| 摘要 |
A sheet feeder has a pair of rearward feed belts declining in a downstream direction at a first angle for supporting a rear portion of a stack of sheets and a forward feed belt declining in a downstream direction at a lesser angle than the first angle positioned for supporting a front portion of the stack of sheets below the rear portion of the stack of sheets. With this arrangement, the weight of a stack of sheets on the feeder is shifted forwardly to assist in ensuring entraining frictional engagement of the bottom sheet with the forward feed belt. Optionally, a feed wheel overlies the downstream end of the forward feed belt and forms a nip therewith. Preferably the forward feed belt, the rearward feed belts, and the feed wheel are each separately driven with the rearward feed belts being driven through a one-way clutch permitting free movement of the rearward feed belts in the downstream direction. Photocells and a controller allow, on demand, a feeding cycle comprising activation of the forward feed belt followed by deactivation of the forward feed belt and pulsing of the feed wheel followed by pulsing of the rearward feed belts. This feeds a sheet from the bottom of the stack and prepares the next sheet for feeding by contouring the middle portion of this sheet so that it is separated from the stack.
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