Slow opening valve
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorDonald F. Drapeau
Life of this patent
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Abstract
A valve control having a valve body (5) with an actuator stem (16) and a rotating handle (35) connected to the actuator stem by differential drive mechanism (25, 26) which, during uniform movement of the handle in one direction, initially opens the valve (20) at a relatively slow rate and, thereafter, completes the valve movement at a substantially faster rate. A series of stop rings (44-48) are received about the body in frictional abutting relationship and serially rotated by the handle to uniformly resist handle movement independently of the extent of handle movement.
Claims5
A valve comprising a hollow, cylindrical body, a valve seat and a valve member at one end of said body, a valve actuator for said valve member extending through said body, a handle rotatable on said body, differential drive means between said handle and said valve actuator adapted to cause, during opening movement of said valve, relatively slow initial opening of said valve and, thereafter, substantially faster movement thereof, a plurality of stop rings received about said body in side-by-side relationship, means to urge said rings together for producing frictional resistance between abutting edges thereof, lugs on said handles and said rings for serial engagement of said rings by said handle to uniformly resist handle rotation independently of the extent of hand rotation, and a fixed stop on said body to limit rotation of said rings and handle to prevent overstressing of said differential drive means.
Dependencies are inferred from the claim text.