Vacuum processing system and method
Patent 5086801 Issued on February 11, 1992. Estimated Expiration Date: 
November 19, 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.
November 19, 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 2445163 2744719 2950730 3929314 Butterfly valve Nozzle regulating device Fluid flow control valve Compact valve actuator Patent #: 4316597 InventorsApplicationNo. 674433 filed on 11/19/1990US Classes:137/12, By fluid pressure137/494, With separate connected fluid reactor surface137/907, VACUUM-ACTUATED VALVES251/58With mechanical movement between actuator and valveExaminersPrimary: Nilson, Robert G.Attorney, Agent or FirmInternational ClassG05D 016/06AbstractA vacuum processing system and method by which system turbulence is reduced utilizing a vacuum responsive flow controlling valve that is located between a vacuum pump and a vacuum processing chamber to restrict the rate of pumpdown. A valve member of the flow controlling valve, such as a butterfly valve closure plate, is positionally shifted by a pressure differential responsive actuator as a function of the extent to which the pressure in the vacuum processing chamber has been reduced by the pump. During the initial phase of pumpdown, the valve closure member is in its maximally closed position, with evacuation of the vacuum processing chamber occurring solely through a leakage path past the valve member. After a predetermined pressure is reached, the valve member slowly opens as the pressure differential in the actuator increases, until a maximally open position is achieved. | |
