Reverse flow tubing valve

Claim 1

IN COMBINATION, A TUBING STRING EXTENDING LONGITUDINALLY DOWNWARDLY IN WELL CASING, FIRST MEANS PACKING OFF BETWEEN THE TUBING AND THE CASING IN THE WELL, AND VALVE MEANS CONNECTED INTO THE SPRING IN A WELL ABOVE THE LEVEL OF SAID FIRST MEANS FOR CONTROLLING REVERSE CIRCULATION OF FLUID FROM THE EXTERIOR TO THE INTERIOR OF SAID VALVE MEANS, SAID VALVE MEANS INCLUDING A LONGITUDINALLY EXTENDING TUBULAR BODY HAVING AT LEAST ONE FLOW PORT THROUGH THE BODY SIDE, A PRESSURE RESPONSIVE ANNULAR SLEEVE MOVABLE LONGITUDINALLY OF THE BODY BETWEEN UNSEATED AND SEATED POSITIONS TO CONTROL REVERSE CIRCULATION OF FLUID THROUGH THE PORT, AND YIELDABLE MEANS ACTING TO TRANSMIT FORCE URGING THE SLEEVE TO SAID SEATED POSITION, SAID SLEEVE HAVING A FIRST SHOULDER LOCATED TO REMAIN CONTINUOUSLY EXPOSED TO THE SLEEVE AND TUBING EXTERIOR SO AS TO REMAIN SENSITIVE TO APPLICATION OF EXTERIOR FLUID PRESSURE THEREON OPPOSING SAID YIELDABLE MEANS FORCE WHEREBY SUFFICIENT EXTERIOR PRESSURE MOVES THE SLEEVE TO UNSEATED POSITION TO ESTABLISH SAID REVERSE CIRCULATION, THE SLEEVE ALSO HAVING A SECOND SHOULDER LOCATED FOR EXPOSURE THROUGH SAID PORT TO THE PRESSURE OF FLUID WITHIN SAID TUBULAR BODY THEREBY AIDING THE FORCE TRANSMITTING ACTION OF SAID YIELDABLE MEANS, THE TUBULAR BODY AND SLEEVE HAVING ANNULAR SURFACES WHICH ARE ENGAGED IN SAID SLEEVE SEATED POSITION TO PREVENT CIRCULATION THROUGH SAID PORT, THE UNSEATED SLEEVE AND SAID BODY FORMING A SUFFICIENT REDUCED FLOW PASSAGE IN THE PATH OF SAID REVERSE CIRCULATION BETWEEN SAID DISENGAGED SURFACES AND SAID PORT AND IN ALL UNSEATED POSITIONS OF THE SLEEVE SO THAT THE PRESSURE OF REVERSELY CIRCULATING FLUID IN REDUCED UPON FLOWING THROUGH SAID PASSAGE WHEREBY ONLY THE REDUCED PRESSURE OF THE REVERSELY CIRCULATIONG FLUID CAN REACH SAID SECOND SHOULDER, THE BODY AND SLEEVE HAHVING SLIDABLE ANNULAR SEALING INTERENGAGEMENT IN SPACED RELATION TO SAID SURFACE AND PORT.