US1814024A - Apparatus for removing any ink remains from the printing plate of the form cylinder of rotary intaglio printing machines - Google Patents

Description

1,814,024 INTING PLATE 0F ROTARY IN'IAGrLIICI' PRINTING'IAGHINES Filed May 20, 1930 July 14, 1931. K. DEBUS' APPARATUS FOR REMOVING ANY INK REMAIN-S FROM THE PR '01 THE FORM CYLINDER 22 U *as INVENTUR= Karl Debus Qg/ BY ATTORN Y I Patented July 14, 1 931 UNITED STATES KARL DEBUS, OI BERLIN-WAIDMANNSLUST, GERMANY, ASSIGNOR T BERLINER MASCHINENBAU-ACTIEN-GESELLSCI-IAIT VORMALS BERLIN, GERMANY L. SCHWARTZKOPFF, OF

APPARATUS FOR REMOVING ANY INK REMAINS FROM THE PRINTING PLATE OF THE FORM CYLINDER OF ROTARY INTAGLIO PRINTING MACHINES Application med May 20, 1930, Serial No.

Rotary intaglio printing machines are known which a plate capable of being clamped on the form cylinder serves as the printing form, With these machines, the

scraper serving to strip off the ink must be periodically raised from the form cylinder and this at that moment at which the point of clamping of the printing plate passes by the scraper. It is furthermore known to periodically raise (the inking roller from theprinting form, in order to keep a part of the printing form plate, (the clamping point) free from ink. As now an application of the scraper on any dry point of the printing form plate must under any circumstances be avoided, since in this case both the printing plate as well as the scraper itself would be scratched by the great friction resulting, and consequently beedme useless, it will be seen that the scraper must be raised from the printing form plate before the uninked part of the printing plate passes the scraper position, and must only be applied onto the printing plate again after a part of the inked portion has passed the scraper position. There thus remains with each revolution of the form cyl-inder two colour strips on the form plate which are not scraped, and which must have the kink removed by suction or by wiping, which, litiwever, is not possible in a sufliciently rapid and economical manner. Furthermore, the ink wiped off from the wiping arrangement,- which must necessarily be secured over the scra er, reaches the upper side of the scraper kni 0 when the ink drops off fromthe inking arrangement, so that the knife during operation must be cleaned very often.

The present invention refers to an apparatus on rotary intaglio printing machines'with plates asprmting forms, which makes it possible to work with these machines with the same speed of printing and number of revolu- 454,065, and. in Germany August -1, 1928.

must be placed on the form cylinder before the inked part; thereof reaches the scraper knife, since this requires a certain time for its complete application onto the printing plate. As, however, for the above-mentioned reasons, the scraper knife must not be applied onto the dry printing plate, according to the invention, an apparatus is fitted which applies an ink dissolving medium to the printing plate before and behind the inked part thereof. The scraper can be easily applied on the so treated printing plate, and thus be given the necessary time for fitting closely to the printing plate, and thus the capacity to scrape off the surplus ink particles now arriving, in their entirety. A further advantage of the moistening of the printing plate, which can be regulated beginning from a skin thin 1a er, is given by the fact that the quantity 0 its solvent lost by evaporation is replaced and thus the consistency of the ink can be kept constant.

In describing the invention in detail reference will be had to the accompanying drawing showing an embodiment of the invention by way of example only, in which 1 represents a printing cylinder rotated by any known means not shown in detail and 2 is a plate cylinder fixed on a shaft 3. The shaft 3 carries three cams provided with cam surfaces 4, 5 and 6 rotating together with said shaft and the plate cylinder 2. Obviously instead of using three cams fixed on the shaft the cylinder 2 can be provided with a correspondingly formed hub.

An etched printing plate 7 is clamped on the plate cylinder 2 by means of a strip clamp 8 and a stretchin device 9 arranged within a groove 10 v of t e cylinder 2. A scraper holder 11 holding a scraper knife 12 is rigidly connected with a tooth segment 13 and pivoted underneath the plate cylinder 2. The tooth segment 13 meshes with atooth segment 14 pivoted on a shaft 15 and rigidly connected with a lever 16 pivoted on the same shaft 15. One arm of the lever 16 carries a roller 17 pressing against the cam surface 6 and the other arm of the lever 16 carries a weight 18 by means of which this contact is effected. A

metal strip 19 is attached to the scraper knife 12 adjacent to its holder 11 for the purpose of feeding the surplus ink back into an ink box 20 supported on a bracket 21 by means of connecting rods 22 and supporting bars 23. An inking roller 24 and a carrying roller 25 run in said box 20 and are mounted in a lever 26 pivoted at one end on a shaft 27 and pressing at its other end by means of a spring 28 against a lever 29 carrying a roller 30, w iich engages with the cam surface 5.

