Mechanical Principles

THE DIFFERENT TYPES OF ESCAPEMENT

The escapement fulfills several main functions. First, it stops the finishing Train (wheel train) when the Balance is in a phase of Oscillation free. Periodically (between 2 and 10 times per second for most of them), it releases the finishing Train (wheel train) and transmits brief impulses to the Regulating organ. Thus, the energy stored in the Mainspring is not released all at once. These impulses controlled impulses help maintain the oscillations of the Regulating organ (the balance and hairspring).

Many escapements have been developed over time and can be classified into different categories, according to the type of rest, the number of impulses transmitted per oscillation, the lift angle of the regulating organ, and in particular according to its supplementary arc. More than 1500 escapements or escapement variants have been catalogued. This list is therefore not exhaustive and focuses on the most common and most representative ones.

Cylinder escapement

Swiss lever escapement

RECOIL ESCAPEMENTS

In this type of escapement, the Escape wheel undergoes a slight recoil when it is blocked. This creates disturbances in Isochronism that affect the accuracy of the watch.

FRICTION REST ESCAPEMENTS

In this type of mechanism, one of its parts, linked to the Regulating organ, remains in permanent contact with the Escape wheel when the escapement is locked and the Balance performs its supplementary arc.

FREE ESCAPEMENTS

This type of escapement is designed to minimize friction and maintain better chronometric precision by limiting direct contact between the escapement components and the Regulating organ (the balance) at brief moments during each cycle ofOscillation.