Greubel Forsey Quadruple Tourbillon à Différentiel Sphérique

Greubel Forsey's second fundamental invention featuring four tourbillon cages arranged in two pairs working independently. Each pair follows the Double Tourbillon 30° configuration with an inner 30° inclined cage rotating in 60 seconds inside an outer cage rotating in four minutes. A spherical differential connects the four rotating carriages, distributing torque and averaging timing between the two systems. The movement contains 805 components in the GMT Quadruple Tourbillon version. Patent awarded in 2004.