US1570819A - Method of electroplating and apparatus therefor - Google Patents

Description

Jan. 26 1926. 1,570,819

, B- BART I METHOD OF ELECTROPLATING AND APPARA TUS -'X HEREFOR Filed Oct. 11 1923 2 'Sheeti-sneet 1 INVENTOR Elas Lus Bari o/ii w ATTORNEY Jan. 26 1926. 1 1,570,819

' B. BART METHOD OF ELECTROPLATING AND APPARATUS wna'nn'ron Filed Oct. 11 1923 2 Sheets-Sheet 2 INVENTOR BZaszusBa/rt Patented Jan. 26, 1926.

UNITED STATES 1,570,819 PATENT OFFICE.

BLASIUS BART, OF EAST ORANGE, NEW J EBSEY.

METHOD OF ELECTROPLATING AND APPARATUS THEREFOR.

Application filed October 11, 1923. Serial No. 667,797.

To all whom it mag concern: Be it known that I, BnAsrUs BART, a citizen of the United States, and resident of East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Methods of Electroplating and Apparatus Therefor, of which the following is a specification.

The invention relates in general to an improved method for treating forms, such as molds and articles of commerce to a deposit or coating formed thereon by an electrolyt c action while suspended in the electrolytlc bath and which method will be referred to hereinafter generically as an electroplating operation and the invention also relates to an improved form of mechanism constituting part of an electrolytic apparatus.

In the art of electrolytic deposition it is a usual practice to suspend a plurality of the forms or articles to be coated in a suitable tank, and to pass electric current from a series of anodes to a series of cathode plates positioned in this tank. In actual practice, however, it is found that the electrostatic conditions in certain parts of the tank are diiferent and accordingly certain of the objects under treatment are more heavily and more rapidly coated than are those objects which are disposed in a part of the electric field where the electrical conditions are not so favorable to the desired rapid and efficient electro-depositing or electroplating rocess. The necessity of Watching the different articles while under treatment adds materially to the labor cost; requires the construction of a tank which permits ready access to the articles along the entire "length of the same and even with the exercise of extreme care there is no assurance that all of similar articles in the tank will be uniformly treated or coated. Accordingly, the primary object of the invention is to provide for the handling of the articles in such way that all of the articles will have deposits of equal depth thereon or will be-uniformly coated irrespective of variations in depositing activity at different portions of the bath, and in which it will be'necessary simply to position the articles into the tank at one end thereof and remove the finished articles at the same or another point in the tank aftereach article has been subjected to a treat ment for a prefixed and predetermined time while in the bath. I

Broadly, I attain this hase of the invention by causing all 0 the articles to traverse the same path while positioned in the tank and inthis way assure a uniformity of treatment of all of-the articles and the subjection of each article to all of the varying electrical conditions which may happen to be present in the tank.

It has also been found in practicing the art of electrolytic deposition that the side or projecting portion of the article closest to the anode late becomes more thickly and more rapi 1y coated than the side facing in the opposite direction or more remote from the adjacent anode plate. Further it has been found that the electrolyte which is immediately adjacent the depositing coating becomes impoverished and the resulting plating operation becomes irregular, presumably due to the irregularity in the movement of the depositing salts from the richer to the impoverished portions of the electrolyte.

Another object of the invention incidental to the desideratum to provide a uniform deposit on all portions of the article under treatment, is. to provide for the handling of the articles while in the bath in suc way as will present all portions to be coated to the anode plate or plates in some period during the plating operation, and incidentally to insure the maintenance of rich and uniform electrolyte at all times adjacent the electrolytic depositing surface.

Broadly, I attain this phase of the invention simply by rotating the article while 'it is being advanced bodily through the different electrical parts of the bath. The effect of this rotary movement is to present all ortions of the object repeatedly to each ano e plate during the cycles of movement of the article imder treatment and incidentally to maintain the electrolyte in a:

stirred or gently agitated condition.

Referring to the physical aspect of the disclosure the primary object 0 tion is to provide a simple construction .the invenwhich can be actuated economically to,

maintain the article under treatment in.

proper operative relation to the cathode and anode plates in the bath, and to cause the articles'to move through thebath with a certain interval of lapsed time to insure the requisite thickness of coating when the articles have traversed a given bath, and to maintain the articles rotating or other wise moving to present different portions to the electrolyte plates and to prevent stagnation of the surrounding electrolyte.

