SHAKE (PLAY)

Shake (play) is the space that guarantees the freedom of Movement of a moving component or the safety of a function. Close to the notion of set, it designates the margin deliberately provided so that a part can move without jamming, or so that an organ does not come into unwanted contact with another. Thus we speak of the height shake of a wheel, which corresponds to the value of its axial set between its two bearings: the wheel must turn freely, but without excessive movement. The shake of Dart (safety pin), for its part, is the safety space between the dart of the Pallets (lever) and the circumference of the small roller, ensuring that the dart does not rub during normal operation while ensuring the safety of the Escapement. Too small, a shake causes friction and stoppages; too large, it harms precision or safety. Its Regulation / Adjustment is therefore essential to the proper functioning of the movement.