Lever escapement
Invented in 1755, the detached lever escapement stood the test of time. Its history is a good illustration of the way in which requirements of precision fluctuated over the years. Whilst the few timepieces made with detached lever escapement in the 18th century were regarded as chronometers, during the 19th century lever escapements became a feature of the high-quality pocked watch. Quality was still high, but not to standart of a precision instrument. For popular succes, the lever escapement needed a number of improvements. A lighter construction and the addition of draw to the lever palettes, for example, significantly improved reliability. Different countries developed preferences for different types of lever escapements. English watchmakers preferred escape wheels with ratched teeth, while the French and the Swiss opted for club teeth. In the early years at Glashütte, Ferdinad Adolph Lange used the pin-pallet escapement developed Louis Perron. It was cheap and easy to produce. Around 1855 he went over to a lever escapement with club-toothed escape wheel with sexteen teeth that was to become typical of Glashütte watches. Finally, around 1875, the firm of A. Lange & Söhne began to manufacture lever escapement chronometers - certified watches with large balances and improved regulation - thus returning to the origins of the lever escapement in precision watchmaking [1].
Notes
- The Watch Escapement, Author Henry B. Fried, ISBN 9780317170863, ISBN 0317170864