Vertical refiner

Claim 1

IN A PAPER STOCK REFINER HAVING A VERTICALLY EXTENDING HOUSING, A MOTOR MOUNTED WITHIN SAID HOUSING AND HAVING A VERTICAL MOTOR SHAFT EXTENDING UPWARDLY THEREFROM, AN END CAP FOR SAID HOUSING HAVING AND EXTERIOR WALL CONFORMING GENERALLY TO THE WALL OF SAID HOUSING, AN ANNULAR FLANGE EXTENDING INWARDLY FROM THE TOP THEREOF, AND AN ANNULAR INTERIOR WALL, WHICH WITH SAID EXTERIOR WALL FORMS AN ANNULAR CHAMBER FOR STOCK, SAID ANNULAR INTERIOR WALL ALSO HAVING A BEARING MOUNTED INWARDLY THEREOF AND WITHIN THE LIMITS THEREOF AND FORMING A BEARING FOR SAID VERTICAL MOTOR SHAFT, A PORT HAVING COMMUNICATION WITH SAID ANNULAR CHAMBER, A VERTICAL SHELL MOUNTED ON AND SEALED TO SAID END CAP AND EXTENDING UPWARDLY THEREFROM AND HAVING A FRUSTO-CONICAL INTERIOR WALL, A PORT AT THE TOP OF SAID SHELL IN COMMUNICATION WITH THE INTERIOR THEREOF, A CONICAL PLUG MOUNTED ON SAID MOTOR SHAFT AND EXTENDING THEREALONG AND ROTATABLY DRIVEN THEREFROM AND HAVING A FRUSTO-CONICAL SURFACE SPACED INWARDLY OF SAID FRUSTO-CONICAL INTERIOR WALL OF SAID SHELL AND ADAPTED TO HAVE STOCK PASSED THEREALONG DURING ROTATION OF SAID PLUG TO EFFECT A REFINING OPERATION, AND MEANS PREVENTING THE STOCK PASSING BETWEEN SAID PORTS AND IN THE SPACE BETWEEN SAID PLUG AND HOLLOW INTERIOR WALL OF SAID SHELL FROM CONTAMINATING SAID BEARING INCLUDING SAID INTERIOR ANNULAR WALL AND PLUG, FORMING AN ANNULAR PRESSURE CHAMBER WITHIN SAID INTERIOR ANNULAR WALL, AND A WATER INLET TO SAID PRESSURE CHAMBER SUPPLYING WATER TO SAID CHAMBER TO PROVIDE A BACK PRESSURE OF WATER IN SAID CHAMBER, PREVENTING THE PASSAGE OF STOCK INTO SAID CHAMBER.