Patent GB-426731-A (GB)
Title: Improvements in and relating to sheet delivery mechanism for printing machines
IPC: B65H29/36
Filed: 1933-10-09
Abstract: 426,731. Delivery apparatus for printing-machines. RANGER, A. W., 85, Alfriston Road, Clapham Common, London. Oct. 9, 1933, No. 27799. [Class 100 (i)] In a sheet-delivery mechanism for stop-cylinder and one-revolution, continuously rotating printing - machines, comprising delivery grippers 26 adapted to raise a printed sheet from the printing-cylinder 2, and an endless-chain conveyer 7 having one or more flexible platforms 6 for receiving the sheets from the grippers, the path of the grippers, from the cylinder to the position at which they release the sheet, is cut by the platform when it is travelling on the upper strands or run of the chains, so that the platform can receive a sheet from the grippers and convey it, printed side uppermost, along the upper run of the chains, whereby the sheet is accessible and visible to the operator during its travel. The delivery mechanism is shown as applied to a stop-cylinder press and is supported on a framework 5. The two platforms 6 are carried by two endless chains, supported in places by fibre-lined angle members on the frame 5, which pass around sprocket-wheels 9-14, following a zig-zag path beneath the feed-board 3, and guide rollers extend between the sprockets to support the platforms from sagging. The platforms each comprise two spaced bars 21 between which extend a number of elastic cords. The grippers 26 shown are of the oscillatory type, and are slidably supported on a cross bar 27 mounted in brackets 28 which are secured to a shaft 29. The shaft 29 is carried by pivoted arms 30 adapted to be oscillated against spring pressure by a cam on the shaft of the printing-cylinder 2. Each gripper unit comprises an abutment 33, and a cooperating pivoted finger 34 adapted to be operated against the spring 36 by a rod 35. The rods 35 are all in contact with a blade 37 attached to a spindle 38, and the spindle is adapted to be oscillated to open the gripper fingers when a tumbler 45 secured to the spindle engages a cam 46 in the sheet-receiving position, and a tappet 47 in the sheet-releasing position ; in the latter position the grippers are preferably only just above the platform 6 when it is on the top run of the chains. The tappet 47 is secured to a pivot 48 in which is also secured a lever 49. The lever 49 and tappet 47 are rocked about the pivot 48 by a roller 50 adjustably secured in a slot in a continuously-rotating gear-wheel 51. The time of opening of the grippers can be varied by adjusting the roller 50. The sheet is carried by the platform 6 to the rear of the machine where fingers 57 engage its leading edge to arrest its movement, whereupon it falls on to a piling table 4. The fingers 57, which are normally in the track of the bars 21 of the platform, are adjustably attached to a cross bar 58 carried by arms 59 pivoted at 60 to the framework 5. Each bar 21 is adapted to trip a cam to raise the fingers 57 as each bar passes the fingers. Blades 62 to facilitate piling on the table 4 are carried by a framework pivoted at its lower end to the table, and retained in upright position by a spring- pressed bolt. The oscillatory grippers 26 may be replaced by rotary grippers. In one form a gripper frame is secured to a shaft on which is secured a mutilated gear-wheel adapted to mesh with a further mutilated gear-wheel secured to the printing-cylinder. Both gear-wheels have plain parts arranged so that the grippers carried by the frame will be stopped at the position in which a sheet is to be released. In another form of rotary gripper mutilated gear-wheels are used as in the first form but the gear-wheel with which the gripper frame is secured is positively held in the stationary position by a system of levers operated from a cam on the gear-wheel fast with the printing-cylinder, and the cam also controls the speed of rotation of the grippers for a part of their movement. The grippers instead of being driven from the printing-cylinder can be driven intermittently or with varying speed from any other part of the machine. As applied to a Wharfedale printing-machine, the delivery mechanism is pivotally mounted above the machine and adapted to be swung about the lower left hand sprocket-wheel shaft to which the drive from the machine is connected. The grippers may oscillate about a fixed pivot, or may be of the rotary or oscillatory type. Instead of depositing the printed sheets directly on to a piling table, the flexible platforms may give them up to another conveyer.