ARCHOVY VYKLADAC ARCHOVEHO TISKOVEHO STROJE

摘要

In a sheet fed printing press the sheet delivery apparatus includes a delivery drum positioned adjacent to an impression cylinder of the printing press. The delivery drum has a shaft journaled in the press frame with a pair of delivery sprockets connected the shaft on opposite sides of the delivery drum for rotation therewith. Endless delivery chains are reeved about the sprockets and have a plurality of transversely extending gripper bars secured therebetween in spaced relation to each other. The delivery drum has a recessed portion arranged to receive the gripper bars as the gripper bars revolve about the shaft with the delivery drum. The delivery sprockets have a pitch diameter equal to the diameter of the delivery drum so that the speed of the gripper bars is equal to the peripheral speed of the delivery drum as the gripper bar revolves about the shaft and the speed of the front edge of the sheet is the same as the speed of the trailing edge portion of the sheet until the trailing edge portion leaves the nip between the impression and blanket cylinder of the printing press. Means are provided to adjust the height of the grippers on the gripper shaft to adjust for different thicknesses of the sheets passing through the press. The adjustment means is arranged to adjust the gripper bar with the grippers thereon beyond the periphery of the delivery drum to engage relatively thin sheets and to reduce the height of the gripper bars to the radial dimension of the delivery drum to accommodate sheets having a substantial thickness. Other means are provided to change the angular velocity of the delivery drum and the sprockets connected thereto so that the speed of the gripper bar and the front edge of the sheet is the same as the peripheral speed of the impression cylinder until the trailing edge of the sheet leaves the nip between the impression cylinder and blanket cylinder of the printing unit.