GB1002877A - Method and machine for pin grinding - Google Patents

Abstract

1,002,877. Pin mills. STURTEVANT MILL CO. March 26, 1964, No. 13054/64. Heading B2A. Grinding apparatus comprises an upper casing section 10, Fig. 3, with a feed mechanism to receive the material and guide it into a lower casing section 4, an annular pin-supporting plate 11 detachably secured to the lower casing section and provided with rows of circularlyarranged interchangeable pins P1, P2, which co-operate in a grinding passageway 20 with rows of circularly-arranged pins P15, P16, P17 on a rotatable pin-holder plate 18 fixed to a power driven shaft 12 and means, as e.g. slide valves V, V1, to admit controlled amounts of air to the apparatus. As described, the feed mechanism includes a rotary valve 22 which permits addition of particles without drawing in excess air, and vertically-diverging conduits T, T1 defining passageways 21, 23 by which material introduced into the valve 22 may be fed to the body. Each of the pins P1, P2 has a large intermediate diameter body portion and reduced ends, one of which extends into the grinding passageway 20, while the other is shorter and extends into its holder. By releasing a fastening 30<SP>1</SP>, Fig. 4, clamping ring sections 30 may be removed to permit a pin to be removed from the plate 11 and reversed, so that no grinding is effected at that point. Pins of different sizes may be used to vary the grinding effect. The pins P8-P10, Fig. 5, which may be inserted in the rotor plate 18 without detaching the top plate 11, include recessed socket heads P11-P13. Removable plugs 40, 42, 44 in the plate 11 afford access for a wrench to the socket heads and when a pin is removed the hole in the rotor plate 18 is closed by a plug. A pin mill of the type described may be used to supplement a roller mill.