Patent GB-641102-A (GB)
Title: Hydraulic mechanism for controlling the application of pressures between two or moreobjects
IPC: F16C13/00
Filed: 1947-08-05
Abstract: 641,102. Printing-machines. OILGEAR CO. Aug. 5, 1947, No. 21257. Convention date, Nov. 16, 1938. [Class 100 (ii)] [Also in Group XXIX] A hydraulic device for controlling the pressure between the rolls of a printing-machine, and also for controlling the pressure between operating devices of other machines is constructed with a pump 15, Fig. 1, for delivering liquid at constant pressure to a pipe 16 from which liquid is delivered to hydraulic cylinder 10 fitted with plungers 9 connected to slides 7, 8 which support counterpressure rollers 5, 6 bearing on the impression rollers 4 of one or more printing-couples. Each cylinder 10 is connected to the pipe 16 via a resistance valve 19 and pipe 20 which is connected to a relief valve 18 which opens at a pressure at least equal to that it is desired to exert on the plungers. The outlet of valve 18 is connected to the inlet 17 of pump 15. The pressure required to open both valves 18, 19 simultaneously is somewhat greater than the pressure of the pump 15. In Fig. 1 the section A is fitted with a pair of valves 18, 19, but in section B only one set of valves 18, 19 is provided for the two cylinders. The pressures at which the valves 18, 19 open may be adjusted by means of a nut 24 engaging screws 25, 26 which may be arranged to keep the combined pressures constant. Or two independently-operated nuts may be used, and means may be provided for connecting these for simultaneous operation. In a modification, Fig. 3, two independently-operated pumps 37, 40, may be used, and control valves permit the pressure liquid to be directed to the upper or lower ends of the cylinders 33, 36, so that in the latter case the pressure of the printing rollers may be less than their weight. The pump 37 is adapted to supply the pressure fluid to the upper ends of the cylinder and the pump 40 to the lower ends, and the main control valve 45 is shown in neutral position in Fig. 3, and can be moved to the right or left of the neutral position by means of solenoids 49, 50. When moved to the left against the action of spring 47, pressure liquid passes from pipe 55 to pipe 56 and thence to the upper ends of the cylinders 33, 36 via valves 19a, 18a; 19b, 18b of similar construction to the valves 19, 18, Fig. 1. The pump 40 supplies fluid to the lower ends of the cylinders 33, 36 under control of a valve 62, and the valve 45 is then moved to the right so that liquid leaving the upper ends of the cylinder may pass via pipes 58a, 58b and via relief valve 60a, 60b to pipe 56 and thence via the valve and pipes 53, 39 to the exhaust of pump 37. A valve 62 may, however, be set so that exhaust from the lower ends of the cylinders passes via pipes 68 through the valve to the exhaust of the pump 40. In a further modification, Fig. 7, the pump 40 and valve 62 are dispensed with and replaced by valves 18c, 19c which can be supplied with pressure fluid by a valve 75 similar to the valve 45. In this modification variations in the pressure of the roller 4 on printing-cylinder 1 may be effected by applying fluid pressure to both ends of the cylinders 32, 36. The upper ends of these cylinders can be supplied from the outlet pipe 38 of the pump 37 via pipe 87, valve ports 82, 81, pipe 56 and two sets of valves 19a, 18a; 19b, 18b similar to the corresponding valves 19, 18, Fig. 1. Relief valves 60a, 60b, and 91 are also provided.