Patent GB-373259-A (GB)
Title: Improvements in or relating to printing machines
IPC: B41L21/06
Filed: 1931-02-19
Abstract: 373,259. Printing-machines. BULLOCK, C. A. H., 11, Ludgate Square, London. Feb. 19, 1931, No. 5271. [Classes 100 (i) and 100 (ii).] Cylinder machines; delivery apparatus.-In a.printing machine of the kind in which printing is effected by rolling an impression cylinder 11, Figs. 2, 3 and 7, along a printing forme 2 with the sheet P to be printed located between them, the sheet is maintained in contact with the cylinder for a period after it has been printed so as to be positively lifted clear of the forme, and is thereafter engaged by gripper jaws which follow the cylinder and pass over the two side edges of the sheet after printing so as to grip and deliver it. The impression cylinder 11 is carried by endless chains 3, 4 mounted on sprocket wheels 5, 6 rotated by a handle 73 on the wheel-shaft 9 so that the cylinder 11 moves upwardly over the forme 2. Rotatably mounted on the chains 3, 4 just in advance of the cylinder 11 is a rod 13 having arms 14, 17 thereon carrying rollers 15, 18 engaging the cylinder 11 respectively in advance and rearwardly of the point of the point of contact of the cylinder with the forme, the rod 13 being actuated by a spring 16 for this purpose. As the cylinder 11 approaches the forme 2 after its inoperative stroke, Fig. 3, an arm 21 on the rod 13 is engaged by a fixed stop 22 so as to move the rollers 15, 18 away from the cylinder 11 and permit a sheet P to be fed against a stop 23 fixed to the bed 1 of the machine, the machine being stopped at this moment as described subsequently. When the operating handle is now rotated, the arm 21 is released from the stop 23 and the rollers 15, 18 grip the sheet against the cylinder 11 and carry it into position for printing. During printing the sheet remains stationary, being gripped between the cylinder 11 and the forme 2, the rollers 15, 18 preventing contact with the forme at other points and a transverse bar 74 on the chain preventing the printed part of the sleeve from falling on to the forme. The sheet is delivered by grippers comprising jaws 29, 27, the former of which are carried by plates 34 fixed to the chains 3, 4 and the latter are resiliently pivoted to a member fixed to a bar 25 carried by links 26 pivoted to joints of the chains, a spring 30 acting on the link tending to hold the jaws 27, 29 pressed together. Freely mounted on the bar 25 is an arm 31 having a shoulder 32 normally engaging a stop 33 on the plates 34 to prevent engagement of the jaws 27, 29. At the completion of the printing operation, a fixed stop 35, Fig. 7, on the cylinder guide-rails 20 engages a projection 36 on the arm 31 so as to release the shoulder 33 and cause the jaws 27, 29 to grip the edges of the sheet and carry it behind the bed 1. A plate.75 fixed to the rod 28 assists in the delivery of the sheet. Near the lower end of the bed 1 is a stop 38 which engages an extension 37 on one of the links 26 so as to open the grippers and allow the sheet to drop on to a delivery table. At the same time the arm 31 drops under gravity with the shoulder 32 once again in engagement with the stop 33 ready for the next cycle of operations. Pile tables and feed tables ; sheet-registering devices.-The sheets to be printed are stacked on a platform 65, Fig. 18, having a spring- pressed leaf 67 pressing the front edge of the pile against a flanged plate 66. The top sheet is released from the plate 66 by hand by buckling it against a back stop on the platform 65 and is pushed forward against the front stop 23 when the machine is brought to rest by the engagement of a hand-operated latch with the chains 3, 4. Inking-apparatus.-The forme 2 is inked by two rollers 42, 43, Figs. 9 and 12, carried by the endless chains 3, 4. Links 54 having hooked ends resting on and engaging the spindles 52, 53 of the rollers 42, 43 are riveted to curved leaf-springs 55 which carry rollers 56 at their ends adapted to engage the guide-rails 20 in front of the forme so as to press the inking-rollers against the forme. Ink is supplied from the ductroller 44 to the roller 42 by means of an intermediate roller 41 carried by links 41a slotted to fit over the spindle 52 so as to allow the roller 41 to remain in contact with the two rollers 42, 44 for a period under the action of gravity. After leaving the duct-roller 44 the roller 41 trails behind the inking-roller 42 and is held clear of the forme 2 during its passage thereover by discs 41b on the end thereof engaging guides 24 on the bed 1. The duct-roller 44 is freely mounted on the shaft 9 of the chain sprocket wheels 5 and is formed with an internal ratchet diso engaged once during each revolution of the shaft 9 by a spring blade on the shaft so as to give the roller 44 a partial rotation. The inking-roller 43 receives its ink from a disc 40 suppled by the roller 42 which moves thereover on its way to the forme. The disc 40 is set rotating once during each cycle of operations by a pawl 63 which engages ratchet teeth 64 on the back thereof and is carried by a lever 61 pivoted to a link 60 connected to a crank 59 adapted to be engaged by a cam 62 on the chains 3, 4 so as to cause the lever 61 to rock.