Patent GB-382467-A (GB)
Title: Improvements in or relating to off-set printing machines
IPC: B41F21/04
Filed: 1931-12-28
Abstract: 382,467. Printing-machines. STOKES & SMITH CO., Camden, New Jersey, U.S.A., CLAY, F. E., 45, Ramsbury Road, St. Albans, Hertfordshire, and BASHFORD, J., 56, Bank Street, Luton. Dec. 28, 1931, No. 35835. [Classes 100 (i) and 100 (ii).] Rotary offset machines; feeding sheets.-A rotary offset machine for printing on sheets is provided with means for feeding sheets from the bottom of a pile, to operate at a high speed (8000-9000 sheets per hour). The impression cylinder 14, Fig. 5, and the offset cylinder 15 are arranged in the same horizontal plane below a feed-table 17, and the plate cylinder 16, Fig. 1, is mounted to one side of the offset cylinder and above the plane containing the axes of the cylinders 14, 15. The table 17 carries a pile of sheets under a weight 52 and reciprocates in guides in side frames 20a, Fig. 2. The table is actuated from a crank disc 22 oscillated by a gear sector 24 driven from an eccentric 27 geared to the main shaft 13. The frames 20a can be adjusted by worm gearing about the shaft 25 of the sector 24 to allow of access to the printing cylinders. At each reciprocation of the table 17 the bottom sheet of the pile is separated by an oscillating suction roller 30 driven by a rack on the table and connected by a pipe 46 and valve 47 to a pump operated by a cam on the shaft of the eccentric 27. The separated sheet is guided by an adjustably mounted tongue 33 between feed rollers 31, 32, the upper roller 31 being moved in timed relationship from and to the lower roller 32 to receive and grip the sheet. A stripper 38, a guide brush 39a, and a guide 39 direct the sheet to grippers 42 of the impression cylinder 14. The grippers 42 are closed by a spring plunger 44 and a stationary cam, and press the edge of the sheet against spring-pressed plungers 43a. The sheet is delivered by grippers 48, carried by rings 18, to a board 19 having a jogging movement. Inking-apparatus; damping-apparatus; starting and tripping arrangements.-(1) An inkfountain roller 59, Fig. 1, is intermittently driven from an oscillating lever 63a operated by a cam 63 and a pawl 61 operating a ratchet 60 having an adjustable guard to vary the effective stroke of the pawl. A messenger roller 65 oscillates between the fountain roller 59 and a distributing drum 67 in contact with rider rollers 70, 71 ; another rider roller 72 mav be operated by a hand-lever 73. From the drum 67 ink is supplied to the plate cylinder 16 by distributer rollers 74, 75, vibrator rollers 76, 77, and plate-inking rollers 78, 79, 80. The drum 67 is reciprocated axially by means of a bell-crank lever 81 from the cam 63. The vibrator rollers 76, 77 are rotated by means of a gear wheel 82 on a shaft geared to the plate cylinder, and are reciprocated axially by means including an arm 87 on a shaft 88 oscillated by a lever embracing a pin in an eccentric cup 91 formed in a gear wheel 92. The vibrator rollers are detachably mounted in rotatable seating members formed with recesses to receive flanges on the end of the rollers, and provided with spring-pressed detent pins to engage in apertures in the ends of the rollers. (2) A water-fountain roller is intermittently driven from a crank disc 103, Fig. 2, on the platecylinder shaft by adjustable pawl-and-ratchet mechanism 104. A messenger roller is oscillated by cam mechanism between the fountain roller and a distributing roller positively driven from the platecylinder shaft, and two platedamping rollers are frictionally driven between the distributing roller and the plate cylinder. The damping-apparatus is carried in a pivoted frame 120 which can be locked in operative and inoperative positions. (3) A solenoid 120a, Fig. 1, in a circuit completed by the gripper mechanism when a sheet fails to be fed, moves a trip lever 122 into the path of a cam 121 on a shaft 27a rotated from the main shaft 13. The outer end of the trip lever is connected to a bell-crank lever 123 mounted on a shaft 124 ; the bell-crank lever is connected to a foot-lever 125 and the shaft is provided with a hand-lever 126 for simultaneous operation to start the machine. The hand-lever 126 is connected by a link 127 to toggle-levers 128 for moving the impression cylinder and the delivery rings together away from the blanket cylinder ; quadrants 132 having eccentric pins associated with the togglelevers are provided for adjusting the position of the impression cylinder in relation to the blanket cylinder. The link 127 is connected to rod 133 associated with the suction-controlling valve 47. The trip lever 122 is also connected by means of a lever 134 to a shaft 135 associated with toggle-mechanism 136 for moving the blanket cylinder vertically downwards, and by means of a lever 147 to a shaft 145 connected with a lever 144 for actuating bell-crank levers 141, 142, 143 for tripping the plate-inking rollers 78, 79, 80, which are mounted to move tangentially to the vibrator rollers ; a hand-lever 148 is provided on the shaft 145 for moving the plate-inking rollers into operative position, and is engaged by projections on the lever 147. The shaft 145 is also connected by linkage 150, 151, 152, Fig. 2, with the guard of the pawl 61 to stop the rotation of the ink-fountain roller; the guard is moved into operative position by means of a hand-lever 153. A link 130 corresponding to the link 127, Fig. 1, on opposite side of the machine, is connected to a lever 155 for moving the guard of the water-fountain roller, and a hand-lever 157 is provided for retracting the guard. Printing - surfaces. - The printing plate is secured on the plate cylinder by clamps 53, Fig, 10, which secure the ends of the plate against blocks 54 sliding in guides 55 and adjusted by means of screw-threaded bolts 56, the opposed heads of which abut against each other.