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:
Dec. 13, 1994
Filed:
Jul. 20, 1992
Vincent P Jalbert, Middlebury, CT (US);
Otis Elevator Company, Farmington, CT (US);
Abstract
An ultrasonic wave is propagated through a brake pad to determine various brake conditions including brake pad wear, brake status (engaged/disengaged), a wet brake failure or a brake drag failure. The propagation and reflection time of an echo signal generated at a far boundary of the pad is indicative of brake wear. Brake drum or disc speed is determined by using radial indicia on the periphery of the drum or disc to modulate an ultrasonic wave reflected from or transmitted through the drum or disc and demodulating the sensed modulated signal as a speed indication. The various other conditions are determined by means of filters, comparators and logic.