Patent GB-407719-A (GB)
Title: Improvements in or relating to pressure adjustments for cylinders of printing and other machines
IPC: B41F13/40
Filed: 1932-06-23
Abstract: 407,719. Printing-machines. ROBINSON, L. T. A., 75, Crystal Palace Park Road, Sydenham, London. June 23, 1932, No. 17783. [Class 100 (ii).] Impression adjustments.-For controlling the pressure between two cylinders 1, 2, e.g. the impression and printing cylinders of an intaglio printing-machine, the cylinder 2 is supported at each end upon toggle mechanism which can be operated manually or by fluid pressure in order to apply or release the pressure between the cylinders. Adjustment of the pressure is obtained by means of adjustable wedges 5, 6, which act between fixed bearings of the cylinder 1 and the movable bearings 9, 10 of the cylinder 2 and are operated independently by screws and hand-wheels 7, 8. The bearings 9, 10 are slidable in slots 11, 12 in the frames 13, 14 and are fitted with cap-like plates 17, 18 to which the upper links of the toggle mechanism are pivoted. The toggle links are formed of solid rods 21', 23<1>, and to their sides are screwed plates 21, 23. The pivotal connections between the toggles comprise gapped bearings which permit only limited rotation of the toggles when the cylinders are tripped. The lower toggles are carried by supports 37 bearing on adjustable wedge members 38, 38<1> held in place by plates 42. The wedges 38, 38<1> can be adjusted in a direction parallel to the axes of the toggle pivots by means of screws 107, 108 formed on a rod 103 and on a sleeve 106, which are normally caused to rotate together by operating either of two handles 104, 105 connected by a clutch 110, 111. By pulling out the handle 104 against the action of a spring 112, the screws can be operated independently. The toggles are connected by pivots 45 to links 48 pivoted to bell crank levers 52 which can be operated by hand-levers 56, or by pneumatic means. The pneumatic means comprise one or two pressure cylinders 62 for each cylinder 2, and in each cylinder is a piston 61 connected by a rod 60 and link 59 to the bell-crank 52. Control of air to the cylinder is effected by a three way cock which can be set to an " off " position in which air leaves the cylinder, to a neutral position, or to an " on " position in which air enters the cylinder. The cock is fitted with a vertical operating-rod 74 controlled by a handle 76 moving over a graduated quadrant 77, and the rod 74 may be connected by a lever 81, and link 82, shown diagrammatically in Fig. 3, to a similar operating handle 84 on the other side of the machine. The toggles can thus be operated from either side of the machine by a lever 56, or at either side of the machine by means of one of the two hand levers 76, 84. When a number of printing- couples are used for multi-colour printing, rods 94 connect the means for operating the cocks for controlling the air pressure, and the arrangement is such that all the cocks can be operated simultaneously from the side of any machine. An additional lever 100 is provided which allows the toggle mechanism of the desired couple to be operated independently of the other couples. This lever operates a sleeve 99 through which the rod 74 passes, and owing to lost motion between the rod and the sleeve the rod 74 can be operated without turning the sleeve 99 which is the operating member for the rods 94 by means of which the toggle mechanisms of the presses are operated simultaneously.