GB785103A - - Google Patents

Abstract

785,103. Disc mills. ZWINZ, F. Jan. 19, 1956 [Jan. 20, 1955; Nov. 11, 1955], No. 1894/56. Class 59 In a disc mill comprising a stationary disc and a rotary disc each in the form of a hollow truncated cone and having grinding means disposed on the base surface of the disc in three zones succeeding each other from the central portion of the disc to the outer rim thereof, the grinding means in each zone are irregularly spaced and differ from each other and from those in another zone in depth, width and/or configuration. As shown, a stationary grinding disc 1 has chopping teeth 2, tearing teeth 9 and discharge grooves 14 which differ from the chopping teeth 5, tearing teeth and discharge grooves of a co-operating rotary grinding disc 4 as regards depth, width, configuration and/or spacing. Each chopping tooth 2 is provided with a bead 3 and each chopping tooth 5 with an extension 6. One of the chopping teeth 2 is formed with a nose 7, Fig. 3. and at least one of the chopping teeth 5 has a crushing face 8. The chopping teeth 2 and tearing teeth are formed with groove-like recesses 13 The discharge grooves 14 are intersected by grooves 15 to 19 arranged at different angles, each of the grooves 19, Fig. 1, conforming to at least part of a spiral continuously approaching the outer rim of the disc and the walls of the grooves preferably being recessed in the form of half screwthreads. In a modification, Figs. 7 to 9 (not shown), the central part of the rotary disc is provided inside the chopping teeth with at least one row of substantially radiallyspaced catching teeth co-operating with the nose of the chopping tooth of the stationary disc, the catching teeth comprising boltlike projections each of which terminates in an inclined end face.