Patent GB-547141-A (GB)
Title: Improvements in or relating to printing machines
IPC: B41L47/24
Filed: 1941-11-17
Abstract: 547,141. Addressing and like machines. ADDRESSOGRAPH-MULTIGRAPH CORPORATION. Nov. 17, 1941, No. 14785. Convention date, Nov. 16, 1940. [Class 100 (ii)] In a printing machine in which printing-devices are fed in succession to print on sheets fed also in succession, the feeding mechanism for the printing devices is normally inactive but is rendered operative at selected instants by the passage past a feeler device of certain of the sheets, or special control sheets which separate groups of the sheets to be printed. Any predetermined number of sheets can thus be printed by any printing device. The change of printing device may be accompanied by a stoppage of the machine for inspection, the stoppage being effected by the opening of a driving clutch by mechanism actuated by the feeler. The sheets S, Fig. 1, to be printed, each receive, in the machine shown, three impressions from the same printing plate, and are fed from a pile 39 between feeler discs 109, 112 on to continuously running tapes T. Three stops 167, 172, 178 actuated by cams on a shaft 135 hold the sheet in three different positions in each of which it is printed by an operation of the pivoted platen P actuated by cams on a shaft 52 which makes three revolutions for one revolution of the shaft 135. The printing plates D, Figs. 1 and 3 are fed from a magazine M by pawls 51 on a pair of chains 50 passing round sprocket wheels, one pair 49 of which is fixed to a shaft 46 and driven intermittently to advance the plates D on to an anvil A beneath the platen P. The driving device for the chains comprises spaced pins 82 on one of the wheels 49 and a pawl 78 carried by an arm 77 oscillated about a pivot 74 by cams on the shaft 52. Normally the pawl 78 at the end of its idle stroke, engages a finger 88 to prevent the pawl engaging the next pin 82 so that the plate feeding mechanism is normally inactive. The finger 88 is carried by a lever 87 pivoted at 86 and carrying a stud 89 which normally engages a stop shoulder 89<SP>1</SP> on an arm 91 which is rigidly connected with arms 103, 100. The arm 103 is connected to a spring 104 which holds the shoulder 89<SP>1</SP> in stopping position, and the arm 100 is connected to the core of a solenoid 97 having in its circuit a pair of normally open contacts 126, 127, Fig. 9, which are automatically closed when a special control sheet passes between the feeler discs 109, 112. When this occurs, the solenoid actuates the arm to withdraw the shoulder 89<SP>1</SP> from the stud 89 and allow a spring 94 to swing the lever 87 so that the finger 88 is withdrawn from the path of the pawl 78 which thereupon engages a pin 82 to bring the next printing plate over the anvil A. The parts 88, 87, 80 89<SP>1</SP> are then immediately reset by means of a cam 137 on the shaft 135 depressing a bell-crank lever 140 connected by an adjustable link 146 to an arm 150 rigidly connected to the lever 87. The upper feeler disc 109 is carried by an arm 117, Fig. 9, pivoted at 114 and carrying a roller 119 co-operating with a cam 120 on a shaft 122 which makes one revolution for each sheet fed so that during the passage of each sheet between the discs 109, 112, a drop 121 in the cam 120 passes beneath the roller 119. During the passage of the ordinary sheets to be printed, the sheets support the disc 109 and prevent the roller 119 from entering the drop 121 but on the passage of a special sheet or record sheet which is provided with a slot, the disc 109 is unsupported and falls and closes the contacts 126, 127 as above described. The same action occurs upon the failure of a sheet to be fed and in order that the operator may in that case, remedy the defect and remove from the machine the printing plate just fed off the anvil A and also the remains of the batch of sheets which should have been printed by that plate, the feeler is also arranged to stop the machine for inspection at each change of printing plate. This is effected by causing the movement of the disc 109 to open a clutch 55, Fig. 1, between a belt pulley 57 and the main shaft 53 from which the shafts 52, 135 and 122 are driven. The clutch comprises a pawl 183, Fig. 15, carried by a disc 181 fixed to the shaft 53 and normally engaging a notch 186 in a collar portion 180 of the pulley 57. A cam 187 pivoted at 188 carries a pin 190 engaging an arcuate slot 191 in a plate 192 pivoted at 193 and provided with an operating handle 195. A member 203, Fig. 9, pivoted at 204 is normally held by a spring 206 so that a shoulder 202 thereon engages a shoulder 201 on the plate 192 to hold the cam 187 in the inoperative position shown in Fig. 15 A rod 211 pivoted to the member 203 passes freely through a lug 214 on the arm 117 and terminates in a hook 215 which co-operates with a shoulder 217 on a cam 216 fast on the shaft 122. When the disc 109 falls due to the absence of a sheet or the passage of a control sheet the rod 211 also falls and brings its hook 215 into the path of the shoulder 217 which thereupon pulls on the rod 211 turning the member 203 so that the shoulder 202 leaves the shoulder 201 allowing the plate 192 to be turned by a spring 196, Fig. 15, to move the cam 187 into the path of the tail 199 of the pawl 183 which is thus disconnected from the notch 186, A hand lever 207, Fig. 9, adapted by engagement with a boss 210 on the member 203 to turn this member against the action of the spring 206, is provided for manual control of the clutch.