US2545294A - Anode control for plating tanks - Google Patents

Description

March 13, 1951 w. MESSINGER ETAI.

ANODE CONTROL FOR PLATING TANKS 2 Sheets-Sheet 1 Filed March 5l, 1948 Flea INVENTORS. WILLIAM MESSINGER DONALD B. L YTLE THE /E ATTORNEYS.

March 13, 1951 w. MEsslNcsl-:R Erm.

ANODE CONTROL FOR PLATIN@ TANKS 2 Sheets-Sheet 2 Filed March 3l, 1948 FIGS.

FIG.

INVENTORS. WILLIAM MESSINGER& BYDONALD B. LYTLE Patented Mar. 13, 1951 ANODE CONTROL FOR PLATING TANKS William Messinger, Philadelphia, Pa., and Donald B. Lytle, Bronxville, N. Y.; said Lytle assignor to Time, Incorporated, New York, N. Y., a corporation of New York Application March 31, 1948, Serial No. 18,167

1 Claim. (Cl. 204212) The present invention relates to tank structures for use in electroplating operations and, more particularly, to an improved tank structure by means of which chromium plating operations may be effectively carried out in the plating of large cylindrical objects.

It has been found, in chromium plating operations, that large cylindrical objects are extremely difficult to plate with a uniform plating of chromium where such objects are supported in a horizontal position and merely dipped while being ro tated in the plating solution during the plating operation. `.'By providing a plating tank which is capable of supporting such objects ina vvertical position, the objects may be `immersed and the plating operation carried out, but where the objects are of considerable diameter as well as length, the problem of maintaining a desired and uniform current density has presented a serious obstacle to plating operations of objects in the vertical position, as above described.

It is an object of the present invention, accordingly, to provide a plating tank structure which is of such formation as to permit long objects,

`such as cylinders, to bereceived and supported in a vertical position during the plating operation and, while so supported, providing means whereby the current density of the surface being plated is eiectively controlled.

Yet another object of the present invention is to provide a plating .tank structure of the above character wherein large and long cylinders may be supported in a vertical position during plating operations and rotated while in such position, the invention further contemplating the provision of means for controlling the area of the object that is subjected to the plating operation during rotation, as well as controlling the current density as desired.

Further objects of the invention will be apparent as it is described in greater detail in connection with the accompanying drawings, wherein Figure 1 is a view in vertical section taken through a plating tank constructed in accordance with the present invention, the View being taken on the plane indicated at I-l of Figure 2 and looking in the direction of the arrows;

Figure 2 is a plan View of the tank structure shown in Figure 1;

Figure 3 is a View similar to Figure 1, showing a modified form of anode;

Figure 4 is a view in horizontal section, taken on the line 4 4 of Figure 3, and looking in the direction of the arrows; and

, Figure 5 is an enlarged. view of the mechanism at the bottom of the tank shown in Figure 3.

Referring to the above drawings, a plating tank is illustrated as being formed with an outer shell I I having a plurality of reinforcing structural channel members IIa secured thereto, together with a top angle flange I2 and a bottom plate I3. The'bottom plate I3 may be formed with a well I i within which the bottom extremity of the object being plated may be received. For example, if a large cylinder Il) is being plated, the cylinder shaft maybe received within the Well I4 thus to remove it from the active plating area within the tank.

A suitable liner I5 of lead or other inert material is provided within the shell II and formed and secured in such position that the shell is effectively sealed from the plating solution contained Within the tank during the plating operation. vertically extending reinforcing anglebars I6 may be provided, as will be well understood by those skilled in the art. A suitable supply of a, plating solution may be provided through inlet and outlet pipes Il and I8, respectively, all in accordance with known plating practice. An overflow pipe I8 is provided adjacent the top of the tank.

