US1997458A - Electroplating machine - Google Patents

Description

April 9, 1935. E. T. EHRHARDT ELECTROPLATING MACHINE 5 Sheets-#Sheet l Finled Deo. 14, 1933 APH] 9; 1935 E. T. EHRHARDT v ELECTROPLATING MACHINE Filed Dec. 14, 1933 3 Sheets-Sheet 2 Eil D DDEE@ April 9, 1935. E. T. EHRHARDT 1,997,458

ELECTROPLATING' MACHINE Filed Dec. 14, 1955 5 Sheets-Sheet 5 n w mim@ n ,m NxNm W/ WJ UM WTB E E B O NQ www mw E u@ w h Q J T E, J4 .A TWNJ n lhl NS www wm f1. ...l Nr 31 JJ x .QU i EN m SQ wm M A. ,l Lm NN f Y wm @n 1 A @NVN QNJQC k QN N .NQNN Am WNU f Y l lwww," A?? Num @5% Aw MNNQQN www@ mln F Nl. M Su www Patented Apr. 9, 1935 UNITED STATES lawns TEN ELECTROPLATING MACHINE setts Appucatim December 14. 193s, serial Naroasss 1 Claim.

This invention relates to machines for electroplating various articles such, for example, as iron nails and tacks, and more especially to a machine for brass plating shoe nails by electro-deposition.

One of the objects of my invention is to provide an electroplating machine capable of continuous plating.

In previous electroplating machines of the l rotary barrel type, the anode surface, figured in square feet, was considerably less than the cathode surface. To overcome this difference in anode and cathode surfaces and to effect the plating process, it was necessary to employ an electrolyte having a relatively high cyanide content. As the large cathode surface carries high current density, the relatively small anode surface is overtaxed, which results in the anodes becoming coated by reason of the fact that the electrolyte is unable to keep the anodes clear so that the current can pass through them. This can be remedied by decreasing the cathode surface so as to equalize the anode and cathode surfaces. It can also be remedied by reducing the current density but this would necessitate a longer period of time to effect the plating process. Another way inwhich this can be remedied is by adding cyanide to the electrolyte which would increase the dissolving action on the anodes. While the additional cyanide increases the dissolving eiect, it also increases the conductivity of the electrolyte, which in many cases would cause excessive heating of the electrolyte and consequent excessive and objectionable gassing. This gassing is obviously dangerous to the health of the operator. The excessive heat and current is also detrimental to the electrolyte, and the necessity of using more current naturally increasesthe cost of operation.

Moreover, with previous machines of the rotary barrel type, the barrel was iilled nearly to capacity and it was necessary to revolve the barrel and mass for a long periodl of timein an effort to subject all parts of the mass to the electric field and effectively plate the entire mass.

Previous machines consequently required excessive amounts of current and then Vfailed to plate the entire mass. Much of this current was wasted and often it caused excessive gassing and heating of the electrolyte. Even after ,a long period of revolution, the material removed from the barrel was often found to be of inferior grade, that is, the plating was not uniform and the mass contained articles which were variously colored.

Furthermore, in previous rotary barrel types of electroplating machines, it has been necessary (Cl. 20d-11) to interrupt the plating process to fill the barrel manually and to remove the mass from the barrel manually after the plating process has been conipleted. Since this obviously required considerable time and in view of the fact that the barrels were of relatively small dimension, the output of a single machine was necessarily limited.

It is, therefore, another object of 4my invention to provide an electroplating machine which has none of the objectionable 4features and characteristics of previous machines, and one which produces plated articles of superior quality at greater speed and at a lower cost than was possible with previous machines.

A further object of the invention is to provide a machine for electroplating articles in.

which all portions of the mass of articles are constantly subjected to the electric field during their passage through the machine.

The above and other objects and advantages of the invention will appear from the following description and appended claim when considered in connection with the accompanying drawings forming a part of this specification.

In said drawings:

Fig. 1 is a vertical section, partly broken away, of a machine embodying the invention.

Fig. 2 is a top plan view thereof, partly in section, and partly broken away.

Fig. 3 is a transverse vertical section taken substantially along the line 3-3 of Fig. 1.

Fig. 4 is a vertical section taken substantially along the line t--i of Fig. 1; and

Fig. 5 is a vertical section taken substantially along the line 5 5 of Fig. 1.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention 'claimed herein beyond the requirements of the prior art.

Referring now to the drawings wherein there floor. Supported adjacent opposite ends of the tank and projecting thereinto are hanger members or supports I2 and I3. These hangers, which are best shown in Figs. 3 and 4, are formed of metal andare preferably substantially V-shaped, the upper ends of the legs of the hangers being flanged outwardly at 2a and |3a, respectively, and secured to the tank flanges Illa by bolts orthe like I4. Secured to each of the hangers and projecting upwardly above the tank are metal braces or supporting members I 5 and I6, these members having perpendicular flanges |5a and |6a, respectively. Each lange is provided with a hole or opening |1 to which the hook of a lifting block and tackle may be attached. The tank contains electrolyte which is preferably maintained at the level noted at A.

