US2642392A - Electroplating apparatus - Google Patents

Description

June 16, 1953 c. .g. SOMMERS ELECTROPLATING APPARATUS 2 Sheets-Shut 1 Filed July 14, 1949 FIG. 1

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//vv /v1'0, CARL J. OMMER5 @Jiw A7 oe/ve'r Patented June 16, 1953 ELECTROPLATING APPARATUS Carl J. Summers, St. Louis, Mo., assignor to Sommers Bros. Mfg. 00., St. Louis, Mo., a corporation of Missouri Application July 14, 1949, Serial No. 104,790

1 Claim.

This invention relates generally to electroplating machinery and more particularly to the rotating barrel type of plater, and has among its objects the production of such an apparatus that will be neat and simple in construction and operation, long-lasting, having a large work capacity, and which will be otherwise satisfactory and effiicent for use wherever deemed applicable.

One of the principal objects of my invention is to so construct such an apparatus that the workreceiving drum need not cease its rotational movement when lifted above the level of the plating solution.

Another principal object of the invention is to provide in such a drum a multiplicity of drain openings so that when the drum is lifted above the liquid after plating is completed, the electrolyte will readily drain back into the tank from said rotating drum, and whereby none of the valuable liquid will remain entrapped in crevices of the work pieces, thus not only saving money, but resulting in cleaner and drier work pieces and with a minimum of liquid dripping onto the floor or adjacent areas along the path of travel of the work en route to the finishing operations.

An added object of the instant invention is to provide electrical insulation material caps or covers for the terminals of the cathode elements of the device, so constructed as not to collect and build up a mass of the plating metal thereat, thus insuring travel of the metal to the pieces of work being plated without waste and with a minimum of work stoppage due to unintentional locking of the parts through the undesired plating of the parts of the drum itself.

Another added object of my invention is to so construct the various elements of the device that the gas bubbles that attach themselves to the pieces of work being plated will be broken up and released from such attachment by the tumbling of said pieces as they are rotated in and out of said electrolyte solution during the plating operation.

A still further object of this invention is to provide a current control for the plating circuit, so that said current will automatically be switched on when the drum is lowered into the solution, and will be switched off when the drum reaches a predetermined height above said solution, thus saving current for effective plating use only.

Still another added object of the invention is to so construct the various parts of the apparatus that the contents that have been plated may be dumped into a tray or chute arranged alongside the plating tank, after the drum has been turned or oscillated through an arc of more than from immersion in the electrolyte solution to point of uppermost lift therefrom, the side Wall closure of the drum first having been removed for such discharge purpose.

Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art to which this invention appertains, as will be more apparent from the disclosures herein given.

To this end, my invention consists in the novel construction, arrangement and combination of parts herein shown and described, and as will be more clearly pointed out in the following specification.

In the drawings, wherein like reference characters represent like or corresponding parts throughout the views,

Figure 1 is a top plan view of my improved apparatus with the electroplating current switched on, but with the drum closure element removed in order to show the interior of the barrel more clearly;

Figure 2 is a longitudinal cross-sectional view of the same, taken substantially along the line 22 of Fig. 1, but with the drum raised to its uppermost or unloading position;

Figure 3 is a transverse cross-sectional view taken substantially along the line 3--3 of Fig. 1, and indicating the discharging position of the drum in dotted line and approximately the immersed position of the same in full lines;

Figure 4 is a transverse cross-sectional view taken substantially along the line 4-4 of Fig. 1;

Figure 5 is an enlarged cross-sectional detail view of one of the ends of the plating drum; and

Figure 6 shows an electrical means for controlling the drum as distinguished from the manual means shown in Figure 1.

Referring more particularly to the drawings, wherein I have illustrated one of the preferred embodiments of my invention, there is shown a plating tank having front and rear walls I and 2, side walls 3 and 4, and a bottom 5, and adapted to receive the bath or electrolyte solution 6, the inside of said tank being preferably made acidresistant by lining with rubber or in other suitable manner.

A drum of a size and capacity to receive the desired quantity of pieces of Work to be plated, is arranged to be rotatably driven while within the electrolyte bath, as well as while lifted therefrom, and is made of some suitable acid-proof non-metallic insulation material, as for example of Lucite or hard fiber, and in the instant form is of generally hexagonal cross-section, with the pair of end walls that may be made circular as shown, the fixed longitudinal Walls 8 and the co-operating removably attached longitudinal wall 9 that provides a cover or closure to enable pieces of work to be placed into or discharged from the drum through the opening sealed by said cover. A multiplicity of openings or apertures are provided through the longitudinal walls of the drum to act as a sieve.

Although the end walls 1-! are shown as being circular, a preferably hexagonal insulating element H is secured to the respective end walls at both ends and against which said walls 8 and 9 lie, and there are inner and outer insulation collars I2 and I3 positioned on the outer faces of the elements H and I as shown, to provide a sufiicient amount of bearing for the stub axles l4 extending axially through these elements into both ends of the drum, said axles acting as the terminal ends of the cathodes of the plating circuit.

