Plastic internal screen

Claim 1

In combination in a sieve assembly, a sieve structure, said sieve structure comprising: a flexible member having apertures therein through which material to be treated may be passed; edge bounding means forming a framework to which the flexible member is mounted and providing a planar rigidity to the flexible member; and a sieve structure cleaner means carrier, said carrier comprising; a pair of end wall means and a pair of sidewall means, said end wall means and sidewall means terminating at their upper edges, in a common plane, flange means extending outwardly from the upper edges, said flange means lying in a common plane whereby the upper surface of said flange means may be disposed in planar, abutting contact with the lower surface of the edge bounding means of the sieve structure, first ridge means extending from one of said wall means in one of said pairs of wall means to an opposite wall means, the upper surface of said first ridge means providing abutting support for the sieve structure disposed thereabove, second ridge means extending from one of said wall means in the other of said pairs of walls means to an opposite wall means, at least a portion of said second ridge means providing abutting support for the sieve structure disposed thereabove, apertured bottom means, said wall means, ridge means, and bottom means being unitarily formed and forming a plurality of five-sided compartments, each of said compartments tapering inwardly in the downward direction, said sieve structure cleaning means carrier being composed of plastic, means for connecting the sieve structure to the carrier whereby six-sided compartments are formed, sieve cleaner means within each of said six-sided compartments, means for preventing buildup of treated material at the junctions of the first and second ridge means in the compartments, said buildup prevention means comprising a depression formed in the second ridge means at their junctions with the first ridge means, and the depth of said depressions being less than the height of the sieve cleaner means contained in said compartments.