim 1 or Claim 2, wherein said combination is suspended by a cable from said fixed carrier.

4. Resistance welding apparatus comprising the combination and arrangement of parts substantially as hereinbefore described with reference to and as shown in the accompanying drawings.