Complication · Timing
Split-Seconds Clamp (Pinces)
Partially verifiedThe clamp mechanism holding one hand of a split-seconds chronograph.
Definition
The clamp mechanism holding one hand of a split-seconds chronograph.
Historical origin
Part of nineteenth-century split-seconds development; several makers refined the arrangement.
How it works
A pair of jaws closes on a heart cam to hold the rattrapante hand while the primary hand continues.
Releasing the jaws lets a spring snap the held hand forward into step with the running hand.
Pocket watch context
A feature of high-grade pocket chronographs with split-seconds work.
Wristwatch context
Among the most demanding wristwatch chronograph mechanisms to build and service.
Identification
- A pair of sprung jaws around a second heart cam
- A third pusher controlling the split function
Servicing notes
This is specialist work. Levers, springs and cam profiles in complicated work are calibre-specific, and incorrect reassembly commonly damages parts that cannot be bought. Refer the movement to a watchmaker experienced with this mechanism.
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.