High pressure fluid seals

Claim 1

IN A PRESSURE ACTUATED FLUID SEAL ADAPTED TO PREVENT LEAKAGE OF FLUID BETWEEN A RELATIVELY ROTATABLE SHAFT AND HOUSING, SAID HOUSING COAXIALLY SURROUNDING SAID SHAFT IN SPACED RELATION THERETO, SEALING SURFACE MEANS TO PROVIDE A PAIR OF AXIALLY SPACED PLANAR POLISHED SURFACES SEALINGLY CONNECTED TO SAID SHAFT IN NONROTATABLE RELATION THERETO, THE IMPROVEMENT COMPRISING A PAIR OF TELESCOPING ANNULAR PISTONS DISPOSED BETWEEN SAID PLANAR POLISHED SURFACES, AT LEAST ONE OF SAID ANNULAR PISTONS BEING SEALINGLY AND NONROTATABLY ENGAGED TO SAID HOUSING, FLUID PASSAGE MEANS TO CONDUCT FLUID UNDER PRESSURE BETWEEN SAID ANNULAR PISTONS TO URGE THEM AXIALLY APART AND INTO ABUTTING CONTACT WITH SAID RESPECTIVE PLANAR POLISHED SURFACES, SAID PISTONS CONSTRUCTED AND ARRANGED SO THAT THE FORCE PER UNIT AREA OF CONTACT OF EACH OF SAID PISTONS WITH ITS RESPECTIVE SHAFT PLANAR POLISHED SURFACE IS LESS THAN THE PRESSURE OF SAID FLUID.