Zero-sum device in a chronograph clock

摘要

The drive from the main timepiece mechanism (11) passes to the display axes through a friction clutch (1) maintained in contact by a spring (12). When a return to zero with the timepiece in motion is required a hammer (4) operates on the hearts (5,6) on the display axes and in addition actuates a shuttle (A) with an inclined plane (B) such that the upper disk (2) of the clutch is lifted against the spring