GB1368365A - Actuating mechanism for operating handle of electrical switching device - Google Patents

Abstract

1368365 Actuation of switches; automatic circuit-breakers SQUARE D CO 18 Aug 1972 [21 Sept 1971] 38550/72 Heading H1N An actuating mechanism for moving an operating handle of an electric switch, e.g. an automatic circuit-breaker, to "on" and "off" positions, comprises a reversible motor having an output shaft 21, a crank arm 22 resiliently connected adjacent one end to the shaft, a handle actuating member 30 secured to the other end of the crank arm, normally closed " on " and "off" limit switches 44, 46, and a lost motion connecting device between a limit switch actuator 42 and the crank arm. As shown the resilient connection is provided by a blade spring 24 which extends through a slot in the base 22c of the U-shaped crank arm and through the shaft 21 and is secured between pins 25. A link 33 has pins 34, 35 extending on either side of the spring 24 into a rectangular aperture 22d in the crank arm 22. An actuating lever 37 is pivoted at 40 and to the link 33 at 38, the lever 37 extending through a U-shaped part of the limit switch actuator 42. The free movement of the lever 37 in the U-shaped part of actuator 42 is sufficient to allow a geared motor (not shown) to fully close or open a circuit-breaker (not shown) before the appropriate limit switch is opened to stop the motor. This free movement or lost motion is also sufficient to permit a tripfree action to occur and to enable the circuitbreaker handle to move into an intermediate tripped position. In alternative arrangements, an extended portion of the spring blade may operate a limit switch actuator, Fig. 6 (not shown), or the switches may be operated by cam surfaces on a member connected to the crank arm, Fig. 7 (not shown).