US2055070A - Electroplating apparatus - Google Patents

Description

Sept. 22, 1936.

E. ERECKSSON ELECTROPLATING APPARATUS I Filed Nov. 25, 1932 2 Sheets-Sheet l za j 5/727/ ind J50 f Jaw/ M Sept.22, 1936. v E. ERICKSSIQN 2,055,070

ELIECTROPLATING APPARATUS Filed Nov. 25, 1952 2 Sheets-Sheet 2 fmi/ [rzckadazz I Patented Sept. 22, 1936 Q I PATENT OFFICE nmc'rnormrmc arrsns'rns Ericksaon, Chicago, 11]., assignorto Standard Process Corporation, Chicago, 11]., a corporation of Delaware Application November 25, 1932, Serial No. 644,388

Claims. .(01. 204-5) This invention relates to an electroplating apparatus designed to expeditiously deposit a dense layer of metal of the same thickness upon a cylinder while it is being rotated through the elec- 5 trolyte. More particularly, the invention-relates to an apparatus for electroplating a thin remov- .able shell upon a cylinder intended for use in rotograv'ure and similar printing presses, so that the shell will have thecharacteristics of unilO form density and thickness, enabling it to be etched for use in intaglio printing or the like with a minimum aniount of burnishing or polishing prior to the etching.

In rotogravure or similar printing, it is now 15 customary to' provide 'a printing cylinder of a fixed diameter having a surface polished to a mirror-like finish, and to form the printing surface upon said cylinder by electroplating thereon a thin layer of metal, such as copper or the like,

go of about .006 inch thickness, the layer of copper being deposited upon the cylinder in such manner that it can subsequently be stripped therefrom by slitting the deposit longitudinally of the cylinder. In view of the fact that the printing 8111'- face is obtained by etching minute depressions in the outer surface of the deposit, it is essential that the deposited metal be free of imperfection and have a density that is uniform throughoutthe layer and that it be of exactly the required thickness at every point. The electrodeposition of layers having the characteristics just stated has been found to require an apparatus that, in its operation, will insure the con tinuous circulation of fresh electrolyte through the gap, separating the electric poles, to the end that precisely the same depositing action takes place at every point between said poles.

It has also been found essential, in order to secure the uniform deposit required for the special use of the eclectic-deposited layer to'which attention has above been directed, to maintain the poles between which the current flows substantially parallel to each other where immersed in the electrolyte.

It has been further found that in order to secure the formation of the desired coating of uniform thickness and density, it is essential that the cylinder, whichconstitutes one of the electric poles, be rotated through the electrolyte at a relatively high surface speed such as 8 to 8 hundred feet per minute, that electrolyte of substantially the same character be continuously maintained in the gap between the electric poles, and that a uniform relatively high current density be maintained across said gap when the latter approximates 1% inches, the preferred distance between the poles.

The primary purpose of the present invention is to provide an apparatus capable of emciently electroplating printing cylinders to provide them 5 with the layer of metal having the characteristics above described after the manner found to be essential in actual practice.

A further object of the invention is to provide an electroplating apparatus, in which use can be 1 made of bars of the metal to be deposited of uniform width and thickness, and in which the stationary pole'is made approximately parallel to the surface of the cylinder by supporting the bars in cradle-like structure having a supporting sur- 15 face that generally parallels the surface of the cylinder upon which the deposit is to be made.

A still further obiectofthe invention is to provide an electroplating apparatus designed so that bars of the metal to be deposited of uniform width 20 and thickness may be completely consumed in the apparatus without sacrifice of the essential characteristic that the stationary pole generally parallel the surface of the cylinder, where said cylinder is immersed in the electrolyte. 25 Still another object of the invention is to pro-q vide a stationary pole for an electroplating apparatus consisting of a trough-like supporting cradle constructed of material that is not affected by the electroplating action and including bars of uniform width and thickness arranged in the trough of the cradle side by side and/0r end to end so as to substantially completely cover the trough and approximately parallel the surface of the cylinder which is used to constitute the other pole of the-apparatus,

Another object of the invention is to provide an electroplating apparatus, designed for the purpose of depositing a uniform dense layer of metal'upon a cylinder, in which the cylinder is 40 arranged and disposed so that its rotation causes a continuous circulation of fresh electrolyte between it and its cooperating stationary pole and in which use is made of the circulation of the electrolyte, thus initiated, to purify the solution. 45

