Sheet feeder for a writing system

Claim 1

In an automatic writing system including a frame, a cylindrical platen rotatably mounted on said frame, a printing station, an operative console, and a data processing central unit, an automatic sheet feeder comprising: a control unit for controlling the sheet feeder functions; a first container, fixed to said frame, for containing fresh sheets; a second container, fixed to said frame, parallel to and located above said first container for collecting the printed sheets; guiding means for guiding the sheets from said first container to said second container, said guiding means comprising a first pair of parallel spaced apart plates connected to said frame for guiding the fresh sheets from said first container to said printing station, a second pair of parallel spaced apart plates connected to said frame for guiding said printed sheets from the printing station towards said second container, an upper driving roller rotatably mounted on said frame between said second pair of plates and said second container for driving said printed sheets, an arcuate shield having its concavity directed towards said second container and being partially wrapped around said upper roller, and a wedge deviator in an upper position with respect to said platen cooperating with said first and second pairs of plates for guiding the fresh sheets from said first pair of plates to said printing station and for guiding the printed sheets from said printing station to said second pair of plates; a rotational power source selectively operable by said control unit and mechanically linked to said upper roller for driving the printed sheets from said arcuate shield and for piling them into said second container in reversed position with their printed faces in the same order of printing; and a sheet separator located between said first container and said first pair of plates for supplying to the printing station only one sheet at a time, said sheet separator comprising: a support pivotally connected to said frame and located under said first container, a first pulley rotatably mounted on said support and a second pulley rotatably mounted on said frame, a closed loop belt wound around said pulleys, a motor mounted on said support and mechanically linked to said first pulley and selectively operated by said control unit for rotating said pulley, an annular belt located with respect to and partially overlying said closed loop belt, supporting means connected to said frame for supporting said annular belt and spring means connected between said support and said frame to urge said closed belt against said annular belt.