GB356215A - Improvements in sheet delivery apparatus for printing - Google Patents

Abstract

356,215. Sheet-delivery apparatus. RANGER, Ltd., H. and RANGER, A. W., 86, Hatton Garden, London. June 4, 1930, No. 17291. [Class 100 (i).] In endless-chain gripper mechanism for delivering sheets from stop-cylinder printing-machines, the delivery grippers receive the printed sheet from the cylinder when the cylinder grippers are remote from the feed point and move away at a speed substantially equal to the peripheral speed of the cylinder to remove the sheet from the cylinder on the upper strands of the chains, accelerate to straighten the sheet, and then retard to deposit the sheet printedside up. As applied to a Wharfedale :nachine, Fig. 1, the chains 1 pass over sprocket wheels 2, 3 and carry two sets of grippers 9 so that while one set is taking a sheet from the impression cylinder 7 the other set is depositing the previouslyprinted sheet on a table 45. The shaft 4 of the sprocket-wheel 2 is driven from a continuouslymoving main-shaft 16 of the printing-machine bhrough variable-speed gearing so that the speed of the grippers 9 is gradually reduced from the time it grips the sheet on the cylinder until the cylinder 7 stops, and is then accelerated to straighten the sheet and afterwards retarded so as to deposit the sheets on the table 45. A sprocket wheel 20, Fig. 6, secured to an elongated boss 24 of a toothed wheel 25 freely mounted on the shaft 4 is drawn from the shaft 16 through chain gearing 21, 22. Fixed to the shaft 4 is a toothed wheel 26 which is geared to the wheel 25 through meshing gear wheels 28, 29 mounted on an arm 27 free on the shaft 4. A lever 31 pivoted at 311, Fig. 5, is connected to the end of the arm 27 and has a roller 33 caused to bear against a cam 34, fixed to the boss 24, by a spring 32 secured to the lever 31. By suitably designing the cam 34, the required variation of speed is obtained. The cam 35, Fig. 1, for opening the grippers 9 to receive the sheets is pivoted on the shaft 4 and is oscillated by links 36, 36<1> operated by a cam on the shaft of the cylinder 7 so as to move with the grippers and hold them open until they have received the sheet. If the cylinder is tripped, the cam 35 remains stationary in its rearward position so that the grippers close before they reach the cylinder and damage thereto is prevented. Guides 49 for the gripper-carrying blocks 11 on the chains prevent vibration of the chains. Sector-shaped discs 43, 44, Fig. 9, are adjustably secured to the shafts 4, 5 of the sprocketwheels 2, 3 and support the sheets as they pass around the wheels. The discs 43 can be swung about the shaft 4 to give clearance when making ready, and can be reset against a stop-bar 47. As applied to a Continental. or overhead-feed type of machine, Fig. 9, the cam 35 is fixed and rollers 51 are provided to keep the sheet in contact with the cylinder 7. Also, the discs 43 may be extended for this purpose. Knife-edge guides 52 are provided to support the sheet along the upper strands of the chains. Alternatively, wires, tapes, or air blast may be used for this purpose. The apparatus may be adapted to slit the sheets by grooving one set of sectors 44 and providing slitting discs 54 co-operating therewith. More' than two sets of grippers may be employed if desired.