US3503815A - Method of producing a multi-colored metal design on an arcuate metal base - Google Patents

Description

Mardh 31, 1970 R. M. JOHNSON 3, 3,

METHOD OF PRODUCING A MULTI-COLORED METAL DESIGN ON AN I ARCUATE METAL BASE Filed May 27, 1968 CHROME COPPER INVENTOR ROBERT M. JOHNSON flmwm ATTORNEYS /3 y///////// -BRASS FIG? United States Patent 3 503 815 METHOD OF PRODUCIPIG A MULTI-COLORED METAL DESIGN ON AN ARCUATE METAL BASE Robert M. Johnson, 265 Benefit St., Providence, RI. 02903 Continuation-in-part of application Ser. No. 418,726,

Dec. 16, 1964. This application May 27, 1968, Ser.

Int. Cl. C23f 1/02; B29c 17/10; 1323b 25/00 US. Cl. 156-6 6 Claims ABSTRACT OF THE DISCLOSURE The method of producing a multi-colored metal design on an arcuate surface by superimposing different metals in substantially fiat planes, making the design and then curving the metal so formed into a desired shape.

Cross-reference to related applications This application is a continuation-in-part of my application Ser. No. 418,726 filed Dec. 16, 1964, now abandoned.

Background of the invention Attempts have been made to utilize a plastic base upon which plating has been had of various metals with the removal of these metals to expose different metals and the plastic base, such as in Patent 3,731,333 to Ko but this procedure has not been able to produce the design in relief as the resin base cannot be removed by acids or some mechanical processes in a convenient manner. Further the design must remain in a fiat form or the form in which it is completed and the resin base with plating cannot be formed into arcuate shapes such as a bowl or the like in any known commercial way but must rather be maintained in its fiat condition. Further certain effects in a resin base material and the appearance of metal cannot be provided. Further, plating is a slow process and layers of plating are relatively thin and cannot serve as a base material to an extent so that a relief may be provided.

Summary of the invention Providing on a metal base superimposed layers of additional metals of different colors and with acids etching away from the outer surface, first the outer metal and so on to the base metal in a suitable design exposing sequentially different colored metals and etching into the base metal sufficient to provide in relief the design formed of the metal superimposed thereon and additionally forming the surface so etched from fiat to an arcuate form with the design therein.

Brief description of the drawing FIG. 1 is a perspective view of a flat composite metal disc after it has been treated to produce a design thereon;

FIG. 2 illustrates this disc formed into a bowl;

FIG. 3 is a top plan view of a film having a Portion of the design desired formed thereon;

FIG. 4 is a top plan view of another film having a further portion of the design formed thereon;

FIG. 5 is a sectional view on a greatly enlarged scale of a disc showing the three layers of material before forming a design;

FIG. 6 is a view similar to FIG. 5 with a sensitized material coating the upper surface of the disc and a film applied thereto;

FIG. 7 is a section on line 7-7 of FIG. 1;

FIG. 8 is a section on line 88 of FIG. 1;

FIG. 9 is a fragmental plan view of the center portion Patented Mar. 31, 1970 Description of the preferred embodiments I will describe the invention with reference to a particular article and with reference to certain specific metals known to have different colors but it will be understood that other articles and other metals may be utilized, substituted or reversed for those shown and specified. The purpose of referring to a specific article and to specific metals is to lend clarity to the description and is not of a limiting character.

The article which is here referred to is a bowl formed of all metal and having a design on its inner arcuate surface. I desire to have three different color metals in this design and I have chosen as the three metals chromium, copper and brass, each having a different characteristic color.

Generally the outer body metal will be of a sufiicient weight to maintain the strength desired of the article formed and in the present showing is brass. For the purpose of coloring and forming a design of contrasting colors, I superimpose upon this heavier body brass material layers of other metals, there being superimposed on the brass a copper material such as by plating and then superimposing upon the copper plate a chromium plate. These are each relatively thin. The design is formed by etching away portions of a superimposed material by using a resist to prevent the etching where it is desired that that material shall remain, thus forming a design as desired. In some cases in order to provide a portion standing up in relief higher than the portions surrounding it the brass may be further etched away to provide this effect. Further a tone effect may be provided by suitably treating the surface where a roughened background may be had and this is subject to further plating if desired.

