Patent GB-146674-A (GB)
Title: Improvements in or relating to die presses or machines for printing or embossing from engraved plates
IPC: B41F1/40
Filed: 1919-05-12
Abstract: 146,674. Wood, F. W. May 12, 1919. Embossing and intaglio-plate printing; embossing - surfaces; i n k i n g apparatus; stopping, tripping, throw-out, and like arrangements. - A machine for printing or embossing from engraved plates is constructed with an upper die which is arranged face downwards, and reciprocates in its own plane and coacts with a vertically reciprocating counterpart on to which the sheets are fed from a board which is normally arranged flush with the upper surface of the counterpart, the inking and wiping arrangements for the plates and all the operative mechanism except the die fittings being arranged below the feed-board. The embossing- surface is mounted so as to be adjustable angularly, and is prevented from moving laterally during the impression. The pressure between the counterpart and the die is adjustable, and can be cut off entirely if desired. The inking and wiping arrangements are tripped during the outward movement of the plate carriage, and the inking- roller is timed to come into action just before the engraved part of the plate reaches it on the return movement of the carriage. The inking and wiping devices may be tripped permanently if desired, and are adjustably carried by a common bracket, and a scraper is arranged between these to return the ink direct to the duct. The wiping-band is actuated by ratchet mechanism, the pawl of which has a constant throw, but cooperates with a hood which screens the teeth for a portion of the throw which is adjustable by hand, or automatically from the wound-up reel, which is provided with a ratchet-wheel and three non-return pawls offset with respect to each other by a space equivalent to a third of a tooth, thereby preventing the wiping-band from becoming slack. As shown, the sheets are fed from a board 19, Fig. 2, on to the counterpart 20 attached to a plate 21 removably fitted in the head piece 22 of a ram casing, operated by a block 23 and toggle mechanism 76 from a shaft 73 geared to a power shaft 75. Between the ram head 22 and the block 23 is arranged an adjustable wedge 31 operated by a screw 32 which adjusts the distance of the gap between the printing or embossing members, and also the pressure of the printing operation. The pressure is transmitted through two members 24, 25, the upper one of which is normally held by a catch 28 in the position shown, but when this catch is operated by a hand-lever, a spring rod 27 pulls the upper member to the right, and the solid portions of the member 25 engage recesses in the upper member 24, and pressure is not transmitted. The die is mounted in a holder 8 angularly adjustable in a circular cavity bounded by a flange 7 depending from a carriage 6 which is reciprocated in guides 5 formed in a bracket 4 secured to a stationary cross-head 3. The die is registered in printing position by a spring-depressed block 12, which can be raised out of the path of a die by a cam-actuated lever 18, the block 12 engaging an inclined catch 17 on the flange 7 and preventing rebounding of the die-carriage in a lateral direction. On the outwards motion of the die a bracket 36, in which the inking and wiping mechanisms are mounted is in its lowest position, but on the return motion a cam 51. which is oscillated from the press-actuating mechanism, raises the bracket 36 to operative position. A clutch may be arranged to be hand-operated to prevent the inking &c. devices from being brought into operation if desired. The inking-roller 35 is arranged in a duct 45 adjustable vertically or horizontally by screws 48, 47, and a scraper 49 consisting of a flexible steel blade in a rigid steel mounting effects a preliminary cleaning of the plate and returns the ink to the duct 45. The cleaning of the plate is completed by a wiping-band 52 which passes from a reel 53 over a pad 34 pivoted at 37 in a head piece 38 fitted in a box 39 secured to the bracket 36, a sliding wedge 40 serving to adjust the head 38 vertically. The pad 34 is also adjustable vertically by a worm-operated screw 42, and is formed with depending sockets for receiving cushioning-springs. The band 52 is wound up on a collapsible drum 55, which is rotated intermittently by oscillating pawls on a disk 58 operated by a lever 56, Fig. 8, connected to a connecting-rod 57 which operates the link 70 that reciprocates the die carriage. The pawls are masked for part of their oscillation by a hood conr,ected to a slotted plate 62, which can be operated by hand to control the feed, or automatically from a bell-crank 65 with a roller 64 resting on the wound-up portion of the web. To prevent the wiping-band from becoming slack during the return movement of the pawls, the motion of the shaft of the drum 55 is prevented by moving backwards by a ratchet-wheel fitted with three pawls which are offset from one another to the extent uf a third of a tooth, so that the greatest step allowable is equal to a third of a tooth.