The invention features the positioning of a plurality of carriages on an endless track, positioned above the tank which carriages are driven by some suitable mechanism, such as an endless chain drive, and each carriage is provided with means for facilitating the quick mounting of the articles thereon and the similar demounting of the finished articles as they pass the operator and without interrupting the continuity of drive of the articles in the bath.

It is understood that the electric current used in the electroplating operation is low in voltage but extremely high in amperage. and as an example of one such current it may be noted that in one practical operation of the invention herein disclosed a current of one volt and from one hundred to two hundred amperes were used.

With such high amperage extreme care must be exercised in order to minimize any resistance to the passage of current to the article under treatment. It not infrequently happens that bad connections across hinged parts for instance cause the parts to become red hot. Accordingly, another object of the invention is to provide a form of travelling carriage for supporting the articles as they are moved through the bath and which carriage will feature the minimizing of resistance to the passage of electric current therethrough to the supported articles.

Featuring the general desideratum for simplicity of construction and economy in operation another object of the invention is to provide a simplified means for furnishing rotary movement to the suspended articles as an incident to the movement of the carriage along the tracks.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawin s and in part will be more fully set forth 1n the following particular description of one form of mechanism embodying my invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the accompanying drawings 0 Figure 1 is a transverse sectional vlew taken on the line 1- 1 of Figure 2 showing a portion of an electrolytic tank of conventional form with one of a series of article supporting carriages shown in end elevation and constituting a preferred embodiment of Z ne of the physical features'of the invene 10D 1 Figure 2 is a view in side elevation of the structure shown in Figure 1 looking at the same in the direction of the arrow numbered 2; and.

plan view looking down Figure 3 is a to he arrow numbered 3 in as indicated by t Figure 1.

In the drawings there is shown in diagrammatic outline one side of an electrolytic tank 10 of conventional construction and which tanks are usually from fifty toa hundred feet in length and eight or ten feet wide. The tank contains a sultable anode a in an electrolyte 11. electrolyte in the tank is an endless track, a portion at one side of the tank being shown at 12. This track is a copper bar operatively connected to an electric current generator and hereinafter referred to as a source of electric energy. The upper face ofthe track is provided with a concaved groove 13 and one side of the track, such for instance, as the inner side 14.- is vertically disposed to form a side contacting face. Positioned above the track is a source of power herein shown to be an endless chain 15 o eratively Positioned above the connected with gear wheels (not s own) at opposite ends thereof for driving the chain parallel with and in a plane above the track. Positioned along the length of the chain are a. plurality of carriages one of which 16 is illustrated. The carriage includes, in effect, a longitudinally extending frame 17 provided on its underside with a pair of supporting rollers 18 and 19, journalled therein respectively on shafts 20 and 21 for supporting the carriage from the track. The periphery of the rollers are convex in axial cross-section so that the rollers will conform to and fit in the concavity of the grooved upper face of the track and provide a relatively extensive contact between the track and the rollers, as shown in Figure 1. The carriage includes an offset bracket 22 somewhat U-shape as shown particularly in Figure 1 and extending transversely of the frame 17 and projecting'laterally beyond the side face 14 of the track. A vertically disposed shaft 23 is journalled in the bracket and is free to slide therein for a limited vvertical movement. A friction disk 24 having a concaved groove 25 on its under face and concentrically disposed with reference to the shaft, is secured to'the shaft adjacent the upper end thereof. The groove 25 is designed to fit and frictionally engage the top of the roller 19 to provide a friction gear between one of the rollers engaging the track and the depending shaft.

It will be seen from this construction thatthe movement of the carriage along the tracks will cause the roller 19 to rotate the friction disk resting on the same and thus cause the shaft 23 to rotate about its vertical axis. At the same time the rollers are intended to maintain a polished contact with the upper grooved face of the track and likewise to maintain a similar contact respectively on pins 28 and 29 carried b an extension 30 formed at the lower end 0 the bracket 22. It is obvious that these rollers maintain a rolling contact with the side face 14 ofthe track and tend to minimize any tendency of the carriage to swinglaterally of the track. Inv order to further insure the passage of the electric current to the shaft and thus avoid any resistance which may develop at the hearings of the several ro lers, a sliding contact brush 31 is carried by the extension 30 and bears resiliently on the side face 14 of the track.

