US1688647A - Process of correcting printing plates - Google Patents

Description

@cflz. 23, 1928. 1,688,647

E. E. NOVOTNY PROCESS OF CORRECTING PRINTING PLATES Original Filed Feb. 9, 1926 We; 18 17 9 -r A M/[@ L I I f WNTOR.

4' v I n I W ;%RNEY.

Patented Oct. 23, 1928.

UNITED STATES PATENT oFncE;

EMIL E. NOVOTNY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO JOHN STOG- DELL STOKES, 0] SPRING VALLEY FARMS, HUNTINGTON VALLEY POST OFFICE,

PENNSYLVANIA.

PROCESS OF CORRECTING PRINTING PLATES.

Original application filed February 9, 1926, Serial No. 87,111. Divided and this application filed November 18, 1926, Serial No. 149,452. Renewed April 20, 1928.

This invention relates to a process of correcting printing plates. The method is particularly directed to the correctin of a particular type of printing plate W ereln the printing plate comprises a speclal, nonhomogeneous sprayed metal having great thermoplasticity.

The present application is a division of my copending application Serial No. 87,111, filed February 9, 1926, for printing plate and method of making the same.

Briefly stated, my method is directed to the correction of metallic printing plates formed through the action of a metallic spray in such a manner that a porous, non-homogeneous structure will be produced. This printing plate body, because of its lack of homogeneous qualities is capable of being rendered thermoplastic by being heated to a temperature well below its melting point and may, therefore, be compressed throughout its entire area or within certain localized areas in order that the regularities or irregularities required of a printing plate-may be compressed therein by any suitable means. Any equipment capable of applying the required uniform pressure to produce the regularities and irregularities, such as a suitable hydraulic press or other similar equipment, is suitable for my purpose. If the printing plate were of solid homogeneous metal, compression would produce more or less lateral flow which would tend to distort the body of the plate.

After long experimentation with eutectic alloys in the form of foil and plastic metal, I have discovered that an alloy such as foundary type, monotype, or similar metals including various alloys comprising metals such as lead, tin and antimony, is most useful for my purpose. These alloys when applied to a suitable original by means of a metallic spray properly adjusted form a structure which is not homogeneous, and the particles are therefore combined in a structure having a smooth, clean, polished working face but a body'of more or less 0 en porous structure. The particles upon stri ing the surface of a properly prepared matrix deposit thereon without reboundin therefrom and form small, thin, scaleli e portions, apparently having oxidized faces, the oxide or perhaps the cooling of the thin sections preventing the formation of a solid homogeneous welded body. Apparently, too, where alloys are used, certain of the lowest melting components, such as the eutectic alloys of the composition, are thrown out to the edges and these tend to hold the structurein form, with the addition, however, of a certain intermeshing or commingling of the odd size par- 7 ticles of the spray. Be that as it may, however, actual experimentation has proven that these non-homogeneous plates, whether made of an alloy or of a solid metal but so long as they are sprayed in an open non-homogeneous manner, will display remarkable thermoplas1c propert es. This is very well covered in my copendmg application previously reigrged to, Serial N 0. 87,111, filed February 9,

Even though the printing plate should have a relatively tough facing section formed by depositing harder metals either by means of thespray or by means of an electrolytic deposit, the body portion when made by my spray method will still retain its thermoplastic properties, and therefore it is not essential that the printing plate be made entlrely of non-homogeneous material as it may be a composite structure.

This composite structure may comprise a plate consisting of similar materials throughout but having a fine deposit on its face sect1on followed by a relatively coarse deposit for the backing or body section, or may consist of dissimilar materials such as, for example, the application of a harder and tougher material for the working face. In other words, a printing plate comprising substantially a body portion of sprayed metal havlng open, porous non-homogeneous characteristics is useful for my purpose.

In the accompanying drawings Fig. 1 is a cross sectional View of a printing plate made by my method wherein a fine face spray is first applied and which is subsequently backed with a coarser sprayed body forming section.

Fig. 2 is a cross sectional view of a modified form of printing plate similar to that shown in Fig, 1 with the exception, however, that a harder face coating is applied either by means of a spray or by a subsequent electrolytic deposit.

' proximately/100 to 500 F. where monotype metal is used for the production of the printing plate. The printing plate face 18 is preferably placed against the polished surface plate S and proper pressure is applied by means of screw 22 .operating against the platen 23. A suitable resilient blanket (not shown) is preferably placed between the back of the printing plate 20 and the lower section of the pressure platen 23 in order that a light pressure may be applied and that any irregularities may be taken up in this blanket. A suitable cooling means is provided as by means of the inlet hole 24 and outlet hole 25, for the admission of cooling water in order 7 that the plate may be quickly cooled by circulatin cooling water in a properly cored cooling plate.

While'I have herein shown and described certain preferred embodiments of my invention I wish it to be understood that I do not con ne myself to all of the precise details herein set forth, as modifications and variations may be made without departing from the spirit of the invention or exceeding the scope of the appended claims. I

What I claim is- 1. The herein described method of leveling a printing plate which consists in providing a printing plate comprising an open, porous sprayed metallic structure having great thermoplasticity when heated below the melting point of the metal and placing said plate on a suitable support, and while thermoplastic applying pressure to cause the face of the printing plate to assume the desired regularities and irregularities and then allowing the printing plate to set by cooling.

2. The herein described method of leveling a printing plate which consists in providing a printing plate comprising an open, porous sprayed metallic structure having great thermoplasticity when heated below the melting point of the metal and placing said plate on a suitable support, and while thermoplastic applying pressure to cause the face of the printing plate to assume the desired regularities and irregularities and then allowing the printing plate to set by cooling, and shaving the back thereof.

3. The herein described method of leveling a printing plate which consists in providing a printing plate comprising an open, porous sprayed metallic structure having great thermoplasticity when heated below the melting point of the metal and placing said plate on a suitable support, and while thermoplastic applying pressure to cause the face of the printing plate to assume the desired regularities and irregularities and then allowing the printing plate to set by cooling, and leveling the back thereof.

Signed at Philadelphia in the county of

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