Moisture and pressure sensitive fluid control circuit
Patent 4938248 Issued on July 3, 1990. Estimated Expiration Date: 
May 3, 2008. 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.
May 3, 2008. 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 ReferencesInventorAssigneeApplicationNo. 189575 filed on 05/03/1988US Classes:137/78.3, Soil moisture sensing239/63, WITH CUTOFF OR FLOW VARYING MEANS OPERATED BY MEANS RESPONSIVE TO DISCHARGED FLUID (E.G., GROUND MOISTURE SENSING)251/29With additional pilot valve controlExaminersPrimary: Chambers, A. MichaelAttorney, Agent or FirmInternational ClassA01G 025/00AbstractA control circuit includes one or more pressure activated fluid flow valves and one or more moisture and pressure sensitive controllers. Each controller includes a body with three chambers separated by movable diaphragm assemblies, one of which moves in response to changes in pressure exerted by the amount of moisture or fluid in the environment. Responsively, a passageway through the other diaphragm allows the passage of fluid and thus venting of the flow valves when a low moisture or fluid condition is detected.Field of SearchSoil moisture sensingChoked or throttled pressure type With additional pilot valve control Diaphragm or bellows surface PLANT IRRIGATORS AND/OR FERTILIZERS, APPARATUS OR METHOD WITH CUTOFF OR FLOW VARYING MEANS OPERATED BY MEANS RESPONSIVE TO DISCHARGED FLUID (E.G., GROUND MOISTURE SENSING) | |
