US748093A - Device for lithographic transferring. - Google Patents

Description

paper is ordinarily made use of in a dam- No. 74.8,C93.

NITED STATES Patented December 29, 1903.

PATENT OFFICE.

GEORGE E. PANOOAST, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE AMERICAN LITHOGRAPHIO COMPANY, A CORPORATION OF NEW YORK.

DEVICE FOR LITHOGRA PHIC TRANSFERRING.

SPECIFICATION forming part of Letters Patent No. 748,093, dated December 29, 1903.

Original application filed February 10, 1899, Serial No. 705 ,186. Divided and this application filed May 20,1903. Serial lie-157,931.

To a whom, it may concern.-

Be it known that I, GEORGE E. PANOOAST, a citizen of the United States, and a resident of Brooklyn, in the county of Kings, State of New York, have invented certain new and useful Improvements in Devices for Lithographic Transferring, of which the following is a specification.

My invention has reference to lithographic transferring, this application being a division of an application filed by me on the 10th day of February, 1899, Serial No. 705,186.

It has for its object to attain more accurately and reliably than heretofore the transfer of a design from a printing-surface to another surface adapted to receive it and to be thereafter developed itself into a printingsurface.

It consists of the novel parts, improvements, and combinations herein set out.

Heretofore in the art of lithographic transferring it has been customary to print an impression of the design in ink upon" paper which has been specially prepared for the purpose and which is called transfer-paper. It is a somewhat soft paper,whose surface has been prepared with suitable sizing. It is adapted to be soaked off from the printing-surface after it has been turned over upon it and has given its ink to it, and ithas a more or less soluble face and composition to that end. These peculiarities render it exceedingly liable to stretching and shrinking longitudinally and laterally, and hence constitute it a variable and unreliable conveyer where the accuracy of location of the design as a whole upon the printing-surface and all the parts of the design, one part with respect to another, is important. This liability to error is exemplified by the liability of the paper to stretch with handling-for instance,when it is beinglifted from the stone or printing surface. This tendency is increased by the circu mstance that the transferpened condition, the dampening rendering it more or less soft and extensible. Moreover,

the paper has the tendency to vary its length (No model.)

and breadth, depending upon the extent to which it is dampened. If too much dampened, it has a tendency to elongate and widen. If too try, it will be found to have slightly shrunk. The difiiculty is especially great in dealing with a large design, where a large superficies of the transfer-sheet is made use of in transferring a design from one printing'surface to another. For example, it is not an unusual circumstance for the design upon a large sheet of this transfer-paper to be as a whole an eighth of an inch or more longer than the design on the stone from which the impression has been taken-in the case of a desigmsay, twenty inches by twentyeight inches. For this reason the use of large sheets of transfer-paper in transferring is avoided wherever possible. For instance, where the printing-surface, as is ordinarily the case, is large and contains a great many designs placed close together, if duplicate printing-surfaces are desired it is customary to painstakingly stick up on a setting-up plate the various transfer impressions of the separate small designs on the small pieces of transfer-paper, each time a new printingsurface is to be made, exactly in the same slow, tedious, and expensive manner used for making the first printing-surface.

My invention will prevent all distortion and inaccuracies caused by the stretching or shrinking of the transfer sheet or conveyer, and will therefore also obviate the necessity of painstakingly and by hand grouping the small designs that are to go onto one printingsurface more than once.

In place of the transfer-paper as the material of the transfer sheet or conveyer I have devised and employ asheet or conveyer that is non-stretchable and non-shrinkable longitudinally and laterally and that has an even and uniform surfacesuitable to receivean imprint of adesign from a printing-surface. In its preferredforrn the sheet or conveyer consists ofa thin foundation-layer of hardrubber composition, as vulcanite, and a thin surface cushioning layer of soft rubber, the two layers being secured to one another at all points and preferably made integral by of an inch in thickness and is of suchachar:

acter as to be non-stretchable and not-shrin kable longitudinally and laterally. The surface-cushioning layer is about one thirty-second of an inch thick and is evenly and uniformly surfaced.

The method of transferring by means of the described transfer-sheet, which method forms the subject-matter of my prior application above referred to, is as follows: I first suitably cleanse the surface of the sheet and then preferably apply to it a uniform layer of suitable size such as will receive the ink. After that is suitably dry I print the design in ink or other suitable medium from any suitable printing-surface which is to be reproduced upon the uniforrn-sized surface of the conveyer-sheet. I then bring the thusprinted face of the sheet into contact with a suitable and suitably-prepared stone or other planographic surface prepared to receive the design and adapted to be thereafter developed into a printing-surface for the design, applying pressure with or to said contact, but in such way'as not to shift in the slightest degree the position of the conveyer-sheet as a whole upon the planographic surface after the contact has once been made. I then remove the conveyer-sheet, after which I suitably develop the planographic surface into a printing-surface of the character desiredfor instance, into a planographic or lithographic printing-surface by suitable light etching or into a relief printing-surface by a suitable deep etching, supplemented by routing out, if desired, &c.

