Automatic Elevator Control System.

This invention relates to an autoatic elevator control system including high and low speed, up and down, braking, emergency stop, door interlock, slack cable, overtravel, motor overload, select floor and runstop operations. The system employs an electrically passive elevator wherein position sensing is achieved at each deck by a pair of proximity switches. The control system logic uses these proximity switches to denote low speedelevator high, stopelevator at deck and low speedelevator low condition. The system automatically takes into account elevator overshoot and well as interim high speed operations. The system design criteria and logic are established to allow for use of self testing proximity switches and miniature high speed relays that may be visually monitored and easily tested. These relays are used for low current logic functions and not for power transfer functions. Author