Interlock for hydraulic control valves and the like

Claim 1

IN A CONTROL VALVE OF THE TYPE HAVING A BODY MEMBER AND A VALVE MEMBER MOVABLE THEREIN TO EACH OF A PLURALITY OF POSITIONS TO CONTROL FLUID FLOW THROUGH PASSAGES IN THE VALVE BODY, MEANS FOR PREVENTING MOVEMENT OF THE VALVE MEMBER TO ONE OF SAID POSITIONS WHENEVER A PREDETERMINED CONDITION OBTAINS IN A FLUID PRESSURE OPERATED SYSTEM WITH WHICH THE CONTROL VALVE IS ASSOCIATED, COMPRISING: (A) COOPERATING STOP ELEMENTS CARRIED BY THE BODY AND VALVE MEMBERS, ONE OF WHICH IS MOVABLE TOWARD AND FROM AN OPERATIVE POSITION AT WHICH IT IS COOPERABLE WITH THE OTHER STOP ELEMENT TO PREVENT MOVEMENT OF THE VALVE MEMBER TO SAID ONE POSITION THEREOF; (B) A RETAINING ELEMENT COOPERABLE WITH SAID MOVABLE STOP ELEMENT; (C) MEANS MOUNTING THE RETAINING ELEMENT ON ONE OF SAID MEMBERS FOR MOVEMENT RELATIVE THERETO FROM AN ACTIVE POSITION AT WHICH IT HOLDS THE MOVABLE STOP ELEMENT IN ITS OPERATIVE POSITION, TO AN INACTIVE POSITION AT WHICH IT RELEASES THE MOVABLE STOP ELEMENT FOR MOVEMENT OUT OF ITS OPERATIVE POSITION; (D) YIELDABLE BIASING MEANS URGING THE RETAINING ELEMENT TOWARD ITS INACTIVE POSITION; (E) AND ACTUATING MEANS CARRIED BY ONE OF SAID MEMBERS FOR EFFECTING MOVEMENT OF THE RETAINING ELEMENT TO ITS ACTIVE POSITION IN RESPONSE TO A SIGNAL THAT REFLECTS A PREDETERMINED CONDITION IN A FLUID PRESSURE OPERATED SYSTEM WITH WHICH THE CONTROL VALVE IS ASSOCIATED.