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.