A further object of the invention is to provide an electroplating apparatus including a filter associated with the receptacle in which the electrolyte is disposed so that in the normal use of the apparatus the electrolyte will flow continuously through the filter and .be returned to the receptacle so" as to agitate the electrolyte therein and maintain a uniformity in character of said electrolyte Still another object of the invention a m mes vide an electroplating apparatus including afllter and a positive pumping means, independent of the action of the electroplating apparatus, to insure a circulation of the electrolyte from the filter to the receptacle containing the electrolyte forming a Part of the apparatus and to, in said circulation, insure an agitation of the electrolyte in the receptacle. j

Still another object of the invention is to provide a cylinder electroplating apparatus including novel means for readily providing the cylinder shaft sections, provided for application of V a deposit of metal upon a cylinder in which open which is provided with the journal boxes are used to support the cylinder desirable anti-friction bearings fitting within said boxes by mount ing the same upon sleeves that may be detachably clamped upon the shaft sections of the cylinder.

Still further objects of the invention will appear as a description thereof proceeds with reference to the accompanying drawings in which:

Figure 1 is a plan view of the preferred form of electroplating apparatus constituting the present invention. v V

Figure 2 is a vertical sectional view of the apparatus appearing'in Figure 1.

Figure 3 is an end view of the apparatus as seen from the right of Figure 2.

Figure 3a is a detail view on an enlarged scale showing the split sleeve for clamping the cylinder shaft in position. I

Figure 4 is an end view of the receptacle or tank on a slightly enlarged scale.

Figure 5 is a view of a preferred form of ourrent collector brush arrangement. for the cylinder constituting one of the electric poles of the apparatus.

Figure 6 is a diagrammatic view showing the.

cradle arrangement for supporting the bars constituting the stationary pole of the apparatus and the relation of the cylinder and electrolyte level to said bars.

Figure 7 'isa side view ofv the cradle for supporting the separate bars constituting the stationary pole of the apparatus.

Like reference characters indicate like parts throughout the several figures. l

The electroplating apparatus of the present invention comprises a tank or receptacle in, which may be constructed of wood in convenient form,

and which may preferably be lined internally with lead or similar metal, as indicated by H. The lining I I may be carried over the edges of the tank or receptacle and may if desired cover the exterior .of the tank or receptacle as indicated at I2, so that the wood, from which the tank or receptacle is preferably -constructed. is completely protected from contact with the electrolyte, even if any of the electrolyte is splashed over the edges of the tank or receptacle. The lining is formed to cover notches l3 formed in the ends of the tank for the passage of the shaft sections of the cylinder constituting one of the electrolyte within the tank, and adjacent one or both electric poles, and is turned inwardly adjacent said notches to form a housing It for detachable sleeves that are applied to shaft sections of the cylinder prior to the insertion of the cylinder in the electrolyte. The tank may be constructed in any convenient form though preferably it is constructed in rectangular form.

At each end of the tank or receptacle on the exterior thereof angle irons orsimilar supporting members l5 extend transversely between vertical frame members of the tank, being secured to said frame members in any convenient manner, asby brackets l6 and blocks ll. Extending between each of said members l5 and the base of the apparatus are a plurality of struts l8, the

ends of which are threaded into suitable connector's serving'to rigidly -unite said ends to the bars l5 and the base of the apparatus so that any weight resting upon the bars I5 is transmitted through said struts to said base. The cylinder to be electroplated in the apparatus, constituting the present invention, is supported upon the bars IS, in a manner hereinafter described.

Supported on the floor of the tank or receptacle just described is a cradle i9, illustrated best in Figures 6 and 7 of the drawings. Said cradle consists of a multiplicity of parallel vertically extending supporting bars 20 and 2|, that'are connected together in spaced relation by horizontally extending members 22 and 23, said members preferably being notched at intervals to receive the vertical members 20 and 2| in lateral immovable relation therein. Extending between the oppositely disposed vertically extending members 20 and 2| respectively, are a plurality of frame members 24 which are suitably secured to said members and rest upon the horizontal members 22 and 23 of the cradle. The supporting members 24 and the upper edges of the vertically extending members 20 and 2| are formed toprovide a curved supporting surface 25 which is con; structed of a contour that approximately parallels the surface of the cylinder to be electroplated in the apparatus, when said cylinder is in place therein. That is, the supporting surface 25 is preferably of arcuate form drawn from the axis of rotation of the cylinder. Deviations from a true are drawn from said center are contemplated-as coming within the scope of the present invention so long as the supporting surface 25 approximately parallels the surface of the cylinder when the cylinder is in place in the apparatus.

