GB913993A - A grate for sorting purposes comprising parallel plate-shaped elements arranged in side by side relationship - Google Patents

Abstract

913,993. Sifting apparatus. HALSTRICK, R. Aug. 31, 1959 [Sept. 2, 1958], No. 29589/59. Class 117. Granular materials are screened by a grate comprising sets of closely adjacent plates 1, 2 on edge and combined alternately in frames of which at least one moves relative to the other, the movement being such that each plate moves in a closed circular path lying in the plane of the plate, and the plates of at least one frame has means along its length for retaining grains of the material being screened. As shown in Figs. 1 and 2 the means comprise perforations 4 evenly spaced lengthwise of the plates; each plate has, in addition, evenly spaced lugs 3 extending to the adjacent plates and, in operation, larger grains are received in the perforations and act in a similar manner to the lugs by sweeping over and cleaning adjacent plates. The lugs in one plate may alternate with the perforations therein, and motion of the frames may be such that a lug of one plate moves around a perforation in an adjacent plate. The upper edges of the plates may be in the form of successive arcs, Fig. 1, or of toothed form, Fig. 4. In Fig. 6, the perforations extend to the upper edges of the plates, and the slits in each plate may be in the same, or opposite direction, to the direction of movement of the granular material. In further embodiments lugs of various shapes are located around the perforations and may extend to the adjacent plates. Instead of being received in perforations, the grains may be held within groups of small lugs; a group of small lugs may surround a perforation which holds a large grain. Alternatively a perforation may be surrounded by a group of smaller perforations. The plates may be resiliently supported in the frames to allow their lateral deflection.