US915021A - Method of backing electrotype-plates. - Google Patents

Description

G. E. DUNTON. METHOD or BACKING ELEGTROTYPE PLATES. APPLICATION FILED JUNE 14, 1907. 0 5 02] Patented Mar. 9, 1909.

2 SHEETS-SHEET 1.

' I I Smuzntcz v wihloaeo v G. E. BENTON, METHOD OF BACKING ELEU'IROTYPE PLATES,

APPLICATION YILED JUNEM,1907,

2 SHEBTS-SHEET 2 GEORGE E. mirror, or NEW YORK, N. 1'.

METHOD OF BACKING ELECTROTYPE-PLATES;

' Specification of Letters Patent.

"Patented March 9, 1909.

Application filed June 14, 1907. Serial No. 379,004.

1'0 all whom it may concern:

residing at New. York city, county of New York, Stateof New York, a citizen of the 5 United States, havevinvented certain new and useful Improvements in .Methods of Backing Electrotype-Plates; and I do hereby declare the following to be a full, clear,

, andexact description of the invention, such as willenable others skilled in the art to which it pertains to make and use the same. My, invention relates 'to-. an improved method of backing up electrotype shells in the manufacture of electrotype plates and has for its object, to apply a well defined and regulated ressure to the backing within the confines o a closed receptacle, which with its closure or cover has previously been heated to an even temperature with the backing metal, Forcing additional metal into said rece'p acle while the metal is fluid. Maintaining the pressure during the cooling process so that theentire surface of the backing I will be forced evenly againstthe .00 per shell I. andthe plate be free from all inequa 'ties and imperfections and thereby produce; an electrot pe plate that has an even, solid and perfect y level printing surface. I

. In backing up electrotype shells, by the or-' dinary .methods, considerable difficulty has con ex erienced in producing perfectly D {straight evel faces or printing surfaces as owing to' the shells being so thin and delicate,

or from inequalities in the texture of the cop- 85 per, they become distorted during the process ofbacking, showing inequalities known as shrinkages or indentures and often other serious defects. These defects are usually 4 taken out by pounding on the back of the 40 plate, the exact spot having been reviously marked, which when done with t e utmost care even and by ex ert skilled workmen, at

a great loss of'time, amages the printing su rface tosueh an extent that it is very often rendered useless. v

@I produce. the copper electrotype shell in the usual manner by the electrodeposition of the metalupon a conductive wax mold. Having secured the desired thickness of 'metal for the shell which may be made of copper, nickel, steel or any other suitable material, I remove the shell from the wax by pouring hot watcr'over the surface of the shell Which-heats the metal and breaks the 'adhesion between the wax and the metal when the shell can be readily stripped or l pulled away'from the mold, I then'rinse this Be it known that'I, GEORGE E. DnNToN,

metallic shell in boiling lye to remove all traces of the wax which may have adhered thereto and then plunge said shell into a pickle of acidulated water to remove all traces of the lye, then after rinsing in running water the shell is reasonably clean.

By my process the metal is heated to a molten state in the melting pot of a furnace. The platen of a press or the closure or cover of a box or other recc tacle or a plate of metal is swung into an allowed to float on the surface of said molten metal until it is of the same tern crature as said molten metal, said platen, c osure or cover or plate is then removed and abaeking pan containing a metallic shell the-hack of which has been "forms a thin coating over and adhering to the backof the metallic shell. This process which is known to electrotypers as tinning the shell,-can be carried on over a separate gas heated table, If done this way the tinned shell isthen placed on the backing pan and allowed to remain in the melting 0t until the,'solder begins to lose its bright uster, or oxidize, molten metal is then poured over the back of the shell to weigh it down after which the pan and shell are lifted out of the melting pot and placed on the backing stand where enough additional metal is poured over the back of the'shell to fill the pan even with the t p of the rim or to the desired thickness. While'the metal of the backing is still in a molten or fluid state, the previously; A heated closure, platen or cover of the press is forced down onto said backing until it rests upon the rim of the pan or within the rim of the pan or rests upon set screws, by this'mcans any desired tlnckness of plate may be obtained, while not depart ing from the idea oi'maintaining a closerkboic. The density of the lead forms the basis of the backin metal supplemented by the pressureexcrte b the, force of the screw, while the pan, Shell closure, or; platen or cover are hot and the metal is molten and elastic it exerts an equal pressure upon the backing and build u egree up to the cooling .area of the shell from the pan in whole or 1 n part, it is of service in supporting the blanks portions while the shell is under pressure; i he blanks can also be supported filling the recesses with a paste composed 0 any suitable material such for instance as a compound of flour, g V pumice stone. To stil urther augment the possible pressure and to,ma 1ntain. a constant oint of the metal I inject or force additiona metal into the box or receptacle by meansof ressure, whichmay beexerted by means 0 .a pump placed at any convenient point, or by any other means preferably on the platen or cover or the desired result may be obtained by simple gravity, that is pouring additional metal into a lip or jetty raised above the platen or cover, providing means to shear the jet off before removing the platen. The metal is cooled or set under pressure. The cooling should commence at the pan and betransmitted through the shell beginning at the face or shell and extending through the platen cover or closure of the box. By this means 'whatever shrinkage may occur in the backing will follow to the last oint' that cools, the back of the plate. T is cooling may be accomplished by different methods,