The frame of the cradle so far described is preferably constructed of wood and the wood is treated with-a bituminous composition, rubberoid or similar paint protecting it from the action of the receptacle. Supported on the cradle frame just described is a sheet of metal 26, preferably .lead, which follows the contour of the supporting surface 25. Preferably the sheet of lead is cut so as to provide a multiplicity of extensions 2?, each of which is connected to a split sleeve 28 that is clamped around a bar 29 preferably constructed of copper. The bar 29 is supported in brackets 30 secured to the top ofthe' ends thereof are provided with connectors 3| that are united in any suitable manner to a conductor forming a part of the system for supplying electric current to the apparatus. When the apparatus is used for plating cylinders the positive conductor is connected to the connector 3|, the bars supported in the cradle presently to be referred to in this instance constituting the anode of the electroa new layer of metal may be electro-deposlted plating apparatus. If the apparatus is used for, deplating cylinders as it is capable of being used as hereinafter pointed out, thecurrent may be reversed in any approved manner and the bars supporting the cradle in this instance constitute the cathode of the apparatus.

The cradle just described is used to support a multiplicity of bars 32 of copper, or the metal that is to be deposited upon the cylinder, in side by side and/or end to end arrangement upon the cradle. The bars 32 may be arranged to compietely cover the cradle. As illustrated, each of I would result if a pole consisting of a plate-like width and thickness to line the supporting struc- V may be arranged .bars and the apparatus continued in use. This the bars 32 is of the same width-and thickness and when disposed in the cradle, as illustrated, produces a plate-like electric pole presenting the desired curvature approximately or exactly paralleling the surfaces of the cylinder to be electroplated in the apparatus. This arrangement provides a simple mode of using bars of the same width and thickness to form an electric pole hav ing the curved contour essential to the eilicient production of the electro-deposited layer havin the characteristics above pointed out. 3

Said bars can be substantially completely used in the electroplating operation without resulting in disintegration of the curved pole, such as structure especially constructed to provide the desired parallelism between the cylinder surface and the surface of the pole were utilized. Furthermoreby utilizing a supporting cradle such as just described, and .bars of metal of uniform ture of the cradle, it is possible to completely use the metal in the electroplating operation, because when the bars have been used to the extent of about one-half of their weight or less, the partially used bars are removed and the cradle is relined with new bars and the partially used bars in juxtaposition upon the new is an effective way to use the described arrangement and result in a complete use of the partially disintegrated bars in the electro-plating action and the subsequent use of the new bars upon which the partially disintegrated bars are supported. The described arrangement accordingly provides a simple and inexpensive apparatus en-- abling uncurved bars of uniform width and thickness to be used to form a curved electric pole and at the same time enables the metal from which the curved pole is thus formed to be completely consumed in the electro-plating operation, though an electric pole is assured that has a form found to be necessary in order to secure the ,character v of deposit that is required in the, formation of shells intended to be'subsequently etched and used in printing operations.

Thepylinder 33 to be electroplated in the apparatus of the present invention constitutes the base of a printing cylinder having shaft sections 3t and 35 extending from opposite ends thereof which shaft sections are secured in suitable bearings in the printing press when the cylinder has been provided with a layer of metal in the present apparatus and said provide the printing surface.

The surface of the cylinder, tion in the apparatus of the present invention, is provided with a metal like finish and contains a surface layer of metal, suchas nickel that will not. unite to the metal, subsequently deposited thereon, so intimately as to prevent subsequent stripping of the electro-depos'ited layer after the training it with a tation thereof, with means for completing the layer has been etched toprior. t its inserthus depleting the cylinder in the same appara- 1o tus. When it is desired to remove the printing surface in this manner, it'is necessary that the base be provided with a surface that is unaffected by.the= deplating action so that the cylinder can be again replated and reused without the neces- 15} sity of grinding or polishing the surface thereof in order to secure the absolutely smooth and the 'true cylindrical surface that is essential in a printing cylinder. 5

