Complication · Precision
Overload Protection
Partially verifiedA mechanism that prevents the mainspring from being over-wound or damaged by excessive force.
Definition
A mechanism that prevents the mainspring from being over-wound or damaged by excessive force.
Historical origin
Critical for automatic watches and high-torque hand-wound movements.
How it works
Uses a slipping bridle in the barrel (for automatics) or a Geneva stop-work (for manual) to limit the winding range.
Some modern versions use a torque-limiting crown.
Pocket watch context
Standard in better-quality pocket watches as stop-work.
Wristwatch context
Universal in automatic wristwatches; a specialist feature in hand-wound ones.
Identification
- Lack of a hard stop when winding
- Clicking sound of a slipping bridle
Servicing notes
The barrel walls must be correctly lubricated with braking grease.
General guidance only. Complicated mechanisms should be assessed and serviced by a qualified watchmaker or clockmaker specialist, not adjusted at home.
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., Watch and Clock Encyclopedia
- Britten, F. J., Old Clocks and Watches and Their Makers
- Horological Journal (British Horological Institute), technical articles
Where sources disagree, the disagreement is stated rather than resolved silently.