Patent GB-1041057-A (GB)
Title: Off-set printing machine
IPC: B41L19/00
Filed: 1963-06-04
Abstract: 1,041,057. Offset printing-machines. AGFA A.G. June 4, 1963 [June 13, 1962], No. 22218/63. Heading B6C. In an offset printing machine having keys for initiating various functions of the machine, the key mechanisms are so interconnected that they can be operated only in certain sequences, e.g. if keys causing the machine to print are operative, a key for actuating an offset-cylinder cleaning mechanism cannot be actuated. The machine as shown has four keys, namely a printing key 5, a motor key 6, a key 7 for controlling an offset-cylinder cleaning apparatus 37 ... 40, Fig. 2, and a key 8 for moving a stop 45, Fig. 4, from a full-line position which it occupies when the machine is operating, to the dotted line position for positioning a pile 47 of sheets to be printed. The keys are in line and are pressed upwardly by springs 14, and each has a transversely - extending pin 9 ... 12. Beneath the pins is a horizontally-slidable bar 19 which has stop surfaces 19e, 19f normally preventing operation of keys 5, 7, and a cam surface 19c which, when engaged by pin 10 on depression of the motor key 6 causes the bar 19 to be moved rightwardly against the action of a spring 20 so as to release the keys 5, 7 and also close a switch 21, 22 of the drive motor. The key 6 is held in depressed position by a latch 25, and to release it the key has to be depressed still further against the action of a second spring 28 and washer 27. If, after the initial depression of key 6, the printing key 5 is depressed to cause engagement of the cylinders of the machine, the pin 9 thereon moves a bar 50, Fig. 4, to the left so as to operate a spring-controlled lever 48 and thus release a lug 44b on a lever 44 fixed to the front pile stop 45, so that the stop moves to its inoperative position by spring action. At the same time, a stop surface 50c on the bar 50 moves under the pin 11 to prevent operation of the cleaning key 7. Also, a pawl 53 on the bar 50 engages a ratchet wheel 5 on a spindle 54, the wheel 55 being fast with a notched wheel 58 engaged by a retaining pawl 57 and with a spoked wheel 59. The wheels 55, 58, 59 rotate one step for each actuation of the key 5, and the spoked wheel 59 moves a bar 60 momentarily to the right for each step. A first depression of the key 5 causes the bar 60 to render the printing machine and sheet-feed operative through levers 61, 62 and a suitable coupling mechanism. A subsequent depression of the key 5 causes the printing machine and sheet feed to be thrown out of operation. When the printing machine is rendered operative it causes, through rod 63, leftward movement of another horizontal bar 64, Fig. 4, which by means of a stop surface 64b prevents depression of cleaning key 7 and by means of a latch surface 64e prevents extra depression of the motor key 6 to release it. If the cleaning key 7 is depressed, with motor key 6 already depressed, in order to effect cleaning of the offset cylinder, its pin 11 acts on a cam surface 23a, Fig. 5 (not shown), of a bar 23 to move the bar horizontally to the left. The bar 23 has a surface 23a which is moved under the pin 10 to prevent release of the motor key 6 by further depression, and a stop surface 23c which prevents actuation of the printing key 5. The key 7 is latched in its depressed operative position, and is released by depressing it beyond this position by devices similar to those provided for key 6.