Mechanical principles → Complicated mechanisms → Types of escapements

CYLINDER ESCAPEMENT

The cylinder escapement was invented in 1725 by George Graham, who drew inspiration from the “hog’s trough” escapement of his mentor, Thomas Tompion, and significantly improved its performance. By 1750, the cylinder escapement had become the most widely used, replacing verge escapements thanks to its superior timekeeping precision.

Despite its advantages, the cylinder escapement suffered from low efficiency and underwent continuous refinement for over 150 years. Abraham-Louis Breguet achieved its highest performance by combining a hardened steel escape wheel with ruby cylinder lips. From the mid-19th century onwards, the cylinder escapement was gradually phased out, ultimately replaced by the more efficient Swiss lever escapement.

This is a frictional rest escapement. The numerous friction points inherent in its operation result in poor efficiency due to significant energy loss. However, it is still capable of delivering good chronometric performance.

The escapement consists of two main components: the escape wheel and the cylinder. The cylinder is an integral part of the balance staff, forming its central section. It features a cut-out slot, the vertical edges of which, known as the lips, alternately receive impulses from the teeth of the escape wheel.

Advantages:

The cylinder escapement achieves an amplitude of around 150°, which is greater than that of the verge escapement, allowing for improved timekeeping performance.

Although still relatively inefficient, the cylinder escapement offers better efficiency than verge escapements.

Disadvantages:

The escape wheel teeth remain in constant contact with the cylinder, generating significant friction. This affects efficiency and demands exceptional cleanliness, precise lubrication, and consequently, frequent maintenance.

The cylinder escapement requires high manufacturing precision, careful material selection, and finely finished surfaces to function correctly.