US687575A

US687575A - Offset device.

Info

Publication number: US687575A
Application number: US73958799A
Authority: US
Inventors: Oscar Roesen
Original assignee: Individual
Current assignee: R Hoe and Co Inc
Priority date: 1899-12-08
Filing date: 1899-12-08
Publication date: 1901-11-26
Anticipated expiration: 1918-11-26

Description

Patented Nov. 26, l90l. 0. ROESEN.

OFFSET DEVICE.

UNITED STATES PATENT OFFICE.

OSCAR ROESEN, OF NEW YORK, N. Y., ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO ROBERT HOE AND CHARLES W. CARPENTER, OF NEW YORK, N. Y., UNDER THE FIRM-NAME OF R. HOE AND COMPANY.

OFFSET DEVICE.

SPECIFICATION forming part of Letters Patent No. 687,575, dated November 26, 1901. Application filed December 8, 1899- Serial No. 739,587. (No model.)

To all whom, it may concern:

Be it known that LOSGAR ROESEN, acitizen of the United States, residing at New York, county of New York, and State of New York, have invented certain new and useful Improvements in Offset Devices, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to certain improvements in devices for preventing offset.

In perfecting printing machines if the freshly-printed web or sheet comes in contact with the covering or tympan on the impression-surface of the couple making the perfecting impression the ink from the freshlyprinted paper comes off onto the tympan of the said surface, and after a certain amount has been thus deposited thereon it begins to set back on or, as it is termed in the art, to offset onto the sheet. This smuts the sheet and seriously interferes with good printing, especially in fine bookwork and in heavy cutwork,where large amounts of ink are used. Many devices have been used to prevent this offset. In the more practical forms of such devices an absorbent surface is used, which is either carried by the impression cylinder which receives the offset or runs between it and the web, this surface being either an oifset-web, which is run constantly through the machine with the material to be printed, or a tympan-web, which is carried by reels located inside of the impression-cylinder and is wound from one to the other with more or less frequency during the printing operation.

The devices before adverted to are objectionable in that they require more or less complicated mechanism for their successful operation. They also remove a certain portion of the ink from the printed sheet, this being especially objectionable in fine bookwork and in cutwork of all descriptions, where it is very desirable in order to produce an impression having the proper finish and luster that as much as possible of the ink placed on the sheet by the printing-surface be retained and allowed to dry thereon.

The object of this invention is to produce an improved and practical offset surface which shall do away with the complicated mechanisms now commonly used for this purpose.

With these and other objects in view the invention consists in certain constructions and in certain parts, improvements, and combinations, such as will be hereinafter described, and fully pointed out in the claims hereunto appended.

In the accompanying drawings, Figure 1 is a detail elevation of so much of a printingmachine as is necessary to illustrate my in- Vention. Fig. 2 is a sectional elevation of an improved cylinder provided with my improved form of offset device.

Referring to the drawings, Fig. 1 illustrates diagrammatically any suitable form of perfecting printing-machine, the machine herein shown being of the rotary type. The frame of the machine is indicated at 1, and the said frame supports a rotary printing-couple of the ordinary type, the plate or printing-cylinder of said couple being marked 2 and the impression-cylinder 3. The printing-cylinder of the second or perfecting couple is marked 4, and the impression-cylinder of this couple is marked 5. The web W to be printed is shown as entering between the

cylinders

2 and 3 and being printed by them on one side, after which it is passed between the cylinders 4 5, from which it receives the impression on the other side. A suitable inking mechanism, which need not be herein described, as it may be of any form, is shown. The second impression cylinder, against which the freshly-printed surface of the web comes, is provided with a porous surface 6,

which when moistened becomes ink-repellingg 'f is presented to the passing printedweb or sheet. This surface will preferably be metallic and preferably consist of aluminium, as this metal is so porous that it readily absorbs the moisture which is applied thereto, and this absorption of moisture renders it ink-repelling. Other surfaces might be used-such, for instance, as zincbut aluminium is preferred, not only on account of its porosity, but also because on account of its softness and ductility it readily adapt-s itself to any unevenness in the height of the printing-surfaces such,for instance,as those produced by underlaying. While this metallic surface may, if desired, be applied directly to the surface of the cylinder, it will preferably, in order to improve the impression qualities, have interposed between it and the cylinder an elastic surface 7 of some suitable material. This surface may consist of paper or any other suitable material, but preferably will consist of rubber.

Any suitable means may be provided for holding the metallic offset-surface and its supporting-surface in position on the cylinder. In the machine shown the surfaces 6 and 7 are shown as secured at one end in the ordinary gap by being passed over pins 8. Fingers ,9, mounted on a shaft 10 and held in position by the springs 11, serve to hold the sheets on the pins. The rubber or other sup- .porting sheet is preferably secured at its other end by being passed around a reel 12, which is operated in any suitable manner. The aluminium or other porous offset surface is held at its opposite end in clamps 13, mounted on a' shaft 14. This holding device may be of any suitable construction, but will preferably be of the construction shown in the patent to Spalckhavergranted August 1, 1899, No. 629,930, inasmuch as a clamp of this description. permits of a very narrow opening or gap in the impression-cylinder.

The aluminium or other metallic sheet will preferably be prepared in much the same way as such sheets are usually prepared for printing-surfaces-that is to say, its surface will be etched and then roughened by sand-blasting or in any other suitable manner.

Although any suitable etching-acid may be used, the acid employed will preferably consist of a weak solution of phosphoric acid, inasmuch as the purpose of the acid in this case is to absolutely remove all the grease from the surface of the aluminium plate, so that the ink will not adhere thereto. This will be accomplished by the solution of phosphoric acid, and this acid does not bite the surface of the plate so'much as nitric acid, which is the etching-acid ordinarily used.

