Patent GB-274686-A (GB)
Title: Improvements in and relating to multi-colour printing machines
IPC: B41F13/02
Filed: 1926-11-03
Abstract: 274,686. Ringier & Co., Verlagsanstalt & Vereinigte Buch-und Steindruckereien. Oct. 8, 1926, [Convention date]. Feeding and registering webs.-To ensure that the successive impressions of a rotary multi-colour printing- machine are correctly superposed, the web is provided at intervals with perforations which co-operate with feelers controlling relay devices for axially moving the printing cylinder of the second and succeeding printing-couples and for varying the position of the guide roller of a longitudinal tensioning device, in order to compensate for lateral or longitudinal deviations in the web. The web from the roll 1, Fig. 1, is guided between the cylinders 4, 5 of the first printing-couple A and passes through perforating-mechanism B where it receives two perforations transversely of its length, the space between successive pairs of perforations being equal to the circumferences of the printing cylinders of the printing-mechanisms. From the perforating-mechanism the web passes over a drying- table 43 and guide rollers 44-47 and around a guide roller 48 mounted on the arm 49 of a bellcrank lever 49-50, the arm 50 being engaged by a screw-threaded shaft 52 geared to a. motor M to vary the angular position of the bell crank to compensate for longitudinal variations in the web. Rollers 57, 57<a> guide the web around a rotating regulating-cylinder 58 provided with feelers adapted to register with the perforations in the web, and from these the web passes between the rollers 61, 62 of the second printing- couple C and over a drying drum 64. Further printing-mechanisms may be provided, each having a regulating-cylinder and longitudinal tensioning-devices. The regulating-cylinder 58, Fig. 12, is provided on its circumference with two recesses containing pivoted feelers or contact pins 69, 70 projecting radially therefrom. The feeler 69 on a pivot 71 is adapted to swing in the transverse direction of the web when the latter deviates laterally, and makes contact with one of two contact members 72, 73, thereby energizing one of a pair of relays 118, 119, Fig. 1, adjacent to the regulating-cylinder, and one of a pair 95, 96 adjacent to the printing cylinder 61 on the second printing-couple. The relays 118, 119 control rods 97<1>, 98<1> which are linked to levers controlling the engagement of pawls with two ratchet wheels 86<1>, 87<1> fixed on a shaft 85<1> rotatably mounted in the machine frame, the ratchet wheels acting to turn the shaft in opposite directions. The pawls are pivoted on an oscillating arm 84<1> connected to a crank driven by a pinion 80<1> on the shaft of the regulating- cylinder 58. The end of the shaft 85<1> is screwthreaded to engage within a boss 91<1> on a segment 92<1> secured to the hollow shaft 105 of the regulating-cylinder so that when the web deviates laterally a pawl is allowed to fall into engagement with a ratchet wheel and an axial movement is imparted to the regulating-cylinder to restore the feeler 69 into the corresponding aperture of the web. The relay circuit of the regulating-cylinder 58 is in parallel with the relay circuit of the printing cylinder 61 which is provided with similar pawl and ratchet mechanism for producing an axial movement of the printing cylinder corresponding to the compensating movement of the regulating-cylinder. Wires 107-112 within the shaft 105 connect the feeler contacts to slip rings 106 on the shaft and, to ensure that the slip rings remain in contact with brushes 113 during the movement of the shaft, the brushes are supported by a member 115 on a segment 116 which moves with the shaft. If an alteration occurs in the web in its longitudinal direction a perforation does not register with the feeler 70, which is on a pivot parallel to the axis of the regulating-cylinder, and the resultant movement of the feeler into contact with one of . two contact members adjacent to its lower end closes one of a pair of relay circuits controlling switches in the supply circuit of the three-phase motor M geared to the shaft 52 of the tensioning- device, the switches being adapted to change two of the phases to control the direction of rotation of the motor. A hand-operated device for longitudinally registering the feelers 69, 70 with the perforations in the web comprises a pair of toothed wheels 136, 137, Fig. 6, mounted upon a vertically slidable support 127 controlled by a screwed shaft 129 which is geared to a handwheel 135. The wheel 137 engages one of a. train of wheels 138, Figs. 1 and 6, geared to the regulating-cylinder and to the perforating and printing mechanisms, so that they receive an equal amount of rotation. The regulating-cylinder is adjusted axially by a hand-wheel 94<1> on the screwed shaft 85<1>. The printing cylinder 61 of the second printing mechanism is adjusted axially in a similar manner, and, by unclamping it from its driving-mechanism, it may be rotated until the second impression registers with the first coloured impression on the web. The perforations are made in those portions of the web which are finally cut, means being provided for adjusting the punches relatively to the first coloured impression on the web. A drum 7, Figs. 1 and 2, mounted on a hollow shaft 8 is provided with two dies 19, 20 with cylindrical bores to receive two spring-pressed punches 22, 23 mounted within recesses in discs 27, 28 on a hollow shaft 29. The shaft 29 is adjustably mounted on an axle 31 which is rigidly mounted between two levers 14, 15 provided with bosses 12, 13 so seated in the machine frame that they may be rotated to ensure the coincidence of the punches with the holes in the dies, a bolt 38 on the arm 15 serving to clamp it to the frame in its set position. Helical springs 16. 34 pressing against ball-thrust bearings on the shafts 8. 31 prevent axial movement of the drum 7 and the shaft 29. The drum 7 is driven by a toothed wheel 40 engaging a gear 41 on the printing press and is provided with a toothed rim 35 engaging a gear wheel 36 on the shaft 29 to drive the discs 27, 28.