Escapement

What is an Escapement?

The escapement is the device that converts the continuous rotational energy stored in the mainspring into the precise, rhythmic ticking of a mechanical watch. Without it, the mainspring would simply uncoil all at once and the hands would spin freely.

The most common type found in vintage and modern mechanical watches is the lever escapement, invented in its modern form in the 18th century. It consists of three primary components:

• The escape wheel — a toothed wheel that advances one step with each tick
• The pallet fork — a lever with two angled jewels (pallets) that alternately catch and release the teeth of the escape wheel
• The balance wheel — the oscillating regulator that rocks back and forth, unlocking the pallet fork with each swing

How It Works

Each time the balance wheel swings to one side, it nudges the pallet fork, which releases one tooth of the escape wheel. The escape wheel advances slightly, gives a small impulse back to the balance wheel to keep it oscillating, and is then locked again by the other pallet. This cycle repeats thousands of times per hour — typically 18,000 to 36,000 times — producing the characteristic tick.

Escapement Servicing

The escapement is the most delicate part of the movement and is especially sensitive to dirt, dried oil, and wear. During a service, the escape wheel and pallet fork are cleaned ultrasonically, inspected under magnification for worn or chipped jewels, and lightly lubricated with a specific escapement oil. Improper oiling — too much or too little — can cause the watch to gain or lose time dramatically.