Abstract: Disclosed is a vibrating material sorting screen with a substantially variable tilt angle and a tilt angle measuring device where the screen has a gear box which is horizontal when the screen is horizontal and inclined when the screen is inclined and further where the gear box has a plurality of oil level sensors or indicators therein which are sized, placed and configured to provide proper oil volume while the screen is oriented horizontally or at various inclines.

Abstract: A sifting screen shaker assembly defined by a generally vertical hollow frame includes a pivotally supported yoke at its base provided with a foot pedal at its apex to articulate a pair of vertical links that are confined in their motion by the convolutions of shaped apertures, with the ends of the links articulating a screen assembly supported within a hinged tray above a collection receptacle in which the sifted particulates passed by the screen assembly are collected while additional particulates are added. The particulates accumulated in the screen assembly are then periodically discarded by articulating the tray around its hinge.