Escapement escapement was used for a washstand design in ancient Greece and the Hellenistic world, particularly Ptolemaic Egypt, while liquid-driven escapements were applied to clockworks beginning in Tang dynasty China and culminating during the Song dynasty. However, the fully mechanical escapement in mechanical clocks was first invented in medieval Europe during the 14th century. The importance of the escapement in the history of technology is that it was the key invention that made the all-mechanical clock possible. The invention of the first all-mechanical escapement, the verge escapement, in 13th-century Europe initiated a change in timekeeping methods from continuous processes, such as
Escapement of this escapement over the lever are of an uncertain value. In an effort to attract publicity, in recent decades some high end mechanical watch makers have introduced new escapements. None of these have been adopted by any watchmakers beyond their original creator. Based on patents initially submitted by Rolex on behalf of inventor Nicolas Déhon, the constant escapement was developed by Girard-Perregaux as working prototypes in 2008 (Nicolas Déhon was then head of Girard-Perregaux R&D department) and in watches by 2013. The key component of this escapement is a silicon buckled-blade which stores elastic energy. This blade is flexed