Anchor escapement made today use it. Tower clocks are one of the few types of pendulum clock which the anchor escapement did not dominate. The varying force applied to the wheel train by the large exterior hands, exposed to wind, snow, and ice loads, was better handled by gravity escapements. The deadbeat escapement has two faces to the pallets, a 'locking' or 'dead' face, with a curved surface concentric with the axis on which the anchor rotates, and a sloping 'impulse' face. When an escape wheel tooth is resting against one of the dead faces, its force is directed through the anchor's
Escapement patented it in 1782. The early forms had two escape wheels. The duplex escapement was difficult to make but achieved much higher accuracy than the cylinder escapement, and could equal that of the (early) lever escapement and when carefully made was almost as good as a detent escapement. It was used in quality English pocketwatches from about 1790 to 1860, In the duplex, as in the chronometer escapement to which it has similarities, the balance wheel only receives an impulse during one of the two swings in its cycle. The escape wheel has two sets of teeth (hence the name