Patent GB-355830-A (GB)
Title: Improvements in or relating to sheet-fed rotary printing machines
IPC: B41F13/28
Filed: 1930-05-31
Abstract: 355,830. Inking apparatus. LINOTYPE & MACHINERY, Ltd., 9, Kingsway, London, and JAKEMAN, J. W., 3, Clarendon Avenue, Altrincham, Cheshire. May 31, 1930, No. 16881. [Class 100 (ii).] In a sheet-fed rotary printing machine in which the forme cylinder presents a gap between the two ends of the forme and means are provided for tripping the printing couple and the inking rollers, means are also provided for preventing the inking rollers from resuming their untripped or operative position until the gap is in position for receiving them. The invention is described as applied to a three-cylinder offset lithographic press wherein the transfer cylinder 2, Fig, 1, is capable of being automatically moved into and out of contact with the plate cylinder 1 and the impression cylinder 3 by known means, such as eccentrically-mounted journal boxes 4 which support the shaft 5, and levers 6, 7. The tripping of the inking rollers 8 relatively to the plate cylinder 1 is effected through a connecting rod 9 pivotally attached at its lower end to the lever arm 6, and at its upper end engaging by its slot 9a with a crank pin 10 secured to a rock shaft 11. A second crank pin 12 secured to the rock shaft 11 has secured to it the lower end of a link 13 constituting the first of a series of levers and links operatively connected to the cradles or frames 14 in which the inking rollers 8 are journalled. A toothed segment 15, secured to the rock shaft 11, meshes with a segment lever 16, which is rotatably mounted on a stay-rod 17, and carries with it a second lever 18, which is pivoted thereto by a pin 19 so that it can swing relatively thereto in the same direction as the axis 26 of the cylinder 1. The lever 18 is retained within a channel formed in the segment lever 16 by the pivot pin 19, which passes through the sides of the channel. and through the lever 18. A roller 21, carried by the lever 18, co-operates with a cam ring 22 secured to, and concentric with, the plate cylinder 1. As shown in Fig. 5, the cam ring is provided with recesses 22a, 22b, 22c, and the recess 22a may be inclined to the cylinder axis 26 uniformly throughout its length, or the inclination may vary continuously from the leading end to zero at the back end. When the printing couple is in printing relationship the roller 21 stands within the cam ring, but when the connecting-rod 9 is moved downward consequent upon the tripping of the printing couple, the inking rollers 8 are tripped and the segment lever 16 and lever 18 are swung outwardly as that the roller 21 is caused to traverse the inclined chamfered surface of the recess 22a about the pivot pin 19 and against a compression spring 20 situated in a recess in the lower end of the channel. When the roller 21 has passed completely across the cam ring the spring 20 forces it towards the plate cylinder at the outside of the cam ring. On the printing couple being untripped, the connecting rod 9 ascends to permit the inking rollers 8 to drop by gravity into their operative position, this being prevented by the roller 21 coming into contact with the outer surface of the cam until the recess 22b is presented to the roller 21, at which juncture the roller 21 passes within the cam ring under the weight of the inking rollers 8 which drop into operative position at the time when the cylinder gap is presented beneath them. A hook 28, which engages the crank pin 10, is pivoted to the connecting-rod 9 and can be swung out of engagement with the pin 10 to allow the inking rollers 8 to remain in operative position irrespective of the tripping and untripping of the printing couple. A lever handle 25 secured to the shaft 11 enables the inking rollers 8 to be manually raised and lowered at any time at which the cam ring recess 22c is presented to the roller 21.