Patent ID: 8443984

Claim:
A vibratory screen machine, comprising: a wall member; a guide assembly attached to the wall member and having at least one mating surface; a concave support surface; a central member; a screen assembly including a frame having a plurality of side members and a screen supported by the frame, the screen including a semi rigid support plate and a woven mesh material on a surface of the support plate, a portion of the screen assembly forming a screen assembly mating surface configured to mate with the at least one mating surface of the guide assembly; a compression assembly attached to an exterior surface of the wall member, the compression assembly including a retractable member that advances and contracts; and an acceleration arrangement configured to impart an acceleration to the screen assembly, wherein as the retractable member advances it pushes the frame against the central member forming the screen assembly into a concave shape against the concave mating surface, the top surface of the screen assembly forming a concave screening surface.