Patent GB-190411919-A (GB)
Title: Improvements in Plate Printing Presses.
Inventor: BLAISDELL FREDERICK ELIJAH
Filed: 1904-05-25
Granted: 1905-02-10
Abstract: 11,919. Blaisdell, F. E. May 25. Printing from engraved plates.-In a plate printing-press, the printing-plate is secured to an intermittently-rotating drum. The impression is effected by a roller travelling on a table which is raised and depressed by toggle-levers. The rotation of the drum carries the printing-plate past an inking-roller and a wiper of the endless-band type. A pneumatic lay-over is used to hold the sheet in position to receive the impression and to strip the printed sheet from the plate. The printing-plate 25 is held by suitable devices to a flat surface on a drum 27 fast on a shaft 28. A cam-shaft 22 carries a grooved cam which actuates a bell-crank lever 32 pivoted on a stud 33 and carrying a toothed sector 34 which gears with a spur-wheel loose on the shaft 28. A driver on the boss of this spur-wheel engages a dog on a counterpoise 39 fast on the shaft 28. The upward rock of the sector 34 rotates the drum, which remains stationary during the return of the sector. The momentum of the drum is checked by an adjustable brake band which co-operates with a drum on the shaft 28. In order that the machine may be stopped at any time to allow the printing- plate to be wiped by the operator, the driving- shaft 12 is connected by a pinion with a spurwheel 16 loose on a shaft 17 which is geared to the cam shaft 22. A foot-lever is connected by a link to a clutch lever 50, Fig. 3, engaging a clutch 52 on the shaft 17. On depressing the lever, the clutch 52 expands a split ring 54, which is secured to the shaft 17 and lies in a recess in the wheel 16, so that the wheel 16 is locked to the shaft. The clutch remains closed until opened by a disc 56 on the shaft 22 having a projection which engages a lever 58 at each revolution. This lever causes a pawl, pivoted to a collar 64 loose on the shaft 17, to depress an arm 66 on the lever 50 and so to open the clutch. The clutch can be held open for any length of time by a foot-lever connected with an arm on the lever 58. The printing-plate is locked in the printing position by a bell-crank lever 71 having a tooth which engages a notch in a snail fast to the drum 27 The tooth is freed from the notch by a cam 68 on the shaft 22 connected by a rod 70 with the lever 71. The inking-mechanism consists of a fountain 75 in which turns a roller 76 geared to a second adjustable roller 77. The roller 76 is geared to a spur-wheel 86, which is driven by chains 90, 96 from a chain-wheel fast to the wheel 16. The fountain 75 has flanges loosely embracing a block 99 so that it can be adjusted parallel with the inker 107 by means of two screws 103. The block 99 is supported by a bracket 98 on which it can be adjusted by a screw 106. The inker 107, which carries ink to the plate 25, is carried by an arm on a shaft 109 which is rocked by a lever and a cam on the shaft 22. A sliding rod enables the inker to be held out of contact with the plate and the roller 76. An arm on the shaft 109 carries a roller which engages a cam on the drum 27. This cam allows the whole width of the plate to be inked, and additional adjustable cams, engaging the same roller, enable the width of plate inked to be varied. The platewiper consists of an endless band or a series of pads or a strip, and is cleaned as described in Specification No. 9775, A.D. 1902. A scraper 127 removes the ink from the wiper 126, which is then washed with a solvent by means of a band 128 supplied from a trough 129. A scraper 130 removes the solvent, and a fan 131, driven by a belt from the shaft 12, dries the wiper. The wiper is intermittently traversed on its drums by the action of a cam-groove in the disc 56, which actuates a lever 133 connected by a link 135 with a pin 136 sliding in a slot 137 in a lever 138. This lever carries a toothed sector gearing with a spurwheel 141 loose on a shaft 94. A pawl attached to the wheel 141 engages a ratchet-wheel fast to a chain-wheel loose on the shaft 94. A chain 145 connects the chain-wheel with the shaft 147 of the wiper. The wiper frame 149 is fast on the shaft 94 and is rocked by a pair of bell-crank levers 150 actuated by cams on the shaft 28. Additional adjustable cams determine the width of plate to be wiped. The rate of travel of the wiper is adjusted by moving the pin 136 in the slot 137. The wiper frame 149 has an adjustable balance weight carried by an arm 159 on the shaft 94. The wiper may be held out of action by pushing in a bar 162 which raises the arm 159. One bearing of the shaft 147 is adjustable so as to cause the wiper to travel evenly. A composite paper-blanket 167 is fixed at one end to a shaft 168, Fig. 16, which is held from rotating by a detent 171. Half the thickness of the blanket is fixed to each of the shafts 172, 173, provided with tighteners 175. The blanket is carried on a table 170 which supports by means of rollers 182 the carrier 180 of the impression roller 181. The carrier 180 is reciprocated by a lever and cam on the shaft 22. The roller 181 gears by means of spur-wheels with a rack on the table 170. The table 170 is moved vertically in guides by togglelevers 193, 195 connected with a block, the height of which can be adjusted by a wedge actuated by a screw. The toggle is straightened by a cam 209 on the shaft 22 which engages a roller on the central pin 196 of the toggle. A second cam 210 engages a roller 211 carried by arms 212 projecting from the lower toggle-lever 195 in order to depress the table. The cams 209, 210 are locked to the shaft 22 by a clutch actuated by a hand-lever. The pneumatic lay-over consists of a tube having a mouth along the edge of the sheet. Air is supplied by a pump, the piston of which is driven by a cam on the shaft 22. The lay-over is raised and lowered by a lever actuated by the table 170.