Patent GB-446633-A (GB)
Title: Improvements in or relating to cylinder printing presses
IPC: B41F3/00
Filed: 1935-12-10
Abstract: 446,633. Printing-machines; feeding webs. AUTOMATIC AKT.-GES. FUR AUTOMATISCHE DRUCKMASCHINEN, 143, Alte Jakobstrasse, Berlin. Dec. 10, 1935, No. 34175. Convention date, Dec. 17, 1934. [Classes 100 (i) and 100 (ii)] A web-fed stop-cylinder machine is constructed so that the reciprocating bed 3 prints on the web as the bed moves in the direction of the arrow 4, Fig. 1, the impression cylinder 5 rotating in the direction of the arrow 6 during the printing stroke and being held stationary during the return movement of the bed. The web-feeding arrangements include a looping device 24 which is reciprocated in a vertical or oblique direction by mechanism actuated from the bed 3 reciprocated by the main driving- wheel 2 of the machine. The web-guiding rollers are so arranged that the freshly printed web passes with its impression on the outside of the rollers so as to prevent set-off. The web is fed in by constantly driven rollers 10, is formed into a loop 11, passed over a guide roller 12 and brake device 13 and is then passed into the main feed device A which comprises a roller 14 driven intermittently by an oscillating segment 17 geared to the roller 14 by a freewheel device. The web then passes over a roller 15 which co-operates with roller 14 to feed in the web, and then over guide rollers 22, 23 forming part of the looping device 24, over a fixed roller 26, around rollers 27, 28 arranged near the impression cylinder 5, over the upper roller 25 of the looping device and back to a roller 16 which acts with roller 14 to feed the web out of the printing-machine to a perforating device B and other feed rollers C and perforating devices D. As the bed moves to the right to make the impression, the looping device is moved downwards by an oscillating member 33 having a gear sector 34 which is driven from a rack on the bed, and a sector 31 which oscillates a gear-wheel freely mounted on the shaft of the roller 26 and causes a rack on the looping device to be reciprocated. The roller 23 descends to the position shown by dotted lines, and as the bed returns and the cylinder remains fixed, the web is drawn up by the roller 25 and is also fed out of the machine by the rollers 14, 16 and a new length is fed into the machine by the rollers 14, 15. The side of the web which is unprinted contacts with the rollers 27, 28, 25 over which the printed web first passes, and the web is practically dry by the time the printed surface engages the roller 16. When the web is to be printed a second time its maximum width is equal to half the width of the impression cylinder as the two widths of web are passed simultaneously around the cylinder 5. The course of the first web is as described above, but the once printed web is passed through a reversing device E and is led back again to the cylinder 14 to receive a second impression. If a perfected impression is desired, the web is turned by means of two bars 45 inclined at an angle of 45‹ to the web, but if a multi-colour impression is required, three turning bars 48, 49, 50 are employed as shown in Fig. 4. The twice-printed web is led to the perforator B, and the once-printed web to the reversing device.