US1680097A - William s - Google Patents

Description

Patented Aug. 7;, i928.

Uiti@ STATES WILLIAM S. EATON, OF SAG HARBOR, NEW YOR.

.PRINTING PLATE.

Application led August 31, 1926. Serial No. 132,666.,

My invention relates to printing plates,

l and more particularly to plates of this type for use in engraving and embossing machines wherein, after the inking of t-he plates, the surface ink is removed by means of wiping cloths or similar agencies.

Heretofore plates or dies from which a large number of impression are to be made, have been made of high grade steel, it having been necessary to harden the steel before using it upon the presses in order to prevent the lines of the engraved matter thereon from being weakened or efi'aced by the action thereon of the wiping cloths or other material when the making of a large number of impressions therefromis desired.

Copper plates have heretofore been used almost exclusively when only short runs of a press are required. Such copper plates are made of fairly thin sheets of metal, and in some instances, as when the presses require thicker plates to be used, separate thick metal f' erties equal to, or greater than,

holders, or base plates upon which such copper plates had been removably mounted, have been employed.

Copperv plates, however, have not been heretofore used in that class of p-rinting work which requires the hardening of the plate or die.

With the above conditions in mind, I have produced a printing plate which is suitable for use upon engraving or embossing presses in lieu of the ordinary hardened steel vplates or dies, and which will possess wearing propsuch hardcned steel plates or dies, notwithstanding that the plate of my invention. is composed mainly of cheap low grade materials and requires no hardening of any kind to impart to it a desired long life.

in a plate embodying'my invention,`the engraving of )matter thereon is not only much simpler than with high `grade steel plates and dies, but the expense of hardening the dies and the loss arising from the hardening operation are entirely dispensed with. Furthermore, in a plate embodying my rinvention, re-touching of a die after long use may be done without drawing the temper from the die and re-hardening.

A plate embodying my invention, not only has an initial low cost of production by reason of the low grade of materials entering thereinto, but the production of completed printing plates is facilitated and cheapened whether the printing lines be made by hand,

or by machine, engraving, or by acid etching.

The invention consists primarily in a printing plate embodying therein a heavy base ot' low grade unhardencd steel, a thin surface stratum ot high grade unhardened metal, and a thin stratum of a uniting medium between said base and said surface 4strat-um, whereby substantially every portion of said base and said stratum. is permanently. united with said base; and in such other novel features of construction and combination of parts, as are hereinafter set. forth and described, and more particularly pointed out in the claims hereto appended.v Referring to the dra-wings,l Fig. l is a perspective view of a printing plate embodying the invention; and

Fig. 2 is an enlarged section ou t-he line 2-2 of Fig. l. Like letters refer to like parts in both vof said views. p

ln the embodiment of the invention shown in the drawings, the base a is of cold rolled steel which may be readily obtained of any desired thickness, and of any desiredl Width, so that, in the production of plates, it is merely necessary to cut long bars of the cold rolled steel stock into the desired lengths, this being a very simple and cheap operation. Cold rolled steel is sufficiently smooth, and suliciently accurate in its dimensions to require no grinding or polishing, and is very low in cost as compared with the grades of copper or steel now used for printing plates or dies.v Permanently united to one tace of the base ais a thin metallic stratum of copper Z), sufficiently highly polished to be suitable for the printing surface of an in taglio plate. This copper stock may also be obtained on the open market in a. form Asuitable for use in printing plates, and requires merely cutting to size and a final bufiing action to adapt it for use in the plate of my invention.

rlhe stratum is permanently united to the base a by a soldering or sweating 0peration so as to sufficiently firmly unite every port-ion of the stratum 5 with the base a.

