US2061591A - Electrolytic device - Google Patents

Description

Nov. 24, 1936. F. R, RAPIDS ELECTROLYTIC DEVICE Filed March 21, 1935 `Patented Novay 24, 1936 UNITED lsrxri-:s

PATENTl OFFICE 3 Claims.

This invention relates to an electrolytic devicev and more particularly to a device for e'ecting the electrodeposition of metals or for use in the `stripping of a metal from a metal coated article. More particularly, the invention relates to a device in the nature of a brush for use with a. relatively viscous solutlon of an electrolyte in the application of a metal coating by brushing the solution of the electrolyte over the surface of the article to be coated while at the same time passing an electric current through the solution of the electrolyte to the work and thereby effecting a deposition of a metal.

It is an important object of this invention to provide a device for the electrolytic deposition or removal of metals that does not require the use of a stationary bath of the electrolyte but which permits the carrying out'of the operation upon either small or large articles regardless of Whether they are portable or not.

It is a further important object of this invention to provide a device in the nature of a. brush for the effecting of the electrodeposition of metals in much the same manner as one would apply a paint or the like.

It is a further important object of this invention to provide a portable device that may be employed in electrodepositing metals'upon permanently positioned metal structures that would otherwise require the dismantling of the structuresif the usual plating baths were to be employed.

Other and further important objects of this invention will be apparent from the disclosures in the specification 'and the accompanying draw'- ing.

This invention (in a preferred form) is illustrated in the drawing and hereinafter more fully described.

On the drawing:

- Figure 1 isa longitudinal sectional view of a device embodying the principles of my invention,

` with parts ,in .elevation and with the electrical circuit shown' diagrammatically.

`FigureZ is a plan view-.of the device.

Figure 3 4is an enlarged `sectional view taken substantially on the; line III-,III of Fig. 1.

As shown on the drawing:`

The reference numeral Ill indicates generally 50 a brushing device embodying the principles of my invention and comprises a handle I I, a bristle brush I2 and a metal ferrule I3 encasing the upper ends of the bristles and secured to the handle II by means of rivets I4, or similar fastening means. The handle II is of suitable electrical insulating material, such as wood, molded plastic, a rubber compound, or the like. The brush proper I2 may be composed ofanimal bristles, ber bristles or strands of metal wire, or any suitable medium capable of a brushing, wiping or scouring action may be employed.

'I'he rivets I4 also serve to secure to the ferrule I3 a spring contact member I5 having at its free end a finger button I6 providing a contact point I1 adapted to be spring pressed against a second contact point I 8 affixed to the handle II. Said handle II is suitably provided with a longitudinally extending bore I9 through which extends a wire 20 that is connected to the contact point I8. The function of the manually operable switch S, provided by the member I5 and contact points I1 and I8, is to permit the electrolyte to be brushed on first with the current ofi and then, by closing the switch, to carry out the plating operation. The switch, however, is not absolutely essential.

A battery 2I provides a source of electrical current for operating the device. Either one or more dry cells may be conveniently used, or for heavier work, it may be desirable to use wet cells or other source of current. Instead of being separate from the brushing device III, the battery 2| may comprise one or more dry cells that are contained withinA or attached to the handle II.

A work block 22, which serves to support and form contact with a work piece 23 is connected to the negative side of the battery 2l by means of a wire 24 and a contact post 25. The workblock 22 may be entirely eliminated and the wire 2li connected directly to the work piece 23, as by means of a clamp, by soldering or other suitable means. f

In using the brushing device of my invention, the brush I2 is rst dipped into a solution of an electrolyte, a portion of which is picked upby the brush and adheres thereto as a film or mass 26. vSaid film of electrolyte 26 extends from the metal ferrule I3 tothe surface of the work 23 that is to be coated or from which a metal coating is to be stripped. When the switch S is closed, the electrical circuit from the battery 2l is thus `complete through the wire 20, the contact points I8 and II, the spring contact member I5, ferrule I3 and electrolyte 26 to the work 23. The other side of the circuit is completed through the work block 22, the binding post 25 and wire 24.

In the plating operation, the metal of the ferrule I3 forms the anode and may serve to supply metal to the electrolyte composition to replace that which is electrodeposited onto the work.

