| 摘要 |
574,595. Printing-machines. WARSDEN, H. E. Feb. 4, 1944, No. 2125. [Class 100(ii)] [Also in Group XXIX] The lithographic printing - plates such as are used in rotary offset presses are damped by means of sprays of atomized fluids which are applied directly to the plates by means of a number of spray nozzles, which as shown are supplied with water from a tank 24, Fig. 1, connected by a pipe 30 to a water manifold 33, Fig. 3, and with compressed air supplied by a pump 27 to a manifold 32 via a reducing valve 108 which permits of control of the force of the spray. A number of spray nozzles are used, but some can be put out of action if a narrow plate is used, and each spray is fitted with independent controls for the air and water supply, but the active nozzles are put into and out of action simultaneously, although they may be controlled so as to deliver an air blast only to dry the printing-plate, and finally the nozzles are set so as to deliver an atomized spray. The nozzles are arranged in a box-like spray guard S fitted with ends adjustable longitudinally for dealing with narrow plates, the guard S being formed with a drain channel 105 leading by a pipe 29 to a tank 28 or to waste. The sprayers are connected by stirrup fastenings 31 and bolts 34 to the manifolds 32, 33, and the air supply to the sprays is controlled by a valve 52 governed by an adjustable spring 57, and the air passes to a chamber 44 and inclined ports 46 to entrain water delivered to a nozzle 41 under control of an adjustable spring-controlled needle valve 48. The valves 48, 52 are con- - trolled by cams 61 detachably secured to a shaft 62 which is manually adjustable by an arm fitted with a pointer 68 moving over a scale 67. Each sprayer is fitted with an adjustable cam follower 63 on a lever 58 pivoted at 58a and provided with a U-shaped member 59 which actuates the air valve 52, and a projection 60 which actuates the water valve 48 subsequent to the actuation of the air valve. In a modification, Fig. 10, the means for controlling the sprays is so mounted as to be out of-operation when the press motor is not running. The control shaft 62 and associated devices as described above are mounted in swinging bearing brackets 75 which are normally maintained by tension springs 78, in such position (counter-clockwise of the position shown in Fig. 10), that the cams 61 do not contact with the cam followers of the levers 58. On starting the motor of the press, an electromagnet 83 is energized and its solenoid 84 actuates a lever 85 against the action of a spring 88 to move the brackets 75 clockwise and bring the cam 61 into the position shown in Fig. 10 in which the cams can operate the levers 58. In a further modification applicable for printing sheets by a machine in which a segmental plate is used, the action of the spray means is interrupted by cam means so as to act only upon the plate portion of the plate cylinder. |
