GB946357A - Improvements relating to printing machines - Google Patents

Abstract

946,357. Rotary offset printing machines; sheet delivery apparatus. ADDRESSOGRAPHMULTIGRAPH CORPORATION. Aug. 29, 1961 [Sept. 26, 1960], No. 31127/61. Headings B6C and B6H. On the actuation of a control device, preferably automatically on receipt of a signal from a counting apparatus, the master sheet of a rotary offset printing machine is automatically stripped from the master cylinder and conducted to a receiving tray. In the machine shown the master sheet is secured in the gap of the master cylinder 10 by clamping mechanism located in the gap and comprising clamping members 30, Fig. 6, which are spring-loaded through springs 31 and movable pins 26 against the leading edge of the sheet, a bar 40 abutting the pins and carried by pivoted brackets 41 which are movable by arms 43 fixedly mounted on a shaft 42, an arm 42A secured at one end of the shaft and a spring-loaded pawl 47 pivotally mounted on the arm 42A. The pawl 47 may be rocked to rotate the shaft 42 and move the clamping members 30 by engagement with a cam-plate 46, Fig. 4, pivotally mounted on the frame of the machine such that the pawl and cam-plate only interact during rotation of the cylinder 10 in a non-printing (i.e. clockwise) direction. Release of the clamping members 30 after a predetermined number of prints is accomplished by providing the arm 42A with a cam follower 60 which is adapted to engage a rise 70R on a cam 70 pivotally mounted on the machine frame. This cam, biased into a non-operative position by a spring 110, is moved inwardly to the dotted position of Fig. 4-on actuation of an arm 75 by a solenoid associated with counting apparatus. The arm 75 is withdrawn from a spring-loaded latch 73 which, on pivoting, allows a spring-loaded bellcrank 85 to actuate a bell-crank 92 directly contacting the cam 70. Movement of the bellcrank 85, which is fast with its mounting shaft 86, on actuation of the arm 75 is prevented at one position of the blanket cylinder 14 by the interengagement of a cam 117, Fig. 3, on the cylinder shaft with a cam follower 116 carried by lever 115 secured to the shaft 86. The bell-crank 85 is accordingly free to pivot counterclockwise only when the cam rise 117R passes off follower 116. The master is stripped and initially guided towards a tray 120 by three spaced stripper fingers 130, Figs. 4, 8, each having arcuate surfaces 130A and 130B and being adjustably mounted on a shaft 132 which is pivotally supported between the side members of the machine frame on spring- loaded studs 148A, Fig. 7. One end of the shaft 132 carries a spring-biased follower 170 which is normally locked against movement but on actuation of the cam 70 is allowed to move into a depression 171D on a cam surface 171 fixed to the shaft of the master cylinder so that the shaft 132 is turned clockwise to move the stripper fingers inwardly to engage the released master. The master is then fed to the tray 120 by an ejector unit 200, Figs. 2, 4, which is removably mounted on the machine and comprises steel rollers 246 and rubber rollers 247 which are mounted between side plates 203 and 204 on shafts 255 and 248 gear-driven from the machine drive. The unit has a plurality of guide fingers 230, Fig. 4, which, with the surfaces 130B of the fingers 130, form a throat through which passes the master being stripped. The master is subsequently guided through a passageway defined by the lower arcuate surfaces of the fingers 230 and the upper face of a removable plate 245 mounted between the plates 203, 204 and which has notches 245N embracing the rollers 247 and is so shaped as to guide the master being stripped into the bight of the rollers 246, 247. The ink forme rollers 190 and 191 are lifted from the master cylinder immediately prior to the opening of the clamp ing members 30 either by manual or automatic operation of a control device.