GB264253A - Improvements in graders, sorters and like appliances - Google Patents

Abstract

264,253. Pessell, C. A., and Pessell, R. C. Oct. 20, 1925. Fixed sieves; sieves and screens, forms and construction of.-A screen for grading or sorting minerals, roots, fruit, &c. consists of spaced rods or bars arranged in two parallel series in different planes, the bars in one series being disposed intermediate the bars in the other series. The material is conveyed over the screen by a number of tine-carrying bars mounted on endless chains and means are provided for varying the a distance between the bars in the upper series and between the upper and lower series so as to vary the size of the grading openings. In the construction shown in Figs. 1, 3 and 4, the upper series of bars 5 are arranged in an inclined plane and, at their lower ends 13, are hinged to a transverse member of the supporting frame. The bars are made of angle section material, the horizontal part a of which is cut away about midway of their length leaving the upper parts 5<a> in the form of vertical slats the ends of which are connected by springs 16. The lower series of bars 17 are in the form of slats pivoted about a, transverse shaft 18 and disposed between the bars of the upper series. The means for varying the spacing of the bars consists of a transverse shaft 14 carrying a number of edge and face cams 15 which respectively determine the height of the bars 17 and the distance between the bars 5. Alternatively this adjustment may be provided at the lower end of the screen or at both ends. The material is deposited from a hopper 4 on to the lower end of the screen over which it is carried by a conveyer consisting of chains 8 passing round sprockets 9 - - 12 and carrying transverse bars 7 with tines 6. A rotary brush 20<a> mounted on a vertically adjustable shaft 21 may be provided for cleaning the material. The apparatus is supported by a frame 1, 2, 3 which may be mounted on a wheeled vehicle.