. preferably'by a blast of air from a pressure lower conducted to the underside of the receptacle through suitable pipes. After the metal has become perfectly set or hard, the' plate is removed from the pan by unscrewing the wheel of the screw removing the cover or platen and the plate is washed or cleaned by any suitable means.

There is an advantage in tinnin'g the shells revious to applying the backing metal, also in doing the tinning u on a separate and independently-heated ta le. First it expedites the work by, elimhiating the operation of melting the solder over the back of the metallic shell upon the backing pan as any number of shells may. be tinned in advance of the backing and the operation at the metal pot is confined wholly to the heatim of the shell (to the temperature of the metajand curing the metal onto'aud over the shell. S econd, after the shells are tinned the muriate of zinc which adheres to the backof the shells in small dissolute patches, owing to the evaporation of the water in which the inuriate was .reviously dissolved, by the application of eat sufiicient to melt the solder, may be washed off the back'of' the shell with water before the shell is placed on the backing pan sum and powdered of the cover.

-iurnace, backing stand,

to receive the metal. Otherwise this excess of muriate of zinc which .will float on the top of the molten metal "which has been poured over the shell, must be removed or skimmed off to keep the surface of the metal bright and clean. If this muriate of zinc is allowed to remain on the surface of the metal, the platen .or cover will solder or adhere to the metal,

upon being pressed down onto and in contact with the surface o'fthe metal, and considerable metal has become cooled or set.

'I wish to call'particular attention to the fact that I exert additional pressure upon my electrotype shell. First by the use of a closed box or receptacle having a fixed rim and removable closure, cover or platen both being heated to the temperature of the metal which is to be used in backing the electrotype shell. Secondby making this combination into a closed box by screwing the heated closure down onto the rims or inside of the difiiculty will be experienced in separating the cast from the platen or cover when the rims to any desired depth by means of set screws provided at suitable points which does not detract from the idea of the closed box. Third, by means of a pump at any suitable location or position pre erably on the cover of the receptacle I am able to exert additional pressure on the shell by laced forcing more metal into the box after the closure or cover has been screwed fast in position resting on the rims of the receptacle or box, and b makin this pump which is pivoted suitab y at its ase s rear off the jet rom the back of the cooled cast so that the closure, cover or platen maybe removed from the back of the metal.

I term this process backing electrotype' shells by hydrostatic pressure, although I do not limit myself to the use of a jetty. as

before mentioned, so. long as I maintain a closed box orreceptacle which with its removable cover or platen and contents have been heated to an even or equal temperature and the exerting of pressure on an electrotype shell during the process of backing. First by the reaction 0' the metal against .the cover of a closed box or receptacle or the pressure of the cover onthemetal exerted by a screw, screws or clamps applied to the top of additional metal to that already contained within the box or receptacle at the time the cover is screwed or forced down closing the receptacle or box, preferably by the means Sccond, by the introduction of a suitable pump conveniently located on:

the top side of the platen or cover of the box.

In the drawings, which illustrate an apparatus to carry out my methodt Figure 1, is side view comprising a melting ot of a ress an a pipe leading fronr-a blower. view of the melting pot showing the closure inserted therein. Fig. 3, a sectionel w'iewof *ig. 2, a sectional showing t a platen 9, comprisinga closure for said resure on the shell.

