GB247683A - A machine or apparatus for treating or preparing moulding-sand and for analogous uses - Google Patents

Abstract

247,683. Ketin, T. Nov. 29, 1924. Oscillating sieves; rotary sieves. - A self-contained or portable machine for treating moulding sand or the like consists of a pulverizing mill and a superimposed system of oscillatory or rotary sieves through which the sand or like material is passed to the mill. Preferably a disintegrating device is provided in the discharge shoot of the mill to break up clods that may occur in the material. In the construction shown in Fig. 1 the machine consists of a base 1 carrying a motor and suitable transmission gear for actuating the various moving parts. The pulverizing pan 2 of the mill is stationary and the mill runners 15 are driven by a vertical shaft 17, which also drives scrapers carried by an arm 13. An aperture in the base of the pan is normally closed by a pivoted door 40 controlled by a lever and leads to the discharge shoot 45 in which is situated the disintegrator consisting of fixed bars 46 and two concentric rows of rods 47, 48 on a disc carried by a rotating shaft 49. The top of the pulverizing pan is covered by a tray having two annular channels 6, 7 swept by scrapers 10, 9 on an arm 8 connected to the shaft 17. Above the tray a sieve consisting of a perforated conical plate 11 is supported on the shaft 17 and is oscillated about the shaft by a bell crank lever pivoted at 35 and driven by an eccentric. The material is first passed through the sieve 11, the oversized parts falling into the channel 7 from which they are discharged outside the machine by the scraper 9, the material passing through the sieve being collected in the channel 6 and discharged into the mill by the scraper 10 through an aperture closed by a sliding plate 56. The pan 2 may be provided with a hopper for the direct introduction of material thereto. In another construction, Figs. 4 and 6, two rotary sieves are mounted on horizontal shafts driven bv the shaft 17. One sieve comprises two concentric perforated members 76, 77 of coarse and fine mesh respectively enclosed in a stationary casing 71. The material passing through the sieve into the casing is discharged by paddles 75 through the opening 78 into the tray 6. The other sieve, which is used for treating sand from a previous moulding operation, comprises a cylindrical perforated member 66 and a number of segmental perforated plates 67 of coarser mesh with spaced longitudinal openings. The sieve contains grinding balls 65 and is contained in a stationary casing 68 with a feed hopper 64 and discharge opening through which the sifted material is discharged into the tray by scrapers 70. The material in the pulverizing pan may be moistened by water fed to a circular trough 79 and distributed by pipes 81 and sprinklers 82.