To control the energy release

Mostly the energy stored in mechanical, in hydraulical, in chemical, in electrical systems when released its discharge is sudden. It is the case of the potential energy of a mass located at a fixed height. Different devices in different times have been adopted to solve this problem.

Hysplengio of Hero of Alexandria  (1st centuty AD)

Verge and foliot of De Vick clock, built 1379, Paris

Clock escapement (XVI century)