Abstract: Screen separators and a screen tensioning system for separators that facilitates rapid measurement of screen tension. Each separator subframe screen is suspended between opposed subframe walls. Suitable linkages distribute vibration during the aggregate sifting process. Screen edge flanges are secured by tensioners that control a screen suspension bracket. A carriage bolt fitted through bracket orifices and the walls coaxially receive a resilient grommet captivated by an adjustable sleeve nut. As the nut is tightened, screen tension increases and the grommet diameter increases. A portable gauge with an internal U-shaped measurement sleeve is fitted over the deformed grommet to measure screen tension. A plurality of gauge calibration points bordering the deformed grommet determine applied screen tension.

Abstract: A ventilator grill for a motor vehicle interior comprises a front plate fixed to a fascia panel parallel rear plate movable relative thereto and connected to a ventilation hose. The front and rear plates define two arrays of apertures and are spaced apart by a set of tubes, the ends of which are pivotable in the apertures. The back plate may be moved by a control knob projecting through an aperture in the front plate so that the direction of the air stream from the grill can be varied.