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:
Jan. 29, 1991
Filed:
Nov. 22, 1988
Robert A Dunbar, Swampscott, MA (US);
John M McClelland, South Weymouth, MA (US);
Walter Kidde Aerospace, Inc., Wilson, NC (US);
Abstract
A flame detector that comprises a housing adapted to contain a flame sensor and circuitry for processing signals produced by the sensor; the housing has a predetermined outer diameter, and a thin, highly thermally reflective coating is adhered to an outer surface of the housing to shield the sensor and circuitry from high ambient temperatures, whereby the detector is operable at the high ambient temperatures while having an outer diameter that is substantially the same as the predetermined diameter. A flame that has a predetermined flicker rate range is detected by detecting radiation within a compartment with a sensor, determining whether the detected radiation has an intensity which exceeds a predetermined threshold intensity, determining whether the detected radiation that exceeds the threshold has a flicker rate that is within the predetermined range, and determining whether a predetermined number of flickers that occur at a rate within the range have been detected within a variable time interval, and, if so, indicating that a flame is present within said compartment, the variable time interval starting upon detection of an initial flicker and ending after a predetermined delay unless a subsequent flicker is detected during said delay, a subsequent flicker detected during said delay extending the variable time interval for a predetermined time period such as that of the predetermined delay.