GB829811A - Improvements in or relating to sifting machines - Google Patents

Abstract

829,811. Filters. ORVILLE SIMPSON CO. June 14, 1957 [Dec. 17, 1956], No. 18851/57. Class 46. [Also in Group II] Liquid containing granular or fibrous material is fed through a sleeve 6, Fig. 1, on to a cone 18 and falls on to the periphery of a circular screen 15 to which is imparted a gyratory wobbling motion so that as the material is deliquefied it follows a path towards the screen centre where oversize material falls through an opening 25 to an outlet sleeve 34, and the finer material and liquid falls into a conical pan 2 and is led away through a sleeve 35. The central part of the screen may be arranged slightly below the level of the screen perimeter. Screen cleaning apparatus consists of a perforated plate 71 between which and the screen a number of balls are housed. Radial deflectors 74 of triangular cross-section with their sloping sides of different inclinations cause the balls to move circumferentially on the plate 71 and to bounce against the underside of the screen. The latter is clamped between the opposed flanges of the upper and lower parts of a housing 1 movably supported at three equally spaced points upon support members 40 which engage arms 41 extending from the housing. The supports, which impart the gyratory wobbling movement to the housing and screen, are mounted on a ring 62 resting on posts 63 secured to the floor, and each support includes a pedestal 55 which adjustably receives a sleeve 53 housing a rotary shaft 48 mounted in bearings 49, 50. An eccentric stub shaft 47 extends from each main shaft and is received within a bearing 44 mounted within a resiliently mounted sleeve 45 carried by the arm 41. A hollow flywheel 56 with a counterweight 66 is secured to each shaft 48 and is driven by an electric motor 60. Each shaft 47 rotates about an axis inclined to the screen plane, and the axes of the shafts 47 are inclined differentially with respect to one another. There is thus produced a gyration of the housing and screen and, because of the said inclinations of the shaft axes, vertical movements are imparted to the housing at the screen periphery to cause a wobbling motion. The inclination of each stub shaft 47 is adjustable in order to vary the screen motion according to the material to be treated, and for this purpose each motor 60 is mounted on a bracket 61 projecting from the sleeve 53, and arms 67, 68, Fig. 2, project from the bracket and are traversed by hold-down bolts 69 pivoted to the pedestal 55 and engaged by nuts 70. The lower portion of each sleeve 53 is arcuate and is received in a complementary shaped slot in the pedestal 55, so that the tilt of the axis of the shaft 47 may be varied in the plane of the slot by adjustment of the nuts.