Damping devices, which may be of any suitable description, will be employed to keep the surface wet. In the machine shown they consist of a water-trough 15, having a fountain-roll 16. A suitable ductor-roll 17 takes the water from the roll 16 and delivers it to the distributing-rolls 18, by which it is applied to the aluminium or other metallic surface.

Aluminium and some other metallic plates are, as is well known, used for printing-surfaces, those parts of the plates which carry the design being prepared to take the ink by having the design transferred to them by greasy inks, the remainder of the plate or surface being etched and dampened, so as to repel the ink. It is obvious, therefore, that if the entire surface of such plates be treated so as to be ink-repellent no ink will adhere from the printed sheet as it runs in contact therewith. d

An impression-cylinder which is so located as to come in contact with the freshly-printed side of a sheet or web if protected in the manner described will not receive any ink from such sheet or web. It 'cannot therefore offset onto the web or succeeding sheets, and, furthermore, since no ink is taken from the printed sheets or web by the surface of the cylinder a greatly-improved product will result.

Vhile the cylinder will preferably be prepared by placing a rubber or other elastic covering thereon and then securing a thin sheet of aluminium or other ink-repelling metal thereto, it will be understood that the invention is not necessarily limited to such a construction. For instance, the rubber or other elastic covering may have a thin coating of metal foil applied to its surface, or a metal surface may be applied in any other suitable or desirable manner, the'essential feature of the invention being to provide a cylinder which is to come in contact with an inked sheet with a suitable surface of porous material, preferably metal, which when dampened becomes ink-repelling.

What I claim is- 1. An impression device for printing presses comprising a suitable base, the base having a separate impression-s11 rface or coating thereon which when moistened becomes ink-repelling, substantially as described.

2. An anti-offset impression device comprising a porous or grained surface,.which surface when moistened becomes ink-repelling, substantially as described.

3. An anti-offset impression device comprising a porous or grained metallic surface, which surface when moistened becomes inkrepelling, substantially as described.

4. An anti-offsetimpression device comprising a gummed and etched surface, which surface when moistened becomes ink-repelling, substantially as described. I

5. An anti-offsetimpression device co mprising a gummed and etched metallic surface, which surface when moistened becomes inkrepelling, substantially as described.

6. An anti-offset mechanism comprising an impression device having a porous surface which when moistened becomes ink-repelling, and means for moistening the impressionsurface, substantially as described.

IIO

10. An anti-offset impression device com prising a gummed and. etched porous or grainedmetallic surface, which surface when moistenedbecomes ink repelling, substantially as described.

11. An anti-ofiset mechanism comprising an impression device having a gummed and etched porous surface which when moistened becomes ink-repelling, and means for moistening the impression surface, substantially as described. 1

12. An-offset device consisting of a cylinder having a porous surface which when moistened becomes ink-repelling, substantially as described.

13. An offset device consisting of a cylinder having a porous metallic surface which when moistened becomes ink repelling, substantially as described.

14. An olfset device consisting of a cylinder having an aluminium surface,substantially as described. I

15. An ofiset device consisting of a cylinder having a porous surface which when moistened becomes ink-repelling, and a suitable backing under said surface, substantially as described.

16. An offset device consisting of a cylinder having a porous metallic surface which when moistened becomes ink-repelling, and a suit able backing under said surface, substantially as described.

17. An offset device consisting of a cylinder having an aluminium surface and a suitable hacking under said surface, substantially as described.

18. In an offset device, the combination with the cylinder, of means for holding a suitable rubber backing thereon, and means for securing a porous surface which when moistened becomes ink-repelling in position over the backing, substantially as described.

19. In an offset device, the combination with the cylinder, of means for holding a suitable rubber backing thereon, and means for securing a sheet of aluminium in position over the backing, substantially as described.

20. An offset device including a cylinder having an etched porous metallic surface which when moistened becomes ink-repelling, substantially as described.

21. In an ofiset mechanism, the combination with a cylinder having a porous surface, of means whereby the surface is kept dampened during the printing operation, substan tially as described.

22. In an offset mechanism, the combination with a cylinder having a porous metallic surface, of means whereby the surface is kept damp during the printing operation, substan tially as described.

23. In an ofiset mechanism, the combination with a cylinder having an etched porous metallic surface, of means whereby the sur face is kept damp during the printing operation, substantially as described.

24:. In an offset mechanism, the combination with a cylinder having an aluminium sur= face, of means whereby the surface is kept damp during the printing operation, substantially as described.

25. In an ofiset mechanism, the combina= tion with a cylinder having an etched aluminium surface, of means whereby the sur face is kept damp during the printing opera= tion substantially as described.

26. In an ofiset mechanism, the combination with a cylinder havinga porous metallic surface, of suitable water-distributing de= vices running in contact with said surface, substantially as described.

27. In an ofiset mechanism, the combination with a cylinder having an aluminium surface, of suitable water-distributing devices running in contact with said surface, substantially as described.

28. In an oflset mechanism, the combination with a cylinder having a suitable elastic backing, of an etched aluminium surface, means for holding the backing and the surface in position, and suitable clamping devices, substantially as described.

29. In an offset mechanism the combination with a cylinder having a rubber backing, of an etched aluminium surface, means for holding the backing and the surface in position, and suitable clamping devices, sub stantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

OSCAR ROESEN.

Witnesses:

OTTO L. RAABE, H NRY S. MOUNT.