It is necessary in the practical operation of the device of the character under discussion, to provide some means for quickly positioning the articles in place as the carriage moves past the operator, and for this urpose the lower end of the shaft is provided with a bifurcated head 32 through which is extended a hook pin 33, designed to be engaged by a hook 34. This hook may be formed directly on the article to be electroplated and which article is shown symbolically at 35. It is a usual practice to position the articles to be coated in a suitable carrier and the reference character 35 may symbolically represent such a carrier of the article as well as the article itself. For the purpose of holding the. hook in place against accidental displacement and further for the purpose of 'maintaining the electric path between the shaft and the article, a spring contact brush 36 has one end secured to the head 32 and bears ticle 34. From this construction it is seen that current isconducted through the brush across the hinge connection provided by the hook and pin and here again every effort is made to minimize resistance to the passage of the electric current.

In operation and assuming that the tank is filled with the desired electrolyte and that the anode and cathode plates are in position and the device otherwise in usual 0 erative position, the operator will place tiie articles to receive the deposition, one after another on the succeeding carriages as they pass his station at one end or other suitable point of the tank. The travel of the chain drive is so regulated that the articles receive their desired thickness of deposition when they have describedone, or any other desired multiple of cycles of movement through the tank. The movement of each article through all portions of the tank will on the arinsure a uniform treatment of all of the articles irrespective of the difference in the depositing or other plating activity at different portions of the path of movement. As the articles are rotated about the axis of the supporting shaft it will result that all portions of the article are brought into position facing the anode at each cycle of movement. of the article and the speed of rotation is so regulated that the different sides of the article are repeatedly presented to each anode plate as the articles are moved across the face of the plate.

By practicing the method herein suggested it is possible to obtain a uniform coating or deposit'on all similar articles which have passed through the apparatus. Further, there is a saving in labor cost for there is no necessity of inspection by the operator at difierent portions of the tank and one 35 operator at one end of the tank can easily demount a finished article and-promptly replace it with a fresh article to be treated. Considering the structural features of the disclosure this uniformityin coating is attained with economy both in the amount of electrolyte used, in the anode consumption and in the current consumption. Incidentally there is also featured the practical elimination of heatingefiects with resulting saving in wear on t e equipment. There has been eliminated any necessity of lifting bulky apparatus and the operation is contmuous.

.Having thus described my invention, I claim:

1.'In the art of electrolytic deposition where a series of anodes are used and where the depositin operation is of different activity in di erent parts of the bath, the

method which consists in causing the article to be coated to traverse continuously a path through the several parts of the bath where the depositing activity is variable,

subjecting the article to the electrolytic depositing action of the bath for a prescribed period of time and causing the article durmg its passage to present all sides thereof repeatedly to the different anodes.

2 In the art of depositing a metal electrolytlcally on a plurality of similar articles 1n an electroplating apparatus where the current strength is apt to vary in different parts of the bath, the step which includes the moving of all of the articles simultaneously with the same speed for equal intervals of lapsed time and in the same direction over an endless path through "the fields of different current strengths while subjecting the articles to the electrolytic depositing action of the bath whereby each article is subjected substantially to the same plating operation.

3. In the art of coating articles by elccconsists in ositioning the article to be coated in'an e ectrolytic bath where the paths between the anodes and cathodes are of different electrolytic strength, and moving the articles bodily across said paths of different strengths and along a closed, nnn-llncar path while subjecting thearticle to the elec trolytic depositing action of the bath and to a rotary movement about a contained 3X13. 4. In the art of coating articles by electrolytic precipitation, the method which consists in positioning the article to be coated in an electrolytic bath where the paths between the anodes and cathodes are of dif ferent electrolytic strength, and movin the article horizontally across said paths 0 different strengths while restrained from vertical movement and subjected to the electrolytic depositing. action of the bath.