Immersed in the electrolyte and supported for rotary movement by the hanger members I2 and I3, is an electroplating barrel or cylinder shown as a whole at 20, this cylinder extending lengthwise of the tank and being slightly inclined as shown in Fig. 1. The barrel may be formed of any suitable non-conducting material such as bakelite, micarte, hard rubber, or wood and canvas. As shown, the barrel comprises a foraminous cylinder 2| which is re-enforced by a plurality of longitudinally extending wooden bars or strips 22. At the low end, the barrel is provided with a non-metallic annular ring 23. Adjacent its high or upper end and the hanger I3, the barrel is provided with an annular ring or member 24 which projects inwardly beyond the perforated cylinder 2| to provide a slightly restricted opening at this end of the barrel. Secured to the periphery or the ring 24 is an additional ring or member 25 havingits outer surface rounded. Beyond the rings 24 and 25, the barrel has fixed to it an annular metal memberA 26 carrying a ring gear 21 for a purpose to be hereinafter described. Adjacent the hanger |2, the barrel 20 is provided with an external annular ring-like member 28 generally like the member 25 adjacent its opposite end.

Each of the hangers- I2 and I3 (see Figs. 1, 3, and 4) carries a pair of idle rolls or pulleys 29. The grooves of these pulleys support the barrel rings 28 and 25 and thus provide means for rotatably supporting the barrel in its inclined position.

Work is fed to the open upper end of the barrel and for this purpose I have provided a chute 30 which is supported in any suitable manner, as by means of a bracket 3|, which is bolted to the end flange Illa. 'I'he chute directs the material or Work to be electroplated into the barrel at its high end. The work feeding-mechanism also comprises a hopper or feed box 32 which is supported in any suitable manner at the upper end of the machine and is adapted to feed the work into the chute 30.

The -ring gear 21 referred to above meshes with a gear 33 carried upon a short shaft 34, the outer end of the shaft being provided with a sprocket or gear 35. Adjacent the intake end of the tank I0 suitable frame work 36'is provided, this frame supporting a horizontal shaft 31 carrying a pair of sprockets 38 and 39 and a power pulley 40. An auxiliary frame 4| is mounted upon the frame 36 and carries a horizontal shaft 42 upon which is mounted a sprocket 43 and a cam 44, the cam engaging the underside of the hopper 32 (Figs. 1 vand 5). Power is applied to the pulley 40 from any suitable source through the medium of a power belt 45. As the shaft 31 is rotated by the pulley 40, the gear 33 meshing with the ring gear 21, is driven through the medium of its connection with the power shaft by sprocket chain 46 to rotate the barrel l2|). It will be noted that a sprocket chain 41 connects the sprockets 38 and 43 and when the shaft 31 is rotated the shaft 42 and its cam 44 are likewise rotated, the rotation of the cam causing the intermittent up and down movement of the hopper 32, thus feeding by gravity the shoe nails or other work to the chute 30. Since the barrel is inclined, rotary movement imparted thereto causes the progressive movement of the work from its high or intake end toward its lower or discharge end, by a combination of forces, consisting of gravity and positive forward impulses imparted to the work by the inner surface of the barrel.

Since the barrel is mounted for rotation about an inclined axis, all portions of the inner .surface of the barrel are periodically and alternately -advanced and retracted with respect to a horizontal line, or transverse vertical plane, during rotation of the barrel. As the barrel rotates, the inner surface thereof tends to move the work from the lowermost point therein, on an upwardly and forwardly inclined line, because of the inclined axisI on which'the barrel is rotated. After the work moves upwardly and forwardly to a predetermined extent, it falls away from the inner surface of the barrel and rolls or tumbles downwardly on a line defined by a vertical plane. When the work strikes the bottom, it will tend to roll or tumble forwardly somewhat by reason of the inclined inner surface of the barrel, and it will then. be again moved upwardly and forwardly by the rotation of the barrel. Thus, a, thorough tumbling of the work in the apparatus of this invention is essential to progressive movement of the work through the plating barrel.

