ARMIN STROM Let's talk about the Gravity Equal Force mechanism

The inspiration behind Gravity Equal Force was a desire to transmit equal force to the balance, thereby increasing the consistency of rate. Building upon the classic stop-works mechanism, Armin Strom developed an ingenious stop-works declutch system that operates inside the mainspring barrel to limit the torque delivered to the balance, providing smooth power delivery. This represents the first time a stop-works declutch mechanism has been added to an automatic winding movement. Utilizing a Geneva wheel mounted to the barrel housing cover, the rotation of the mainspring barrel is limited to just 9 full turns out of a possible 12.5. This represents the central 72% of the mainspring’s potential torque curve, the flattest and most consistent portion. As the barrel housing unwinds around the arbor, a pin counts off the rotations on the Geneva wheel until it reaches the locked position and prevents further unwinding. This limit keeps the power delivery to the balance as consistent as possible and the amplitude in optimal range. Once it reaches the upper limit, the declutch mechanism guarantees the slip of the mainspring and allows the micro rotor to turn evenly when fully wound. A small declutch lever is attached to the Geneva wheel that marks its rotation and power reserve from full to empty. Sitting atop the barrel cover, the power reserve location will change as the watch is wound, providing some playful variation in the dial display. Visit our website for more information