GB846323A - Improvements in or relating to cleaning devices for rotary printing or duplicating machines - Google Patents

Abstract

846,323. Printing machines. ADDRESSOGRAPH - MULTIGRAPH Ltd. May 2, 1958 [Sept. 18, 1957], No. 29406/57. Class 100(2) A device for cleaning ink from the offset roller of a rotary printing or duplicating machine comprises a frame pivoted to the printing machine alongside the offset roller 3 on an axis parallel to the axis of the offset roller, an ink removing roller 14 carried by said frame, reservoir means 10 carried by the frame and serving to coat the ink-removing roller with a liquid ink solvent, a solvent control roller 28 carried by the frame and pressed against the surface of the roller 14, means for adjusting the force with which the control roller is pressed against the roller 14, and means for rocking the frame about its pivotal axis between a position where the roller 14 is in contact with the offset roller 3 and a position where it is not in contact with the offset roller. The frame comprises side members 7, 8 connected by a rod 9 and a shallow tray which constitutes the reservoir 10, and pivoted at 11 to side plates 1, 2 respectively of the printing machine. A rod 18 is rotatably mounted in the side members 7, 8 and projects slightly beyond the plate 8 in the direction of the plate 2: the rod can be rotated by a handle 19. Fastened to each end of the rod 18 is a finger 21 having a cam surface 22 and a projection 23. The cam surfaces 22 co-operate with pins 24 on the plates 1, 2 so that when the lever 19 is pushed downwards from the position shown in Fig. 3 the frame is rocked about the pivots 11 until the ink-removing roller 14 contacts the offset roller 3. The positions of the pins 24 on the plates 1, 2 are adjustable so as to vary the pressure with which the roller 14 bears on the offset roller 3. When the lever 19 is moved upwards the frame falls back under the influence of gravity and resumes the Fig. 3 position. The surface of the roller 14 is of rubber or rubber-like material and is softer than the surface of the offset roller 3. A strip 25 of absorbent material secured to a metal strip 26 has its lower edge immersed in inksolvent in the reservoir 10 and is pressed into contact with the surface of the roller 14, so as to transfer solvent thereto, by a spring-loaded latch 27 pivotally mounted on the rod 18. The roller 14 is rotatable about a shaft 14B fixed between the members 7, 8 and is axially reciprocable therealong as it is rotated by contact with the offset roller by the engagement of a lug 16 on a block 17 with a cam groove cut in the circumference of the roller near one end, the distance of the groove from the end of the roller varying at different points along its circumference. A stub axle at each end of the solvent control roller 28 is mounted in a block 30 which is slidable towards and away from the roller 14 in guides 31 secured to the side members 7, 8. A bar 33 is pivotally mounted between the side members 7, 8 and has a spring plate 32 mounted thereon at each end, the free ends of the spring plates 32 bearing downwards upon the blocks 30. Further spring plates 34 are mounted on the bar 33 and their free ends are aligned with the free ends of the spring plates 32 but do not engage the blocks 30. A short lever 35 associated with each plate 34 is pivoted on the rod 18. Screws 36 having wide, knurled heads 37 are screwed into the levers 35. When the levers 35 are positioned parallel to the plates 34 the heads 37 bear flat against the plates 34 thereby causing the roller 28 to be pressed against the roller 14. Adjustment of the screws 36 by screwing them into and out of the levers 35 serves to regulate the pressure between the rollers 28 and 14 and therefore the amount of ink-solvent fed to the offset roller 3.