Parametric Graham Escapement

The escapement is the part of a mechanical clock that keeps the pendulum swinging despite friction losses by imparting it with the potential energy of a weight, or spring, while transforming the regular swings of the pendulum into regular increments of rotation of the escapement wheel, which can then drive a gear train to show seconds, minutes, hours, etc...

http://en.wikipedia.org/wiki/Escapement

A Graham escapement is also known as a dead-beat escapement because it does not force the whe