Patent GB-316240-A (GB)
Title: Improvements in printing machines
IPC: B41F3/20
Filed: 1928-04-26
Abstract: 316,240. Cossar, T. April 26, 1928. Cylinder machines.-A printing-machine of the kind described in Specification 28998/10, in which a web is printed by an impression roller carried by chains and by a forme supported by adjustable wedges and inked by rollers carried by other chains moving around the forme, is constructed so as to print from sheets which are fed and delivered automatically. The machine is also provided with hand-operating means for moving the wedge devices in order to trip the impression, or selective automatic trip devices may operate to trip the impression if only one of two or more impression cylinders is required to print. The impression cylinders 14, Fig. 1, are carried by chains 12, 13 passing over sprockets 8 - - 11, and the cylinders are provided with bearer rollers and supports therefor, and also gear with racks 23 which are adjustably mounted, and cause the cylinders to rotate in the direction of the arrow B. The type is carried by a table 34, which is capable of being moved longitudinally, from its operative position to the position shown in dotted lines in Fig. 1, by means of a rack 38 engaged by pinions on shafts 40, 41 connected by sprocket gearing. The table is guided by side guide rails 36, 37 spaced apart sufficiently to permit of passage of the inking- rollers which are carried by chains 26, 27. The inking-rollers may be arranged as described in Specifications 8633/14 and 8634/14. The pinion on shaft 41 engages rack 38 before the other pinion disengages it. The type forme is held on the table 34 by a yieldingly-supported pivoted latch which can rise and fall with the table 34. Impression adjustments.-The type table 34 is supported by a number of longitudinally movable wedges 35, Fig. 11, in horizontal lubricated guides, and the wedges can be moved by a bar 122 connected to rods 129 operable by a rack- and-pinion and a hand-wheel to trip the impression or vary the printing-pressure. The rods 129 can also be operated automatically by means of levers 126 with sector gears 131 engaging racks 132. The racks are automatically operated when it is desired to trip the impression, and the machine may be set to print from one cylinder and miss the other cylinders carried by the chains, the bed 34 being lowered when no impression is desired. The rack 132, Fig. 4, is connected adjustably to a rack 133, so as to control the final printing pressure, and a segmental gear 134 engaging rack 133 moves the rack 132 and thus the wedges 35. The gear 134 is operated by the selective trip mechanism shown in Fig. 4, and comprises freely mounted levers 154, 155 connected by rods 160, 162 to opposite ends of an arm 161 on the shaft 145 of gear 134. A camoscillated lever 149 is fitted with a yielding pawl 152<1> which can engage either of the projections 157, 159 on the levers 160, 162, and so control the position of the printing-forme. The pawl 152<1> is operated by a bell-crank lever 163, which can engage or not with an oscillating finger 180 carried by a bell-crank 175 according as its controlling lever 182 is moved or not towards the depressed parts 184', 184<2> of the selective control cam 184. When the cams are not desired to operate, they, are masked by segmental members 187, 187<1> of the same radius as the high parts of the cam. Gripper mechanism.-The sheets are advanced singly to the " take-point " shown in Fig. 15, and are received by spring-closed grippers 60 on cylinder 14. The grippers are opened to receive the sheets by the engagement of an arm 65 on the gripper shaft 61 with a roller 74 on a bracket 73, and the grippers close by spring action. The shaft 61 is geared to a lever arm 66 fitted with a roller 69, which opens the grippers for delivering the printed sheet by engaging a fixed cam projection 75, Fig. 20.