Escapement

An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock´s hands. The impulse action transfers energy to the clock´s timekeeping element (usually a pendulum or balance wheel) to replace the energy lost to friction during its cycle and keep the timekeeper oscillating. The escapement is driven by force from a coiled spring or a suspended weight, transmitted through the timepiece´s gear train. Each swing of the pendulum or balance wheel releases a tooth of the escapement´s escape wheel, allowing the clock´s gear train to advance or "escape" by a fixed amount. This regular periodic advancement moves the clock´s hands forward at a steady rate. At the same time, the tooth gives the timekeeping element a push, before another tooth catches on the escapement´s pallet, returning the escapement to its "locked" state. The sudden stopping of the escapement´s tooth is what generates the characteristic "ticking" sound heard in operating mechanical clocks and watches.