Arnold & Son Constant Force Tourbillon
Arnold & Son Constant Force Tourbillon
© Arnold & Son
Constant Force Tourbillon is a wristwatch by Arnold & Son.
Constant force is an essential element in the quest for higher precision because it is difficult regulating a consistent output, e.g. isochronal time when the power input from the mainspring is constantly changing. Imagine trying to drive a car at a consistent speed with an engine that continually varies its power output.
To maximize power consistency in the Constant Force Tourbillon, Arnold & Son began at the beginning, i.e. the mainspring barrel, as this is the source of the movement's power. Instead of using just one mainspring barrel, which would produce significantly different amounts of torque between fully wound and nearly empty, the Constant Force Tourbillon has two symmetrical barrels in series, visible dial side at 10 30 and 1 30. The first mainspring barrel alone powers the gear train, while the second barrel tops up the first whenever its torque output drops below optimal. This ensures that the power to the regulator flows as constantly as possible.
Reference:
- 1FCAR.B01A.C112C
Movement:
- Exclusive Arnold & Son mechanical movement A&S5119, hand-wound, 21,600 A/h
- Double barrel
- Tourbillon cage mirror-polished with hand-chamfered polished edges and circular satin-finished surfaces.
- 39 jewels
- 90 hours power reserve
Case:
- 18 ct red gold
- Ø 46 mm, H ? mm
- Domed, antireflective on both sideses sapphire crystal
- Transparent caseback in sapphire crystal
- Waterproof to 3 atm
Dial:
- Anthracite open dial
Functions:
- Hours, minutes, dead-beat seconds
- Constant force
Bracelet:
- Hand-stitched brown bottier alligator leather with patina
Limitation:
- 28 pieces