GB711849A - Improvements in or relating to a printing machine - Google Patents

Abstract

711,849. Printing-machines. ADDRESSOGRAPH-MULTIGRAPH CORPORATION. Feb. 14, 1951, No. 3569/51. Class 100 (2) Blankets. - In a planographic offset printing machine, there is provided a layer of resilient material around the offset printing cylinder for normal offset printing, and a covering of sheet material on said layer adapted to receive and transfer ink for limited runs. Preferably, the material is translucent or transparent, and may be of smooth vellum paper, enamelled paper, glassine or cellulose derivative foils. In a machine such as that described in Specification 499,800, the covering B, which constitutes an additional blanket, is guided by plates 81, 83, 85 between the printing cylinder and the offset cylinder 52 having a layer of resilient material 51, which constitutes a normal blanket, and thence between the latter cylinder and the impression cylinder 61 over which sheets S to be printed on are fed The blanket 3 is used for short runs, in order to avoid repeated washing of the blanket 51. The length of the blanket B may be the product of the circumference of the cylinder 53 and the number of prints to be made from the plate 17. If only one print is to be made, the blanket B may be secured to the cylinder 53 in the same way as the blanket 51, by the tensioning means 57, 59. After use, the blanket B can be discarded, or if it is translucent or transparent, so that the image can be viewed through it positively, can be kept as a record sheet.