Practically any metal may be used, such as zinc, copper, cadmium, nickel, tin, iron, lead, chromium. and others. It is not necessary, however, that the metal of the ferrule be the same as that to be electrodeposited since the active electrolyte can always be replenished by repeated dippings of the brush applicator into the electrolyte composition. Consequently, the anode may be lead, iron, tin, or any other suitable metal, regardless of the particular metal to be electrodeposited. The solution of the electrolyte 26 is composed of an aqueous, alkaline or acid solution of a compound capable of furnishing ions of the metal to be plated out.

In order to insure a complete circuit through the electrolyte solution, it is preferable to employ a solution of a relatively viscous nature as comparedwith the usual electrolyte solutions of plating baths. Such a solution may be prepared by dissolving any suitable metallic compound, salt, or the like, in a water or acid solution and adjusting the solution to the desired viscosity, using as a thickening agent, such materials as starch,

gums, sugars, gelatin, petroleum jelly, or the like. By incorporating these or similar thickening agents, in proportions of between 2.5 and 40% by weight, say, the viscosity of the electrolyte may be built up to any desired extent, ranging from a thin syrupy consistency to a semi-solid, or jell.

The viscosity of the electrolyte solution should be such that it does not run too much on the Work and make the operation a sloppy one, but will adhere to vertical surfaces, to projections and the like. The lower limit of viscosity appears to be about secs. (Saybolt Universal at 62 F.). Thisis at least twice the viscosity of the usual plating baths.

As a specific example of a suitable electrolyte solution, the following composition is given, in

The above composition of the electrolyte solution is merely by way of exempliiication, since obviously any suitable ionizable metal compound or salt can be used, depending upon the particular metal to be electrodeposited. As is well understood by those skilled in the art, electro-deposition of the metal from the electrolyte occurs upon the closing of the circuit and this metal is constantly replenished by metal from the ferrule I3.

The bristles of the brush I2 serve not only to spread the electrolyte over the surface of the work 23 but also have a brushing or scouring action that aids in the removal of foreign particles, oxides, and the like, from the surface of. the work. It is, however, preferable to clean the work before applying the electrolyte solution and this may be accomplished in any of the usual manners, as by scouring, pickling, abrasion, or the like.

After the work has been cleaned, the electrolyte solution is brushed onto the work, with the switch S open, to a uniform thickness. This aids in obtaining a uniform coating, since it gives the electrolyte an opportunity to thoroughly cover and wet the surface of the work. The current may, however, be kept on from the start, if desired. One advantage'of the use of a exible brush is that the electrolyte solution may be readily coated over irregular surfaces and carried into deep indentations, depressions and similar points of the surface contour.

After the electrolyte solution has been brushed on, the circuit is closed and the brushing continued to accomplish the plating operation. The thickness of the coating of metal plated out in this manner will obviously be governed by the time of application, the current density, the concentration of the metal compound in the electrolyte solution and other conditions known to those skilled in the plating art. In order to get a good, even and uniform plate, the brush strokes should be regular and even and should cover the entire surface that it is 'desired to coat. After the plating operation is complete, the layer of electrolyte solution may be wiped or washed of! and the work piece washed.

Where the device is to be used to strip a metal coating of a plated article, the current is reversed. In this case, the nature of the electrolyte is moreor less immaterial, since the solution of the electrolyte merely serves to complete the circuit to transfer the metal stripped from the work to the ferrule. The electrolyte solution should, of course, have suiiicient body to adhere to the brushing agency and complete the circuit.

The use of a thickening agent in the electrolyte solution seems to have the added function of absorbing or adsorbing the hydrogen that may be liberated during the plating operation, since I have observed that there is practically no gassing and no trouble from polarization, using my process. The main function, however, of the thickening agent is to give the electrolyte solution sufcient body that it will adhere to the brushing element and form a continuous electrical circuit between the metal anode or cathode and the work to be plated.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. A device for use in the electrodeposition of metals, comprising a brush having a handle and bristles attached thereto, a metal ferrule encasing the attached end of said bristles, an electrical conductor in electrical contact with said ferrule and a manually operable make-and-break mechanism carried by said handle for connecting said conductor to a source of current.

2. A device for use in the electrodeposition of metals, comprising a brush having a handle and bristles attached thereto, a metal ferrule encasing the attached end of said bristles, a spring contact member secured to said ferrule, a contact carried by said handle for cooperation with said member and a wire extending along said handle from said contact for connection to a source of current.

3. A brush for use in the electrodeposition of metals, comprising a handle, bristles extending from one end thereof, a metal ferrule encasing said end and extending into contact with and overlying said bristles and an electrical conductor connected to said ferrule.

FELIX R. RAPIDS.

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