Patent GB-938558-A (GB)
Title: Improvements in and relating to rotary duplicating machines
IPC: B41L11/00
Filed: 1961-09-27
Abstract: 938,558. Duplicating machines. W. RITZERFELD, and G. RITZERFELD. Sept. 27, 1961 [Nov. 2, 1960], No. 34666/61. Class 100 (2). A rotary duplicating machine for printing parts of a printing master sheet on to moistened copy sheets comprises a printing drum and a counter-pressure roller arranged for controlled co-operation, the counter-pressure roller being divided into a plurality of portions, and a copy sheet moistening arrangement having one member or a plurality of adjoining members for applying moisture to the copy sheet, said member, or said members jointly, extending along the length of and in a direction parallel to the counter-pressure roller and the action of a portion of said one member or the action of at least one of said members on the copy sheet being controllable separately from the remainder, and at least one of the counter-pressure roller portions being eccentrically or axially slidably mounted relative to the other portion or portions and adapted to be rendered effective or ineffective for printing by an eccentric movement or axial sliding thereof effected electromagnetically, mechanically, or by manually operable control means. In the embodiment shown in Figs. 1 and 3 a printing drum 1 carries a master sheet 2 and a counter-pressure roller 7 mounted on a shaft 8 is movable towards the drum 1 on energization of electromagnets 11, the armatures 12 of which are connected to levers 9 which are pivoted at 10 and which support the shaft 8. The roller 7 is subdivided into two axial portions, a long portion 7a mounted on a part 23, and a shorter portion 7b mounted on a part 24 which is eccentric with respect to the shaft 8. Operation of a switching rod 16 causes a latch 18 pinned to the eccentric shaft 8 to engage behind a locking pawl 19. On rotation of the shaft 8 the portion 7b has the same spacing from the drum as the portion 7a and printing occurs across the breadth of the counter-pressure roller. This continues until a further electromagnet, Fig. 2 (not shown), is energized causing the pawl 19 to be rotated and the latch 18 released, so that the part 24 is returned to its lowered position. The latch 18 simultaneously controls an indicator, Fig. 2 (not shown), which is fixed to a pivoted lever and is visible in a window. The moistening device 6, Fig. 5, comprises a felt strip 42 and is provided with an electromagnet 44 which controls the position of a flap-like portion of the strip bounded by a slit 43. Cams 88, 89 and 90 are effective on contacts K1, K2, and K3, respectively, and the length of the cams determines the length of the copy sheet portion, considered in its direction of movement, which is not moistened. When switches S1 S2 and S3 are opened contacts K1, K2 and K3 are rendered ineffective and the electromagnet 44 is deenergized, the felt strip thereunder is swung back towards the copy sheet 35, and the supply of moistening liquid is reconnected. In the embodiment of Fig. 6 (not shown), two sections of the felt strip are adapted to be raised, and in the embodiment of Figs. 7 and 8 (not shown), the section of the strip bounded by slits is raised by mechanical means. In the moistening device of Figs. 9 and 10 (not shown), part of the felt strip is adapted to be masked by a slide. The moistening arrangement 94, Fig. 13, comprises a felt strip 98 held permanently in contact with a moistening transfer roller 100 and a felt strip 101 which is movable towards and away from the roller 100 by a lever 102 which is moved by adjustable cams 91, 92, 93 through rollers 103, 105 and intermediate lever 104. In the apparatus shown in Fig. 12, a portion 79b of the counter pressure roller 79 is mounted coaxially with a longer portion 79a and is adapted to be moved axially to an ineffective position shown in dotted lines by means of a fork 82, on energization of an electromagnet 84.