GB1341927A - Machine for manufacturing welded steel structural parts - Google Patents

Abstract

1341927 Welding by pressure EVG ENTWICKLUNG U VERWERTUNGSGESSELLSCHAFT mbH 23 Nov 1971 [27 Nov 1970] 54396/71 Addition to 1277838 Heading B3R A machine for resistance welding transverse rungs Q between two longitudinal rods L1, L2 comprises means 6a for feeding the longitudinal rods convergently and at constant linear speed, means for introducing the transverse rungs between the longitudinal rods to move therewith at the constant linear speed and resistance welding heads 1 linked together in an endless chain 3 the path of the chain having a straight run extending parallel to the plane of the longitudinal rods, each head having a gripper for receiving a transverse rung and for introducing the rung between the longitudinal rods and two electrodes, one one each side of the gripper, movable together and apart for welding the transverse rungs to the longitudinal rods. Thrust devices are provided to apply welding pressure to the longitudinal rods where they contact the rungs as are means to feed rungs and supply current to the electrodes. Sixteen welding heads are linked by pivot pins to form a chain 3 passing over sprocket wheels 4, 5, the upper run of the chain being at the level of two longitudinal wires L1, L2 fed by rollers 6a, 6b. Each head has two electrode holders 10, 10<SP>1</SP> slidable towards one another by engagement of rollers 24, 24<SP>1</SP> on the heads with cam rails 28, 28<SP>1</SP> and away from one another by springs. Between the holders 10, 10<SP>1</SP> on each head is a clamp for a transverse rung comprising a spring urged jaw and a pivoted jaw having a cam roller coacting with a cam surface beneath the run of the chain. Three intermittently rotating wheels 44 are provided at the lower run of the chain to supply transverse rungs into the clamps on the heads which carry the transverse rungs to the upper run of the chain where the electrodes 11, 11<SP>1</SP> on the holders 10, 10<SP>1</SP> are moved together to weld the longitudinal rods to the transverse rungs. The wheels 44 each have three notches which are fed one at a time when a lowermost position with a transverse rung which is carried when the wheel rotates to a position where the rod is forced out of the notch into a clamp. A reciprocating bar feeder may be used instead. The clamps which may be provided with magnets release the transverse rods after welding. Current for welding is supplied from a contact 30 to the electrodes via the rollers 24 and return via the conductive rail 28<SP>1</SP> and current for heat treatment is supplied from a contact 31 downstream of contact 30.