In order to provide a bowl with a design thereon by the method which I will here refer to, it is necessary that the design be formed upon a flat surface first and I provide a disc designated generally 10 of the proper size and shape from which the bowl shown in FIG. 2 and designated generally 11 may be formed by suitable dies and presses.

This disc 10 comprises a bottom body portion 12 of brass sufficiently thick to be strong enough to sustain the shape and usage to which a bowl will be put. It may be of an inch in thickness. Secured to this brass body there is a layer of copper 13 which may have superimposed upon it a layer of chrome 14. The copper layer 13 may be plated upon the brass body 12 and the chrome plated upon the copper layer 13 by electroplating or each of these layers may be a thin plate which may be fused together, it being often referred to as annealing one layer to the other. If plating is done, no fusing is necessary. The thicknesses of the superimposed material of copper and chrome may be variously provided but basically are very thin but of a sufficient thickness so that the under metal will not show through the metal above it. The thicknesses shown in the drawings are, of course, largely exaggerated in order to bring out the invention. In FIG. 5 the various "materials are labeled for clarity.

Assuming that the body of brass is plated with copper and chrome as shown in FIG. 5. I then provide a coating over portions which are to remain the color of the chrome or top material so that when acid is applied the remainder or non-coated area may be removed. One method of providing such a coating which is to coat the outer metal, which in this case is chrome, is to use a material which will be responsive to light, such as a photographic or sensitizing solution, usually of a silver salt or commercially available sensitizing solution, which will 3 cover the entire area of the chrome. I will then provide a film which I have here desginated as 15 in FIG. 3. This film will be transparent in the portion 16 which extend diametrically across the circular film and will be opaque in the portion 17 shown by the shading and will be of the size of the design which is to be formed. The film may be of the celluloid type, such as a photographic film, with blocked-out opaque areas 17 leaving transparent areas 16. This film will then be placed over the sensitized coated body and then exposed to light (see the sectional view of FIG. 6). The light will cause the portions of the sensitized solution which are hit with the light to be burned in and so transformed that they will not be soluble, while the portions-which are not struck with light under the opaque areas such as 17 will remain soluble and are washed away in a developing solution of methyl Cellosolve acetate 1 part and Xylol 3 parts. After this operation is performed, the film is removed and the work disc will be placed in a bath, which bath is of a character which will dissolve chrome, but will not dissolve copper or brass. One such bath is essentially sulphuric acid and glycerine and is marketed by Lithochemical & Supply Co. of Lynnbrook, N.Y., under the tradename LITH KEM-KO. Thus, the unprotected exposed areas beneath the opaque portions 17 of the film which have been washed away will be dissolved away by the acid, leaving the copper beneath, which is the layer beneath the chrome, while the areas protected by the coating remaining on the outer chrome surface will remain. These copper areas will correspond to the areas 17 shown on the film, while the chrome areas will correspond to the areas shown at 16 on the film.

In the formation of this design, however, it is desired to also expose some brass and to provide circular bands of copper. The next step is to strip the entire surface of the disc of the first applied sensitized coating and to recoat it all over with a light sensitized material, and then a second film designated 20 and shown in FIG. 4 is provided which will have opaque areas 21 in the areas in which it is desired for the brass to be exposed and transparent areas 22 in the areas in which it is desired that the copper will be coated with a sufficient resist to prevent removal of the copper by acids. Likewise, the chrome areas which have been formed will also have a transparent portion which will provide a resist to further acid treatment. This film is then placed over the sensitized disc and exposed to light which strikes through all portions except the portions which are opaque. The portions of the sensitized coating that are hit by light are burned in and become fixed on the metal surface, while the portions which are opaque, not being hit by light, remain soluble and are washed away by a developing solution as above explained. Then upon washing this surface again the soluble portions are removed now from the areas which are to be brass color and the disc is then placed in an acid, such as ferric chloride or nitric acid, which will dissolve copper, leaving exposed brass in the areas corresponding to the opaque areas of the film 20.

