OVERBANKING

The Overbanking is a malfunction of the Escapement, likely to cause immediate stopping of the Movement. It occurs when the Pallets (lever) Lever / Rocker from one Banking pin to the other when it should not — typically under the effect of a shock — while the Balance completes its additional arc, the Impulse pin (roller jewel) out of the Fork. When the Balance returns, the Impulse pin (roller jewel) no longer meets the Fork on the correct side: it strikes against the back of it instead of entering it, which blocks the Escapement and freezes the watch. Overbanking reflects a fault in the Escapement’s safety, which the devices designed for this purpose — Dart (safety pin), small roller and horns of the Pallets (lever) — are precisely meant to prevent. Frequent Overbanking indicates faulty Regulation / Adjustment (poorly adjusted safety devices, excessive Amplitude) or sensitivity to shocks. Understanding Overbanking means grasping the importance of the safety components that ensure the reliability of the lever Escapement, even in the event of shocks or high amplitudes.