A yoke element l5 having the pair of side arms |6-I6 is fixed or keyed at an end of one of said arms to a rotatable shaft l1 journalled on the end wall 4 of said tank, said shaft being driven through a worm and wheel gearing I8 controlled by the handle I9.

The outermost end of one of said axles I4 is rotatably mounted in an acid-proof insulating element fixed to the other end of said lastmentioned one of said pair of yoke side arms I6l6.

In this manner, actuation of said handle l9 controls the oscillation of said yoke and drum carried thereby, to lift or to lower the latter relatively of said electrolyte bath in the tank. It will be noted that said drum may be swung upwardly through an arc of more than 90 above the horizontal, the entire swing of the drum being approximately through an arc of 180, and the limits of such swing is indicated generally in the two positions of Fig. 3.

A pair of lead wires 3B-38 are electrically connected to the outer ends of the stub shafts or axles l4l4, said wires each being connected to a switch element 2| mounted to oscillate in unison with said yoke and are preferably insulated from the parts other than the cathode and said switch elements. A pair of switch elements 22-22 are fixed on the rear wall of the tank and insulated therefrom, said elements being electrically interconnected to the conductor 23. The other conductor 23' of the plating current circuit is indicated and communicates with a bar or rack 24 on which the plating metal anodes 25 may be suspended within the liquid.

When the drum is at a position above the plating liquid, the movable switch elements 2l-2I mounted to move in unison with the yoke are out of contact with the cooperating switch elements 22-22, but as soon as the drum is lowered sufficiently into the liquid, the switch elements movable with the yoke make contact with the fixed switch contacts (as seen most clearly in Fig. 3) and at which time the current is on and in use.

A link 26 is movably connected to be suspended from the inwardly projecting end of each of the pair of stub shafts or cathodes l4-l4, so as to ride loosely on said cathodes, each of said links having a second link element 21 loosely carried at its end so as to drag along the inside of the drum as the latter rotates. Of course, the pieces of work that are to be plated are loaded within the drum and make contact with one another and with the cathodes through said links.

In order to sheath the innermost ends of said cathode stubs, caps or covers 28 may be employed as indicated most clearly in Fig. 5, the upper ends of the links 26--26 riding on said cathodes between said caps and the adjacent insulating elements I2I2, it being understood that said caps too. are made of acid-proof insulating material. Thus there will be a minimum tendency to build up or deposit plating material at the ends of the cathodes, as the upper links will ride constantly on the stubs and prevent the retention of metal deposits thereat, and the caps 28 will not attract such deposits.

A source of power such as an electric motor 29 is mounted adjacent the tank to rotate the drum at slow speed through proper reduction gearing, the driven shaft being of two cooperating sections 30 and 3!, with a control clutch 32 interposed for movement therebetween. The section 3| is mounted on the tank end wall 3 in the bearing 33. The yoke is journalled on said section 3| and is rotatable relatively thereto.

A pinion gear 34 is keyed to said shaft section 3| and in constant mesh with a larger gear 35 fixed concentrically to the adjacent end wall I of the drum, so that when the clutch permits drive to the drum, the latter will rotate, but when the same is unclutched, the drum rotation will cease.

It may be mentioned at this place, that although a hand-operated mechanism is shown as used for raising and lowering the drum relatively of the electrolyte bath, other types of operating means may be employed, as for instance an electrically-driven motor that will drive in forward or reverse direction, and may be stopped at any point of drive, but the simple form is herein shown for the sake of simplicity.

A tray or chute member 35a may be employed to receive the pieces of work after plating, said chute being preferably mounted on or adjacent the rear wall of said tank and provided with a downwardly inclined bottom 36 along which the Work pieces may travel by gravity to any repositary such as a bucket, table, conveyor, etc., for movement to a point of further treatment, such as for bufiing or the like, as desired.

One of the longitudinal upper portions of said chute may be provided with a channel member therealong having the pair of spaced apart flanges 3'|--3| to straddle the adjacent upper edge of the tank and hold the chute in place, and permitting removal of the chute by the simple lifting of the chute therefrom. A guide flange or apron element 40 extends upwardly from said channel member (as indicated in Fig. 3) and as noted in the dotted line substantially uppermost position of the drum, the pieces of work may be readily discharged or dumped onto said chute through the drum opening, said opening preferably overhanging or being rearwardly beyond said apron in unloading position, to thereby facilitate such unloading after the closure element has been detached from sealing position.

In the device described, the drum may be completely drained after the plating operation has been completed, because the drum continues to rotate even after it has been lifted from the bath; hence any of the liquid that may have lodged in crevices, openings, corners, etc. of the pieces of work will drain therefrom and flow back into the tank liquid, this not only saving the comparatively valuable liquid but serving to minimize the slopping of the liquid onto the floor or other adjacent areas in the path of travel of the work pieces from the drum, and also improving the pieces of work for subsequent work operations, as they will be nearly dry.

