Patent GB-536814-A (GB)
Title: Improvements in or relating to machines for treating printing plates
IPC: B41D5/00
Filed: 1939-10-25
Abstract: 536,814. Finishing printing plates. WOOD NEWSPAPER MACHINERY CORPORATION. Oct. 25, 1939, No. 28664. Convention date, Jan. 17. [Class 100 (ii)] In a machine for finishing curved stereotype plates in which the plates pass into a shaving arch on rollers forming an inclined runway; one or more of the rollers is positively driven to control the speed of the plate. A blast of air may be directed upon the plate to clean it before it enters the arch and the shaved plate may pass to a cooling and washing tank and thence to a drying apparatus. Oil may be sprayed on to the shaving knife at intervals to prevent chips sticking thereto or to remove chips therefrom. The plates are supported during their passage through the machine on two inclined rows of rollers most of which are freely rotatable but some of which are positively driven so as to control the speed of the plates into and out of the shaving arch 1. The plate is moved on to the rollers from an inspection stand 2 and is brought to rest against a stop 34 which is depressed at the proper time by a cam 93 on the knife shaft 6 to allow the plate to pass into the arch 1 into engagement with a stop 66, Fig. 3. Lifter bars 63, Fig. 11, are then actuated by a rock shaft 107 arm 109 and link 133 to raise the plate off the rollers and into contact with a water cooled liner 106 in the arch 1. As the plate is raised its edges are sprung inwardly by rods 116 connected to the bars 63 and actuated by levers 122 and a cam 126 on the shaft 107. The shafts 107 are moved in a direction to lower the bars 63 by spring rods connected to arms on the shafts and are moved in the opposite direction to raise the bars by a cam on a shaft driven from and at the same speed as the knife shaft 6. Mechanism is provided whereby this cam can act at every revolution of the shaft 6 or at every other revolution thereof in which case the plate is held for two revolutions of the shaft 6 and is shaved twice. The knife shaft is provided with two radially adjustable shaving knives 24, 25 end trimming cutters 168, 169, and with a pivoted pawl 67, Fig. 2, carried by a spring pressed plate. 175 slidable in the shaft 6. This pawl serves, by snapping up behind the plate as it engages the stop 66, to prevent rebound of the plate and also, when the stop 66 is lowered at the end of the shaving operation to start the movement of the plate out of the arch. For this purpose the plate 175 carries a roller 178 adapted at the end of the shaving operation,.to engage a fixed cam projection 180 which moves the plate 175 a short distance towards the stop 66. The plate passes from the arch 1 into a cooling arch 201 and in its passage depresses levers 186 thereby opening awater supply valve to supply cooling water to a perforated pipe 194 above the plate and to a perforated water jacket 193a beneath the concave surface of the plate. In this arch the plate engages a stop 90 which may be actuated manually or by a cam 91 on a shaft extension 195 of the knife shaft to allow the cooled plate to pass beyond the arch to a position above a perforated air pipe from which air jets are directed on to the concave side of the plate to dry this side of the plate. The valve for controlling the air supply is actuated by a cam on an extension 195a of the shaft 195. Air jets controlled by a cam on the knife shaft are also provided to remove foreign mater from the convex side of the plate as it passes into the shaving arch. An oil injector, Fig. 31, is arranged to spray oil on the shaving knives when these are out of their shaving position. Air is supplied to the injector from a pipe 430 connected to an air supply through a non-return valve opened at intervals by a cam and the oil is drawn up through a pipe 436 from a tank through a non-return valve which ensures that the pipe 436 is constantly full of oil.