Component record · Keyless work

Keyless Works

Verified

The system of levers, wheels and a sliding clutch (usually operated by pulling out the crown) that allows a watch to be wound and its hands set entirely via the crown, without a separate winding key.

What it does

Switches the stem's function between winding the mainspring and setting the hands, and transmits the crown's rotation to whichever function is selected.

How it works

In the wound (pushed-in) position, the stem's winding pinion engages a clutch wheel that drives the crown wheel and ratchet wheel, winding the mainspring when the crown is turned.

Pulling the crown out moves a setting lever, which pivots a yoke that slides the clutch out of the winding train and into engagement with the setting wheels, so turning the crown now rotates the cannon pinion and hands via the motion works instead.

Numerous keyless-works patterns exist (Swiss lever-set, pin-set, negative and positive setting systems), but nearly all rely on the same essential principle of a sliding clutch redirecting the stem's rotation between two possible destinations.

Evolution

Keyless winding and setting progressively displaced separate winding keys through the second half of the 19th century, driven by convenience and reduced risk of losing the key; standardised keyless patterns (e.g. the widely used sliding-pinion/set-lever system) became near-universal by the 20th century.

Known variations

Sliding pinion (set-lever) system, most common
Rocking bar keyless works
Pin-set systems (crown always winds; a separate recessed pin sets the hands), common in American railroad-grade pocket watches

Identification for collectors

Pulling the crown to a defined 'click' position that changes its function from winding to setting is the hallmark of keyless works
Pin-set watches instead require a small pin be pressed to enable hand-setting