US1857929A - Decorating and etching metals - Google Patents

Description

My 10, 1932. I J. c. MGFARLAD .1,857,929

DECORATING AND ETCI'ING METALS Y c -0 11e May 10, 1932. J. MQFARLAND 1,857,929

DECORATING AND ETC-HING METALS Filed June 22. 1928 2 sheets-shea 2 .is ing- Patented May 10,1932

UNITED Asrrrrrzs PATENT ori-'ICE JAMES C. MCFARLAND, OF FORT THOMAS, KENTUCKY, ASSIGNAOR T THE WAJ'JSNOR-TH 'WATCH CASE CO., OF DAYTON, KENTUCKY, A CORPORATION OF KENTUCKY DECORATING D' ETCHING METALS Application led June 22,

The present invention pertains particularly to a process of decorating metals, and etching such metals, if' desired.

The primary ob] ect 1s to provlde a process 5 well suited to the production of decoratedv base metal plates, or other base metal objects,

- yfollowed by etching, if desired. The process Y is well adapted, for example, to the purpose of decorating the movement block of a watch.

11,9 In theprocess, use is made of the princlple that chromium 'plating can be readily accomplished, whilst, on the other hand, a plating of chromium will not itself readily receive another plating, Such as a precious metal plat- Chromium is extremely hard, resistant, and

lwill not tarnish. `Accordimgly, chromiumv plating may itself be employed advantageously in a decorative design, which may comprise a. chromium plate design c and a complemental metal plate design o ontrasting color, such as gold," green gold, copper, or the like.

The process may belap-plied, for example,

to the decoration of the'movement block of 'a watch, the movement block being composed of any suitable base metal, or base metal a1-.

loy, suclras a composition commonly known as 12% nickel.' Such a composition may be composed of Ni, 12%; Cu, 70% Zn, 18%.

The process is capable ofvariations. The

accompanying drawings illustrate preferred methods It is to be understood, however,

that variations in the steps may be employed.l

In the drawings-h Fig. 1 shows d1agrammatically a base plate and a chromium plating applied thereto; Fig. 2" illustrates a further step in which a suitable-resist is applied to the chromium plating; Fig. 3 illustrates a further step in vwhichl the exposed chromium has been removed, exposing the base metal at certain areas; and Fig. L illustrates a further step inl which -aplating of some other metal, such as gold or copper, has been appliedto the exposed areas of the base plate. Figs. -5'-8 i1- lustrate the'steps which may -be employed when it is desirable to etch the base plate after the operation of plating with a metal insoluble in FeCL. Figs. 9-15 show diagrametc. to enable/the various parts of the watch 192s. serial No. 287,535.

matically the steps to produce a design by contrasting finishes. Figs. 16-20 illustrate steps using a photographic resist in applying a chromium design to a base plate and giving the latter a Vfinish contrasting withl that of the chromium. f

For clearness, the various coatings are shown of exaggerated thickness, but it is to be understood Ithat-this is merely for purpose of illustration. l Y

' It is to be understood, also, that where the process is applied to the decoration of a watch movement block, the base plate is provided with suitable recesses, perforations, bearings,

05 movement to be applied, housed, etc.

In .the illustration given 1n Figs. 1 4, A designates a base plate; B, chromium plating; C, a resist design; A', the exposed surface of the base plate; and D, a m tal plating applied to the exposed areas of thbase plate, so that the chromium plating design and the othenmetal plating design give the desired decorative design, as a whole.

In the practice of the process illustrated in Figs. 1 4, the face of the plate is 'first given theA desired topographical contour and is polished, or pumiced, if desired; a plating of chromium is then 'applied to the entire surface; a suitable resist design is then 'applied to the chromium plating; the back o the plate, or object, is coatedwith a suitable resist, such as paint; the exposedchromium plating (areas between the areas of the resist design) is then removed, as by use of a suitable reagent, such as dilute hydrochloric acid, or dilute sulphuric acid; theresist preferably is removed at this stage;-and the ex posed areas of the base plate are then plated with another metal, such as gold,gold alloy, silver, platinum, or copper. The other metal will not plate uponthe chromium-covered areas,but will plate upon the exposed surfaces of the base plate. Thus, the chromium serves as a resist during the operation of plating with gold, for example'. Usually, the other metal used for plating will have a color contrasting with the color of the chromium plating. i

The method described results in a deco- 10 rated metal plate, or metal body, the decolute sulphuric acid, for example.

example, erric chloride may be em loyed to vetch the base metal The etched sur aces may be decorated in any desired manner. Such silver. moved and the sllver may be used as a reslst a process is shown in Figs. 5-8, where E desi nates the base-plate, F the chromium lating, G the plating insoluble in FeCla, and

the etched surface of the plate E. U Where etching is to beperformed, the precious 'metal employed for plating may be The chromium plating may be rewhile the base metal is being` etched. Thus one may obtain an etchedblank. 'The silver. 'may1 be removed, if desi-red, and the surface of the etched blank may be decorated in any.

ap roved way.

modification of the process of 'decorating b applying platings, as described above,

e stated, as follows:

mag late the surface with chromium; apply a suitable resist in the form of a suitable design; remove the exposed chromium with a suitable solvent, such as dilute hdrochloric acid; remove the resist, thus exposing the un derlying chromium plating; etch, by means' of a suitable solution, such as FeCl3, the exposed areas of the' base plate, the chromium plating serving as a resist; and plate the etched area with a metal, such as gold, green gold, or copper, which'forms a contrast in color with the chromium plating. The chromium plating will not receive the new plating, butthe etched areas of the base plate wi l receivethe new plating. E

Gold, silver, platinum, and their alloys. may thus beplated upon the base plate, but Will not be received upon the chromium. The` precious metals mentioned may be termed platable-metals which are insoluble in ferrie chloride. The same is true of chromium.

