Patent 7077244 was granted and assigned to Otis Elevator Company on July, 2006 by the United States Patent and Trademark Office.
An elevator system (20) includes wireless communicating portions (40, 42) that communicate with each other to provide elevator cab (22) position information within a hoistway (24). In one example, a first communicating portion (40) is supported on the elevator cab (22) that generates a radio frequency trigger signal (58) that is received by a second communicating portion (42) at a selected position along the hoistway (24). The second communicating portion (42) responsively generates an ultrasound signal (64) that is received by the first communicating portion (40). A characteristic of the received locating signal, such as the timing between the trigger signal and the receipt of the locating signal, provides position information regarding the cab within the hoistway.