As soon as the operator determines that the drainage is complete, the rotation of the drum is stopped, the cover or closure element removed and the drum lifted still further and swung in its arc of oscillation to slightly beyond a vertical position relatively of the journal shafts l1 and 3| which are in horizontal alignment, and in the last-mentioned position the contents of the drum will almost empty itself into the chute with slight help from the operator.

In the modification illustrated in Fig. 6, the correlated parts for controlling the swing or oscillation of the barrel is shown schematically for the sake of clarity, the arrangement being such that there is an electrically-controlled means for lifting and lowering the drum relatively of the electrolyte, and wherein the drum will be automatically stopped at both ends of said oscillatory movement.

A reversible drive motor 4| has the pair of leads 42-42 and 4343 for selectively driving the same in either of the two directions, with the main line current entering at 4444 and with the two-way switch 41 for throwing the motor into either direction of drive.

A mechanically controlled auxiliary switch 45 is interposed in the line 4242 and a similar switch 46 is in the line 4343, so that throwing said auxiliary switches to off position when current is flowing therethrough will stop the motor.

A worm 48 is fixed to the motor shaft and meshes with the gear wheel 49 that is keyed to the stub shaft II that carries one end of the yoke member arm I6. As the motor is driven in one direction of rotation, the worm will oscillate the plating drum through the predetermined travel in one direction, and upon reversal of the motor the arm will carry the drum in the reverse direction of oscillation to the other end of its travel.

A control element 50 is arranged to be moved in unison with the rotation of the worm to alternately engage said auxiliary switches 45 and 46 to throw one or the other to off position, said element 50 being preferably mounted to engage with the teeth of said worm so as to be shifted horizontally in alternately reverse directions as the direction of worm drive alternates.

The pair of limit positions of the drum are indicated in dotted lines in Fig. 6, of the plating position and of the unloading position.

In operation, assume that the main switch 41 is in one position, say uppermost in the diagram, so that the main line current will flow through the circuit 42-42 and rotate the worm in one direction, say that it drives the element 50 to the left. Obviously, the drum is oscillated downwardly into the plating solution until the element 50 actuates the auxiliary switch 45 and opens that circuit, whereupon the motor stops and the drum does not drop any lower. Thus, there may be a predetermined horizontal shifting of the element 50 to stop the oscillation of the drum at a predetermined depth in the solution.

Now, when the plating is finished, the main switch may be thrown to the other pair of contacts to energize the motor through the other line 4343 for reverse drive, and the worm rotates in reverse direction from its preceding drive, carrying the auxiliary switch control element 50 towards the right, and as soon as the latter engages the auxiliary switch 46 it opens the drive circuit 4343 and the upward oscillatory travel of the barrel stops.

Hence, the operation is very much simplified, and personal skill and judgment minimized, for with one throw of the switch the drum is actuated in one direction relatively of the plating bath, and stops at the level for which the mechanism is set, and at the alternately reversed direction of throw of said main switch, the drum travels in its arc to the other limit or stop and the drive ceases. It is to be understood of course, that said vertical movement of the rum is independent of its rotary movement and is also independent of the control for the plating current.

A spring 5| may be interposed to engage the auxiliary switches to retrieve them to their on or closed positions after disengagement with the element 50.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, arrangement, combination and construction, herein shown and described, except as limited by the state of the art to which this invention appertains, and by the claim hereunto appended.

What I claim as new and desire to secure by Letters Patent is:

In an electroplating device, a tank for an electrolytic solution, a drum for articles to be electroplated, an integral U-shaped frame mounted transversely of the tank, the outer ends of the arms of said U-shaped frame having axially aligned horizontal pintles, said drum having its ends rotatably mounted on said pintles, a pintle carried by one of said frame arms intermediate its ends, said last-named pintle being rotatably mounted in a bearing carried by one side of the tank, means cooperating with said last named pintle for pivotally rocking said frame, a drive shaft journalled on the tank opposite the last named pintle in axial alignment therewith, the other arm of said frame being rockably mounted intermediate its ends on the drive shaft in a bearing opening passing through said last named arm, whereby said drum is arcuately movable downwardly into the tank and upwardly out of the tank, and a gear carried by the drive shaft to the inner side of the last named arm, said gear meshing with a gear carried by the adjacent end of the drum.

CARL J. SOMMERS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 679,357 Betts July 30, 1901 1,135,660 Chase et a1 Apr. 13, 1915 1,505,424 Purinton Aug. 19, 1924 1,695,795 Belke Dec. 18, 1928 2,035,633 Bogle Mar. 31, 1936 2,315,272 Potthofl Mar. 30, 1943 FOREIGN PATENTS Number Country Date 277,032 Italy Aug. 2'7, 1930

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