Arnold & Son pushes precision chronometry ever further with the Constant Force Tourbillon, featuring a patented constant force device with 60-second tourbillon and true beat seconds. The Constant Force Tourbillon is part of the Royal Collection and, like every other model from Arnold & Son, features an in-house mechanical movement. To maximize power consistency in this timepiece, Arnold & Son began at the beginning, i.e. the mainspring barrel, as this is the source of the movement’s power. So, it 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.
The Constant Force Tourbillon features a patented constant force mechanism. Instead of power from the mainspring feeding directly to the escapement/tourbillon, it charges a small hairspring which in turn releases a consistent amount of power to the escapement/tourbillon once each second. The device also drives the true-beat seconds hand (also known as jumping seconds or dead seconds), a highly cherished Arnold & Son complication.
While the constant force mechanisms optimize precision with the movement in stable positions, the 60-second tourbillon averages out gravitational errors on the escapement by constantly rotating it through 360°. The difference between the rotating tourbillon and rotating constant force device is that the former turns continually while the latter steps in increments of one second.
The Constant Force Tourbillon is a limited edition of 28 timepieces, and is available in a 46 mm 18-carat red gold case with anti-reflective sapphire crystal and sapphire display back for viewing the superbly hand-finished movement. It comes on hand-stitched brown bottier alligator leather strap with patina.
