“My watch has stopped - Why?” -  Page 4

No. 20 and No. 20A show set and unset Center Jewels which have been cracked by a bump, usually one which also breaks the crystal.

The Click, No.21, prevents the Mainspring from completely releasing and leaving the watch without power. Under constant pressure it gradually wears away and must be replaced.  The Click Spring, No. 22, which holds the Click, is very sensitive to atmospheric changes and breaks very easily.

No. 23 depicts the complete Winding mechanism of a watch. Also shown are the component parts: No. 23A – Stem; No. 23B – Winding Pinion; No. 23C – Clutch.  Any of these parts breaking make winding the watch impossible. A broken Stem is shown by No. 23D.

When a Mainspring breaks, it may do so with sufficient force to break the Barrel, No. 24, the housing for the Mainspring.  The teeth may be jammed by the impact of the recoil, or the hooks which hold the ends of the Mainspring may give.  One of these hooks is on the Barrel Arbor, No. 24A.  An Arbor with a worn hook, stripped thread or defective square must be replaced.