Breguet overcoil (Breguet spring)

Rolex parachrom hairspring / Timed breguet hairspring

Balance spring with terminal curve whose final curve is formed around the actual balance spring according to precise calculations. With this invention, Abraham-Louis Breguet was able ti considerably reduce the effects of the dynamic balance error of a flat Archimedean balance spring.

40.142 (0735) de Breguetspiralfeder reguliert nl en Timed breguet hairspring pt Espiral breguet regulado es Espiral breguet regulado ru Спираль брегетированная, правленная fr Spiral breguet réglé it Spirale breguet regolata

Literature

• The Marine Chronometer. Its History and Development, ISBN 0-907462-05-7
• Time and Timekeepers, ISBN 0780800087