GB333635A - Improvements in grinding mills - Google Patents

Abstract

333,635. Stimson, E. F. Feb. 28, 1930. Disc and like mills.-In a. grinding mill having relatively rotated concave and convex grinding surfaces with mutually inclined axes of rotation, both the grinding surfaces are positively driven. As shown in Fig. 1, the concave disc a is rotated by bevel wheels m, l driven by a shaft k, and the convex disc c is rotated at a slower speed through shaft q, worm r, worm wheel s and gear wheels u, v. The spindle f of the convex disc is provided with a universal joint e and the boss g of the disc forms a ball joint eccentric to the centre of a disc i provided with gear teeth x engaged by a pinion w formed on an extension of the shaft t which is driven by the worm and worm wheel. The concave disc a is provided with an annular flange a<1> which is pressed on to the disc c by springs a<2> abutting a flange b<2> on the hollow spindle b of the disc a. Plungers a<3> are moved into contact with the convex disc c by screws to adjust the clearance between the ring a<1> and disc c. The material is fed to the discs through the hollow spindle b and is ground by the rotational and' precessional motion of the disc c. A liquid seal i<1> protects the driving gear of the disc c and an oil seal b<3> prevents overflow of oil on to the discs. In Fig. 3 the shaft d of the convex disc is oscillated in guides by a crank-pin y and slide z.