The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 04, 1992
Filed:
May. 01, 1991
Richard E Watt, Spring Valley, CA (US);
Willilam R Hoelscher, El Cajon, CA (US);
John H Parker, San Diego, CA (US);
United States Elevator Corp., San Diego, CA (US);
Abstract
A position sensing system includes a coded tape vertically mounted in an elevator shaft and a sensor unit mounted on an elevator car to detect code indicia on the tape. The sensor unit is connected to output circuitry for converting the sensor outputs to elevator position data for transmission to an elevator controller. The tape has two parallel tracks of indicia extending along its length. The first track comprises a pseudo-random code sequence which is non-repeating along any N successive bits for the length of the tape, and the sensor unit includes a first set of sensors for detecting the indicia in the first track and producing an N-bit output representative of a coarse elevator position. The second track has spaced indicia forming a fine scale between successive coarse code positions on the first track, and a second set of sensors detects the fine code indicia and produces fine code position information at successive points between each pair of coarse code positions as the sensors traverse the tape.