Patent GB-721909-A (GB)
Title: Controlling and change-over device for cylinder printing machines, more especially two-revolution machines, providing double inking of the printing forme
IPC: B41F3/10
Filed: 1952-06-10
Abstract: 721,909. Printing-machines. MASCHINENFABRIK-AUGSBURG NURNBURG AKT.- GES. June 10, 1952 [July 27, 1951], No. 14590/52. Class 100 (2). Two-revolution machines; cylinder trips.- A device adapted to provide for double inking of the printing forme in a two-revolution cylinder printing machine comprises a number of constantly rotating control cams each associated with a control lever which can be engaged with or disengaged from the cam, each lever rendering inoperative means controlling a function necessary for printing operation with single inking. The control cams 5, 6, 7, Fig. 2, are rotatably arranged on a spindle 2 secured to the machine frame 1 and driven at half machine speed by gear 3. The control levers 9, 10, 11 are freely mounted on a parallel shaft 8 which is rotatable by a hand lever 12 and carries projections adapted to engage abutments on the levers and displace them from engagement with the cams. As shown in Fig. 3, the lever 9 carries a follower roller 14 which is urged into engagement with the cam 5 by a spring 17 attached to the other arm of the lever. A slotted link 26 pivoted to the lever 9 engages a pin 29 on a lever 28 urged in a clockwise direction by a spring 27 and arranged to control the mechanism for moving the impression cylinder into pressure contact with the former. In the position shown in Fig. 3 the lever 28 is effective to cause the impression cylinder to be moved to operative position. When the roller 14 is engaged with the fall part of the cam the link is displaced to the right by spring 17 and causes rotation of the lever 28 in an anticlockwise direction, this preventing movement of the impression cylinder to operative position. By this means, since the cams rotate at a speed equal to a quarter of that of the impression cylinder, the impression is only thrown on once in four revolutions, the forme being inked as before once in each two revolutions. The lever 12 may be rotated in an anticlockwise direction to cause the pin 24 to engage a projection 25 from the lever 9 so as to displace the lever out of contact with the cam. The double-inking device is thereby rendered ineffective and the machine functions as a normal two-revolution machine again. A similar arrangement to control the feed of sheets is shown in Fig. 4. The lever 11 has a roller 16 engaging the cam 7 under the action of spring 31 and is connected to a link 32 controlling a valve 33 in the pipe 34 supplying the suction separators of the sheetfeeding mechanism. When the roller 16 is on the fall part of the cam the suction is shut off, and no sheet is therefore fed to the printing machine. The lever 12 rotates an arm 43 so that a pin 44 thereon engages an adjustment screw 46 on the lever 11 and displaces it to a position out of contact with the cam. The machine will then have a sheet fed every printing cycle. To prevent the intentional absence of a sheet in alternate printing cycles causing the machine to be stopped by the faultyfeed detector mechanism, this mechanism is rendered ineffective by lever 10, Fig. 2, controlled by cam 6 in similar manner and adapted, when operative, to cause the opening of a pressbutton switch in the detector control circuit during printing cycles when no sheet is fed. Lever 12 causes the switch to remain closed. The lever 12 is retained in either position by a sliding pin 21 operable by the knob 20 and engageable in either of a pair of holes 22 in the frame 1.