Patent GB-306597-A (GB)
Title: Improvements in printing processes and apparatus
IPC: B41C1/06
Filed: 1927-11-25
Abstract: 306,597. Connolly, F. J. Nov. 25, 1927. Transferring designs; offset machines.-A printing-plate bearing a number of accurately disposed copies of a single original design is produced by mounting the original upon a reciprocatory carrier geared with a rotary offset cylinder by which impressions from the original are transferred to the plate which is' mounted on a cylinder geared to the offset cylinder, the disposition of the impressions being determined by transverse and longitudinal adjustments of the carrier relatively to the offset cylinder. The original design 5, Figs. 1 and 2, is formed on a strip 5<a> secured by clips 4 to a platen 3 carried by a plate 1 which is adjustable transversely of the machine by screws x geared together and operated by a hand-wheel z. The plate 1 is supported by a platform 6 vertically movable in a frame 7 carried by a bed b slid able longitudinally of the machine. 'The vertical movement of the platform 6 is effected bv a wedge member 6a operable by an arm 18, Fig. 5, provided with an eccentric end 13 mounted on a cross-shaft 12 carried by the member 6<a> and engaging between lugs 16 on the frame 7. Racks c on the bed b engage gears g on a shaft d carrying an offset cylinder r, and a gear h fixed to the shaft d engages a gear j fixed to a shaft k of a cylinder q on which the plate t to receive the impressions is secured. The shaft k is mounted in eccentric bearings operated by a pedal p to bring the plate t into and out of contact with the cylinder r. One of the gears q is loose on the shaft d and the other is releasablv secured thereto and is provided with lateral teeth engaging pinions g<1> carried by rings g<2>, g<3> secured together and to the shaft d so that, upon releasing the gear g from the shaft and rotating the pinions g<1>, the offset cylinder can be adjusted angularly relatively to the gears g, after which the gear is again secured to the shaft. The gears g engage pinions v on a shaft v<1> provided with a driving pulley or hand-wheel w. In operation the pedal p is actuated to separate the cylinders q and r and the shaft v<1> is rotated to move the bed b to the right, Fig. 2, to impart an impression from the original 5 to the cylinder r. The platen 3 is then lowered by operating the wedge member 6a, the bed is returned to its original position, and the platen again raised. The cylinder r is then adjusted angularly by the pinions g<1> so that the next impression Y, Fig. 2, will be spaced from the first impression X<1> to the required extent. A fine adjustment of this spacing may be effected by an adjustment of the frame 7 by a screw 7a and hand-wheel 10. After the cylinder r has received a circumferential row of impressions it is returned to its initial angular position and the platen 3 is moved laterally to the required extent by means of the hand-wheel z, and the series of operation is repeated so that a second circumferential row of impressions spaced from the first row is obtained. When the whole of the cylinder r is covered with the impressions, the cylinders t and r are brought into contact and the bed b is moved to the right with the platen in its lowered position. The plate l thus receives the whole of the impressions from the cylinder r and is then ready for use or for development for use as a printing plate. The edges 14 of the platen 3 are preferably bevelled and the edge of the design 5 is caused to coincide with the inner edge of the bevel so that during the transfer of an impression to the cylinder r the previous transfers are not brought into contact with the platen. Blankets.-The cylinder r may be clothed with a blanket of rubber, vulcanite, celluloid, or casein.