GB559853A - Improvements in or relating to printing presses - Google Patents

Abstract

559,853. Printing machines. GOSS PRINTING PRESS CO., Ltd., and WHITEHEAD, W. A July 2, 1942, No. 9169. [Class 100 (ii)] A late news or like printing mechanism comprises an impression cylinder assembly movable laterally into operative relation with either of a pair of printing cylinders, means for synchronising the speed of each printing cylinder with that of the impression cylinder assembly prior to its engagement with the impression cylinder assembly, and means operative upon synchronisation of the speeds for automatically moving the assembly into engagement with the selected printing cylinder. In one form, Fig. 2A, the shaft 20 of the impression cylinder is mounted in bearing housings 22 movable in guide slots 24 in the frame 23 to move the cylinder alternately into contact with type cylinders which are mounted on the shafts 43, 44. The shaft 20 is driven through an Oldham coupling 33, 34, 35 from a gear 40 driven by bevel gear from the press, and drives the active type cylinder by means of a gear 46 on the shaft 20 and gears 47, 48 on the shafts 43, 44. When driving one of the gears 47, 48, the other gear is out of mesh with the gear 46. To change from one type cylinder to another, the stationary cylinder after receiving its type matter, is driven by an electric motor 50 or 51, Fig. 4B until its speed is the same as that of the impression cylinder. When this occurs a motor 70, Fig. 4A operates mechanism for moving the bearing housings 22 laterally to move the impression cylinder into contact with that type cylinder and out of contact with the other. The motor 70 drives a cross shaft 73, Figs. 4A and 4B carrying worms 76 engaging worm wheels 77 on shafts 78 carrying eccentrics 79 for operating the housings 22, the movement being limited by the engagement of a lug 81 on one of the wheels 79 with one or the other of two adjustable stops 82, 83. As this occurs one or other of two switches 145, 146 is operated by dogs on the other worm wheel 79 to stop the motor 70 and also the motor 50 or 51 driving the type cylinder. The shaft 73 is movable axially to allow for continued rotation of the shaft by the inertia of the armature of the motor 70. This movement compresses one or the other of a pair of springs 84 on the shaft, which return the shaft to normal position at the beginning of the next rotary movement of the shaft in the opposite direction. The motor 70 is energized at the same time as the motor 50 or 51 for speeding up the type cylinder but is prevented from rotating by a pawl 86, Fig. 4A engaging a gear wheel 72 in the driving train of gears. This pawl is released by a solenoid 88 energized automatically when the speed of the type cylinder is synchronized with that of the impression cylinder. This synchronization is effected by means of gears 41, 42 Fig. 2A, driven from the gear 40 and carrying pawls 52 urged by springs into contact with the gears 47, 48. A ratchet recess is provided in each gear to receive the pawl when the speeds of the gears 41, 47 or 42, 48 are identical. At the same time a projection on the pawl closes a pair of contacts to energise the solenoid 88 to free the motor 70. Instead of sliding bearing housings 22, the shaft 20 may be mounted in eccentric bearings, and instead of a single impression cylinder, two cylinders geared together and movable as a unit may be employed. Specification 184,987, [Class 100 (ii)], is referred to.