Pittway Corporation

George A Schoenfelder

James Fredrick Wiemeyer

Frederick J Conforti

Dragan Petrovic

Kalvin Watson

Fred J Conforti

Gerald D Rork

Stephen L Siegel

Richard E Hiltenbrand

Thomas William Shoaff

James S Slater

William M Koster

Stanley S Dederich

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.

Miniature photoelectric sensing chamber

A dual mode fire suppression system includes first and second, different, fire suppression nozzles. Each nozzle is coupled to a fire suppressing medium. A fire detector is coupled to at least one of the nozzles. The detector monitors an adjacent region, and, is insensitive to the medium associate with the coupled nozzle. In the presence of a detected first fire condition, the detector activates the coupled nozzle which releases the respective medium. The detector continues to monitor the adjacent region and in the absence of the first fire condition, the first nozzle is deactivated. In the presence of a detected second fire condition, different from the first condition, the second nozzle is activated.

Dual sprinkler system

An outer electrode for a combustion products detector comprising a cylindrical body including a plurality of first slats alternating with a plurality of second slats, the first slats being segments of a first surface of revolution, the second slats being skewed from a second surface of revolution having a different diameter from the first surface of revolution.

Outer electrode with improved smoke entry

A battery-powered photoelectric smoke detector periodically samples the air in a smoke chamber. A manually-operated test button is provided for simulating smoke to test the device. The sampling frequency is determined by a first resistance. A frequency changing circuit includes a test switch, the movable contact of which is coupled to the test button and is responsive to operation thereof for connecting it parallel with the first resistance the series combination of a diode and a second resistance for increasing the sampling frequency. Means are provided for back-biasing the diode to disable the frequency changing circuit when the detector detects smoke.

Combustion products detector with accelerated test

A photoelectric smoke detector includes a light source and a light responsive cell and a smoke chamber therebetween all located within a generally cylindrical inner housing which is in turn concentrically located within a generally cylindrical outer housing. The inside surface of the outer housing is reflective, but the inner housing normally prevents light emitted by the light source into the smoke chamber from striking the outer housing. The inner housing contains one or more windows and is rotatable to move the windows to a position wherein light from the source can pass therethrough to the reflective surface of the outer housing and be reflected thereby back to the light responsive cell. The amount of light striking the reflective surface can be continuously adjusted between a normal condition when no light is reflected and a full test condition when a maximum quantity of light is reflected to the light responsive cell. Instead of having windows therein, the inner housing may alternatively have reflective portions thereon. The inner housing is resiliently biased to its normal condition and an actuating tool is provided for effecting rotation thereof.

Growing community of inventors

Downers Grove, IL, United States of America

George A Schoenfelder