GB681828A - Improvements in or relating to rotary screens - Google Patents

Abstract

681,828. Rotary sieves. SMITH. T. S. Feb. 12, 1951 [Feb. 13, 1950], No. 3611/50. Class 117 In a rotary screen for use in a harvesting machine, a plurality of hinged pockets are held in a position within the screen to scoop up and raise the material being screened to a predetermined position where each pocket is allowed to pivot about its hinge to discharge the material. As shown the screen comprises a plurality of spaced parallel rings 11 welded to the base and limbs of U-shaped members 12 which are in turn welded to a central channelsection ring 13. Pockets 14 each comprising a series of spaced parallel curved bars 15 connected at their ends by bars 16, 17 are pivoted by their bars 16 between the limbs of the members 12 to face in the direction of rotation. Each pocket 14 has an am 18 extending rearwardly at right angles and projecting through opening 19 in the ring 13, a torsion spring being arranged on each bar 16 tending to urge the pockets 14 into the discharge position with the arms 18 lying radially of the screen. The screen is driven by a chain 20 which passes round the ring 13 and is driven by a pulley 21 so that where the chain contacts the ring 13 the arms 18 are pressed against the ring periphery to hold the pockets 4 in the operative or scoop position and where the chain 20 leaves the ring 13 the pockets 14 are turned by their springs into the discharge position. A fixed bar may be arranged at the point where the chain 20 leaves ring 13 to delay the movement of the pockets 14. In an alternative arrangement the chain 20 may be replaced by a fixed guide band having an open portion determining the discharge position, the screen being driven by external rollers or by a central driving shaft and spokes. The guide band may be located coaxial with but to one side of the screen, extensions being provided on the arms 18 to engage with the inside of the band. Specincation 633,573 [Group I] is referred to.