Patent GB-310668-A (GB)
Title: Improvements in or relating to printing machines
IPC: B41L47/42
Filed: 1928-05-09
Abstract: 310,668. Tennant, W. J., (American Multigraph Co.). May 9, 1928. Addressing and like machines; platen machines.-A machine for printing from printing-plates fed in succession through the machine is provided with separate impression and platefeeding arms disengageably coupled together so that by operating the plate-feeding arm independently plates may be fed without printing. Repeat impressions may be printed from any selected plate by operating the impression arm while the other arm is stationary, or by means of automatic control mechanism. As shown applied to an addressing-machine, address-plates A stacked in a hopper 20, Fig. 2, are fed along a channel 15 to printing position beneath a platen 94 adjustably mounted in known manner on an impression arm 90 adapted to rock about a pivot 61. The address-plates may be constructed as described in Specifications 270,676, and 275,941, and, to adapt the machine for plates normally designed for rotary machines, such as that described in Specification 269,142, the platen 94 is concave, and a removahle impression bed is correspondingly convex. The address-plates are fed by means of an arm 60 arranged adjacent to the arm 90 and rocked about the pivot 61 by a handle 80, an extension 63 of the arm 60 being connected by universal joints and a link 65, Fig. 3, to a bell-crank 66 connected by a rod 68 to a feeding-device consisting of vertical bars 40 slidably mounted in the channel 15 and provided with shoulders engaging the bottom plate. The plates are fed first to an intermediate position A<1> and then to printing position by dogs on the bars 40, overfeeding being prevented by spring- pressed arms 160, 161 bearing against the side edges of the plates. The arms 90, 60 are coupled together by a pin 81, Fig. 9, keyed to the handle 80, which is moved axially to withdraw the pin 81 from a socket 92 in the end of the arm 90, so that either arm may be operated without the other; a spring-pressed ball 83 retains the pin in the adjusted position. A pad 141 locked by a nut 142 in adjusted position on a screw 140 carried by the arm 60 regulates the depth of the impression. When the plate feed is to be automatically controlled to provide repeat impressions, the rod 68 instead of being connected directly to the bars is pivoted to a block 221, Fig. 5, reciprocating on guide plates 220 arranged below the channel 15. When the block 221 moves to the right, a notched plate 235 mounted thereon engages a pin 232 on one of the bars 40 so that they move to the right; on the return stroke, the bars are moved to the left for feeding by a hook 230 engaging the pin 262, this hook having a fork-and-pin connection with a bellcrank 228 pivoted on the block 221. The plate feed may be interrupted by an intermittentlyrotating cam 210, which periodically raises a lever 212 into the path of a pin 229 on the free end of the bell-crank 228 whereby the hook 231 is disengaged. As shown, the cam is triangular, and is rotated by ratchet mechanism from the hub 204, Fig. 3, of the bell-crank 66, so that the cam rotates one sixth of a revolution at each operation of the arm 60, and two impressions are printed from each plate. A shifting-lever 240 may be moved into a position 246 where the cam 210 and lever 212 are moved sideways along a shaft 206 into an inoperative position, or to a position 248 where a lever 251, Fig. 5, supported by a roller 250 lies in the path of the pin 229 so that the hook 231 is lifted each time the bars 40 move to the right, and is prevented from engaging the pin 232, the plate feed being thereby put out of action to allow an indefinite number of impressions from the plate in position. The whole of the automatic control mechanism may be formed as a detachable unit mounted on its own base-plate 200, Fig. 3. An ink-ribbon 100, Fig. 2, travels from a spool 110 over the address-plate A in printing position to a spool 111, and is wound first on to one spool and then back to the other. The spools carry ratchets 112, 113 respectively, and pawls 114, 115 are alternately in action, the pawls being mounted on a cross-bar connected by a pivot pin both to a bar 125 slidable between guide rollers 126 and to a rod 116 connected by links 120, 121 to the arm 90 so that the ribbon is fed forward at each impression. When a spool is full, its pawl 114 or 115 is checked, and, when the rod 116 moves to the left, the cross-bar rocks about its pivot and moves the other pawl into action. Levers 129 mounted on the same pivots as the pawls and provided with lugs bearing, against the outer sides of the pawls are connected by a spring, which is stretched when a pawl is moved into action and subsequently removes the checked pawl from engagement with its ratchet.