Component record · Power
Stop Work
Partially verifiedA mechanism limiting how far a mainspring may be wound or let down.
What it does
Confines the spring to the most even part of its torque range and prevents overwinding of a fusee.
How it works
A Maltese cross and finger, or a similar interrupted gearing, permits only a set number of barrel turns.
On a fusee it also prevents the chain running off either end of the cone.
Evolution
Common in fine early work, and retained in some high-grade watches for its isochronal benefit.
Known variations
- Maltese cross (Geneva) stop work
- Fusee stop work
Identification for collectors
- A small cross-shaped steel component beside the barrel.
- Its absence on a fusee watch is a warning sign.
Common failure modes
- Broken finger or cross arm
- Incorrect reassembly preventing full wind
Related photographs
No confidently matched photograph of this subject has been found yet. These photographs show a closely related record, and are not examples of the type described on this page.
Sources & references
- de Carle, D., Practical Watch Repairing
- de Carle, D., Watch and Clock Encyclopedia
- Daniels, G., Watchmaking
Where sources disagree, the disagreement is stated rather than resolved silently.