Device for the feeding of flat materials e.g. for printers, in which a retracting mechanism pushes, during one phase of selection cycle, the movable support back against the action of the elastic spring by a predetermined distance

摘要

Sheet feeding device comprises a movable support (17) where a stack of sheets may be arranged and resiliently urged against selection wheels (19). A retracting mechanism (50) is arranged so as to push back during one phase of a selection cycle the movable support (7) by a predetermined distance which is substantially constant and independent of the thickness of the stack of sheets. The retracting mechanism (50) for this purpose comprises a connecting rod (58) displaced by a cam wheel (66) following a backward and forward movement. - DETAILED DESCRIPTION - The connecting rod (58) bears a pawl (57) cooperating with a ratchet wheel (56) suitable for driving a lever (51) integral with the movable support (17). Additionally an actuating mechanism permits the partial opening of the guiding channel (28) when the sheet arrives in a printing zone (35).