- metal into the receptacle 6, and 14, is the with the,ba'clnng metal to the desired thick,

plate or she inserted therein.

receptacle.

leveling the receptacle 6.

side of the receptacle forthe purpose of ,equal ressure 1S maintained upon the shell the receptacle, backing and shell are cooled the melting at showing the receptacle and I backing have become sufiiciently cool to Fig. 4, is a sectional view showing the receptacle'and'i shell with the backing thereon in a molten state on the backing stand ready to have i pressure applied. Fig. 5, is a sectional view 1 1e rece tacle, theshell with the molten metal baclring thereon and a heated platen applied thereto as a closure and a pump for forcing additional metal into the Referring to the drawings, in which like numerals of reference denote like parts throughout the several views :1, represents the frame of the apparatus supported on legs 2, and provided with a meltin pot 3, and a suitable furnace or heater be ow the same (not'shown), a backing stand 4, having-set screws 5, adapted to provide means for 7, is the press which comprises a yoke 8,

ceptacle and w ich is made removable so that it can be removed and heated, a screw 10, and a hand wheel 11, f or exerting pres- 12, isa blower pipe connected to a blower for supplying a blast of cold air to the-underaffording means for cooling the same, the electrotype, shell and backing." v

13, is a pump for forcing additional molten handle thereof;

The 0 eration of the'apparatus is as fol lows he copper shell having been covered ness by the manner already described and the platen having been heated to the .desired temperature the receptacle is placed in osition resting on the set screws 5, and after lieing adjusted by said set screws so as to be perfectly level the heated platen is lowered and deposited on the molten metal backing which has been poured over the copper shell in the receptacle. The platen being in the desired position pressure" is applied thereto by turning the wheel 11, which causes the screw 10, to press down onto the boss of the platen forcing the platen down. onto and into the metal backingto the desired depth, additional metal is forced into the closed receptacle by a pump or other means to make up for the shrinkage loss in cooling, so that an until t e metal or plate has become cold and set, a blast of cold air is then ap lied to the underside of the hacking pan t 'ough the blower pipe 12, by means of a blower until to a SUil1Ql Q,nt1'dfi Whatever shrinkage .thezc'fi'to the 'metal will follow to the last point that cools which is around the edges of the platen, and away from the printing surface of the plate. When the shell and placing said shell in said receptacle, pouring molten metal over said shell to form a backing for the same, pressing the'heatcd closure of the receptacle down u on the molten backing, forcing additiona molten metal into the receptacle and causing it to be distributed over the surface of the metal backing while said backing is in a molten state i .and under pressure and allowing said backing to cool under described.

2. The method of backing electrot e plates consisting in providing a receptzi' cqe aving a closure or cover, heating the backing. metal, heating the said closure to the same temperature as the backing metal, heating a shell in molten pressure, substantially as metal, removing the shell from the molten metal, placing said shell in said. receptacle, pouring molten metal over said shell to form aibacking therefor before applying the closure, pressing the heated closure or cover down upon said backing while it is in a molten state, and cooling and removing the closure and shell, substantially as described.

3. The method of. backing electrotype plates consisting in providing a closed receptacle having a removable closure, heatmg said closure to the same temperature as V backing metal, when said metal is in amolten state, placing a shell in said receptacle, heat.-

ing the-shell, pouring'molten metal over the 'the backing metal by inserting it onto the shell to form a backing therefor, pressin the heated closure down upon said bac g while it is in a olten state, introducing additional metal into. the receptacle and distributing it over the entire surface of the backing of the shell to compensate for the shrinkage of the said backing which'oc'curs when it cools, and removing the closure, substantially as described.

&. The method of backing electrotype plates consisting in providing a receptacle with a closure, heating the closure in molten metal in the melting pot of a furnace until it is of the same temperature as the metal therein, removin said receptacle and shell in the she closure, heating the said pot, removing" the receptacle and shell from the pot, placing metal ever said shell, pressing the heated In testimony whereof I afllx my signature closure dowriupon the molten metal backin in the presence of two witnesses.

forcing additional metal into said rece tec e I v T and onto the backing of the shell be ore it l GEORGE DDBTON' 5 cools, cooling the backing while under presg Witnesses:

sure and finally removing the pressure, sub- WM. J. LovELooK, stantially as described. i H. F. 7.BEOKER.

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