Abstract: A screen assembly 22 includes a conveyor 26 pivotably mounted beneath a screen 24 for segregation of fractions of material, for example from a mobile crusher 10. Hydraulic cylinders (not shown) are used to selectively move telescopic arms 48 (only one of which is shown in the Figures), to raise or lower the conveyor 26 between operative position and inoperative positions. In the operative position the conveyor 26 is substantially parallel to the screen 24 for receiving material which has passed through the screen mesh, in use. In the inoperative position the conveyor 26 is angularly displaced relative to the screen 24 about the pivot, to provide access to the underside of the screen 24, e.g. for maintenance purposes. Removable pins 50 are provided for releasably securing the attitude of the conveyor 26 relative to the screen 24 in the operative position.