rlhe medium used in uniting these parts is indicated at c, and is ordinarily a very thin strat-um of solder. The stratum carries the printing lines, and the thickness of this stratum may be only such as to permit the Acutting or etching of these lines thereon,

although for convenience in manufacture of the plate I ordinarilyuse a stratum of 13 lOl) to 1%; ofan inch in thickness. The overall dimensions, as-to the thickness, of the plate itself will ordinarily be about M), an inch, a1- though this may be varied. l It will lbe observed that the amount of the higher grade metalQin the stratum b is very low as compared with the amount of low grade metal in the base a, the totalI cost of the plate," however, being less than that of an ordinary plate, since even' though the bulk of the metal in the plate be very much greater than the metal used in a steeL die of the same size as` thel plate embodying my invention, the cost of a plate embodying my invention is but a small fraction of that of a high grade -steel plate or die. 'lhe use of copper plates of the same thickness would be prohibitory, and [thick copper plates are seldom used. Irrespective of the metal'used in the facing strip b, the life of a plateembodying. my ,invention wnuld not be comparable to that of a hardened steel plate or die, since 2 the construction of the plate of my invention is such as to not admit of the hardening thereof. prolong the life of the plate, I provide the exposed surface of the stratum' b having the vengraved or etched lines therein, with a coating of electro-deposited chromium d, which material is known to possess a degree of hardness which will resist wear upon this surface in a marked degree. Furthermore,

chromium plating may be readily removed so that inthe event of the breaking down of any of the lines of a plate, the chromium plating may be removed and the plate' re-touched without the necessity for drawing the temper of the plate and re-hardenlng same.

ln fact, a plate embodying my invention requires merely the soldering or sweating of the stratum b to the base a, the cutting of the lines upon said stratum either by means of engraving tools or etching fluids and the electro-depositing or {plating/ofchromium thereon, to condition it for the make-ready of the press. Hardening of any portionof the plate or die not only is unl ce j,orfet ched,"and takes-a lvery vfine chromium .tplated'znishr The' stratum' ,b may-be ap-j @lied-directly to the baseabygmeans of elecjtroY-plating methods,A but sinee this vremlirefc?` necessary, but is impossible by reason of the A, ethods employed in making, and the materialontained in, the-plate` or die.

lnvention' is particularly adlapted for use-ini the production of plates or dies of small vsurface, area, although it may befeifectively used in making intaglio plates for photogravure work.

` use ofa copper surfacing stratum b 1s hlghly'fdeslrable s'iiice this material may notonlybereadily united with the cold rolled steel 'lbase a, but may be readily engraved To overcome this diculty and heavy base of low grade unhardened steel,

special grinding and polishing operations, l prefer to useV sheet copper and unite it vwith the base by soldering or sweating methods as described.

Having described the invention, what l claim as new and desire to have protected by Letters Patent, is v 1. A printing plate embodying therein a heavy base of low grade unhardened steel, a thin surface stratum ofhigh grade unhardened metal and a thin stratum of a uniting medium between said base and said surface every portion of said base and said stratum is permanently united. with said base.

2. A printing plate embodying therein a heavy base of low grade unhardened steel, a thin surface stratum of-high grade unhardened metal and a thin stratum of a uniting medium between said base and said surfacestratum, whereby substantially every portion of said base and said stratum is permanently united with said base, and an electro deposited surface of chromium upon the-exposed surface of said surface stratum.

3. A printing plate embodying therein a stra'tum, whereby substantially face of chromium upon the exposed surface.

of said surface stratum.

5. A. printing plate embodying therein a base of cold rolled steel, a thin sheet of highly .polished copper and a thin stratum of a uniting medium between said base and said surface stratum, whereby substantially every portion of said base and said stratum is permanently united with one face of said base.

6. A printing plate embodying therein a base of cold rolled steel, a'thin sheet of high ly polished copper and a thin stratumof a uniting medium between said base and said surface stratum, vwhereby substantially every portion of said base and said` stratum is permanently united with one face of said base, andan, electrodeposited -surfacetof chromiumupon surface' stratum.-

the exposed surface-of said Inwitness whereof 'I have hereunto s igna'tura'thisgth day of fAugusgfj

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