Clock with rotary pendulum

Abstract

A rotary pendulum without time-keeping function, comprising an inertial body suspended from a clockwork housing of a preferably electronically driven timepiece through the intermediary of an elongate torsion spring, is periodically accelerated by the impact between a vane on the spring and radial camming teeth of an impeller wheel frictionally entrained on a horizontal seconds shaft of the timepiece via a spiral spring anchored to that shaft. The vane, near the upper end of the torsion spring, oscillates only through a half-cycle limited on the return swing by an abutment on the clockwork housing. The inertial body is secured to a latch member at the lower end of the torsion with the aid of a coupling ring on which a drag ring is rotatably mounted, the latter carrying a radial fin engageable with a fixed stop pin as well as with a peripheral lug on the coupling ring whereby the body can turn through almost two full revolutions before being positively arrested. The upper end of the torsion spring is anchored to the housing through a vertically guided coil spring designed to absorb axial shocks; the inertial body is provided at its underside with a central stud received with clearance in a guide bore of an underlying base on which it bottoms whenever such shocks reach a certain intensity.