Well fluid flow regulator

Claim 1

A VALVE FOR CONTROLLING FLOW OF FLUID INTO OR OUT OF A CONDUIT IN A WELL AND ADAPTED TO HAVE ITS OPERATING CHARACTERISTICS CHANGED WHILE IT IS DISPOSED IN THE WELL BY A MANIPULATION CONTROLLED FROM THE EARTH''S SURFACE WHICH COMPRISES, IN COMBINATION, A HOUSING, A PASSAGE IN SAID HOUSING FOR FLOW OF FLUID BETWEEN THE INTERIOR AND EXTERIOR OF SAID CONDUIT, A CHANGE CHAMBER IN SAID HOUSING HAVING A MOVABLE WALL, A VALVE MEMBER CONNECTED TO SAID MOVABLE WALL AND CONTROLLING FLOW THROUGH SAID PASSAGE AND URGED TO ONE OF ITS PASSAGE-OPENING AND PASSAGE-CLOSING POSITIONS BY FLUID PRESSURE IN SAID CHARGE CHAMBER, A PASSAGEWAY COMMUNICATING BETWEEN THE INTERIOR OF SAID CHARGE CHAMBER AND THE EXTERIOR OF SAID HOUSING FOR PERMITTING THE PRESSURE OF WELL FLUID EXTERIOR OF THE HOUSING TO BE APPLIED TO THAT IN SAID CHAMBER, VALVE MEANS CONTROLLING FLOW THROUGH SAID PASSAGEWAY VALVE MEANS, AND MEANS MOVABLE THROUGH SAID CONDUIT TO MOVE SAID PART AND BEING CONTROLLABLE FROM THE EARTH''S SURFACE.