Wide temperature range sealing structure

Claim 1

THE IMPROVEMENT COMBINATION, WHICH COMPRISES ENDWISE EXTENDING INNER AND OUTER MEMBERS, ASSEMBLED TO RORM AN ANNULAR SPACE, AND A RELATIVELY RIGID INTERNALLY TENACIOUS SEALING ANNULUS OF FLUOROCARBON TYPE MATERIAL ASSEMBLED IN SAID SPACE FOR SEALING OFF BETWEEN SAID MEMBERS OVER A TEMPERATURE RANGE CHARACTERIZED IN THAT THE ANNULUS TENDS TO SHRINK RADIALLY UPON COOLING FROM TEMPERATURES WITHIN THE HIGHER REGIONS OF SAID RANGE, THE OUTER AND INNER MEMBERS RESPECTIVELY HAVING INWARDLY AND OUTWARDLY FACING SHOULDERS IN PRESSURE SEALING CONTACT WITH SAID ANNULUS WHEN THE MEMBERS ARE FIRST ASSEMBLED, SAID OUTER MEMBER HAVING AN AUXILIARY SHOULDER FACING ENDWISE TOWARD SAID SEALING ANNULUS FOR ESTABLISHMENT OF PRESSURE SEALING ANNULAR ENGAGEMENT THEREWITH, A PORTION OF SAID OUTWARDLY FACING SHOULDER INWARDLY OF THE ANNULUS TAPERING ENDWISE IN A DIRECTION TENDING TO THRUST THE SEALING ANNULUS TOWARD THE AUXILIARY SHOULDER WHEN THE ANNULUS UPON COOLING SHRINKS INWARDLY ABOUT SAID TAPERED PORTION, THAT PORTION OF SAID INWARDLY FACING SHOULDER WHICH LIES OUTWARDLY OF SAID TAPERED PORTION OF THE OUTWARDLY FACING SHOULDER BEING ITSELF TAPERED TO EXTEND IN SUBSTANTIALLY PAALLEL RELATION THEREWITH, THEREBY TO PREVENT FORCIBLE REDUCTION OF THE RADICAL THICKNESS OF THE ANULUS BY SAID INWARDLY AND OUTWARDLY FACING SHOULDERS AS THE ANNULUS MOVES TOWARD SAID AUXILIARY SHOULDER FOR ENGAGEMENT THEREWITH.