GB1135726A - Method and apparatus for upsetting steel wires - Google Patents

Abstract

1,135,726. Upsetting. NIPPON CONCRETE KOGYO K.K. 3 May, 1967 [2 Dec., 1966], No. 20642/67. Heading B3H. The end of a steel wire W such as a concrete reinforcing rod, is upset at an elevated temperature which satisfies the formula where t is the heating time in sees., T is the working temperature in ‹ C., and α and # are constants dependent upon the size and composition of the wire. This may be of highmanganese high-carbon steel. The upsetting is effected by clamping the rod or wire W between a fixed jaw 3 and a movable jaw 2 actuated by a pneumatic piston 6 and fixed to copper electrodes 8, 9 connected with the upsetting head 20 in a resistance heating circuit supplied by a tapped transformer Tr. In operation, a foot switch S is actuated to energize a solenoid valve 14 which admits air above piston 6 to close the jaw 2. As pressure builds up in duct 16, a pressure switch S 1 is closed to energize timer T and also to close solenoid switch M. This energizes transformer Tr and simultaneously solenoid valve 24 admits pressure air to the right of piston 21 whereby head 20 contacts the end of the wire W to commence the heating cycle. Subsequently, timer T opens switch M to stop the heating current and upsetting continues until switch S 2 is tripped by finger 26 to reverse the piston 21. The working temperature is adjusted by the control arm 34 of transformer Tr and the heating time is adjusted manually or automatically by the timer T.