Flow regulating apparatus

Claim 1

IN A FLUID FLOW REGULATING DEVICE INCLUDING A GENERALLY CYLINDRICAL FLUID PASSAGE AND A GENERALLY CYLINDRICAL FREE PISTON VALVING MEMBER AXIALLY RECIPROCAL THEREIN RESPONSIVE TO PRESSURE DIFFERENCES AT THE TWO ENDS OF SAID PISTON FOR REGULATING RATE OF FLUID FLOW THROUGH SAID DEVICE, RECIPROCAL SLIDING SURFACES OF SAID PISTON AND CYLINDER BEING LUBRICATED BY A FILM OF THE FLUID FLOWING THROUGH SAID PASSAGE AND WHEREIN SENSITIVELY OF SAID DEVICE DEPENDS UPON FREE FLOATING ACTION OF SAID PISTON, SAID PISTON BEING GENERALLY COAXIALLY RECIPROCAL WITHIN SAID CYLINDER WITH SAID PISTON SUFFICIENTLY LOOSE FITTED WITHIN SAID CYLINDER TO CANT SLIGHTLY THEREIN, THE IMPROVEMENT IN SAID PISTON WHICH COMPRISES A SHORT TAPER AT EACH PISTON EDGE NORMALLY TENDING TO SCRAPE THE FILM OF FLUID FROM THE CYLINDER WALL DURING CANTED RECIPROCATION THEREOF, EACH OF SAID TAPERS DEFINING A CIRCUMFERENTIAL ANGULAR SURFACE ON SAID PISTON BETWEEN EACH SUCH EDGE AND THE CYLINDER WALL SUFFICIENT TO DRAW AND RETAIN FLUID BETWEEN THE RECIPROCALLY SLIDING SURFACES AND PREVENT STICKING OF THE PISTON IN THE CYLINDER IN SUFFICIENT IN LENGTH TO APPRECIABLY CHANGE OTHER CHARACTERISTIC OF SAID PISTON AND CYLINDER, SAID PISTON RETAINING GENERALLY COAXIAL RECIPROCATION WITHIN SAID CYLINDER, THE ANGLE OF EACH OF SAID TAPERS WITH REFERENCE TO THE CYLINDRICAL PLANE INCLUDING THE CIRCUMFERENTIAL PISTON, BEING AN ANGLE GREATER THAN THE ANGLE HAVING THE TANGENT: