Hydraulically-operated automatic air release valve for pulsating-pressure pumps

Claim 1

AN AUTOMATIC AIR RELEASE DEVICE FOR THE HYDRAULIC TRANSMISSION SYSTEM OF A PULSATING-PRESSURE PUMP COMPRISING A BODY HAVING A PISTON CHAMBER WITH AN INLET END AND AN OUTLET END, SAID BODY HAVING MEANS FOR CONNECTING SAID INLET END TO THE HYDRAULIC TRANSMISSION SYSTEM, AN ANNULAR CHAMBER COMMUNICATING WITH SAID PISTON CHAMBER INTERMEDIATE SAID ENDS THEREOF, SAID ANNULAR CHAMBER BEING SHORTER IN LENGTH THAN SAID PISTON CHAMBER, A RECIPROCABLE PISTON IN SAID PISTON CHAMBER, SAID PISTON HAVING A LENGTH GREATER THAN THAT OF SAID ANNULAR CHAMBER BUT LESS THAN THAT OF SAID PISTON CHAMBER, STOP MEANS FOR LIMITING MOVEMENT OF SAID PISTON IN SAID INLET END OF SAID PISTON CHAMBER AFTER SAID PISTON HAS MOVED TO POSITION BEYOND THE END OF SAID ANNULAR CHAMBER ADJACENT SAID INLET END, MEANS FOR YIELDABLY HOLDING SAID PISTON IN SAID LIMITING POSITION IN SAID INLET END, AND VALVE SEAT MEANS AT SAID OUTLET END OF SAID PISTON CHAMBER TO LIMIT THE MOVEMENT OF SAID PISTON IN SAID OUTLET END OF PISTON CHAMBER AFTER SAID PISTON HAS MOVED TO A POSITION BEYOND THE ADJACENT END OF SAID ANNULAR CHAMBER AND TO COOPERATE WITH SAID PISTON IN SEALING SAID OUTLET END OF SAID PISTON CHAMBER WITH RESPECT TO SAID ANNULAR CHAMBER.