Proportional throttle valve
Patent 4809746 Issued on March 7, 1989. Estimated Expiration Date: 
August 7, 2006. 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.
August 7, 2006. 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. 06/894282 filed on 08/07/1986US Classes:137/501, Pressures across fixed choke137/486, Responsive to change in rate of fluid flow251/282, Reciprocating251/30.01, Electrically actuated pilot valve251/44Differential reaction surface for line pressureExaminersPrimary: Hepperle, Stephen M.Attorney, Agent or FirmInternational ClassesF16K 39/04 (20060101)F16K 39/00 (20060101) F16K 11/07 (20060101) F16K 11/065 (20060101) Foreign Application Priority Data1985-08-10 DEAbstractA proportional throttle valve which varies the throttle cross-sectional area in dependence upon a control signal and thus governs the flow rate. The invention relates to a throttle valve in which the position of the valve member remains constant independent of pressure fluctuations upstream and downstream of the throttle cross-section. For this purpose the pressure acts on equisized opposing faces of the valve member. An annular face of equal magnitude lying opposite the control face is subjected to the pressure in a line leading from the pressure-limiting valve for setting the control pressure to the tank so that pressure fluctuations in this tank line cause corresponding variations of the control pressure and the position of the valve member remains constant. | |
