APPARATUS FOR ENGAGING AND MOVING INDIVIDUAL FLAT STRUCTURES, ESPECIALLY PAPER SHEETS OR PRINTED PRODUCTS

摘要

INVENTOR: WERNER GLATZINVENTION: APPARATUS FOR ENGAGING AND MOVING INDIVIDUALFLAT STRUCTURES, ESPECIALLY PAPER SHEETS ORPRINTED PRODUCTSABSTRACT OF THE DISCLOSUREAn apparatus for destacking a stack of flexible flatstructures, especially paper sheets or printed products, compris-ing a suction head which can be moved, by means of a drive devicealong a closed path of travel. This suction head is periodicallyconnected, by means of a valve arrangement, with a source ofnegative pressure, and thereafter is again disconnected from suchsource. This valve arrangement comprises a cylindrical valvebody attached to a drive shaft of the drive device for the suctionhead. This valve body rotates in a valve housing having threehousing connections which, viewed in the direction of rotation ofthe valve body, are arranged behind one another. The forwardmosthousing connection, viewed in such rotational direction, is con-nected withthe negative pressure source, whereas the intermediatehousing connection is connected with the suction head. The lasthousing connection serves for venting and is connected with thesurroundings. The valve body has a recess extending over part ofits circumference and opening in the direction of the circumfer-ential surface of the valve housing. During its rotation thevalve body, by means of its recess initially connects the forwardmost housing connection with the intermediate housing connection,and thus, the suction head with the negative pressure source.During further rotation this connection is interrupted and there-after the intermediate housing connection is coupled, by meansof the recess, with the last housing connection, so that thesuction head is again exposed to atmospheric pressure. The valvearrangement is synchronized with the movement of the suction headso that at that point in time when the suction head engages witha flat structure this suction head is operatively coupled withthe negative pressure source, whereas at the point in time ofrelease of the engaged flat structure the suction head is con-nected with the atmosphere. The described valve arrangement,even at high rotational speeds of the valve body, allows for afaultless establishment of the requisite negative pressure orvacuum at the suction head.- 2 -