GB318446A - Improvements in and connected with web-delivery mechanism for printing presses - Google Patents

Abstract

318,446. Marks, Sir G. C., (Harris- Seybold Potter Co.). Dec. 14, 1928. Tripping-arrangements .-The printed web is fed from a rotary press, such as the lithographic multicolour offset press shown in Fig. 12, by means of feed-rollers 27, 32, Fig. 1, driven from the cutting-rollers at the same speed as the printing cylinders, and the rollers 32 can be moved away from the driven roller 27 so as to trip this normal web delivery means, and simultaneously the web is brought under the control of other rollers 74, 84 driven at a slower speed. The tripping of the rollers 32 and bringing into action of the rollers 74, 84 is controlled by the trip mechanism which operates the eccentric bearings of the printing and offset cylinders of the printing- units A, B, C, Fig. 12, a rod 127, Fig. 1, being lowered simultaneously with the operation of the mechanism for tripping the cylinders. The rod 127 is connected to an arm 60 journaled on a shaft 36 to which is fixed an arm 49 provided with a spring-pin adapted to be received in an aperture 57 in the arm 60, as shown in Fig. 1, or to be received in an aperture 58 when it is desired to keep the rollers 32 out of action altogether. The rollers 32 are mounted in rock-levers 34 journaled on the shaft 36, and a yielding adjustable lost motion connection is provided between brackets 37 fixed to the shaft 36 and the upper end 41 of the levers 34. This connection comprises a screw 43 passing through an aperture in the end 41 and screwing into an aperture in the bracket 37, and a spring 45 on the screw. The arm 60 is connected by a link 126 to an arm 114 journaled on a shaft 88, and a fixed arm 103 can be secured by a spring-pin to either of two apertures 111, 112 in the arm 114, according as it is desired to maintain the freely mounted rollers 84 permanently out of contact with the roller 74, or to permit them to contact therewith when the link 126 is lowered. The rollers 84 are mounted in lever arms 86 freely mounted on the shaft 88 and having an adjustable connection with brackets 91 fixed to the shaft. The rollers 84 can thus be caused to contact with the roller 74 at the same time as the rollers move out of contact with the roller 27. The roller 74 is freely mounted on its shaft 73, which is constantly driven at a speed less than the normal speed of the web by the worm and bevel gearing from the shaft of the roller 27. As the rollers 84 are lowered into contact with the roller 74, a clutch on the shaft 73 is moved axially by means of a link 124 and bell-crank lever 120, so as to cause the roller 74 to be driven at the low speed of the shaft 73. The web is thus advanced at a low speed while the cylinders are tripped, and on restarting the press it is not necessary to re-thread the web, whilst waste of paper is kept down owing to the slow speed of the web.