Hydro-mechanical detent mechanism

Abstract

Abstract A DETENT MECHANISM IS PROVIDED FOR HOLDING A SELECTIVE CONTROL VALVE IN A PAIR OF ACTIVE POSITIONS RESPECTIVELY WHEREIN ONE OR THE OTHER OF THE WORK PORTS OF A DOUBLEACTING HYDRAULIC CYLINDER IS CONNECTED TO A SOURCE OF FLUID PRESSURE WHILE THE REMAINING WORK PORT IS CONNECTED TO A SUMP. THE DETENT MECHANISM INCLUDES A CAM WHICH IS FIXED TO AND SWINGS WITH A LEVER FOR SHIFTING THE CONTROL VALVE. WHEN THE LEVER IS SWUNG TO SHIFT THE CONTROL VALVE TO ONE OR THE OTHER OF THE ACTIVE POSITIONS, ONE OR THE OTHER OF A PAIR OF RECESSES IN THE CAM IS RESPECTIVELY PLACED IN REGISTER WITH A ROLLER OF A CAM-FOLLOWING DETENT ELEMENT. A PISTON ROD IS BEARINGLY ENGAGED WITH THE DETENT ELEMENT AND A FORCE FOR HOLDING THE ROLLER IN THE RECESSES IS DERIVED FROM THE CO-ACTION OF A BIASING SPRING POSITIONED AGAINST A PISTON CARRIED BY THE ROD AND A PRESSURE DROP COUPLED ACROSS THE PISTON, WHICH PRESSURE DROP IS INDUCED BY A METERING VALVE FOR METERING FLOW TO THE CYLINDER. THE PISTON ROD INCLUDES SECTIONS OF DIFFERENT DIAMETERS EXPOSED TO FLUID PRESSURE AT THE OPPOSITE SIDES OF THE PISTON AND WHEN THE PRESSURE DROP ACROSS THE PISTON FALLS TO ZERO AS THE CYLINDER REACHES AN END OF A STROKE, THE PRESSURE THEN NORMALLY EXISTING AT THE OPPOSITE SIDES OF THE PISTON ACTS UPON THE DIFFERENT AXIALLY-PROJECTED AREAS OF THE ROD AND PISTON TO EXERT A FORCE SUBSTANTIALLY EQUAL AND OPPOSITE TO THAT OF THE BIASING SPRING. THUS, THE DETENT FORCE TENDING TO KEEP THE ROLLER IN ONE OR THE OTHER OF THE RECESSES IS REDUCED TO THE POINT WHERE THE FORCE TO A RETURN-TO-NEUTRAL SPRING ACTING ON THE CONTROL VALVE OVERCOMES THE DETENT FORCE AND MOVES THE CAM TO DISENGAGE THE ROLLER FROM THE RECESS.

Inventors

• 👤 C Kittle

Bibliographic Details