5. In the art of coating articles by electrolytic precipitation, the method which consists in moving an article bodily through the electrolyte while subjecting the article to a rotary as well as to a longitudinal movement along a closed, endless path.

6. In the art of electrolytic deposition, the method which consists in causing the article to receive the deposit to travel through the electrolyte over a cylindrical path while presenting difi'erent parts of the article to the anodes.

ticle through the electrolytic bath while subjecting the article to the electrolytic depositing action of the bath and incidentally causing'the moving article to generate a poptinually moving current in the electroy e. g c

' 9. In the art of electrolytic deposition, the method which includes the step of advancing the article to be plated over a closed path while in the electrolytic bath thereby to stir the electrolyte and cause it to move continuously in a closed path.

10. In a device of the class described, the combination of a track, a carriage including a frame extending lengthwise and above the track, means for advancing the carriage along the track, a pair of longitudinally spaced rollers riding on top of the track and supporting said frame and throu h the frame supporting the remainder of t e carriage, said carriage including a bracket extending transversely of the frame and having a portion otfset laterally from the track,

of its weight on one of the rollers engaging the top of the track.

11. In a device of the class described, the combination of an endless track, a carriage provided with rollers for supporting the same on the track, an endless chain operatively connected to the carria e to move the same along the track, a vertlcally disposed shaft journalled in the carriage and r0- vided with means for suspending artlcles therefrom, a driven disk fixed .to the shaft and resting on one of the rollers to provide a friction gear drive between the track and the shaft.

12. In a device of the class described, the combination of an endless track, a'carria e provided with rollers for supporting t e same on the track, an endless chain opera- .tively connected to the carriage to move the same along the track, a vertically disposed shaft journalled in the carriage and rovided with means for suspending art cles therefrom and a friction gear drive connection between one of the rollers and said shaft.

13. In a deviceof the class described, the combination of an electrolytic tank, a support constituting a source of electric energy positioned above the liquid level in the'tank, a bracket suspended from the support, a vertically extending shaft journalled in the "bracket and provided with means for suspending articles in the liquid in the tank, said shaft being connected electrically to the support and adapted to convey electric energy therethrough to the supported article and means operatively connected to the shaft for rotating the articles in the bath.

14. In a device of the class described, the

combination of an electrolytic tank, means for supporting in said tank a plurality of articles to be coated, means for subjecting the articles to the electrolytic depositing action' of said bath and means'operatively connected to said supporting means for rotating the articles each about a contained vertical axis.

15. In a device of the class described, the combination of an electrolytic tank, means for supporting in said tank a plurality of articles to be coated, means for subjecting the articles to an electroplating operation and means operatively connected to said supporting means for bodily moving all of the articles continuously over a closed path while so subjected.

16. In a device of the class described, the combination of a track constituting an electric conductor, a carriage provided w th a roller running on said track, a shaft 1on1- nalled in said carriage and operatively connected to the roller to be rotated thereby and ower means engaging the carriage for moving the same along the track, said roller and shaft constituting part of an electric circuit for transmitting electric energy from the track through the rotating shaft.

17. In a device of the class described, the

combination of a track having a grooved.

top face, a carriage movable along the track and rovided with a roller with a contacting ace fitted to the groove in the top face of the track, a driven disk mounted for rotary movement in the carriage and provided with a concentric groove fitting the contacting face of the roller and a supporting shaft journalled in the carriage and driven by said disk.

18. In a device of the class described, the combination of a track constituting a source of electric energy and having an exposed top and side face, a carriage movable along the track, a vertically disposed shaft provided with a rolling physical and electric contact with the side face whereby electric energy is transferred from the charged track 9 directly to the shaft, a rolling contact between the top faceof the'track and the shaft to cause the shaft to rotate as the carriage is moved along for advancing the carriage along the' track.

19. In a device of the class described, the combination of a track constituting a source of electric ener y, a carriage,"power means for advancing t e carriage along the track, means for supporting an article from the carriage, a driving connection between the track and said supporting means for causing the supported article to rotate, said driving 7 connection and supporting means constituting an electric circuit. for transmitting electric energy from the track to, the supported article.