Supported adjacent the low end of the barrel 20 exteriorly of the tank and at opposite sides thereof are frame structures secured to the floor. One of said structures comprises uprights 5| located at one side of the tank and connected by suitable cross members. The other of said structures comprises a pair of uprights 52 locatl ed at the opposite side of the tank. The uprights 5| support adjacent their upper ends, a shaft 53 upon which is mounted a drum or block 54, and a power pulley 55 over which passes a drive belt 56 leading from a suitable source of power. The upright frame members 52 support adjacent their upper ends a shaft 56 upon which is mounted a similar drum 51. Within the tank there is supported a frame structure Acomprising a pair of transversely disposed parallel spaced members 60 each of which is provided with two upright arms 6| carrying rotatable gears 62, the gears being mounted on suitable shafts 63 carried by the arms 6I. The drums 54 and 51 are provided at their opposite ends with gears having teeth 54a and 51a, respectively. The frame structures 5| and 52 support pairs of spaced gears or sprockets, similar to the gears or sprockets 62. An endless conveyor belt comprising a body portion 1|) having on opposite sides chain members 1|, passes around and into the tank as best shown in Fig. 3 and the chains engage the teeth of the various gears 54, 51, 62 and 64. The conveyor is formed of any suitable non-metallic material and is provided at spaced intervals with buckets or scoops 12 which are adapted to pick up the finished work as it issues from the low end of the rotating barrel and carry it upwardly out of the tank and discharge it by gravity into a.

chute from which the work passes into a rinse tank 8|. In order to assist the discharge of work from the conveyor, ,the latter may be subjected to the action of a fluid spray supplied from a nozzle |00. 'Ihe buckets 12 are preferably foraminous so that the electrolyte will drain from them and will not be removed from the tank.

The mechanism described above is for delivering the work, that is the material to be electroplated, to the machine and for removing or transferring the plated work from the machine. As shown, the work is removed by an endless conveyor and transferred to a suitable rinse tank, from which it can be removed in any desirable manner. It will be understood that the Work is fed progressively, partly by gravity from the hopper to the chute and thence through the rotatablebarreltotheconveyorwhichremoves it. Thus the material is handled and plated by mechanical means without the necessity of any manual handling.

In order to electroplate it, the work or material is subjected to an electric eld while it is submerged in the. electrolyte contained in the tank I0. The supports i5 and I6 have attached thereto arms or brackets and 86, which adjustably support negative electrodes or cathodes 81 and 88, respectively. It will be noted that the negative electrodes extend into the barrel at its opposite ends and have attached to their free ends short lengths of chain or danglers 81a, and 88a'which engage the work as it passes through the barrel. The supporting members I5 and I6 carry at the opposite side of the barrel supporting arms or brackets 90 and 9i respectively, which are curved and adjustably support a positive electrode 92 which extends through the barrel and is positioned at a point which is out of contact with the work. In addition to the positive electrode or anode 92, the electrolyte is supplied with additional current through the medium of a plurality of positive electrodes or anodes 95 having hook-like upper ends 95a which engage and are supported by longitudinally extending rods 96, these rods being attached to the positive pole of a source of electrical energy. It will be seen that the anodes 95 are submerged in the electrolyte and extend in a series longitudinally of the tank on vopposite sides of the rotary barrel. The anodes and cathodes referred to are all connected in any suitable manner with the positive and negative poles of a source of electric energy and together serve to provide the necessary electric leld through which the mass of work passes during the electroplating process.

As shown in the drawings the mass of work is relatively shallow and therefore all portions of the mass are constantly subjected to the electric eld during passage through the machine, thus effecting the perfect and complete electroplating of all of the material.

It will be understood from the foregoing that the barrel of my machine is loaded and unloaded automatically without interruption of the plating process, and that my machine has the advantage over previous machines by employing a relatively large anode surface and a relatively small cathode surface. Therefore, there is sufficient anode surface to supply all of the necessary current without the necessity of anelectrolyte having a high cyanide content to keep the anodes clear. The possibility of excessive gassing and heating is entirely eliminated in my machine. There is a large saving in currentand the nished work is more uniform in density and color.

It will be understood further that while I have shown the positive electrode 92 as extending through the barrel, this electrode can be eliminated if desired or it may be located at some other point within the tank. Nor is my invention intended to be limited to the use of the negative electrodes 8T and 88 since it may prove desirable to position the negative electrodes at a different location. A single negative electrode would serve the purpose. The kinds or types of electrodes kshown in the drawings are merely illustrative of what may be used in my machine, but it is not intended to limit the invention to any particular kind or type of electrodes.

I claim:

In a continuous electroplating machine, in combination, a tank adapted to hold an electrolyte, a substantially cylindrical work receiving barrel supported in an inclined position and having an internal surface smooth' and devoid of transverse obstructions whereby to feed entirely by gravity a continuous stream of articles to be coated, means for rotating said barrel in said electrolyte, said barrel having a work inlet opening at its upper end and a work discharge opening at its lower end, means for feeding work into said barrel, means for rotating said barrel to cause the work to move continuously, the inclination of the barrel being sufcient to cause the Work to be fed by gravity progressively from its upper end to and through said discharge opening, a negative electrode adapted to be engaged by said work, a positive electrode adapted to extend into said electrolyte, and means for removing from said tank the work discharged from said barrel.

EDWARD T. EHRHARDT.

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