Crutch

In a common anchor escapement the crutch is attached to the escapement arbor and ends in a fork or other connection to the pendulum rod or leader. It transmits the escapement's impulse to the pendulum and follows the pendulum's movement back to the escapement. The crutch is not normally the part that supports the pendulum's weight: suspension and impulse linkage have different jobs. Forks, pins, slots and leaders differ between constructions.

Beat concerns the relationship between alternate escapement actions and the pendulum's swing. Some clocks provide a beat adjustment; others require specialist setting of their linkage. Crutch length alone is not a universal beat control, and a beat screw is not present on every clock. Uneven ticking, contact with the case or a stop may involve mounting, suspension, clearances, power or escapement condition. An external symptom does not identify a bent crutch as its sole cause.

A useful photograph shows the connection, not merely the movement's front plate. Record the actual fork or pin arrangement and any established earlier alteration. Preserve uncertain condition as uncertain: a still photograph cannot show freedom throughout the swing or quantify an impulse. During a move, protect the suspension and hanging parts according to exact instructions rather than bend the crutch to make the pendulum fit a new position.