Thin land seal unit with seal type pressure regulator

Claim 1

A PRESSURIZED GAS CHAMBER, A FLUID-PERMEATED CHAMBER PRESSURIZED TO A GREATER EXTENT THAN SAID GAS CHAMBER, RELATIVELY ROTATABLE AND CONCENTRIC FIRST AND SECOND MEMBERS OF CIRCULAR CROSS SECTION DEFINING AN ANNULAR PASSAGE BETWEEN SAID CHAMBERS, AXIALLY SPACED RING FLANGES CARRIED BY SAID FIRST MEMBER AND EXTENDING RADIALLY THEREFROM AND TERMINATING WITH SLIGHT RADIAL CLEARANCES FROM SAID SECOND MEMBER SO THAT SAID MEMBERS AND SAID FLANGES ROUGHLY DEFINE AN ANNULAR CAVITY, A SEAL UNIT INCLUDING TWO AXIALLY SPACED SPLIT CARBON-TYPE RING SEALS LOCATED IN SAID CAVITY, MEANS TO URGE SAID SEAL RADIALLY AGAINST SAID SECOND MEMBER AND AXIALLY AGAINST THE AXIALLY ADJACENT SURFACES OF SAID RING FLANGES TO SEAL ACROSS SAID CLEARANCES, EACH OF SAID SEALS SHAPED TO PRESENT TWO AXIALLY SPACED, NARROW, SUBSTANTIALLY PARALLEL, CIRCUMFERENTIAL, CONTINUOUS LANDS AS THE SOLE SEALING SURFACES BETWEEN SAID SEALS AND SAID SECOND MEMBER, AND MEANS TO PROVIDE A CONTINUOUS BACK PRESSURE TO THE GAS CHAMBER SIDE OF SAID SEAL UNIT.