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The Encyclopedia of Horology

Detached escapement

English (right-angle) lever escapement

Partially verified

The pallet fork and balance-roller impulse jewel are arranged at a right angle to the line joining the escape wheel and pallets, generally combined with a ratchet-tooth escape wheel; the layout descends directly from English fusee-watch practice.

Schematic arrangement

How it is laid out

Escape wheelPallet forkBalance & impulse pin

Outline schematic only, drawn to show the characteristic arrangement of wheel, locking member and oscillator. It is not a dimensioned working drawing and should not be used for setting up or repairing a movement.

Advantages

  • Well suited to full-plate fusee construction
  • Robust in service
  • Tolerant of the thicker plates typical of English work

Drawbacks

  • Bulkier than the Swiss straight-line layout
  • Less suited to thin, going-barrel movements

Attribution and period

Developed through the early nineteenth century from Thomas Mudge's original lever

Horological firsts are frequently contested. Where an invention is attributed to a named maker, that attribution is recorded as such rather than treated as settled fact.

Diagram

escape wheelpallets and leveroscillator
Schematic: escapement arrangement. An outline schematic drawn to show the arrangement of the parts discussed here. It is not a dimensioned working drawing and does not depict a particular maker's calibre.