Patent ID: 7331706

Claim:
A device for the simultaneous zero-resetting of two time counters, especially of a chronograph, the pivot axes of which are fixedly connected to respective heart-shaped zero-resetting cams ( 7 , 8 ), comprising a zero-resetting lever ( 2 ) containing two hammers ( 6 c , 6 d ), means ( 5 ) for exerting selectively upon this lever ( 2 ) a torque for pressing the two hammers ( 6 c , 6 d ) against the respective zero-resetting cams ( 7 , 8 ), and articulation means ( 2 d , 2 e , 6 a , 6 b ) for articulating these hammers relative to the zero-resetting lever ( 2 ); in which the force generated by said torque is essentially directed toward a first ( 7 ) of the zero-resetting cams, wherein the articulation means comprise two pins ( 2 d , 2 e ), a first of which ( 2 d ) is engaged in a guide slot with limited displacement amplitude ( 6 a ), orientated so that, in the zero-resetting position, the force (F 1 ) dropped perpendicularly from the axis of the first pin ( 2 d ) onto this guide slot ( 6 a ) intersects the straight line joining the axes ( 7 a , 8 a ) of the zero-resetting cams ( 7 , 8 ) at a point closer to the second of said cams ( 8 ) than is the point of intersection on this same straight line of the direction of the force exerted upon this first pin ( 2 d ) by said torque, and the second pin ( 2 e ) of which is engaged with play in an opening ( 6 b ) to allow a limited rotation of said hammers ( 6 c , 6 d ) about the axis of the first pin ( 2 d ) so as to ensure a simultaneous contact of the hammers ( 6 c , 6 d ) with the two shoulders of said respective zero-resetting cams ( 7 , 8 ).