GB349593A - Improvements in and relating to stencil duplicators - Google Patents

Abstract

349,593. Rotary duplicators. GESTETNER, D., Neo-Cyclostyle Works, Tottenham Hale, London. Feb. 1, 1930, No. 3527. [Class 100 (ii).] Stencil-printing apparatus; set-off, preventing.- To prevent offset, excess of ink is removed from the printed sheets by means of a roller, which is operated in unison with the stencil carrier and is associated with means adapted to remove from the surface of the roller the ink taken up thereby. As shown applied to a machine of the type comprising a stencil-carrying band 4 travelling over inking-rollers 3, the lower roller being rotated from a hand-crank 5, which rotates also a cam 11 for tripping an impression roller 19, the printed sheets are passed between a roller 30 and a coacting pressure roller 53, and the ink taken up by the roller 30 is removed by a doctor 34 assisted, if required, by a felt or other wiping-device. The roller 30 is made of hardened steel or consists of a copper or other metal-surfaced roller, and the doctor is made of steel or a rubber or other composition and may be ground to fit the curvature of the roller or inclined to the axis of the roller. Also, the roller 30 is removably mounted between the side members 37 of a framework 38 and is rotated by gearing from the crank 5, and the doctor is secured to a bar 35 engaging a slot in a cross member 36 connecting the members 37 and is pressed downwardly by springs 55 fixed to a bracket 57. The frame 38 is pivoted at 39 so as to swing down to provide accessibility, and is secured in operative position by a spring plunger engaging one of the members 37. The roller 53 is mounted in arms 44 pivoted at 45 to the frame 38 and is pressed upwardly by springs 47 to an extent limited by screw stops 50. The ends of the roller 53 are of slightly larger diameter than the central portion to avoid excessive pressure on the paper.