GB1266852A - - Google Patents

Abstract

1,266,852. Grading and cleaning apparatus. F. S. DAVISON. 24 Feb., 1969 [31 Jan., 1968], No. 5022/68. Heading B2H. An apparatus for grading and cleaning root crops, e.g. potatoes, includes a screening structure 1 comprising a set of spaced-apart, stationary longitudinal members 12 disposed substantially horizontally and a set of spacedapart, resilient-surfaced transverse members 10, 11 arranged to move in the direction of the length of the longitudinal members and defining with the latter apertures through which undersize roots and waste soil are removed. The longitudinal members 12 may consist of strips of flexible material such as canvas or steel. The transverse members consist of cylindrical rubber bushes 11 axially mounted on and bonded to spindles 10 the ends of which are carried by chains 5 one on each side of the screening structure 1. A resilient spacer 13 is carried at the centre of each spindle between two bushes 11 to prevent excessive opening of the gauging apertures should roots become wedged. The roots are fed on to the screening structure 1 by means of an inclined conveyor 23. An endless conveyor 24 is arranged beneath the screening structure for removal of waste soil and rejected roots. A geared electric motor 25 drives the chains 5 through a driving spindle 2 and sprockets 3 at each end of the spindle. The transverse members are agitated as the ends of the spindles 10 pass over strips 28 whose upper surface is of ratchet form. A number of graders may be arranged in series with short conveyors extending between each pair of graders or the graders may be arranged in tiers.