Patent GB-172698-A (GB)
Title: An improved machine for printing envelopes, bags and the like
IPC: B41L47/46
Filed: 1920-09-06
Abstract: 172,698. Jeayes, C., and Bullen, A. S. Sept. 6, 1920. Printing &c. surfaces ; gripper mechanism; rotary machines.-A machine for printing envelopes, bags, &c., comprises a rotary printing couple, a pile table, a shoot leading therefrom to the printing couple, and a movable sleeve with projecting arms through which a vacuum acts to transfer the envelopes one by one from the pile table to the shoot, which is provided with series of stops periodically projected and withdrawn so that the envelopes fall down the shoot by a succession of jumps. The envelopes &c. to be printed are stacked on edge on the pile table 4, the rear end of the pile being supported by a bcard 43 which is advanced automatically as the envelopes are removed from the front of the pile. The support 43 is carried by rods 48 projecting from a carriage 45 with depending brackets 60 through which loosely passes a ratchet-operated screw 47 engaging a half-nut 48<a> pivoted between the brackets. When the carriage 45 reaches the forward limit of its travel, the half-nut 48a is released from the screw 47 by means of a projection 49a on the underside of the pile table. The envelopes are separated one by one from the pile by suction arms 68 on a revolving spindle 64, each envelope being turned over about its bottom edge and falling on to a shoot 3, down which it is lowered to the printing couple in a series of jumps by means of transverse rows of pins 32, Fig. 3, which are alternately projected and retracted by means of rocking levers 34. The front edges of the envelopes are seized by grippers 20 on the impression cylinder 17, said grippers being normally held away from the cylinder by springs 22, Fig. 21, and closed by means of tracks 24 engaging rollers' 20a thereon. The envelopes are printed by the printing cylinder 1 and carried round by the impression cylinder 17 for about half a revolution, whereupon the grippers 20 are opened, the envelopes falling backwards down a guide 72 against a rotating ribbed roller 75, by which they are stacked against a retreating support 74 between the adjustable sides 76 of a receiving table 73. The machine may be adapted to print several envelopes at each revolution of the printing and impression cylinders. As shown in Fig. 28, three printing plates 84 are mounted round the printing cylinder 1 and zero points 81, 82, 83 are provided to enable these plates to be secured in the, correct position corresponding with the location of the grippers 20 on the impression cylinder 17. A bar 85 is mounted above and between the cylinders and provided with hooked guide wires 88, to ensure the envelopes entering the grippers, and with retaining springs 87 to keep the rear parts of the envelopes pressed against the impression cylinder. The printing plates are secured in position by means of clamps 13, Fig. 14, adjustable along screwed rods 11 rotatably mounted on the printing cylinder. Toothed wheels 14, Fig. 18, mounted on the square ends of the screwed rods 11, are forced into engagement with a toothed plate 15 by means of springs 16 so as to lock the printing plate clamps in adjusted position.