Detached escapement
English (right-angle) lever escapement
Partially verifiedThe 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
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.
How to recognise it
- Pallet fork set at roughly a right angle to the line between escape wheel and pallet arbor.
- Pointed (ratchet-tooth) escape wheel rather than the Swiss club tooth.
- Usually combined with full-plate fusee construction and a table-roller balance.
Servicing and conservation
Ratchet-tooth escape wheels are unforgiving of worn pallet stones, and replacement wheels for a specific English calibre are rarely available, so original parts should be preserved. Full-plate construction means the escapement cannot be inspected without lifting the balance.
Work on an antique escapement by a qualified watchmaker or clockmaker. Conservation of original parts is preferred to replacement wherever the object will still run.
Bibliography
- Gazeley, W. J., Clock and Watch Escapements
- Britten, F. J., Old Clocks and Watches and Their Makers
Photographs
Photographs are matched automatically from freely licensed Wikimedia Commons material. Each caption states the actual subject of the image and credits its author; where a close match for this escapement does not exist, a related mechanism may be shown instead.