31 is a box filled with an ink dissolving medium and supported by rods 22 and bars 23 and 32 and 33 are two rollers, which eriodically transmit the ink dissolving me ium onto the printing plate 7 and are mounted in a link member 34 pivoted on a shaft 35 and rigidly connected with an arm 36. Said arm carries on its other end a roller 37 pressing against the cam surface 4. The box 31 is filled with an ink dissolving medium, such as, Xylol or an ink diluting medium, such as toluol, benzine or the like, in the event that oil colors are used. If, however, water colors are used, water is taken as well as ink dissolving medium as an ink diluting medium.

The process of inking the printing plate and scraping ofi the superfluous ink is as follows.

' The etched printing picture is situated on I tion the smooth part 39 of the plate is moistened by the roller 32, which presses against it, with a thin layer of ink dissolving medium in order to give the plate the necessary smoothness for the sliding of the scraper. surface 4 is shaped in such a way that at the moment at which the picture half of the plate reaches the roller 32, the arm 36 meshing with surface 4 by means of a roller 37 swings upward owing to the weight of the member 34 and the rollers 32 and 33, thereby swinging the roller 32 down from the printing plate. The cam surface 5 has such a shape that in the same moment the lever 29 can swing upward thereby allowing the spring 28 to move upward the lever 26 meshing with the lever 29 and to run onto the form the application roller 25, which thus inks the form.

The cam surface 6 has such a shape that the scraper knife 12 is placed directly behind the groove 10 on the printing plate, the swinging of the knife 12 being effected by the movement of the lever 16 rigidly connected with a tooth segment 14 meshing with a tooth segment 13 connected with the knife holder 11. The scraper knife 12 is then in a position to strip off in its entirety the surplus ink from the picture half 38 of the printing plate 7, although this part of the plate comes al- The cam most a half cylinder circumference later in contact with the scraper.

After the etched picture surface has passed the roller 32, this roller comes again onto the printing plate, while the applying roller 25 after inking the picture half is lifted therefrom, both of those movements being effected by the cam surfaces 4 and 5. The remaining part 40 of the printing plate from the back edge of the picture to the clamping point, is again coated by the roller 32 with'ink dissolving medium. Owing to this and by the arrangement of the scraper underneath the centre of the form cylinder, the effect is attained that the channel 10 necessary for the clamping of the printing plate on the plate cylinder remains entirely free of printing ink. During the passage of the clamping point of the printing plate past the scraper knife '12, this is raisedfrom the form. The printing process itself is the same as with the known rotary intaglio printing machines of usual construction.

It will be readily understood that the in vention is susceptible of many modifications within the spirit and scope of the appended claims. Thus, instead of rollers other means of transmitting the ink dissolving medium, sucg as wicks, sprayers or the like may be use Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. Apparatus for removing any ink remains from the printing plate of the form cylinder of a rotary intaglio printing machine, comprising a scraper knife to be applied on the printing plate in combination with means for moistening the printing plate in front of the part serving as the picture printing surface with an ink diluting medium for the purpose of enabling the scraper knife to be applied also on parts of the printing plate not inked.

2. Apparatus for removing any ink remains from the printing plate of the form cylinder of a rotary intaglio printing machine, comprising a scraper knife to be applied on the printing plate in combination with means for moistening the printing plate in front of the part serving as the picture printing surface with an ink dissolving medium for the purpose of enabling the scraper knife to be applied also on parts of the printing plate not inked.

3. Apparatus for removing any ink remains from the printing plate of the form cylinder of a rotary intaglio printing machine, comprising a scraper knife to be applied on the printing plate in combination with means for moistening the printing plate in front of and behind the part serving as the picture printing surface with an ink diluting medium for the purpose of enabling 4 the scraper knife to be applied also on parts of the printing plate not inked.

. 4. Apparatus for removing any ink remains from the printing plate of the form 5 c linder of a rotary intaglio printing ma- 0 ine, comprising a scraper knlfe to be applied on the printing plate in combination with means for moistenln the printing plate in front of and behind t e partserving as the picture printing surface with an ink dissolving medium for the purpose of enabling the scraper knife to be applied also on parts of the printing plate not inked.

In testimony whereof I aflix my si ature.

KARL DE US.

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