Abstract: An apparatus for controlling an emergency stop of an elevator car 11 is connected in an elevator system 10 including a drive motor 15 coupled to the car, a drive control 18 connected between the drive motor and an AC electrical power source 17 for operating the drive motor and an elevator control 19 connected to the drive control for controlling starting, running and stopping of the elevator car. A controlled emergency stop circuit 21 has a battery supply 28 connected to receive and store electrical power from the power source 17 and is connected to provide electrical power to the elevator control 19. A normally open switch 33,34,36,37 is connected between the battery supply 28 and the drive control 18. A controller is connected to the switch and receives a power failure signal representing a loss of electrical power at the drive control 18.

Abstract: A feedback controlled elevator system driven by a traction drive motor in response to a speed pattern provided by a car controller. The speed pattern is limited when the car approaches a terminal floor within a predetermined terminal slowdown zone adjacent to the terminal floor. A pattern limiting signal is provided in response to digital integration of shaft encoder signals which provides a digital position "x" of the car within a terminal zone. The position "x" of the car is then used to access a read-only-memory which contains the maximum car speed for the specific location of the elevator car. The value from the read-only memory is used to limit the speed pattern.

Abstract: Methods and apparatus for providing a desired terminal slowdown speed pattern as an elevator car approaches a terminal floor in the terminal slowdown zone. Markers are fixedly spaced in the zone, with their spacing being a direct function of their distance from the terminal floor. The markers are detected as the elevator car proceeds past them towards the terminal floor, and a train of signals T are produced having values responsive to the marker-to-marker time, i.e., the elapsed time between successive detections of markers. The velocity V of the elevator car is also detected, and the terminal slowdown speed pattern is provided as a function of the product of V and T, as scaled by a constant which includes the square root of the desired deceleration rate.