Rotating shaft seal

Claim 1

IN COMBINATION WITH INNER AND OUTER RELATIVELY ROTATABLE MEMBERS AND MEANS DEFINING A BEARING CHAMBER THEREBETWEEN, ONE OF SAID MEMBERS HAVING AN EXTERNAL GREASE FITTING AND A PASSAGE THEREFROM OPENING INTO SAID CHAMBER, SAID INNER MEMBER COMPRISING A ROUND SHAFT EXTENDING FROM THE OTHER END OF SAID CHAMBER, A SELFREGULATING PARTIAL SEAL FOR SAID OTHER END OF THE CHAMBER COMPRISING A TUBE FREELY MOUNTED ON SAID SHAFT WITH A CLEARANCE THEREBETWEEN AND HAVING A RADIALLY EXTENDING ANNULAR FLANGE, A RING FIXED TO AN CARRIED BY SAID OUTER MEMBER AT SAID OTHER END OF THE CHAMBER AND HAVING A CENTRAL CIRCULAR OPENING THROUGH WHICH SAID TUBE FREELY EXTENDS AND HAVING THE INNER MARGIN THEREOF ABOUT SAID OPENING POSITIONED ON THE SIDE OF SAID FLANGE WHICH IS OPPOSITE THE CHAMBER, SAID TUBE AND FLANGE BEING MOVABLE IN ONE DIRECTION ON SAID SHAFT BY THE GREASE ENTERING SAID CHAMBER UNDER PRESSURE SUCH THAT THE FLANGE IS TIGHTLY ENGAGED WITH SAID MARGIN OF THE RING AND RELATIVE ROTATION OF THE TUBE AND SHAFT ALLOWS SOME GREASE WHEN THE BEARING CHAMBER IS UNDER PRESSURE TO ESCAPE THROUGH THE CLEARANCE BETWEEN SAID TUBE AND SHAFT, SAID TUBE BEING MOVABLE IN THE OTHER DIRECTION SO THAT UNDER NORMAL CONDITIONS THE RING ROTATES RELATIVE TO THE FLANGE AND TUBE AND THE LATTER IS STATIONARY RELATIVE TO THE SHAFT.