Rotation of the cylinder in the electrolyte may 20 begin immediately upon immersion of a part of the cylinder therein. It has been found desirable to support the cylinder in open bearing boxes and to assemble, the bearings, the gearing for rotating the cylinder, and the current collector upon 25v the cylinder prior to the immersion of a part thereof in the electrolyte. This is accomplished in the present invention by providing sleeves that are clamped upon -the shaft sections 34 and 35 before the bearings are disposed in said open 30 boxes and the cylinder thus immersed in the solution, said sleeves carrying the gear for rotating the cylinder, and the current collector prior to the application of the cylinder to the tank or receptacle. The sleeve 36 consists of a tubular 35 portion 31 formed integrally with an enlarged tubular portion 38 upon which roller bearings 39 are mounted between the boilers 40 and I threaded, or otherwise, suitably secured upon the section 38 of said sleeve. Each sleeve is further 40 provided with a portion 42 that is split longitudinally to provide a removable cap section 43 between which cap and the portion 42 the shaft sections are rigidly clamped by means of bolts 44 passing through aligned ears 5 in the portion $5 secured to the sleeve Be that is' clamped upon the shaft section 35 is a gear M. It will thus be seen that when the sleeves 36 are attached tofthe shaft sections of the cylinder that is to be electroplated by clamping the caps it into embracing engagement with said shaft sections, the bearings 39, the current collector 46, and the gear 41, that is used to rotate the'cylinder inthe electrolyte, are supplied to the cylinder as units thus providing the cylinder with means for sus- 50 of friction during roelectric circuit through the cylinder, and with means for rotating the cylinder, all of which may be applied to the cylinder with great expedition. It will be seen that when it is desired to electroplate a cylinder the sleeves 86 are simply applied thereto in the simple manner stated and when the electroplatingoperation has been tank the sleeves can readily be removed and applied to another cylinder with a minimum loss of time.

"Upon application or receptacle, the bearings of the cylinder to the tank stare-dropped in 75 completed and the cylinder removed from the 70 4 connectedto the speed change gearing within open bearing boxes 48 rigidly attached to the angle bars l5 before described, which are suitably secured to said anglebars as by means of bolts 49, (Figure 4) The gear 41 is brought into engagement with a pinion 50 secured to a shaft 5| forming a part of a speed change device arranged in casing 52. The shaft 8| is driven at varying rates of speed from a motor 68 nioimted upon a suitable base 64 disposed adjacent the tank 'or receptacle, said motor being operatively the casing 52 by means of a belt 65 and pulleys 56 and 61 on the drive shaft of the motor and on the driven shaft of the speed change device respectively. A suitable handle 58 may be manipulated to vary the speed of the shaft 6| so that the angular velocity of the cylinder through the electrolyte may be varied to attain a peripheral speed of 600 to 800 feet per minute irrespective of the diameter of the cylinder upon which the coating is to be electro-deposited. The speed changing device within the casing 62 may be of any approved form.

When the cylinder is positioned with the bearings 39 in the open boxes 48 the current collector 46 (Figure 5) contacts with the ends of a brush 59, consisting of a multiplicity of laminations of phosphor bronze or the like having their respective ends formed to contact with a substantial part of the cylindrical periphery of said current collector. Said laminations are clamped between a grooved supporting member 60 and an overlying grooved clamping plate 6! that may be drawn toward the support '60 by means of a bolt 62 so as to firmly hold'the lam inations immovable with respect to each other and with respect to the current collector 46. The support 60 is secured tothe angle bar IS in any approved manner, so as to be insulated therefrom, and said support is connected in any approved manner, as by clamp 63, to a conductor leading to the source of energy supplying curren to the electroplating apparatus in any manner well'understood in the art. a

In order to maintain the electrolyte free of impurities, and to ensure the uniform character thereof throughout the tank to the end that the uniformity of the plating be ensured, and im'- perfections avoided in theplated coating, the

apparatus of the present invention includes means to filter the solution continuously during the operation thereof and to ensure agitation of the electrolyte so that it is of substantially the same character at every point in the tank or receptacle, and particularly where the electrolyte isdrawn in the gap between poles in a manner hereinafterv described. The preferred filtering arrangement includes a supplementary tank or receptacle 64 which may be constructed of wood and lined, internally and externally with metal,

such as lead. Filters 86 and- 66 extend vertically from the bottom of the thereof, dividing said tank into a plurality of compartments. The filters preferably consist of -an open frame of Monel metal or the like, supporting pure wool felt. The receptacle 64 is in communication with the interior of the tank It by means of an elongated passage 6! (Figure 3) located so that when the electrolyte is at the normal level within the tank 10, the elecrolyte will flow into the auxiliary tank 84. The. electrolyte fiows first into .the compartment to the \left of the filter 86 (Figure 3) and passes through said filter into the compartment between the filters and, and finahy passes through the where the conduit the apparatus is proved manner.

