Abstract: A sheet feeding device for feeding single sheets of paper from the bottom of a stack of paper sheets. The device includes a feed tray angled at approximately 60.degree. with the horizontal and a substantially rigid paper drive member cooperating with a plurality of differentially yieldable retard members. By successively increasing the normal pressure on the members or by changing their coefficients of friction, increments of increasing or decreasing retarding force are provided. Uniform frictional forces between individual sheets are provided by a bail weight.

Abstract: A bottom level sheet feeding apparatus having a tray for receiving a stock of sheets, an endless belt conveyor having an upper run which extends into the tray, a lead surface superposed to the upper run of the conveyor downstream of the tray and inclined downwardly and terminating above the upper run to form a pinch point therewith, an idler roller positioned to support the upper run at the pinch point, and a retard strip superposed to the belt downstream of the lead surface. The lead surface has a relatively low coefficient of friction with the sheets to be conveyed, the upper run has a relatively high coefficient of friction with the sheets and the retard strip has a coefficient of friction with the sheets intermediate those of the lead surface and conveyor belt.

Abstract: A bottom level sheet feeding apparatus having a tray for receiving a stack of sheets, a driven endless belt conveyor with an upstream end extending into the tray, a lead surface plate over a fixed-height idler roller to form a pinch point between the belt conveyor and the lower edge of the lead surface plate, a retard strip, and a pair of puller rolls for transporting fed sheets from the extreme downstream end of the belt conveyor to an appropriate copying mechanism. Both the upstream end of the belt conveyor and the downstream end of the belt conveyor may be lowered and raised relative to the fixed height idler roller. A solenoid or hydraulic piston arrangement is disclosed for lowering or raising the upstream and downstream ends of the belt conveyor.

Abstract: The utility of a document exposing system for a copying machine that has a separate exposure platen for bulky documents with a cover containing a transport mechanism, is improved by providing for the platen cover to swing up and away from the platen by being pivoted on a horizontal hinge axis that is remote the rear edge of the platen and by providing for the single sheet document feeder to pivot away from the side of the platen by turning about a vertical axis located behind the back edge of the platen. Thus, an open, unobstructed volume over and at the side of the platen is provided whereby pages of extremely large bound volumes may be copied.