GB346606A - Improvements in or relating to automatic electric circuit breakers - Google Patents

Abstract

346,606. Electrically-released switches. SIEMENSSCHUCKERTWERKE AKT.-GES., Siemensstadt, Berlin. May 30, 1930, No. 16819. Convention date, July 5, 1929. [Class 38 (v).] The coil 2, on overload, raises a core 6, an extension 7 on which rotates a lever 17 about its pivot on a pin 14 so that a lug 18 on the lever moves clear of a projection on a contact-carrying drum 3, which is moved counterclockwise to the " off " position by a spiral spring 5 connected between it and a member 4. At the same time a nose 20 on the lever 17 is moved from a hole in a plate 10, and a spring 15 connected between the plate 10 and a bush 13 causes the handle 12, bush 13, and pin 14 to move counterclockwise together until the lug 18 again falls behind the projection of the drum 3. The switch is reset by rotating the handle 12 clockwise until the nose 20 again engages the hole in the plate 10. If there is an overload, the switch is released even if the handle is held in the closed position, and a lug 23 is provided, to prevent the lever 17 getting latched to the plate 10. A thermal release may, alternatively or additionally, act on the lever 17, and the switch may be formed as a screw plug. The contacts on the drum 3 are interconnected by a ring 29. In a modification, Fig. 5 (not shown), the lever 17 is pivoted at its centre and engages a spring-detent on the plate 10, the pin 7 having an offset piece engaging the lever 17 near the nose 18 to reduce the releasing force.