Component record · Escapement
Anchor (Verge-Successor) Escapement
VerifiedA pendulum-clock escapement in which an anchor-shaped pallet, rocked by the pendulum via the crutch, alternately locks and releases an escape wheel.
What it does
Converts the pendulum's regular swing into a controlled, stepwise release of the going train's stored energy, and in turn receives impulse from the escape wheel to sustain the pendulum's motion.
How it works
The anchor's two pallets are shaped to engage the escape wheel's teeth alternately as the pendulum swings, each engagement briefly locking the wheel before releasing it to turn slightly and deliver impulse to the pallet, and through the crutch, to the pendulum.
In the original recoil form of the anchor escapement, the escape wheel is briefly pushed backward as each pallet engages, a slight recoil that is visible in the seconds hand of many longcase clocks as a tiny backward tick.
The deadbeat escapement was developed specifically to remove this recoil, giving the escape wheel impulse without any backward motion, improving accuracy in precision clocks.
Evolution
The anchor escapement's introduction allowed much smaller pendulum swings than the verge escapement it replaced, a key advance enabling accurate longcase ('grandfather') clocks; the recoil form was later largely superseded in precision work by the deadbeat escapement, though recoil anchors remain common in ordinary domestic clocks.
Known variations
- Recoil anchor escapement (traditional, common in domestic clocks)
- Deadbeat (Graham) escapement, eliminating recoil
Identification for collectors
- A slight backward 'kick' visible in the seconds hand on each beat indicates a recoil anchor escapement; its absence suggests a deadbeat escapement
Common failure modes
- Worn pallet faces altering lock and drop, degrading rate
- Escape wheel tooth wear from the repeated recoil action
Related photographs
No confidently matched photograph of this subject has been found yet. These photographs show a closely related record, and are not examples of the type described on this page.
Sources & references
- Britten, F. J., Old Clocks and Watches and Their Makers
Where sources disagree, the disagreement is stated rather than resolved silently.