Hydraulic circuit breaker

Abstract

Abstract A CIRCUIT BREAKER DEVICE IS DISCLOSED WHICH IS INTERPOSED BETWEEN A SOURCE OF FLUID UNDER PRESSURE AND A UTILIZATION DEVICE SUCH AS AN ACTUATOR. A PISTON-TYPE SHUTOFF VALVE IS INCLUDED WHICH IS SPRING BIASED TOWARD ITS OPEN POSITION. A PAIR OF FIXED ORIFICES MEASURE THE FLOW TOWARD THE UTILIZATION DEVICE AND FROM THE UTILIZATION DEVICE TO THE RETURN SIDE OF THE FLUID PRESSURE SOURCE. THE PRESSURE DROP ACROSS THESE ORIFICES IS CONTROLLED BY MEANS OF A SLIDE VALVE BIASED IN ONE DIRECTION WITH A LIGHT SPRING. SHOULD A GREATER THAN NORMAL FLOW APPEAR DOWNSTREAM OF THE CIRCUIT BREAKER IN THE CONDUIT TO THE UTILIZATION DEVICE OR A SIGNIFICANTLY REDUCED FLOW IN THE RETURN LINE, THIS WILL BE REFLECTED IN A LOWERED PRESSURE ON ONE SIDE OF THE SHUTOFF VALVE, AND IT WILL BEGIN TO MOVE IN A CLOSING DIRECTION. DAMPING ORIFICES ARE CONNECTED TO LIMIT THE VELOCITY OF MOVEMENT OF THE SHUTOFF VALVE TO AVOID PREMATURE CLOSING DUE TO TRANSIENT CONDITIONS. WHEN THE UTILIZATION DEVICE DEMANDS A GREATER FLOW THAN REQUIRED FOR STEADY STATE OPERATION, A MOMENTARY INCREASED PRESSURE DROP APPEARS ACROSS THE SLIDE VALVE, OPENING SUBSTANTIAL ORIFICES IN PARALLEL WITH THE FIXED ORIFICES AND PERMITTING GREATER FLOW THROUGH THE CIRCUIT BREAKER SO THAT THE PRESSURE DROP REMAINS SUBSTANTIALLY CONSTANT WHILE THE REQUIRED INCREASED FLOW IS PROVIDED. THIS ALSO PERMITS FASTER MOVEMENT OF THE SHUTOFF VALVE IN CASE OF A LEAK TO AVOID EXCESSIVE LOSS OF FLUID.

Inventors

• 👤 Ralph L Vick

Bibliographic Details