GB575883A - Improvements in electric welding apparatus - Google Patents

Abstract

575,883. Uniting by fusion. STANDARD TELEPHONES & CABLES, Ltd., and GILLIVER, G. April 21, 1944, No. 7410. [Class 83 (iv)] An electric fusion welding tool for joining conductors, such as wires or strips &c. to terminal tags &c., comprises means for clamping the wires &c. with their ends in a fixed position with respect to a welding electrode, a shutter normally interposed between the electrode and the wires and means for moving the electrode into contact with the wire ends, such means being adapted also to cause withdrawal of the shutter out of the path of the electrode. The welding current may be provided by a condenser charged and discharged as described in Specification 570,681, so as to join the wires by fusion and so interrupt the circuit automatically. A box is provided with bus-bars 2, 3 connected to the two terminals of the condenser, the bar 2 being connected to a bracket 4 carrying fixed and movable vice jaws 5, 6, the latter of which is spring mounted in a slide 9 moved in guides by a cam 8 operated by a hand lever 7. With the handle in a vertical position, the jaws are open, the aperture being closed by a stop or shutter 14 which is held down by a catch 15 against the action of a spring 29 and is pushed down by a roller 13 on the handle 7 when the latter is raised to its vertical position to open the jaws. The bar 3 is connected to a copper block 16 in which is mounted a spring-returned push-button plunger 17 having at its front end a plate 18 carrying a carbon electrode 19. The plate which is electrically connected to the block 16 by a piece of copper braid 23 carries also an insulated pin 21 for releasing the catch 15 and in addition a contact 22 which is normally in engagement with a contact 26 mounted on a spring 27 flexibly connected by a loose'plug inserted in a socket on the welding equipment. With the bus-bars 2, 3 connected to the terminals of the condenser and the contact 26 to one terminal of the charging source thereof, when the plunger 17 is operated after clamping the wires in position by moving down the handle 7, the contacts 22, 26 separate and the condenser disconnects from the charging source. The pin 21 first depresses the catch 15 so that the shutter is raised by the spring 29 and when the electrode 19 makes contact with the wires the condenser is discharged to effect the weld. On release of the push-button, the contacts 22, 26 again engage to recharge the condenser. The handle is then returned to vertical position to release the clamps and reset the shutter in gauging position.