Rasp hub

Claim 1

A HUB COMPRISING A GENERALLY CYLINDRICAL CENTRALLY APERTURED HEAD WITH ONE FACE HAVING ALTERNATELY RIGHT AND LEFT HANDED HELICAL SURFACES IN A PLURALITY OF SUCCESSIVE SEGMENTS, SAID HEAD HAVING A CIRCULAR CYLINDRICAL SURFACE OUTSTANDING FROM SAID FACE AND CONCENTRIC WITH THE CENTRAL APERTURE THERETHROUGH, A SECOND GENERALLY CYLINDRICAL CENTRALLY APERTURED HEAD WITH ONE FACE HAVING ALTERNATELY RIGHT AND LEFT HANDED HELICAL SURFACES IN A PLURALITY OF SUCCESSIVE SEGMENTS AND A CYLINDRICAL RECESSED SURFACE CONCENTRIC WITH THE APERTURE THERETHROUGH, SAID RECESS OF A DIAMETER TO RECEIVE THE CIRCULAR CYLINDRICAL SURFACE OF SAID FIRST HEAD IN INTERFITTING ENGAGEMENT, AT LEAST ONE RING HAVING COMPLEMENTARY MALE AND FEMALE CIRCULAR CYLINDRICAL SURFACES ON OPPOSITE SIDES THEREOF AND CONCENTRIC WITH ITS CENTER, SAID MALE AND FEMALE SURFACES HAVING DIAMETERS EQUAL TO THE CYLINDRICAL SURFACE AND RECESS OF SAID FIRST AND SECOND HEADS RESPECTIVELY, EACH SAID RING HAVING OPPOSITELY INCLINED ALTERNATELY RIGHT AND LEFT HANDED HELICAL SURFACES IN A PLURALITY OF SUCCESSIVE SEGMENTS ON OPPOSITE SIDES OF THE RING, SAID HEADS DISPOSED WITH SAID RINGS INTERPOSED COAXIALLY THEREBETWEEN AND WITH THE CYLINDRICAL SURFACES AND HELICAL SURFACES OF THE HEADS AND RINGS IN COMPLEMENTARY INTERFITTING RELATIONSHIP, A PLURALITY OF SETS OF SEGMENTAL BLADES RESPECTIVELY INTERPOSED BETWEEN ADJACENT PAIRS OF SAID RINGS AND BETWEEN SAID RINGS AND HEADS WITH THE BLADES OF EACH SET RESPECTIVELY ADJACENT SAID HELICAL SURFACES ON THE SUCCESSIVE SEGMENTS THEREOF, AND A PLURALITY OF REMOVABLE FASTENERS RESPECTIVELY EXTENDING THROUGH THE CORRESPONDING SEGMENTS OF SAID HEADS AND RINGS AND ADJACENT SEGMENTAL BLADES TO DRAW SAME TOGETHER.