GB339275A - A process and device for registering sheets in multiple colour printing - Google Patents

Abstract

339,275. Kings Patent Agency, Ltd., (Schnellpressenfabrik Frankenthal Albert et Cie Akt.-Ges.). July 3, 1929. Rotary machines.-In a multi-colour printing- machine in which sheets are printed with superposed impressions and the sheets are passed between the impressions from one impression cylinder D to another by means of a transfer cylinder U, correct registration of the impressions is obtained by giving the sheet a circumferential movement in the course of the transfer of the sheet. If desired a lateral motion may also be given to the sheet. The transfer cylinder U is fitted with a gripper support B comprising a bottom member 7, side members 5 in which a gripper shaft 1 is mounted, and an upright member 4 against which the tips 3 of the gripper 2 press. The support B is guided by rails 27, 28 and is pressed by springs 31 against stop screws 32 which limit the movement of the support in one direction. The cylinders D, U are geared together, and in their rotation sectors 8, 11 fitted to the support B engage similar sectors 9, 12 which are circumferentially adjustable on the cylinder D. The circumferential adjustment is effected by screws 21 engaging nuts 23 integral with the sectors 9, 12 in which a gripper shaft 24 with grippers 25 is mounted. The sectors 9, 12 are held in adjusted position by screws 17, 18, and the gripper support B adjusts itself automatically to the position in which the grippers 25 are set owing to the engagement of the gears 9, 12; 8, 11. The foremost teeth of one set of sectors are preferably made thinner than the remaining teeth. The gripper support B is preferably constructed so that it can be adjusted laterally while in motion in order to secure correct lateral register of the sheets. The support B is held in place by bars 27 which permit it to move laterally when a projection 35 on it engages a roller 37 which is carried by a threaded bolt 38 mounted in the frame G in such a manner that it can not rotate. A nut 39 operated by a hand-wheel 40 adjusts the position of roller 37 and thus controls the lateral position of the sheet at the time of transfer. The invention may be applied to the three-colour printing-machine described in Specification 252,908, and may be applied to offset machines, and the movable gripper may be arranged on a sheet-transfer cylinder or on an impression cylinder.