Patent ID: 7819255

Claim:
A shaker apparatus, comprising: a basket having an upstream side, a downstream side, and two side walls; at least one wedge guide and one support rail disposed on each side wall; and at least one screen assembly comprising one or more layers of screen mesh mounted on a screen frame; wherein the support rails and the wedge guides are configured to directly engage the screen assembly; and wherein the screen frame comprises: a first and a second side rail, each having an upstream end, a downstream end, a top surface and a bottom surface, wherein a slope of the top surfaces intermediate the upstream end and the downstream end is different than a slope of the bottom surfaces intermediate the upstream end and the downstream end; and wherein either: a vertical height of the side rails proximate the downstream end is greater than a vertical height of the side rails proximate the upstream end; or a vertical height of the side rails proximate the downstream end is greater than a vertical height of the side rails proximate the upstream end.