In accordance with the present invention and in order to provide eifective control for the plating of large objects, such as cylinder Ill-I, the tank I I is provided with an anode bay I9 Within which an anode 20 is received. At the entrance to the bay, doors 2l and 22 are provided, the doors being pivoted on vertical hinges at 23 and 24, respectively. In this fashion the doors may be swung into the tank, as illustrated in Figure 2, the adjustable position of the doors permitting the effective area of the entrance to the bay to be varied in order to restrict the area of plating that is accomplished upon the object carried within the plating tank I I. Shields 26 and 2l formed of inert material are provided in the bay to control the plating operation to produce a plate of even thickness by increasing the length of the electric current path'from the anode to the cylinder ends, thereby avoiding the heavy build-up of plating that would otherwise take place at the ends of the cylinder.

It will be understood that suitable means forming no part of the present invention is to be pro-V,

vided to support and rotate the cylinder within the tank I I so that the entire cylindrical surface to be plated is progressively brought opposite the anode bay I9, and thus in the continuous rotation a plating of uniform thickness and character is built up during the plating operation. The anode 20 is positioned within the anode bay by means of spacers 25 and is suitably connected to a source of electricity to which the object being plated is also connected, all in accordance with standard plating practice. By controlling the position of the doors 2| and 22, the exposed area of the cylinder or other object'` being plated is effectively controlled. Furthermore, since it is well known that there is a xed relationship between current density and temperature of the electrolyte bath and that the heat generated by the electroplating current is considerable, it is possible, by determining the tempera-ture ofthe bath and adjusting the position of the doors 2| and 22, to maintain the required current density to eiect the desired plating operation..

In the form of the invention shown in Figures 3, 4, and 5, the anode 28 is shown as being provided with an intermediate portion 29 having portions 30 that incline away from the cylinder l0, and in this fashion, serve to control the platingoperation so that the thickness of the plate is uniform to the ends of the cylinder.

In the well I4 of the tank, a guide bearing 3| is provided havingv aA base plate 32 which iS mounted in a similarly shaped recess 33 in a second plate 3B. The plate 32 is rotatable in the recessy 33, the recess being formed eccentrically with respect to the Vertical aXis of the plate 35. VIn this fashiorh the vertical axis of the cylinder I0 may be adjusted se that the periphery of the cylinder may be properly spaced with respect to the anode within the anode bay I9. By fori-ning the bearing 3| with a desired eccentricity with respect to the plate 32, careful adjustment of the position of the cylinder may be accomplished.

It is also within the contemplation of this invention to adjust the distance between the anode and the cylinder, and thus regulate the intensity of the plating current, by moving the` anode horizontally toward or away fromthe cylinder. This may be accomplished in any suitable manner such as, for example., by suspending the anode 'from two horizontal copper bars upon which the anode is slideably adjustable, and locking them securely together after the adjustment has. been made.

While the invention has been described with specific reference to the structure shown in the accompanying drawings, it is not to be limited save as dened in the appended claim.

We claim:

A tank for plating elongated cylinders comprising an elongated vertically disposed tank structure for containing an electrolyte and an elongated cylinder, a vertically disposed bay extending outwardly of and opening into the tank at oneT side thereo, an anode in the bay, means for adjusting the position of the anode in the bay, a door between the bay and the tank, a well in the bottom of the tank, a plate mounted for rotation inthe well,Y and a bearing mounted on the plate for eccentric rotation with reference to the plate, and for receiving one end of an elongated cylinder, the door being supported for rotation about a vertical axis to. vary the effective width of the entrance into the` bay during a plating operation and thereby control the current density under varying conditions of temperature the electrolyte, the plate in the well being rotatable to adjust the distance between the anode and the cylinder to be plated, and the cylinder supporting bearingV being rotatable relative to the plate for rotating the cylinder within the tank during the plating operation.

WILLIAM MESSINGER. DQNALD B. LY'ILE.

REFERENCES CITED The following references are, of record` in the le of this patent:

UNITED STATES PATENTS Number Name Date 680,408 Cowper-,Coles Aug. 13, 1901 1,519,572 Wolf Dec. 16, 1924 2,086,226 Hoff July 6, 1937 2,155,392 Ballard Apr. 25', 1939 FOREIGN' PATENTS Number Country i Date 712,505 France A July 21, 1931

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