Grinding apparatus

Claim 1

A GRINDING MILL COMPRISING AN ELONGATED SHELL, A GRINDING ZONE IN SAID SHELL ARRANGED TO CONTAIN A BED OF MATERIAL TO UNDERGO TREATMENT INTERMIXED WITH A PLURALITY OF FREELY MOVABLE GRINDING BODIES, A SUBSTANTIAL PORTION OF SAID GRINDING BODIES BEING OUT OF CONTACT WITH SAID SHELL AT ANY SPECIFIC TIME, MATERIAL MOVING MEANS WITHIN SAID SHELL COMPRISING A SHAFT EXTENDING LONGITUDINALLY OF SAID ELONGATED SHELL AND A RIGID DISC FIXED TO SAID SHAFT AND DISPOSED OBLIQUELY THRETO, SAID DISC BEING DISPOSED AT LEAST PARTIALLY WITHIN SAID BED WHEN SAID MILL IS OPERATING, SUPPORTING MEANS FOR SAID SHELL AND MATERIAL MOVING MEANS OPERABLE TO PERMIT RELATIVE ROTATABLE MOVEMENT THEREBETWEEN ABOUT THE AXIS OF SAID SHELL, AND DRIVE MEANS OPERABLE TO EFFECT SUCH RELATIVE ROTATION THEREBETWEEN, IMPARTING TO AT LEAST A SUBSTANTIAL PORTION OF SAID GRINDING BODIES ARCUATE TUMBLING MOVEMENT ABOUT THE AXIS OF SAID MILL AND OSCILLATORY AXIAL MOVEMENTS OF SUBSTANTIAL EXTEND IN OPPOSITE DIRECTIONS WITH RESPECT TO THE LONGITUDINAL AXIS OF SAID MILL.