GB562131A - Improvements in or relating to the remote control of electric generators particularly for arc welding - Google Patents

Abstract

562,131. Control systems for welding arcs. RIMMINGTON, F. Oct. 14, 1942, Nos. 14377/42, 14764/42, 2103/43 and 10946/43. [Class 38 (iv)] Manual variation of the length of a welding arc is adapted to cause the selective operation of relays R1 ... R4 in a circuit 3, 4 shunted on the arc, whereby the output of a current supply generator G or transformer is adjusted. A reversible motor M may thus operate a current controller C in opposite directions in accordance with a temporary shortening or lengthening of the arc by the operator. Relays may be included whereby the motor is rendered inoperative on the shorting and opening of the arc circuit, and limit switches A, B, which may be jointly or individually adjustable with manual adjustment of the current controller, may be included in the relay circuit. According to Fig. 1 the relay R1 operates at 10 volts, relay R2 at 20-25 volts (during normal arc conditions) relay R3 at 37 volts and relay R4 when the arc is broken. In a modification relays R1, R3 are latched in when first caused to operate and the operator, after watching the effect on the arc, unlatches them, when satisfied, by a second movement of the electrode. In a further alternative, or in association with the last arrangement, the relay may have an adjustable time delay which determines the period of operation of the motor at each actuation. Modifications using an A.C. motor and a rectified current supply to the arc are described. The arrangement may be such as to effect a step-by-step operation of controller and motor. Specification 450,141 is referred to.