GB1186731A - Improvements in or relating to Arrangements for Handling Bulk Material - Google Patents

Abstract

1,186,731. Screening apparatus. H. ANDERSSON. 21 April, 1967, No. 18379/67. Heading B2H. A loading hopper for screening and tipping bulk material, e.g. for removing large stones from road making material and dumping them at a suitable tipping place, includes a screen comprising a first set of fixed bars 1, connected together, Figs. 1 and 2, and a second set of movable bars 2 held by mountings 3 allowing movement of the said bars from a first position (shown in full lines in Fig. 2), in which they are supported in a predetermined screening relationship to the fixed bars 1 when the screen is in a position in which screening can take place, to other positions (e.g. as shown in broken lines in Fig. 2) when the screen is in a position in which tipping of material not passing through the screen can take place. Rods 1 extend from a plate 1a forming part of the bottom of the hopper having an end plate 4 and side plates 5 joined at their bottom corners at the open end of the hopper by a bar 6 which also joins the ends of the rods 1. Rods 2 extend from a plate 2a which is hinged at 3 to extensions of the plate 1a. In operation, the hopper is suspended horizontally above a truck platform and the material is fed on to the screen 1, 2. When a suitable quantity of oversize stones has been accumulated on the screen the hopper is transported to a suitable location and tipped so that its open end is downwards. In this position, the rods 2 swing slightly away from the fixed rods 1 thereby loosening stones which have become trapped between the rods. In a modification, the rods are replaced by square grids, Fig. 4 (not shown). In further modifications, Fig. 5, fixed rods 1c have movable rods located between them in different arrangements. Thus, movable rods 2c have their ends resting in grooves perpendicular to the plane of the screen at each end of the hopper so as to be capable of parallel movement on tipping of the hopper. Alternatively, the slots are V-shaped so that the rods 2e can also move laterally. In another construction the rods 2d have an elliptical crosssection so that during tipping they rotate in end mountings at each end of the hopper to the position shown in broken line thereby increasing the screen apertures.