Temperature responsive seal

Claim 1

A SEAL FOR A ROTARY SHAFT PASSING THROUGH A HOUSING WALL, SAID SEAL COMPRISING: A FIRST MEMBER, MOUNTED IN FIXED POSITION WITHIN THE HOUSING WALL, HAVING AN AXIAL BORE RECEIVING SAID SHAFT IN FREELY ROTATABLE RELATION AND HAVING A SINGLE-TURN HELICAL END SURFACE TERMINATING IN A SHOULDER; A SECOND SEAL MEMBER, HAVING AN AXIAL BORE RECEIVING SAID SHAFT IN FREELY ROTATABLE RELATION, AND HAVING A SINGLE-TURN HELICAL END SURFACE, COMPLEMENTAL TO AND ENGAGED IN MATING SEALING ENGAGEMENT WITH SAID HELICAL END SURFACE OF SAID FIRST SEAL MEMBER AND HAVING A SHOULDER FACING THE SHOULDER ON SAID FIRST SEAL MEMBER; MEANS MAINTAINING SAID SEAL MEMBERS IN SUBSTANTIALLY FIXED AXIAL POSTION, RELATIVE TO SAID SHAFT, TO HOLD SAID SEALING SURFACES IN ENGAGEMENT WITH EACH OTHER; MEANS FOR ROTATING SAID SECOND SEAL MEMBER THROUGH A LIMITED ANGLE RELATIVE TO SAID FIRST SEAL MEMBER, TO VARY THE TIGHTNESS OF ENGAGEMENT BETWEEN SAID SEAL SURFACES; AND A SUPPLEMENTAL SEAL MEMBER, COMPRISING AN ARCUATE CONTINUATION OF THE HELICAL END SURFACE OF ONE OF SAID SEAL MEMBERS EXTENDING BEYOND THE SHOULDER OF SAID ONE SEAL MEMBER AND INTO A CORRESPONDING ARCUATE RECESS IN THE END SURFACE OF THE OTHER SEAL MEMBER, FOR COMPLETING THE SEAL WHEN SAID SHOULDER ARE ANGULARLY DISPLACED FORM EACH OTHER.