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:
Mar. 01, 1988
Filed:
Dec. 28, 1984
Howard M Myers, Greensboro, NC (US);
Benjamin T Siler, Stokesdale, NC (US);
Gilbarco, Inc., Greensboro, NC (US);
Abstract
A shaft encoder for deriving a number of pulses indicative of the extent of rotary shaft motion including a disc having plural relatively narrow opaque regions spaced from each other by relatively wide transparent regions. Light from a pair of sources is directed through the regions toward a pair of light detectors. The detectors and regions are such that under normal operation light from the sources is incident on at least one of the detectors. The wide regions have an extent sufficiently great to prevent them from being clogged by dirt and other debris. In response to neither of the detectors having light incident on them, an indication of a failure of the shaft encoder is provided and operation of an accumulator responsive to the number of light transitions incident on the detectors is prevented. Thereby, a fail-safe apparatus is provided in the event of a failure of any of the light sources, the detectors and circuitry responsive thereto.