GB594884A - Improvements in or relating to electric clocks - Google Patents

Abstract

594,884. Electric clocks. DENTON, L. E. Oct. 19, 1943, No. 16320/44. Divided out of 574,169. [Class 139] In a clock in which contacts are closed by the pendulum to discharge a condenser through an electromagnet to provide maintaining impulses for the pendulum, the latter is connected by a flexible element to a rigid member hinged to a fixed support, contacts carried on the rigid member engaging fixed contacts shortly after the pendulum passes through its mid-position so that movement of the rigid member is prevented during the major part of the swing of the pendulum, The pendulum rod e is suspended from the lower end of a hinged rigid member c by a flexible element f. The bar c carries contacts g<1> and g<2> which co-operate respectively with adjustable contact screws h<1> and h<2> secured to the backboard a. The pendulum bob m has an armature l which co-operates with the pole pieces of an electromagnet k adjustable along the arc of swing. When the pendulum m is slightly to the left of its mid-position, Fig. 5, the contacts g<1>, h<1> are closed and the battery p supplies a charging current to the condenser q, said current passing through the electromagnet winding r. The. armature s is drawn .up and on its return stroke rotates the ratchet wheel u which is geared to the clock dial mechanism. On the return stroke of the pendulum m the contacts g<2>, h<2> are closed and so the condenser q discharges through the winding of the electromagnet k which supplies the impulse to the pendulum m. The pole faces n of the electromagnet k are carved in a plane perpendicular to the plane of swing of the pendulum so that the air gap remains constant even if the clock is out of level.