20. In a device of the class described, the combination of an endless track, a carriage movable on the track, an endless driving member operatively connected to the carriage to draw the same along the track, and a verticallydisposed shaft provided with means for supporting articles below the track, said shaft journalled in the carriage, movable bodily therewith and operatively connected to be rotated by the movement of the carriage along the track.

21. In a device of the class described, the combination of an endless track, a carriage movable on the track, means for propelling the carriage, means for supporting an article from the carriage and mechanism conthe track and means trolled by the movement of the carriage along said trackfor causing said supporting means to have movement relative to the carriage.

22. In a device of the class described, the

combination of an endless track, a carriage movable on the track, means for propelling the carriage, means for supporting an article from the carriage and mechamsm controlled by. the movement of the carriage along said track for causing said supporting means to have movement relative to the {carriage and means for guiding the carriage along the track.

23. In a device of the class described, the combination of a track having exposed upper and side contact faces, a 'carria means for moving the carriage along t 0 track, means for supporting an article-from the carriage and means for providingelec tric contact between said supporting means and both faces of the track.

24. In a device of the class described, the combination of a track having exposed upper and side faces, a carriage, a plurality of rollers'sup orting the carriage on the track, a plura 'ty of rollers engaging the. sideface of the track, means for advancing the carriage along the track and means for removably supporting the articles from the v carriage. a

25. In a device of the-class described, the combination of a track constituting a. source of electric energy, a carriage, means for moving the carnage along said track, and metallic means for supporting an article from the carriage and for conveying electric energy from the track to the supported article. I

26..A11 electrolyte apparatus including a tank; a track above the tank, a carriage movable on the track, means for suspending articles from the carriage, means engaging thecarriage for causing the same to move the articles through the bath in the tank, and means for conveying electric energy to the carriage and therethrough to the article supported by the movin carriage.

27. A carriage adapte to be positioned on a track for use in supportin articles from the track in an electrolytic ath said carriage comprising supporting rollers adapted to engage the track, a vertically disposed shaft", means for rotating the shaft and said shaft rovided with easily manipulated means or securing the articles to the shaft while rotating.

28. In a device of the class described, the combination of an electrolytic tank, means for supporting articles to be electroplated in said tank, said supporting means being of an electric conducting material, and operatively connected to a source of electric energy to convey the energy to the supported articles, said supporting means inc uding articles, said supporting means including portions which are liable tointerpose resistance to the passage of the electric energy andbrushes bridging said portions and adapted to insure the passage of energy to the article without material resistance.

29. In a device of the class described, the combination of an electrolytic tank, means for supporting articles to be electroplated in said tank, said supporting means being of an electric conducting materialand operatively connected to a source of electric energy to convey the energy to the supported a hinged connection and a brush electrica 1y connecting the parts across the hinge connection.

30. In a device of the class described, the combination of a carriage, a shaft journalled in the carriage, power means for moving the carriage and for rotating the shaft, means for hingedly connecting articles to said shaft and an electric brush connecting the shaft electrically with the supported article across said hinge connecting means.

31. In a device of the class described, the combination of a track having an exposed side and constituting a source of electric energy, a carriage provided with means for supporting articles therefrom and adapted to conduct electric current to the article, said carnage supported from the track, a brush movable with the carriage and providing a sliding electric contactbetween the carriage and the exposed side of the trac 32. 1n a device of the class described, the combination with a track constituting 9.

source of electric energy, and having an porting rollers, a vertically disposed shaft,

means for rotatin the shaft and said shaft provided with easily manipulated means for securing the articles to the shaft while rotating, said shaft provided adacent its lower end with a pin adapted to e engaged by a hook and said shaft provided with a spring adapted to secure the hook in place on 'the pin.

341. A carriage for use in supporting articles in an electrolytic bath comprising sufiporting rollers, a vertically disposed sha means for rotatin the shaft and said shaft provided with easily manipulated means for securing the articles to the shaft while rotating, said shaft provided adjacent its low er end with apin adapted to be engaged: by a hook and said shalt provided with a spring adapted to secure the hook in place on the pin and constituting a brush for conducting electric current from the shaft to the hook.

Signed at New York city in the county of New York and State of New York this 22nd day of September, A. D. 1923.

BLA'SIUS BART.

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