Lever escapement and other parts out of harder materials than steel, eliminating the need for lubrication. Materials being tried include silicon, nickel phosphorus, diamond, and diamond-on-silicon. Ulysse Nardin in 2001, Patek Philippe in 2005, and Zenith (watchmaker) in 2013 introduced watches with silicon escape wheels. Lever escapement The lever escapement, invented by British clockmaker Thomas Mudge in 1755, is a type of escapement that is used in almost all mechanical watches, as well as small mechanical non-pendulum clocks, alarm clocks, and kitchen timers. An escapement is a mechanical linkage that gives pushes to the timepiece's balance wheel, keeping it rotating back and
Anchor escapement is still a frictional rest escapement because the sliding of the escape tooth on the dead face adds friction to the pendulum's swing, but it has less friction than the recoil escapement because there is no recoil force. In contrast to the backward slant of the anchor escape wheel teeth, the deadbeat escape wheel teeth are radial or slant forward to ensure that the tooth makes contact with the 'dead' face of the pallet, preventing recoil. In 1826 British astronomer George Airy proved that a pendulum that is driven by a drive impulse that is symmetrical about its bottom equilibrium