Modulating positive shutoff mechanism
Patent 5040559 Issued on August 20, 1991. Estimated Expiration Date: 
March 23, 2010. 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 23, 2010. 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 3059667 3799498 3861643 Quiet safety relief valve Proportional solenoid valve Electro-pneumatic brake system Differential pressure control valve Valve plug design Pulse-width-modulated solenoid valve Patent #: 4765587 InventorApplicationNo. 498006 filed on 03/23/1990US Classes:137/1, PROCESSES251/129.03, With nonelectrical actuator251/129.08, Having means to produce proportional flow251/282ReciprocatingExaminersPrimary: Nilson, Robert G.Foreign Patent References
International ClassF16K 031/06AbstractA system is utilized for controlling the flow of process fluid between an input port and an output port of a valve. A first mechanism controls the modulation of the valve and a second mechanism controls the positive shutoff. An electrical system is responsible for modulation adjustments and a pneumatic system is responsible for positive shutoff control. A third, hydraulic, system is responsible for equalizing the pressure of the process fluid within the valve. | |