tank to the ,top

filter 65 into the compartment between the filter is put in-communication with the bottom of the compartment formed between the filter 65 and the rear wall of the auxiliary tank 64 by means of a conduit 69 (Figure 3). The pump 68 returns the electrolyte to the tank I!) through conduit 10 connected thereto and extending along the wall of the tank l0 adjacent the auxiliary or supplemental receptacle 64, as indicated at H to apoint beneath the stationary pole of the apparatus, H is in communication with a conduit 12 extending across the tank and communicating with a pair of discharge conduits I3 and 14 (Figure l) having open ends discharging the electrolyte returned to the tank by the pump 68, adjacent the bottom of the receptacle It at a plurality of points. The pump 68 is driven by a motor 15 having a pinion in mesh with a. gear 16 aflixed to a shaft 11 connected to the rotor of the pump which may assume any desired form known in the art.

It has been found to be desirable to maintain the temperature of the electrolyte at the same point throughoutthe year so that the action of substantially the same at all times. This result is attained by passing a suitable heating or cooling medium through a coil 18 (Figure 1) disposed within-the tank I0, adjacent the bottom thereof. Said coil is provided with a cooling or heating medium through an inlet pipe 19, and said coil discharges the cooling or heating means through an outlet pipe 80, such fluid being pumped through the coil in any ap- It has been found to be desirable to maintain the temperature of the electrolyte at 100? R, which temperature will require the application of the heating medium to the coil I8 during the winter months and the application of the cooling medium during the summer months of the year;

Referring to-Figure 6 of the drawings in the use of the apparatus the electrolyte is maintained at the level indicated by the line so designated in this figure, and the cylinder is rotated in the direction indicated by the arrow appearing on said view; It will be observed that the edge of the stationary pole, which is substantially completely immersed in the electrolyte as shown, at the side of the cylinder that moves downward through the electrolyte upon rotation thereof, is below the normal level of the electrolyte, and that at the side of the cylinder .which moves upward, when it is rotated in the direction indicated by the arrow, the edge of the stationary pole is slightly above the electrolyte level. The efiect of this arrangement is that the rotation of the cylinder causes a continuous circulation of electrolyte .through the gap between the cylinder and the through the gap continuously over the left hand edge of said pole. The result of action is that the nature of the electrolyte is maintained constant at all times during the electroplating action, resulting in an even deposition upon the cylinder. The uniformity with which the stationary pole is spaced from the cylinder is a further important ,therethrough. The liquid thus discharged from the gap between the poles is caused to flow through the opening 61 so that the liquid that has just passed through the gap is directed toward the.filter.

' The electrolyte accordingly that has passedthrough the gap between the poles is thus caused to flow toward the filter due to the normal rota-- tion of the cylinder, and the flow of electrolyte through the filter is continuously assured by the metal of uniform width and thickness, and of the desired length, which bars may be obtained upon the market at low cost. If cylinders of varying sizes are electroplated as is customary in practice, the rotation of the shaft ilcarrying the driving pinion 50 may be varied so that the surface speed of the cylinder to the electrolyte is equal to 600 or 800 feet per minute. If cylinders of varying sizes are to be plated, preferably, a

cradle having a' supporting surface that parallels the surfaces of the immersed cylinder is employed, though it has been found that where the variation in cylinders is not great, that the same cradle may be used in successfully electroplating printing cylinders of varying diameter.

The invention may be embodied in other specific forms without departing'from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended operation of the pump 68, which serves to withdraw electrolyte from the receptacle and return it adjacent the bottom of the main tank. The circulation thus caused by the rotation of the cylinder and by the action of the pump serves to maintain the electrolyte in continuous agitation so that the uniform character thereof is insured. at all times.

- when the electroplating action has continued so as to form a deposit of the order of 0.006 inch, a coating sufficient for the purpose of receiving an etching for use in rotogravure or similar printing, the cylinder is removed from the receptacle which may be readily accomplished by simply raising the cylinder out of the open boxes 48, in which the bearings rest. The bolts 45 that hold the member 43 in clamping engagement with the shaft sections are then released and the sleeve carrying the current collector l6 and the gear 41 for driving the cylinder respectively are thus simultaneously removed from the cylinder, and

' said sleeves are applied to the shaft sections of the next cylinder that is to be plated, the application of such sleeves to'the new cylinder serving to assemble with respect to such new cylinder the current collector just referred to. The new cylindermay then simply be inserted in the tank by again positioning the bearings39 in the open boxes 48, the current collector again contacting with the bush 59 and the gear 41 meshing with the pinion 50. Rotation of the cylinder can'be started immediately so that the electroplating action is not initiated until after the cylinder is in rotation. This ensures the formation of the desired uniform thin coating or shell upon the cylinder when the bars 32 supported in the cradle have been approximately consumed to one-half of their weight due to the continuance of the electroplating action. Preferably the cradle is then lined with new bars of metal, and the partially consumed bars are, super-posed upon the new bars and the electroplating action then continued with the result that the partially consumed bars are eventually completely consumed in the electroplating action.

