Positive pressure valves
Patent 4210174 Issued on July 1, 1980. Estimated Expiration Date: 
May 30, 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.
May 30, 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 2206425 2646071 3331389 3360007 InventorAssigneeApplicationNo. 05/910741 filed on 05/30/1978US Classes:137/528, Reciprocating valves137/559, Inspection means251/65PERMANENT OR CONSTANTLY ENERGIZED MAGNET ACTUATORExaminersPrimary: Nilson, Robert G.Attorney, Agent or FirmInternational ClassesF16K 17/02 (20060101)A61M 16/20 (20060101) AbstractA positive pressure valve is provided having a valve member with a central magnetically attracted member spaced from and coaxial with a rod like magnet, said valve member and magnet being relatively movable to adjust the magnetic attraction between them and thus the opening pressure of the valve.Field of SearchReciprocating valves | |
