157,500 CHF
The Single Wheel Watch. Pierre-Laurent Gautrin & Fils, Paris, No. 2, circa 1798. An exceptional and exquisitely made 18K gold single wheel, double-face, watch with jump hours, dead seconds, and two escapements, one with pirouette. Three-body, faceted, polished. Notes Functions of the Single Wheel Watch. The “single-wheel” of 60 sharp ratchet teeth is mounted in the center. It delivers an impulse to the impulse pallet fitted to the arbor of the escape lever. This lever is fitted with three racks; the inner one drives the seconds hand pinion, the outer racks, mounted one over the other, are for the impulses. The top one delivers an impulse to the top pallets of the balance for 30 seconds directly from the torque received from the “single wheel”, the lower one in the opposite direction for the next 30 seconds. The direction-switching mechanism has its own escapement; when the “single wheel” drops off the arbor of the escape lever it pushes a lever which in turn allows the arbor to drop down and thus engages the lower rack with the lower pallets of the balance wheel. After that the “single wheel” locks itself on a pivoted detent. The arbor of the escape lever is attached to a fusee-like chain and terminates on a spring-loaded half pulley. During the 30-second impulse by the “single wheel”to the escape lever arbor, the chain winds around the arbor. The energy thus stored in the pulley's spring, via the chain, gives enough torque to the escape lever for 30 seconds in the opp
Auctioneer:
Antiquorum
Date:
2003-10-11
