Abstract: A pair of elevator cars (10, 11) traveling in the same hoistway have their positions sensed (20-23, 29-32) to provide for each a position signal (35, 37) from which velocity signals (64, 65) are derived; lookup tables (66, 61) of safe stopping distance (B, S) for braking and safeties are formed as a function of all possible combinations of velocity (V(U), V(L)) of said cars. Comparison of safe stopping distances for contemporaneous velocities of said cars with actual distance between said cars provides signals (85, 98, 99) to drop the brakes (49, 50) of one or more of the cars, and provides signals (82) to engage the safeties (18, 18a, 19, 19a) of all cars if the cars become closer or if acceleration detectors (117, 118) determine a car to be in freefall.

Abstract: A pair of elevator cars (10, 11) traveling in the same hoistway have their positions sensed (20-23, 29-32) to provide for each a position signal (35, 37) from which velocity signals (64, 65) are derived; lookup tables (66, 61) of safe stopping distance (B, S) for braking and safeties are formed as a function of all possible combinations of velocity (V(U), V(L)) of said cars. Comparison of safe stopping distances for contemporaneous velocities of said cars with actual distance between said cars provides signals (85, 98, 99) to drop the brakes (49, 50) of one or more of the cars, and provides signals (82) to engage the safeties (18, 18a, 19, 19a) of all cars if the cars become closer or if acceleration detectors (117, 118) determine a car to be in freefall.

Abstract: A brake mechanism (10) for an elevator (2) is activated in response to an electronic control signal to prevent movement of an elevator car (16) under predetermined conditions. The brake mechanism is preferably a safety mechanism (10) and does not require a governor sheave, a governor rope, or a tension sheave. The safety mechanism in one disclosed example utilizes a solenoid actuator (22b) and an electric motor (40) and gear box assembly (42) to move safety wedges (18) into engagement with a guide rail (20) to stop the elevator car (16). The safety wedges (18) are held in a non-deployed position during normal elevator operation. If there is a power loss or if elevator car speed exceeds a predetermined threshold, an electronic control signal activates the safety mechanism (10) causing the solenoid to release, which causes the safety wedges (18) move in a direction opposite to that of a safety housing (12) mounted for movement with the elevator car (16).