Movement record · France
Japy Frères ébauche
Partially verifiedRough movements made by machine in large quantities and sold unfinished to watch and clock establishers, who fitted escapements, jewelling, dials and cases.
Technical specifications
- Diameter
- Supplied in many sizes
- Height
- Varies by size
- Jewels
- Supplied unjewelled or partly jewelled, to be finished by the buyer
- Frequency
- Not applicable as supplied; determined on finishing
- Power reserve
- Determined by the finished movement
- Winding
- Supplied for key wind or keyless finishing
- Setting
- Determined on finishing
- Escapement
- Supplied without escapement on many ébauches; cylinder and lever both common when finished
- Balance
- Fitted at finishing
- Complications
- None as supplied
Identification features
- Japy stamps and exhibition medal marks on plates, when present
- A Japy ébauche mark records who made the rough movement, not who made the finished watch or clock
Known variants
- Watch ébauches
- Clock movements
Servicing notes
Because finishing varied by establisher, no single parts specification applies; components generally have to be matched to the individual movement.
General guidance only. Antique movements should be serviced by a qualified watchmaker.
Historical significance
One of the clearest surviving records of the ébauche system, in which making and finishing a movement were separate trades.
Photographs
Photographs are illustrative examples of the type, not necessarily the exact object described. Verify details against the source file page.
Sources & references
- Histories of the Franche-Comté watch and clock trade
- Exhibition medal stamps record awards, not dates of manufacture.
Where sources disagree, the disagreement is stated rather than resolved silently.