Seal for rotating shaft with pressure responsive means

Claim 1

A SHAFT SEAL FOR A SHAFT ROTATABLY SUPPORTED AND EXTENDING THROUGH A WALL OF A HOUSING CONTAINING A FLUID, COMPRISING A RING MEANS DISPOSED ADJACENT THE EXTERIOR SURFACE OF THE WALL OF SAID HOUSING AND CONNECTED TO SAID SHAFT FOR ROTATION BY THE LATTER, MEANS SUPERIMPOSED OVER SAID RING MEANS AND SECURED TO SAID HOUSING TO DEFINE WITH SAID RING MEANS A SEALING FLUID CHAMBER, SAID FLUID CHAMBER BEING CONNECTED TO A SOURCE OF FLUID UNDER PRESSURE TO RECEIVE THE SAME, SAID RING MEANS HAVING A SEAL FACE PORTION, A CONTACT RING DISPOSED ADJACENT SAID RING MEANS AND SUPPORTED FOR SLIDABLE MOVEMENT RELATIVE TO SAID RING MEANS AND FIXED AGAINST ROTATION, SAID CONTACT RING BEING PROVIDED WITH ONE FACE HAVING A PLURALITY OF DEPRESSIONS AND SEALING SURFACES, BIASING MEANS ACTING AGAINST SAID CONTACT RING TO URGE THE SEALING SURFACES OF THE LATTER IN FLUID TIGHT ABUTMENT AGAINST THE SEAL FACE PORTION OF SAID RING MEANS TO PROVIDE A FLUID TIGHT SEAL WHEN THE SHAFT IS STATIONARY, PASSAGE MEANS FOR PASSING SEALING FLUID FROM SAID FLUID CHAMBER TO SAID DEPRESSIONS, SAID DEPRESSIONS BEING SO FORMED THAT UPON ROTATION OF SAID RING MEANS A HYDRODYNAMIC PRESSURE IS GENERATED IN THE FLUID IN THE DEPRESSIONS HAVING A FORCE COMPONENT DIRECTED AGAINST SAID CONTACT RING TO CAUSE THE LATTER TO OVERCOME SAID BIASING MEANS AND MOVE AWAY FROM SAID RING MEANS, A NON-ROTATABLE RING MEANS DISPOSED IN CLOSE SPACED RELATIONSHIP WITH A PORTION OF SAID RING MEANS ADJACENT THE SEAL FACE PORTION TO DEFINE THEREBETWEEN AN ANNULAR PASSAGEWAY EXTENDING RADIALLY OUTWARDLY FROM SAID SHAFT AND COMMUNICATING WITH THE SEALING FLUID CHAMBER WHEN SAID CONTACT RING MOVES AWAY FROM THE RING MEANS SO THAT A PRESSURE SUBSTANTIALLY EQUAL TO THE PRESSURE OF THE FLUID IN THE SEALING FLUID CHAMBER IS GENERATED IN THE FLUID IN SAID ANNULAR PASSAGEWAY DIRECTED TOWARD SAID SEALING FLUID CHAMBER TO THEREBY PREVENT FLOW OF FLUID FROM SAID SEALING FLUID CHAMBER.