GB291373A - Improvements in or relating to electric contacts, particularly for electrically actuated clockwork - Google Patents

Abstract

291,373. Etablissements E. Jaeger. May 31, 1927, [Convention date]. Electric clocks.-The fixed make-and-break contact of an electrically-maintained clock or watch consists of a close-coiled wire spring 24 fixed to brackets 26 by screws 25 which engage with the convolutions of the spring. The coiled spring has a slight curvature and when engaged by the correspondingly curved movable contact 21 (controlled by the armature 9 in conjunction with the pole pieces 11) it yields and the convolutions separate thereby affording a rubbing contact engagement. The clock is driven by a pawl 6 acting on the ratchet-wheel 1 on the return stroke of the armture 9 (to which the pawl is attached) when the electromagnet is deenergized on separation of the contacts 21, 24. The armature, which co operates with the pole pieces 11, is pivotally mounted on a rod 12 and the contact 21 is pivotally mounted on a. spindle 20 supported by brackets 19 depending from a plate 16. A spring 22 between an extension of the contact arm 21 and an extension 23 of the armature-pawl structure serves to drive the pawl on the return stroke. Fig. 4 shows the contact mechanism in the closed position with the armature 9 about to be attracted and move in the direction of the arrow f<2>. This movement carries the lower end of the spring 22 across the dead-centre position, that is, across the pivot 20, whereupon the spring brings back the contact-member to the off position and the movement of its upper end carries the spring back across the line of centres.