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:
Feb. 18, 2003
Filed:
Apr. 24, 2000
Thomas W. Shoaff, Warrenville, IL (US);
Kalvin Watson, Chicago, IL (US);
Dragan Petrovic, Geneva, IL (US);
George A. Schoenfelder, Batavia, IL (US);
Frederick J. Conforti, Wheaton, IL (US);
James F. Wiemeyer, Homer Township, IL (US);
Pittway Corporation, Chicago, IL (US);
Abstract
A low profile, low volume smoke chamber displaces a light source, such as a light emitting diode or laser diode, and a sensor, such as photodiode or phototransistor, to the exterior of the sensing volume. A symmetrical sensing volume results which can be coupled to symmetrical input/output ports via a generally U-shaped flow path. A two part sensing chamber housing is formed with a lower cylindrical base portion and an upper cylindrical cover portion which slideably engage one another. At least the upper cylindrical portion carries a plurality of grooves for suppression of reflections and collection of dust. An exterior end of the upper portion carries a plurality of spaced apart openings which can be filled with a screen. A reduced sensing volume in combination with a selected screen size produces an acceptable signal to noise ratio and response rate while still excluding insects and other non-smoke related particulate matter.