Patent GB-438596-A (GB)
Title: Improvements in or relating to mincing or grinding machines
IPC: B02C18/36
Filed: 1934-04-14
Abstract: 438,596. Mincing-machines ; making gratings; perforating. BILDE, T. E. D., 36, Norr Malarstrand, Stockholm. April 14, 1934, No. 11326. Convention date, Nov. 30, 1933. [A Specification was laid open to inspection under Sect. 91 of the Acts, Oct. 20, 1934.] [Classes 83 (ii) and 83 (iv)] [See also Group VI] The perforations in a cutting - disc of a mincing-machine are of non-circular form with curvilinear cutting-edges, and the cutting-edges extend in the general direction of the major dimensions of the perforations and are disposed radially or substantially radially of the disc. As shown in Fig. 2, the perforations have straight cutting-edges, and are arranged in groups in each of which all the cutting-edges are parallel. In Fig. 3, the disc has a peripheral flange 20, which may be discontinuous, or may be bent back on itself as shown at 20b. The central bearing 21 may be continued rearwardly as shown at 21b. The cutting edges of the perforations may be formed by introducing a punch 30 into parallel sided holes and grinding away the displaced metal 31. The disc may be of chromium nickel steel, rustless or other material suitable for pressing and hardening, cast iron, chill castings, annealed castings or aluminium pressed material, and may be formed with a flange for direct attachment to the mincer barrel without the use of the usual screwed ring. The disc may have oval holes and may be of circular, square, rectangular or elliptical form. It may also be slightly bowlshaped, or conical, convex or concave form. The non-cutting parts of the holes may be rounded, bevelled or partly countersunk. The holes in the disc may be of different sizes in different parts of the disc. The Specification as open to inspection under Sect. 91 states also that inclined holes may be formed by distorting perpendicular holes with laterally moving members engaged with opposite ends of the holes, or by punches which move obliquely either to remove a side of an existing hole or to punch an inclined hole. Various ways of distorting perpendicular holes with punches and grinding away the displaced metal to form cutting edges are described. An apparatus is described for wiping over the edges of perpendicular holes to form acute cutting-edges, wherein the disc is positioned beneath a rotary member having V-shaped projections on its face which press against and wipe the holes. A similar rotary member, moving in the opposite direction, may operate simultaneously underneath the disc. In another process, tapered pieces are punched out of the disc by arranging the punch to work in alignment with holes, of larger diameter than the punch, in a backing member. Alternatively, hummocks are pressed out of the disc, and the tops of the hummocks ground off to produce widely tapered holes. Milling tools may be used to convert parallel sided holes into tapered or curvilinear sided holes, or a tool having a bevelled bottom may be inserted into each hole, and metal rolled up from the lower face of the disc around the bevel to form cutting edges. This subject-matter does not appear in the Specification as accepted.