In the center of this disc I have provided an initial 25 which I desire shall stand out in relief, and accordingly I desire to etch or cut away the base or body 12 further in the circle which surrounds this letter. Accordingly, I provide a third film designated generally 30, the center portion of which only is shown in FIG. 9, and in this film everything outside of the circle 31 will be transparent, while within the circle there will be a stippled area shown at 32. Such remaining coating as previously applied is stripped oif, and fresh sensitizing coating is applied. This film will then be placed over the disc 10 and exposed to light, the light fixing all of the transparent area outside of the circle 31, and also the initial 25 will cause the coating to be fixed while the portion within the circle may be opaque or stippled to partially obstruct light. Where light strikes, the coating will be fixed. The disc will then be treated with acid again which will eat into the brass portion in the circle except where coated at initial 25 or the stippling so that it will be eaten in about the initial 25 as shown at 33 (FIG. 10), where the surface, in the case of stippling, will be somewhat roughened because of the stippling effect and the partial coating provided. This thus provides the initial in relief and also provides about the initial a tone or shading background. The time in which the acid is allowed to act in this last instance may be varied depending upon the depth of etching required.

In some cases the stippling may be used to roughen up a surface so that a resist will better adhere.

In some cases a resist may be directly applied to the material by means of an air brush. Such a resist may be asphalt varnish which may be applied in varying effects to obtain the results of the stippling produced by a sort of stippling application of the asphalt varnish, or in other cases there may be sulficiently applied so that a uniform resist or coating is formed. Also in some cases, opaque water color applied with an air gun may be used as a resist to light on either the original art work, film or sensitized metal to achieve tonal or granulated effects. In Which case, it acts as a resist to light creating an area effective to etching. Also in some cases opaque water colors may be utilized.

The disc thus formed and provided with the design desired in fiat form as shown in FIG. 1 is then formed into a bowl with dies and presses so as to get the configuration desired.

In the utilization of sheets of film, which is the preferred way of forming the design and that which is first given, it is not possible to spread a flat film on a curved surface and obtain this decoration sufficiently accurate due to buckling which will occur in the film. Therefore, it becomes necessary to form the design on a fiat surface by this method and then form the decorated article into the shape which is desired where arcuate surfaces of concave or convex shape are utilized.

I claim:

1. The method making an arcuate ornamental article which comprises the steps of (a) securing in superimposed relation on a metal base additional metals dissimilar in color to each other and to the base one upon the other with the number of different colored metals necessary to produce the number of colors in the design, (b) providing a coating on the outermost metal in some portions to resist etching and subjecting the surface of the outermost layer to a solution which will etch and remove the outermost layer where the coating is absent, (c) repeating the coating and removal step to remove the next metal to the outer metal to expose the third metal and (d) then forming the base and superimposed metals into an arcuate form.

2. The method of claim 1 wherein the superimposed metals are provided by electroplating.

3. The method of claim 1 wherein the superimposed metals are provided by fusing the metals together.

4. The method of claim 1 wherein the base metal is brass.

5. The method of claim 1 wherein the exposure of the metal to one removing solution is less than necessary for completely removing the metal.

6. The method of claim 1 wherein the coating is provided by a light sensitive solution.

References Cited UNITED STATES PATENTS 3,039,177- 6/1962 Burdett 29l55.5 1,974,011 9/1934 Burgess l5613 2,731,333 1/1956 K0 et al. l56-3 3,130,487 4/ 1964 Mears 29-424 JACOB H. STEINBERG, Primary Examiner US. Cl. X.R.

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