Parachute safety device preventing overspeed of theater lighting during descent comprises cables driving drum which drives generator delivering voltage compared by detector to reference voltage

摘要

The parachute device comprises cables (18) fixed to the moving object which drive a drum (15). A generator (21) driven by the drum delivers a voltage proportional to the speed and a detector (25) compares the value of the voltage to a reference value and breaks a contact in the event of overspeed. A spring (16) holds the cables in permanent tension. The drum has a brake (22) which locks rotation in the event of overspeed.