,The method last described may be used 'advantageously upon surfaces exposed to Wear, for example, on the exterior of awatch case, vanity case, A,or -the like. The plating upon the etched surfaces may thus be below the general surface, so that the gold plating, or the like, will not readily wear off. In

' the case of a movement block, the etching is not Aso necessary.

A further modication of the process of applied to portionsof chromium (the resist will not receive the chromium plating) remove the resist, leaving exposed areas of the base plate; plate the exposed areas of the base plate with another metal having a color contrasting with the color ofthe chromium plating.

The modification just stated is more fully described and is specifically claimed in my co-pending application Serial No. 287,536, filed of even date herewith.

The resist design may be applied vin any suitable manner. As an illustration, after the base plate has been plated with chromium, the chromium plating may have applied thereto a sensitive coating; an image may be produced photographically in said coating, the portions of the coating most exposed to light being hardened to produce the image; and the unreacted portions of the'coating may lbe removed by means of a suitable developing agent. Such a processli's described, for

example, in Beebe and Murray Patent 1,574,,

357, granted February 23, 1926. Figs. 1620 illustrate such a process, M designating a base plate with a polished surface'M, N the chromium plating, P a resist applied photographically, and M2 a dull nish which may be the base plate if deslred.

If desired, a suitable Itransfer method may be employed, in lieu of the method just described, to apply the resist.

suitable current density per unit of area will be employed to obtain the desired results', as is understood in the art.

The improved method is applicable to r0- ducing decorative designs on' various ase metals and alloys, such as brasses, bronzes, German silvers, etc.

Also, the method is applicable, with suitable variations, to the production ofa decorative design on precious metals.

- A further variation of the first` described processwhich is applicable, for example, to decorating awatch case, or watch case back, may be stated, as follows:

Produce a dull or polished finish on the surface of the back; apply a chromium plating to said surface; apply to the chromium plating a light-sensitive coating, expose and develop, thus leaving a resist pattern or design of the reacted coating on the back and exposing the chromium pla-ting at other areas; remove the exposed chromium plating, as by means of dilute hydrochloric acid; remove the resist; polish or dull the surface of the back, in which operation the newly exposed chromium plating will not be affected; and, finally, remove the remaining chroy In performing the plating operations,

. designating the base plate having a desired finish H', K the chromium plating, L the resist, and H2 the contrasting finish applied to portions of the base plate. t y

The foregoing detailed description has been given for clearness of understanding v only, and no unnecessary limitations should ybe understood therefrom, b ut the appended claims should be construed as broadly as permissible, in view ofthe prior art.

What I regard as new, and desire to lsecure by Letters Patent, is l 1. A method of treating a metal surface 'having afdull finish, which comprises: pro- A ducing a chromium plating design on a portion of said surface andexposlng the remainmium pla-ting design. r

ing areas; polishing the exposed areas of the original surface; and removing the chro- 2. A method of treating a metal surface, l

which comprises: giving a desired inish to said surface; producing a chromium plating u design on a portion of the surface thus in- Y ished; producing a contrasting finish on the exposed areas of the original surface; and removingl the chromium plating design,

posed area of the original surface while the chromium serves as a resist.

6. A method-of treating ametal surface which comprises: polishlng the surface; chromium plating the polished surface; applying a light sensitive coating to the' chromium surface; photographing a design thereon-ancl developing the film; dissolving the l chromium throughout the areas left unprotected .by the image; and producing a dull finish on the surface from which the chromium has `been removed while vthe remaining chromium serves as a resist.

JAMES C. MCFARLAND.

whereby the original surface lis left with a decorative design comprising designs having contrasting finishes. 3. A method of treating a metal-surface' which comprises: giving a desired finish to said surface; applying a chromium plating to the entire surface thus finished; applylng to the chromium plating a resist design; re- -moving the exposed chromium-plating; re-

l' moving the resist 4from theremaining chromium and producing a contrasting iinish on the exposed areas of the original surface; and removing the chromium plating design, whereby the original surfaceis left with a decorative design comprising designs having contrasting finishes.

4, A method of treating metal surface,

` which comprises: giving a desired finish t0 said surface; producing 'a chromium plating design on a portion of the surface thus iinished; and producing a contrasting finish on the exposed area of the original surface while. the chromium serves as a resist.

5. A method of treating metal sur-face, which comprises: giving a desired finish to said surface; plating the surface. with chromium, applying a light sensitive coating to the chromium surface, photographin a design therein, and developing the film; issolving the chromium throughout the areas left unprotected by the image; and producing a contrasting finish throughout the ex- Viis

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