Patent GB-751091-A (GB)
Title: Improvements in or relating to offset rotary printing machines
Inventor: MESTRE LUIS
IPC: B41L19/00
Filed: 1954-11-01
Abstract: 751,091. Rotary-offset printing-machines. GESTETNER, Ltd. Nov. 1, 1954 [May 12, 1954], No. 31556/54. Class 100 (2). The printing machine described and claimed in Specification 747,005 is adapted for multi-colour printing by the provision of at least one extra plate cylinder to coact with the offset cylinder, each plate cylinder having an ink and a water supply system, and the faulty-sheetfeed detector mechanism described in the above Specification is arranged, when no sheet is fed, simultaneously to separate the blanket cylinder both from the impression cylinder and from the pair of plate cylinders and also to render the ink systems inoperative. As shown in Fig. 1, the offset cylinder 23 cooperates with plate cylinders 25, 25a, and with the impression cylinder 22. The extra plate cylinder 25 is mounted on a sub-frame 26 pivoted to the main frame 20 at 28. One end of a link 30 is connected to the sub-frame at 31 and the other is formed as a stirrup 30, Fig. 4, encircling an eccentric 32 on the shaft 33 of the blanket cylinder. This shaft carries at each end eccentric bushes 34 rotatable in bearings 108 so that by rotation of the shaft the blanket cylinder mounted thereon is moved into and out of contact with the impression cylinder 22 and with plate cylinder 25a. The eccentric 32, also rotating with shaft 33, acts simultaneously to cause the sub-frame to swing towards and away from the main frame. The throw of eccentric 32 is greater than that of eccentric 34 so that as the blanket cylinder, in leaving plate cylinder 25a and impression cylinder 22 moves towards the plate cylinder 25, the plate cylinder 25 is moved a greater distance in the same direction and consequently disengages the blanket cylinder. Rotation of shaft 33 to trip the blanket cylinder and to displace the sub-frame is controlled by way of link 105 and rocker 100 by the sheet detecting means through the mechanism described in Specification 747,005. Water for the plate cylinder 25 is obtained from a trough in which is mounted a water roller, the water being transferred to a plate moistening roller 43 in the manner described in Specification 747,005. The water roller is rotated through a ratchet wheel 40 by a pawl 41 mounted on an oscillating carriage 42. The carriage is oscillated through a link 61 by a rocker 62 connected by a link 64 to an eccentric 67 on a shaft 67a. Ink is also supplied to the plate cylinder in the manner described in Specification 747,005. The fountain roll is rotated through a ratchet wheel on shaft 52 by pawl 53 on carriage 54. The carriage is oscillated by link 60 also connected to rocker 62. The pawl can be displaced out of engagement with the ratchet to interrupt the ink-supply by a lever 118. The lever is actuated by a push rod 119 connected to a lever having a pin 121 engaged by an arm 122 pivoted at 123. The other end of the arm bears on the rocker 100 so that when the rocker moves to trip the offset cylinder the lever 118 is actuated to disable the ink supply. The plate cylinder 25a is supplied with ink and water by a similar mechanism this ink system also being rendered. inoperative when the offset cylinder is tripped. For this purpose the disabling lever is actuated upon movement of the arm 122 by a link 139 acting through a lever 137 and a pusher 136. When it is desired to print in one colour only the extra plate cylinder 25 is moved out of contact with the offset cylinder. To this end it is mounted by means of bearings 150, Fig. 6, on a shaft 148 the ends of which are secured in eccentric bushes 151 rotatably mounted in the walls of the sub-frame 26. A lever 152 connected to one end of the shaft has an operating handle 156 and a locking screw 155 extends through an arcuate slot therein. Rotation of lever 152 moves the cylinder 25 into an inoperative position. Cylinders 22, 23, 25 and 25a are all geared together so that they rotate at the same speed. Specifications 747,003, 747,004, 747,006 and 747,008 also are referred to. based paper, by a roll printing machine using one or more colours in the form of rubber solutions and then applying two or more layers of coloured rubber solution to form a background layer and one or more lower backing layers. The design printing may be effected by repeated passage through the press to produce a desired design thickness and colour intensity. The transfers may subsequently be cut apart, with or without simultaneous embossing. A thick white lower backing layer may be provided which fills the crevices when the transfer is applied to granular rubber, rubberized fabric or other irregularly-surfaced articles. The transfers are applied either cold, by means of a solvent or rubber solution, or hot by vulcanization, the paper carrier being subsequently removed.