GB899783A - Improvements in or relating to printing machines - Google Patents

Abstract

899,783. Rotary printing machines. NEBIOLO S.p.A. Sept. 29, 1960 [Oct. 3, 1959], No. 33499/60. Class 100(2) In a sheet-fed rotary offset multicplour machine wherein sheets are fed by oscillating grippers from a feedboard and through two or more printing couples associated with transfer cylinders, there is a central control lever system adapted, during the operation of the machine, for effecting small radial displacements of the stops in the gripper systems of the oscillating grippers, and the grippers on the transfer cylinders. These adjustments enable the machine to be rapidly pre-set for printing sheets of varying thickness. As shown, sheets taken from a pile 3, Fig. 1, and placed on a feedboard 5, are conveyed therefrom by oscillating grippers 7 to the grippers on an impression cylinder 6 in the printing unit 1, then transferred by the grippers of transfer cylinders 11, 12, and 13 to the grippers of an impression cylinder 14 in the second printing unit 2. The printed sheets are then taken by grippers on a chain 17 and deposited on a pile 18. The gripper stops or pads 7a, Fig. 2, are raised or lowered relatively to the feedboard 5 when an eccentric bush 30, which supports the bearing 32 of a shaft 31 carrying the stops, is rotated by the movement of a rod 19 which is pivoted to a lever 29 secured to a pivot 29a. The pivot 29a is secured eccentrically to a bush 25 which can be rotated about the axes of the pivot 29a by a worm and wormwheel device (Fig. 3, not shown) operated by a hand wheel. A lever 24, secured to the bush 25, is connected by a rod 20 to a cam 22 freely mounted on the transfer cylinder 11. When the bush 25 is rotated, the cam 22 is also rotated to adjust the gripper stops 33 on the cylinder 11, by rocking a pivoted lever 35 which carries a shaft 34 on which the stops are mounted in the cylinder. The lever 35 has a roller 39 at its free end which is engaged by a roller 40 on a two-armed lever 41 pivoted on the cylinder 11, and the other end of the lever 41 has a roller 43 which is engaged by the cam 22. Thus the cam 22 rocks the lever 41, which in turn rocks the lever 35 and adjusts the gripper stops radially. Rotation of the cam 22 is transmitted through a rod 21 to a further cam 45 on the transfer cylinder 13 to adjust the gripper stops therein. Further rods may be similarly arranged to adjust cams on other transfer cylinders. Thus, when the bush 25 is rotated by its hand wheel, all the gripper stops on the transfer cylinders, and those of the oscillating grippers on the feedboard are adjusted. The hand wheel for the bush 25 may be associated with a pointer and a scale graduated to relate to sheet thickness.