Fire-suppressing foam level controller
Patent 4169278 Issued on September 25, 1979. Estimated Expiration Date: 
March 6, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 6, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 1463986 2249994 3131335 InventorsAssigneeApplicationNo. 05/883368 filed on 03/06/1978US Classes:361/178, Fluid (e.g., liquid level, humidity)137/392, Electrical characteristic sensing169/61Electrical controlExaminersPrimary: Miller, J. D.Assistant: Schroeder, L. C. Attorney, Agent or FirmInternational ClassesH01H 47/00 (20060101)H01H 47/12 (20060101) AbstractAn electric circuit for energizing a fire-suppressing foam generator includes a switch that is opened and closed by means operated by electric control circuits, one of which contains a pair of laterally spaced lower electric probe contacts mounted in the protected area and adapted to be bridged by a rising level of foam to close that circuit. The other control circuit contains a pair of laterally spaced upper electric probe contacts above the level of the lower contacts and adapted to be bridged by a rising level of foam to close the last-mentioned control circuit. | |
