Tourbillon Cardan

Greubel Forsey unveils its 8th Fundamental Invention, namely a new kind of flying tourbillon whose three principles combine to reach a new level of chronometric precision. First, the high speed at which the tourbillon rotates, making one revolution every 16 seconds, plus the large size of the balance wheel. Second, the tourbillon’s 30° incline is optimised for contemporary wristwatch wear. Third, the tourbillon is guided by two mobile rings, linked by two 90° axes. In 48 seconds, they tilt backwards and forwards. While this construction may seem similar to gimbals, it in fact differs from traditional gimbals whose two rings are free to move and whose function is to keep an object horizontal. In the Tourbillon Cardan, the tilt of the rings is controlled within a range of +30° to -30°, so that the degree of inclination of the tourbillon never varies. The movement runs at a frequency of 3.5 Hz and incorporates four barrels providing 80 hours of power reserve, shown at 10 o’clock, with further indications of hours, minutes and small seconds. It is housed in a 45.5mm titanium case with a domed sapphire crystal. Greubel Forsey will make 55 of this Tourbillon Cardan over the next five years.