Vorrichtung zum Abnehmen und Zuführen von Blättern aus einem Ries

A device 100 for the feeding of sheets 14 from a ream 18, of the type comprising a main rotating, feeding roller 27; a tray 13 containing the ream 18; and an auxiliary roller 130 arranged adjacent to the feeding roller 27, wherein the tray 13 is suitable for moving cyclically to bring the ream 18 into contact with the feeding roller 27, so that the latter picks one at a time the sheets 14 from the ream 18 and feeds them along a path 131; and wherein the auxiliary roller 130 is adapted for rotating in contact with the sheets 14 picked by the feeding roller 27, but without pulling them and in the direction opposite their feeding direction, the object being that of opposing the picking of double sheets from the ream 18. The device 100 is provided with an improvement consisting of a cap 141 capable of moving in sync with the cyclical motion of the tray 13 with respect to the main feeding roller 27, so as to prevent, by coming between the auxiliary roller 130 and the sheets 14, any contact between them, at least during the motion of the tray 13. In this way, the front edges 140 of the sheets 14 can access the path 131 without running the risk of being crumpled and/or damaged by the auxiliary roller 130 with its rotation and, accordingly, of compromising the proper feeding of the sheets 14 from the ream 18. The device 100 also comprises an innovative clutching control group 101 for selectively transmitting the motion from a motor 26 to the main feeding roller 27. In particular, the control group 101 has a central control member 41 which, when it rotates in accordance with a first direction of rotation (135), is connected to the feeding roller 27 with the purpose of imparting to the latter an intermittent line feed rotation and which also, when it rotates in accordance with a second direction of rotation, opposite the first, is disconnected from the feeding roller 27, with the purpose of controlling, when the latter is stopped, the cyclical motion of the tray 13 to bring the ream 18 into contact with the feeding roller 27. The control group 101 is also suitable for preventing the feeding roller 27 from advancing beyond the control member 41 because of inertia, even by only a minimum angular amount, at the end of each elementary line feed rotation.