GB407879A - Improvements in and relating to sheet delivery apparatus particularly for printing machines - Google Patents

Abstract

407,879. Sheet-delivery apparatus. FABER & SCHLEICHER AKT.-GES., 8, Sedanstrasse, Offenbachon - Main, Germany. Aug. 29, 1933, No. 23971. Convention date, Aug. 31, 1932. [Class 100 (i).] Sheet-delivery apparatus particularly for use in printing machines comprises means which seize the sheet at two opposite edges and depress it. The sheets are carried to a position above the delivery pile 21 by grippers 14, Fig. 1, on endless chains 5. Adjacent to the rear edge of the pile is a transversely-extending suction-tube 22 mounted on rods 24 reciprocated at intervals by cam-and-lever mechanism 36 from a driven shaft 30. The sheets are tensioned longitudinally by the suction-tube which is moved backwardly by the mechanism 36 prior to the sheet being deposited on the pile. At each side of the pile are arranged a number of upwarding-facing suctionnozzles 63 on arms 61 fixed to rods 60 adjustable in sleeves 43, Fig. 3, and given a rocking and sliding movement in their supporting brackets 40 by means of cams 41, 42 on the shaft 30 acting through levers 54 and 48 respectively. The movement imparted to the nozzles 63 is such that just prior to the release of a sheet by the grippers 14 and suction-tube 22, the nozzles are situated immediately beneath the sheet. Suction is then applied to the nozzles so that they hold the sheet at both edges and bring it to rest when it is released by the devices 14, 22. The nozzles 63 are now moved outwardly to tension the sheet transversely and subsequently are lowered stepwise beginning with those at the rear end of the sheet, those at the front end being the last to move downwardly. When the downward movement is completed, the nozzles are moved outwardly so that the sheet drops on the pile. Subsequently the nozzles move upwardly and inwardly beneath the next sheet. The nozzles may be operated so that the depression of the sheet starts either at the front end or at the middle. Further, all the nozzles at one side may move downwards simultaneously while those at the other side move in stepwise manner. Also, two diagonal corners may be initially depressed, and in this form, each set of nozzles 63 at the sides of the pile table may be replaced by a straight suction pipe. Alternatively the nozzles may be replaced by a flexible pipe with suction holes or by grippers. When cardboard is being delivered, the tube 22 is dispensed with and four nozzles, one near each corner of the board or sheet, are employed. Preferably in this case, the nozzles 63 have rubber mouths. The nozzles 63 may be given an initial movement in the direction of the delivery-grippers 14 so that there is no relative motion between the sheet and the nozzles. In a modified arrangement in which the nozzles 63 are dispensed with, the gripper-carrying chains move downwardly towards the front edge of the pile table so that at the delivery point they are just above the pile. The suction-tube 22 also has a vertical movement in addition to its horizontal movement, the vertical movement being caused to take place after the grippers have released the front edge of the sheet. Also, one end of it may move downwardly before the other end. The usual joggers and means for automatically lowering the pile may be provided.