Sizing screens

A sizing screen apparatus for particulate material of different sizes comprising:

• a generally horizontal rotatable circular screen surface having a plurality of elongate radially projecting members free of support means at their outer radial ends and a first driving means connected thereto, a feeder means for feeding particulate material onto the screen surface, a first collection means positioned adjacent to and radially outward of the outer periphery of the surface for receiving and conveying an oversize fraction of the particulate material, second collection means positioned below the surface for receiving and conveying an undersize fraction of the particulate material which passes through the screen;
• a rotatable table positioned below the first and second collection means, means partitioning said table into different parts for receiving and carrying the oversize and undersize material respectively from said collection means discharge outlet means below said rotatable table for said oversize fraction and said undersize fraction, urging means at fixed positions in relation to said rotatable table and adjacent said oversize and undersize outlet means for directing the fractions into their respective outlet means and a second driving means for said rotatable table separate from said first screen driving means so that said table is rotatable at a speed different from that of the screen.