Patent GB-190101472-A (GB)
Title: Improvements in Printing Machines.
Inventor: NEWTON HENRY EDWARD
Filed: 1901-01-22
Granted: 1901-03-02
Abstract: 1472. Newton, H. E., [Hoe, R.]. Jan. 22. Cylinder machines with plane printing-surfaces.-Relates to bed and cylinder machines for printing in two or more colours or for giving two or more impressions on the same side of a sheet. The cylinder is provided with several impression surfaces, only separated from each other a distance required by the gripper gaps, and each surface takes a sheet and retains it until it has printed it against all the formes on the bed at successive strokes of the bed. Fig. 12 shows diagrammatically an arrangement of a planographic machine for printing in two colours, having a continuously-revolving cylinder 32. The bed 3 is shown as provided with two planographic printing-surfaces 4, 5, and it is reciprocated by racks, railroad gear, and crank mechanism of a usual form. The cylinder 32 is raised during the return stroke of the bed by any suitable means, such as eccentrics in the journal boxes operated by cams &c., so that the formes clear the impression surfaces. The cylinder 32 has two impression surfaces 32<1>, 32<11> and two sets of sheet-taking grippers 91, by which the sheets are taken from a feed-board 92. The cylinder is driven from the bed during the printing movement (that to the right of the position shown in Fig. 12) by racks on the bed engaging two spur-wheels loose on hurs at the ends of the cylinder. During the printing stroke, these wheels are locked to the cylinder so as to move it with them by means of levers pivoted on the cylinder and having projections on their ends for engaging notches in the rims of the spur-wheels. The locking-levers are moved to lock the wheels to the cylinder by arms projecting from a hub loose on the cylinder shaft, and this hub is rocked by a lever journalled in the cylinder hub and having one arm engaged by a segmental cam mounted to rotate on the cylinder bearing. This cam is rotated by a train of gearing, and is arranged so that it holds the locking-arms out of the notches except during the printing movement. During the printing movement, the locking-arms are released by the cam, and are engaged, by springs, with the notches. During the return stroke of the bed, the cylinder is driven through half a revolution by a train of gearing operated by a rack on the underside of the bed. The last wheel of this train is loosely journalled on a hub of the cylinder shaft. On this hub is fixed a disc having notches adapted for engagement by a lever on the spur-wheel for locking the cylinder to it during the return movements of the bed and releasing it at other times. This locking- lever is operated to unlock the cylinder by a tappet arm operated by a cam on a shaft of the machine, and is operated to lock the cylinder by a cam fixed on the framing. The grippers 91 are operated, through mechanism mounted in the cylinder, by two cam arms of a lever pivoted on the framing and rocked, so as to bring the cam arms into operative positions at the required times to take and release the sheets, by cam on a rotating shaft of the machine. After printing, the sheets are passed to any suitable form of delivery mechanism, which may consist of a switch 114, tapes 113, a fly 115, and delivery table 116. The printing- surfaces 4, 5 are inked respectively by sets of inking-rollers 400, 500, and these rollers are raised, so as to clear the printing-surface which they are not required to ink, by cam tracks on the sides of the bed. Damping-apparatus 403, 503 are provided for the surfaces 4, 5 respectively. In the operation of the machine, from the position shown in Fig. 12, the cylinder makes one revolution during the first printing stroke of the bed, a sheet S is taken by the grippers 91 and applied to the surface 32<11> by which it is printed against the forme 4. During the return stroke of the bed, the cylinder makes half a revolution, so that, in the next printing stroke of the bed, the surface 32<11> prints the sheet thereon a second time, but against the forme 5, and the surface 32<1> takes a sheet from the feedboard and prints it a first time against the forme 4, and so on. The sheets placed on each of the surfaces 33', 32<11> are thus printed, in succession, by the two formes, and are not removed from the surfaces between the two impressions. Fig. 24 shows diagramatically an arrangement of a stopcylinder machine for printing in two colours. The bed of the machine is driven in substantially the same manner as that of the machine previously described, and the cylinder 32 is raised and lowered by toggle mechanism of a well-known type. The cylinder is driven during the printing stroke of the bed, by racks on the latter gearing with spur-wheels loose on recessed hubs on the ends of the cylinder. These spur-wheels run loose during the return stroke of the bed, the cylinder being stationary, and are locked to the cylinder during the printing stroke by locking - levers on shafts journalled in the cylinder. These levers engage notches in the inner rims of the spur-wheels. The shafts of the locking levers are provided with arms extending into the recess of the hub on which one of the spur-wheels is mounted. In this recess is journalled on the cylinder shaft, a collar having pins engaging the arms on the locking-lever shafts. The collar has also two projecting arms, operated to unlock the cylinder by a cam lever moved into and out of operative position by a cam. The grippers 141 of the cylinder 32 are operated by connections from shafts journalled in the cylinder hubs, and having arms on their outer ends operated by a cam on an arm pivoted on the framing. This arm is rocked by a cam so as to move it into position to operate the grippers at the required times to take and deliver the sheets. In the arrangement shown, the sheets are fed to the grippers 160 of the cylinder 159 and transferred to the grippers of the cylinder 32. The bed is at the left-hand end of its movement, and is about to make its printing stroke in the direction of the arrow. The surface 32<1> has a sheet thereon, which has already received an impression from the forme 4. During this printing stroke, a sheet is placed on the surface 32<11> and receives a first impression from the forme 4, and the sheet on the surface 32<1> receives its second impression from the forme 5. At the end of the movement of the bed the cylinder has moved through a revolution and a half, and comes to rest with the surface 32<11> containing the once-printed sheet, in the place which is shown in Fig. 24 as occupied by the surface 32<1>. In the next printing stroke, the sheet on the surface 32<11> receives its second impression from the frame 5, and a new sheet is placed on the surface 32<1>. The printed sheets are delivered by the cylinder 159 to the tapes 115.