GB319120A - Means for automatically controlling an electro-magnetic device - Google Patents

Abstract

319,120. Quartier, E. Aug. 20, 1928. Electric clocks. - An arrangement for automatically controlling an electromagnetic device such as may be employed for driving an electric clock has a contact making rocking lever adapted to touch a fixed contact, the contact lever being pivotally mounted at or near the free end of an oscillating lever which is operated by the electromagnet and is under the action of one or more springs tending to cause it to take up one or other of two extreme positions with respect to said part. As shown in Fig. 1, a pivoted arm g carrying the core j of the operating solenoid w carries in a forked end 14 a contact lever 7 which is constrained by springs 18 to take up one or other of two extreme positions in which it engages a fixed contact 8 in the solenoid circuit or a stop 22. On attraction of the solenoid core the lever g moves a pawl f pivoted thereto along the periphery of a toothed drum e connected through an escapement to the minute hand of the clock. The contact lever 7 is moved to the dotted position during this movement with a quick action so breaking the solenoid circuit. The stepping of the pawl strains a spring h which drives the drum c slowly until the spring 18 is again brought across the dead-centre position. A quick-action closing movement of the solenoid circuit then occurs and the cycle of operations is repeated. The fixed contact may be in the form of a divided spring blade for obtaining a yielding contact between it and the rocking contact member. The solenoid is provided with a fixed core s and a surrounding magnetic shell n, o for decreasing the reluctance of its magnetic circuit and the lower conical tip of the movable core is provided with a brass projection 6 for preventing adhesion to the fixed core. In a modified form the movable core is arranged in the lower portion of the solenoid and the electromagnetically-controlled oscillating lever is mounted below the operating solenoid. The contact lever in this form is used to control the circuit of a secondary electromagnetic device, independent means being provided to control the solenoid. The operating solenoid may be replaced by an electromagnet.