Patent GB-217819-A (GB)
Title: Improvements in or relating to a delivery mechanism for printing machines
IPC: B41F13/70
Filed: 1923-10-10
Abstract: 217,819. Barker, R. W., (American Bank Note Co.). Oct. 10, 1923. Set-off, preventing. - Relates to delivery mechanism for printing machines wherein damped sheets of paper which have received an impression are wound up within a continuous web treated with wax &c. to exclude, air and avoid evaporation of the damping liquid so that the sheets are maintained at a uniform degree of saturation for the purpose of avoiding loss of register in succeeding impressions. and comprises means for conveying a sheet away from a printing couple, a supply reel of waxed web, a rewind reel, means for rotating the reels intermittently, and a guide between the reels to cause the printed sheets to be delivered to the web adjacent the rewind reel. The supply reel 17 is mounted in slotted bearings 41 and rests on friction drums 42, 43 mounted on shafts having pinions 44, 45 engaging a gear 46 driven intermittently bv means of a ratchet wheel 48 and pawl 47 on an arm 38 oscillated by a pitman 39 connected to a crank arm 49 on a sprocket 40 driven by a chain 55 rotated by change gearing from the printing cylinder 10. The rewind reel 16 has end discs 23 resting on friction discs 25, 26 mounted on shafts having pinions 30, 31 meshing with a gear 32 rotated intermittently simultaneously with the gear 46 by means of a ratchet wheel 33 and pawl 34 on an arm 35 connected by a rod 36 with an arm 37 on the shaft of the arm. 38. As the diameter of the rewind reel 16 increases the amount of rotation communicated to the gear 32 by the pawl 34 is diminished bv the device shown in Fig. 4, consisting of a shield plate 64 carried by an arm 63 having a nut 65 engaged by a screw 66 rotated step by step to lower the arm 63 by means of a star wheel 67 and pallet 68 on the friction disc 26. Between the supply reel and the rewind reel the web is guided over a roller 19, then over a roller 21 suspended freely in the guide 22 to take up slack, and then over a roller 20, where it meets the printed sheet conveyed from the printing couple by a gripper cylinder 71 and tapes 72, 79, 83. The chain 55 is actuated by a gear 50 on the printing cylinder shaft through a pinion 58 engaging either a pinion 56 or a second pinion 57 twice the size mounted respectively on shafts 51, 52 carried in a frame 59 pivoted at 60, the chain passing round sprockets 53. 54 on these shafts. If there are two printing plates on the cylinder 10, necessitating two feeds of the web for each rotation of the printing cylinder, the frame 59 is rocked to engage the pinion 56 with the pinion 58, but if the cylinder 10 carries one printing plate only the pinion 57 is brought into engagement with the pinion 58. The amount of web fed may be varied according to the length of the sheet by adjusting the crank 49 radially of the sprocket 40. Brake bands 29, 70 are provided to prevent overrunning of the friction disc 23 and friction drum 42. The actuating means for the supply reel and rewind reel is rendered inoperative simultaneously with the throw out of the printing couple. For this purpose the driving pawls 34, 47 are adapted to be disengaged from their ratchets bv pivoted curved levers 94, 91 resting on levers 95. 92 which are connected together by a link 96 and actuated by link-work 93 coupled to the rack bar 87 controlling the clutch 85 of the impression cylinder 11.