Pocket watches · Escapement
Duplex-Escapement Watches
VerifiedWatches using the duplex escapement, which delivers impulse to the balance only once every two vibrations from a double-toothed escape wheel.
Mechanism
The balance locks the escape wheel on a locking tooth for one full vibration, then receives impulse from a short tooth on the return swing, giving fine timekeeping when clean but poor tolerance of shock or dirt.
Typical characteristics
- Double set of escape-wheel teeth (long locking, short impulse)
- Roller with a single impulse notch on the balance staff
- Often found in export watches for the Chinese market
Identification characteristics
- Distinctive stepped escape wheel visible under the balance
- Frequently found in silver-cased 'Chinese duplex' export watches
Collector significance
An important frictional-rest stage between the cylinder and the fully detached lever, now largely a specialist collecting field.
Known variations
- English duplex
- Chinese-market duplex
- Waterbury long-wind duplex
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
- Gazeley, W. J., Clock and Watch Escapements
Where sources disagree, the disagreement is stated rather than resolved silently.