GB580703A - An improved electromagnetically operated electric switch - Google Patents

Abstract

580,703. Automatic circuit-breakers; electromagnetic switches. LANDIS & GYR SOC. ANON. July 18, 1944, No. 13721. Convention date, Sept. 28, 1943. [Class 38 (v)] A switch adapted to open its contacts 1, 2 in response to overload or underload, has a novolt retaining magnet 3, an armature 4 pivoted at 11 and connected by a latch 14 to a contact lever 12, also pivoted at or near 11, a third lever 17 being also pivoted at or near 11 and adapted to be tripped on overload so as to move rapidly upwards and strike the contact arm 12 while simultaneously moving the latch 14 out of latching position. On underload, the magnet 3 is de-energized and the circuit is broken by the upward movement of levers 10, 12. Upon an overload a magnet 7, serving also a blow-out coil, attracts an armature 8 thereby rotating a latch 22 and releasing lever 17 which moves upwards under the influence of a spring 21. The lever 12 is moved upwards by a projection 19 on lever 17, thereby opening the contacts. Simultaneously, a projection 18 lifts a coil 27, pivoted at 11, which moves the upper spring contact 28 of an auxiliary switch 5 thus deenergizing the magnet 3, the armature 4 of which is moved upwards by a striker 20 on lever 17. To reclose the switch, a push knob 9 is moved downwards so that a striker 29 thereof moves lever 12 downwards. At the same time, a striker 30 moves the contact 31 of switch 5 downwards, and the stem of knob 9 pushes the coil 27 down and thus releasing contact 28 and pushing lever 17 downwards. This movement allows latch 14, 15 to be moved clockwise by a spring 32 to relatch lever 12. Finally, the knob 9 is released so that the switch 5 is closed and magnet 3 is energized to reclose the contacts 1, 2. Opening upon overload may be effected by a bimetal strip 35 acting on coil 27 to open switch 5 and de-energize magnet 3. The thermal release may act on latch 22 for rapid opening. The invention, with slight modifications, may be applied to a multiple-pole switch.