Deadbeat (Graham) Escapement

The deadbeat, or Graham, escapement is an improvement of the anchor escapement. In the anchor escapement the swing of the pendulum pushes the escape wheel backward for part of its cycle; this recoil disturbs the pendulum and loads the train. The deadbeat removes the recoil: its pallets have a second, curved locking face concentric with the anchor pivot, so the escape-wheel tooth rests without pushing back until it slides onto the angled impulse face near the bottom of the swing.

First used in precision regulator clocks, it superseded the anchor in the nineteenth century and is used in almost all modern pendulum clocks except tower clocks, which often use gravity escapements. The linked Victoria and Albert Museum example, the clock made in 1857-62, is recorded with an escapement 'on the principle of Graham's deadbeat', with steel pads sliding in turned grooves so that the pitch could be set exactly.