Otis Elevator Company

Otis Elevator

August J Dobler

Steven D Coste

Sib S Ray

Julian H Shull, Jr

D Richard Schafer

Retroreflective tape 28, 29 disposed on select positions on an elevator guide rail 13 is sensed by infrared transceivers 24, 25 disposed on an elevator car 10 to provide a signal indicative of the elevator as being at a vertical position in a hoistway designated by said retroreflective tape.

Retroreflective elevator hoistway position sensor

An apparatus and method are provided for detecting brake drag of an elevator machine brake (30). Temperature sensors (44) are disposed in close proximity to a pair of brake pads (35,36) and compared to ambient temperature to determine whether the brake pads are dragging on a rotating brake drum (37). A comparison circuit (47) is used to determine if the temperature of the brake pads has exceeded a predetermined threshold level (55) and to produce an output signal (52) corresponding to the position of the brake pads.

Apparatus and method of thermally detecting elevator machine brake

An emergency terminal speed limiting device (ETSLD) uses terminal zone position checkpoint detection with a binary coding method for the sensible stationary part mounted in the terminal zone. Instead of using three separate stationary vanes of different lengths as cams for actuating three separate switches on the car as they pass by the cams, only two vanes are needed. They can be of shorter length, e.g. equal length, and overlapped in a central part of the terminal zone to create three distinct subzones to thereby create a sensible binary coded subzone indicator. The boundaries of the subzones can be used as position checkpoints. Material and manpower for installation are thereby reduced. The stationary part need not be vanes but could take other forms such as reflective tape. Likewise, the moving sensor part can be other than a cam-operated switch, such as an optical transceiver.

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West Simsbury, CT, United States of America

August J Dobler