Anchor escapement

In horology, the anchor escapement is a type of escapement used in pendulum clocks. The escapement is a mechanism in a mechanical clock that maintains the swing of the pendulum by giving it a small push each swing, and allows the clock's wheels to advance a fixed amount with each swing, moving the clock's hands forward. The anchor escapement was so named because one of its principal parts is shaped vaguely like a ship's anchor.

The anchor escapement was invented by clockmaker William Clement,^{[1] [2][3]} who popularized the anchor in his invention of the longcase or grandfather clock around 1680. Clement's invention was a substantial improvement on Robert Hooke's constant force escapement of 1671.^[4] The oldest known anchor clock is Wadham College Clock, a tower clock built at Wadham College, Oxford, in 1670, probably by clockmaker Joseph Knibb.^[5][6] The anchor became the standard escapement used in almost all pendulum clocks.

A more accurate variation without recoil called the deadbeat escapement was invented by Richard Towneley around 1675 and introduced by British clockmaker George Graham around 1715. This gradually superseded the ordinary anchor escapement and is used in most modern pendulum clocks.