USRE17805E - Steel feinting body and method of peoducing the same - Google Patents

Description

Reissued Sept. 16, 1930 UNITED STATES PATENT OFFICE" 7 HELENA S. SADTLER, OF ERDENHEIM, PENNSYLVANIA I STEEL PRINTING BODY AND METHOD OI PRODUCING THE SAME.

Ho Drawing. Original No. 1,678,231, dated July 24, 1928, Serial No. 718,237, filed June 6, 1924. Application for reissue filed February 11, 1930. Serial No. 427,643.

Because of its durability it, is very desirable that hard steel be employed in the manufacture of printing cylinders or other sprint.- ing bodies having curved printing surfaces,

or printing plates, but owing to the difiiculty of engraving or otherwise forming thereon the design or symbol to be reproduced by printing, printing bodies of such material ave not heretofore been satisfactory. At-

10 tempts have been made heretofore to engrave the metal while in a relatively soft condition and thereafter subject the same to a hardening process but such method has proved unsatisfactory because of the Warping or changing in shape of the body having the characters or designs thereon.

The general object of my invention is to provide hard bodies, such as hardened steel,

articularly cylindrical bodies or bodies havmg curved surfaces, with characters or designs from which printing impressions may be taken, the said characters or designs to be formed thereon after the hardening process has been completed.

It is also an object of the invention to provide an improved printing body in which the outer or printing surface shall consist of hard steel.

Without attempting at this point to set forth all of the various objects and advantages of my invention I shall proceed with a detailed description thereof wherein will be pointed out additional objects and advant 3 form of cylinders or in other forms, especially when a small amount of carbon is employed tocarbonize the same, renders it, quite homotages, or elese such additional objects and ad-' vantages will be apparent therefrom.

In describing my invention I shall refer first to the method employed in the manufacture of printing cylinders and thereafter will refer briefly to the application of the same to 40 the manufacture of printing bodies of steel having hard printing surfaces which are flat or of some other shape than cylindrical.

In the carrying out of my new method in the manufacture of cylindrical printing bodies, whether the cylinders be solid or of tubular formation, I may take as a suitable steel either that known as Shelby steel or nickel steel, but any other high grade or quality of steel may be employed. The steel cylinder is subjected to a hardening process In case it is desired to employ the cylinder for intaglio printing, such for instance as the'printing of transfer designs, it may be desirable to provide the cylinder witha thin hard shell so that'in etching the characters ordesigns thereupon, whether such etching be done by an acid or an electrolytic process, the etching will extend through the hard shell of metal into the softer metal underneath, which latter may be smoothed and cut by the ordinary hand tools employed by engravers for the purpose of touching up and sharpening the design.v It will be understood that the portion of the surfacenot intended to be acted upon in the etching process must be covered by a suitable acid-resistin material. i

will beseen that 'by 'my process I first provideja steel cylinder having a hard surface which may'afterwards'be etched so as to form the reonithe character or design, mul

tiple impressions of which are desired.

The hardening of the steel, whether inthe geneousand of fine texture, thereby making it'poss'ible to obtain extremely accurate etching either by the acid or the electrolytic process.

hardening process will be varied as may be necessary in order to obtain the character of hardened shell which may be desired. The

amount of carbon to be employed and the v The amountof carbon to be employed; as the steel body is subjected .to heat in the It will be apparent that the methodemployed by me in the manufacture of steel printing cylinders having hard printing surfaces may be employed in the manufacture of printing members having steel bodies profaces of cylinders to form cylindrical printin surfaces.

it will be seen that. by my'invention' I am enabled to produce steel printing bodieshaving cylindrical or other forms ofprinting surfaces in which the'hardened surfaces'are ground and polished smooth and even before the charactersor designs are formed therein through the hard shell, and thereafter touching up a portion of the etched design by hand tooling. p

5. The process of producing a printing bodywhich includes etching the surface of a body having a thin, hard outer shell, continuing the tching until the etching extends through the hard shell and thereafter further deepening portions of. the etched design.

6. The process of producing a printing body which includes heat-treating the surface of a steel body to harden the surface and to form. a relatively thin shell which covers a. relatively soft body portion and thereafter etching the hardened steel surface to cut through the said h-ardenedshell into the relatively soft mass underneathto form the desired design therein.

In testimony whereof, I have signed my name to this'specifi'cation.

' HELENA S. SADT-LER.

and that in this way printing bodieshaving V the advantages anddesirable qualities heretofore indicated are readily produced.

Havingthus described my invention, what I claiin and desire to secure-by Letters Patent e j 1. The method of producirig steel printing bodies, which consists in first subjecting the same to a hardening process including the addition of carbon to carbonize the same,

grinding and polishing the hardened body 'to provide the same with atrue andeven sur- 'face,'and thereafter etching saidsurface to form characters or designs thereon.

2. The method offprodiicing steel printing bodies, which comprisesthe hardenin' of the outer portion thereof to form a re atively thin hard shell which covers an inner relatively soft body portion, grinding and polish ing the portion of said body on which it is intended to form the characters or designs from which impressions are tofbe taken to produce a smooth and even surface, and thereafter subjecting the said portion of the body to an etchingprocess to produce grooves therein in; the forin' of characters or designs,

the said etching process bein continued un-' til the lines cut into" the so ter m ss inside of thes'aid outer hardened shell;

3. The process of producing a printing body which includes heat treating the surface of a steel body to harden it, grinding and polishing the surfacefto render it smooth and true and thereafter etching the steel surface in the form of the desired design.

4. The process of. producing a printing body which includes etching the surface of a body having a thin, hardouter shell, continuing the etching until theetching extends