GB1119142A - Offset printing press - Google Patents

Abstract

1,119,142. Perfecting offset press. R. W. CRABTREE & SONS Ltd. 7 Sept., 1966 [3 Aug., 1966], No. 33257/65. Heading B6C. A perfecting web offset printing press comprises a pair of plate cylinders, a pair of offset cylinders co-operating with the plate cylinders, an impression cylinder co-operating with one of the offset cylinders and means for guiding a web either between the two offset cylinders to obtain an image on one or both sides of the web, or alternatively to guide the web between the impression and the co-operating offset cylinder to obtain a double offset effect on one side of the web. Fig. 1 illustrates one embodiment of the invention in which plate cylinders 1 and 2 cooperate with offset cylinders 3 and 4; an impression cylinder 11 which can be moved in and out of engagement with cylinder 3 is arranged above the latter cylinder; arranged above impression cylinder 11 is a third offset cylinder 12 and associated plate cylinder 13 while a further pair of offset cylinders 16, 17 and associated plate cylinders 18 and 19 are positioned away from the cylinders mentioned above. In Fig. 1, web A is perfected between cylinders 16 and 17 and then led between cylinders 3 and 11 which produce a double offset effect (from offset cylinders 3 and 4), and a further image can be applied by offset cylinder 12; thus web A may have four images on one side and one on the other. In Fig. 2 (not shown) web B is perfected between cylinders 3 and 4 and a separate web C is simultaneously perfected between cylinders 16 and 17, while in Fig. 3 (not shown) web E is perfected between cylinders 16 and 17, and web D is perfected between cylinders 3 and 4, led between cylinders 3 and 11 which are out of engagement and is then imaged by offset cylinder 12 in contact with impression cylinder 11 (resulting i.e. in two images on one side, one image on the other). Fig. 4 illustrates a second embodiment wherein offset cylinder 12 forms one of a pair of offset cylinders 12 and 24 with corresponding plate cylinders 13 and 25, while the impression cylinder 26 is larger than the corresponding impression cylinder 11 in Figs. 1-3, and may be in or out of engagement with either of cylinders 3 and 12. In Fig. 4, web F is provided with an image on one side, and five images on the other, including two sets of double offset effects from cylinders 3 and 4 and from cylinders 12 and 24. In Fig. 5 (not shown), web H is perfected between cylinders 16 and 17 and web G is doubly perfected first between cylinders 3 and 4 and then between cylinders 12 and 24. In Fig. 6 (not shown) three webs J, K, L are each perfected once.