I prefer the construction of conveyer-sheet herein specifically described and involving the presence of two layers secured together at all points; but my invention in its broader aspect would be embodied if the conveyersheet be evenly and uniformly surfaced and be of such construction that it is non-stretchable and non-shrinkable. longitudinally and laterally and capable of having printed upon it the design that is to be transferred in ink or other suitable medium and to communicate the same, or enough of it to constitute the design, to the planographic surface adapted to receive the design from the conveyer-surface and to be thereafter developed into a printing-surface for that design.

For the purpose of making a first large printing-surface, which is to have a plurality of smaller designs grouped on its face for purposes of economy, as is usual in the printers art, I take a number of small conveyer-sheetssuch, for example, as have been heretofore described-one for each of the separate designs and of proper size for that design, cleanse and size or otherwise prepare its surface properly, and print upon it from the original stone containing that design. I then take all of these conveyerpieces of transfer-paper are'to-day grouped and stuck up. I then cement the conveyersheets on the setting-up plate in exact position or otherwise attach them to the settingup plate. The latter isthen brought into contact with the lithographicstone or the surface to be developed into a printing-surface and is subjected to pressure as heretofore. Inthis way the ink of the several sep- I arate. designs is communicated in proper position, and location to the lithographic stone or surface to be developed into a printingsurface, the ink of the conveyor-sheets or enough of it leaving the conveyer-sheets to constitute the design and every part ofit on the lithographic stone. The setting-up plate is then removed, which removes also the separate conveyer-sheets cemented to it, leaving the design or group of designs in ink on the face of the stone. Care should be taken that the separate small conveyor-sheets employed are all of substantially the same thickness, or other means may be adopted to the end that all receive sufficient pressure during contact to carry over the ink from the face of the conveyer-sheets to the face of the stone. The stone is then suitably developed into a printing-surface. The first large printing-surface is thus prepared. When a duplicate of that large printing-surface is required, instead of again going through the laborious operation just described I take a large conveyer-sheet of the character herein set out, large enough to cover the superficies of the large lithographic stone, and having suitably inked up the stone and suitably cleansed and sized or otherwise suitably prepared the face of the conveyersheet I lay the latter face down upon the stone and subject it to pressure, thus accurately printing upon the conveyer-sheet the design upon the stone. The conveyer-sheet is then placed face down and while the ink upon it is still damp upon another suitable clean lithographic stone or other planographic surface and again subjected to suitable pressure, when the ink or suflicient of it will leave the surface of the conveyor-sheet and attach itself to the clear lithographic stone or other surface to constitute thereon an exact duplicate in all respects of the large design as a whole or group of designs that appears on the first printing-surface. This second printingsurface is then developed suitably into a printing-surface. A third printing-surface may be made in the same way and any numberof duplicate printing-surfaces, each one of which will be an exact duplicate of the first. This process of duplicating printingsurfaces may therefore be carried on indefinitely, thereby producing any number of printing-surfaces desired without resorting united therewith at all points. The surface of the cushioning layer B is evenly and uniformly finished and is adapted to receive a uniform layer of suitable sizing or to be otherwise suitably prepared to receive an imprint of a design. Preferably, also, the foundation layer A, of hard rubber, which is non-stretchable and non-shrinkable longitudinally and laterally, is of even and uniform thickness and has an even and uniform surface on the back, adapting it to rest upon a suitable level support or plate, such as a setting-up plate, whereby an even pressure during contact may be applied to every part of the conveyersheet. The pressure may be attained by the use of an ordinary scraper passing across the back of the setting-up plate from end to end or it may be a rolling-pressure or it may be a whole-surface contact and pressure. Where scraping or rolling pressure is used, the surface layer A, of soft rubber, should be as thin as possible, for the thinner this layer is made the less will be the local distortion of the design due to the local application of pressure. In all cases, however, the conveyersheet of my invention itself directly carries the ink constituting the design and conveys it to the new surface that is to be developed into a printing-surface, and the contact between the conveyer-surface and the printing-surface in the application of the pressure to such contact is such that the conveyer-surface does not shift or slip on such surface after contact is once begun, but the two surfaces are accurately and reliably brought together, so that the one exactly reproduces the other "in reverse so far as con cerns the design, After the design is transferred to the planographic surface, as herein in transferring designs after the lithographic manner from a printing-surface to another surface adapted to be developedinto a printingsurface, a uniformly-surfaced conveyersheet having a layer of material which is nonstretchable and non shrinkable longitudinally and laterally and a relatively thin surface-cushioning layer secured thereto at all points, and whose surface is suitably prepared to receive an imprint of the design from the printing-si'lrface, substantially as described.

-2. As a transfer-sheet or conveyer for use in transferring designs after the lithographic manner from a printing-surface to another surface adapted to be developed into a printing-surface, a uniformly-surfaced conveyersheet having a foundation-layer of hard rubber which is non-stretchable and non-shrinkable longitudinally and laterally and a rela tively thin surface-cushioning layer of softer rubber secured thereto at all points, and Whose surface is suitably prepared to receive an imprint of the design from the printingsurface, substantially as described.

3. A transfer-sheet consisting of a nonstretchable and non-shrinkable layer or sheet of rubber composition and a surface layer of soft composition, substantially as described.

4:. A transfer-sheet consisting of a nonstretchable and non'shrinkable layer of hardrubber composition and a layer of soft-rubber composition, said layers being integrally united, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEORGE E. PANCOAST.

Witnesses:

JACOB MILLER, WALTER P. TEN EYcK.

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