It will thus be seen that an electricpoleis provided that may generally follow the contours of the cylinder to be plated, though said pole 5 consists essentially of a multiplicity of bars of claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired 'to be secured by United States Letters Patent is:

1. In electroplating apparatus comprising a receptacle for electrolyte, a rotatable cylinder constituting one of the electric poles, a stationary pole approximately paralleling the part'of the cylinder normally immersed in the electrolyte and terminating close to the surface thereof so that the rotation of the cylinder causes the initiation of a circulation of 'the electrolyte from between said poles over the edge of said pole, and 7 means to continue the circulation of the electrolyte discharged over said edge.

2. In electroplating apparatus comprising a receptacle for electrolyte, a rotatable cylinder constituting one of the electric poles, a stationary pole approximately paralleling the part of the cylinder normally immersed in the electrolyte and terminating close to the surface thereof so that the rotation of the cylinder causes the initiation of the circulation of the electrolyte from between said poles over the edge of said pole and a filter arranged to receive the electrolyte circulated by said cylinder. 3.- In electroplating apparatus comprising a receptacle for electrolyte, a rotatable cylinder constituting one of the electric poles, a stationary pole to assist pole approm'mately paralleling-the part of the cylinder normally immersed in the electrolyte and terminating close to the surface thereof so that the rotation of the cylinder causes the initiation of a circulation of the electrolyte from between said poles over the edge of said pole, and a filter to receive said electrolyte circulating over the edge of said pole and pumping means to purify and continue the circulation of said electrolyte respectively. v

91. In electroplating apparatus comprising a receptacle for electrolyte, a supplementary receptacle in communication with said electrolyte receptacle so that the electrolyte will flow into the supplementary receptacle, purifying means in said supplementary receptacle, a movable electric the circulation of electrolyte from said first to said second named receptacle through said purifying means and pump means to return the electrolyte to said first named receptacle.

5. In electroplating'apparatus comprising a receptacle for electrolyte, a supplementary receptacle in-communication with said electrolyte retionary pole.

ceptacle sothat the elctrolyte will flow into the supplementary receptacle, purifying means in said supplementary receptacle, a movable electric pole to assist the circulation oi electrolyte from said first to said second named receptacle through sleeves, a current collector on one or both of said sleeves, a driven pinion arranged adjacent said tank iormeshing engagement with said gearwhen said bearings are positioned in'said boxes, a stationary pole in said tank, and an electric circuit through said current collector and sta- T 7. In'ele'ctroplating machine comprisinga tank, ior th' electrolyta'a rotatable pole, mechanism to operate said pole, a filter adjacent said tank 'disposedso that rotation of said pole causes electrolyte to flow to said filter and means to return -'theelectroly te from the filter-to the tank.

' 8. A cylinder electroplating apparatus comprising a tank, a cylinder rotatably mounted in said tank, a stationary pole approximately paralleling less than one half of the cylinder surface, a supplementary tank including filtering means arranged so that the electrolyte will flow therein a when said cylinder is rotated, and pump means in return the electrolyte from the supplementary tank to the main tank beneath said stationary pole.

' 9. The combination defined in claim 8 in which said stationary pole consists of a support and a multiplicity 0! bars arrangedflatwise side by side on said support.v

10. In electroplating apparatus comprising a tank for the electrolytes cylinder having shaft sections projecting from opposite ends, sleeves clam'pedto said shaft sections and carrying bearings, notches formed in opposite walls of said tank to accommodate said shaft sections, a lining forsaid tank, said lining being formed to cover said notches and to provide housings for said sleeves, open bearing boxes supported by said tank and receiving said bearings, a gear on one of said sleeves, and a driven pinion arranged adjacent said tank for meshing engagement with said gear when said bearings are positioned in said boxes.

EMIL ERICKSSON.

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