US1884512A - Electroplating metallic cylinders - Google Patents

Description

Oct. 25, 1932.

as. BALLARD ELECTROPLATING METALLIC rGYLINDERS Original Filed Deo. 14, 1926 i TTQRNEYS. l

through the device as seen on the line 2--2 Patented 25, 1932 mmmv STATES PATENT oFlcE :anNnsr s. BALLARD, or sAN CALIFORNIA, AssIeNoa To BALLARD rnocnss Co., or sAN rnANCIsco, CALIFORNIA,l A (zo-PARTNERSHIP coNsrsmme or nussnLL .3. LEECH, or. sAN rnANcrsco, CALIFORNIA AND CoLvIN 111. REED, or BUBLINGAME,

GALIIOBNIA Application led :December 14, 1928. Serial This invention relates to a method of electroplating metallic cylinders and an apparatus therefor.

Itis the principal object of the present inaJ ".5 vention to provide means whereby metallic@ cylinders used in rotary/photogravure rocesses may be rapidly and smoothly sur aced by an electroplating process and in a manner lto insure' that the plated surface will be smooth and uniform and that the character of the plating will be such as to insure that it will not deteriorate during or after the plating operation.

The present invention contemplates an -Y electroplating vat fitted with a suitable anode member in the vat and other structures by which the cylinder to be plated may be supported for rotation and may be used as a cathode member in conjunction with the 3 anode and electrolyte in a manner to insure that the electroplating operation may be carried out at high speed in applying a uniform coating of metal upon the cylin er The present invention is illustrated by way of example in the accompanying draw-- ing in which:

Figure- 1 is a view lin transverse. section through the device as taken on the line 1-1 of Figure 2.

Figure 2 is a view in longitudinal section -'of Figure 1.

Referring. more particularly to the: accompanying drawing: v10'i1`1dicates an elect-ro- 5 plating tank or vat within which a suitable electrolyte solution, 11, is disposed. This solution is maintained at a. predetermined' level by some suitable means not shown in the drawing. The tank, 10, consists of a bottom m 12, op osite ends 13 and 1 4, and opposite sides A15 an 16. The ends 14 and 15 are fitted with journals, 17 and 18, to receive the trunnions 192 and 20 of a rotogravure cylinder,21,which cylinder is to be electroplated. The journals p 1'( and 18 are provided with ball bearings 22 which makes it possible for the cylinder to be rotated at a relatively high speed. The trunnions 192 and 20 of the cylinder 21 are encased in members which are im rYious to the action of the electrolyte solution so that ELECTBOPLATING METALLIC CYLINDEBS No. 154,671. Renewed January 1s, 1932.

the surfaces of the trunnions will not become pitted Jduring the electroplating operation. These encasing means include sleeves 23 and 24, the sleeve 23 being placed on trunnion 192 and the sleeve 24being placed on trunnion '55 2O.v These sleeves are formed with collars, 25, which serve as commutator members and will be hereinafter described. Openings, 26, are formed through the collarsto permit lifting means to be inserted through the openings M so that the cylinder may lbe readily manipulated to place it in the vat' and to remove it therefrom. Caps'27 are fastened upon the opposite ends of the trunnion outside of the position of the ball-bearing structure.v One of these caps is fitted with suitable means by which the cylinder may be driven, as for example, a pulley 28. ',lhis pulley may be connected with a driving mechanism through a Y belt. The position of the bearings for the, 79 trunnions of the cylinders is such with relation to the level of the electrolyte Within the vat that the portion of the cylinder lying below thedisc members '25 of the protecting sleeves will be submerged in the electrolyte. 75 By reference to Figure 1 of the drawing, it will be seen that an arcuate plate, 29, is partially submerged within-the electrolyte and disposed beneath the mounted position of the cylinder 21. This plate is of arcuate shape 99 such as to insure that the submerged portion of the plate will conform to the contour of the surface ofthe cylinder and will be spaced a distance therefrom to provide a passageway or throat of uniform width between the surface of the cylinder and the surface of the plate. A portion of the plate 29 extends above the level of the liquid and is connected with the positive wire, 30, leading from a source of electric supply so that this plate may readil be termed the anode plate of the electrop ating apparatus. Anegative wire, 31, leads Vfrom the same sou-rceof supply to a contact brush, 32, which bears against the commutator disc, 25, of the sleeves, thus establishing the cylinder, 21 as the cathode member of the electroplating apparatus. The unsubmerged portion of the cylinder, 21, is temporarily enclosed within orby ashroud, 33, which has ana-rcuate portion conon y forming to the contour of the cylinder and being spaced therefrom, and continuing in a downwardly deflecting portion secured tothe side wall, 16, ofthe vat. A hinge, 34, may be provided as a mounting for the shroud, 33, so that itmay be swung out of the Way when the cylinder is to be removed.

By reference to Figure 1 of the drawing, it will be seen that the anode plate 29 and the shroud substantially embrace two-thirds of the circumference ofthe cylinder at all times, and form an electrolyte assageway, 35, along which electrolyte may e carried as the cylinder 21 is rotated in the direction of the arrow -aas indicated in Figure l. In the present instance, it is highly desirable to increase the flow of current through the surface of the cylinder which has previously been submerged in the electrolyte and upon .which an electroplating action has taken place. This is done by providing a supplemental anode, 36, within the arcuate portion of the shroud 33 and connecting said anode with a wire, 37, which leads to a switch, 38.

At the present time'it is necessary tocarry on the electroplating action upon the cylinders at a comparatively slow rate of speed and with a relatively low rate of the current flow. This increases the time required for electroplating and does not obtain the smooth and.,

uniform surface which can be obtained by the rapid process here disclosed. y

Attempts have beenL made/ to hurry the electroplating action by the use of larger current flow, but this has resulted in producing a spongy and pitted surface not desirable for rotogravure work. By the .use of an initial low current and a subsequent high current flow, the method readily lends itself to a rapid electroplating action while produlcling a firm and uniform surface upon the ro f In operation of the present invention, the apparatus is'assembled as shown in the drawing and a cylinder, 21, to be electroplated is placed within the journal bearings, 17 and 18, after which it may be driven by a suitable means throu h the pulley 28. The current is then supp ied through the wires, 30,

, 37, and 31 and the cylinder is rotated while its lower portion is submerged'in vthe electrolyte, the speed of rotation being such as to produce a surface speed ofv approximately 1,000 feet perminute, although it will be understood that other speeds might be adopted if found satisfactory. In an event, it is desirable to produce a sufficient y high speed of rotation of the cylinder to cause it to lift the electrolyte from the surface of the electrolyte in the tank and to draw it along the electrolyte passageway, l35, be-

tween the surface of the cylinder and the shroud. This will cause 'it to be drawn u and thrown over the top of the cylinder and back into the tank as it strikes the deflect-V ing portion of the shroud, 33..A By this means electrol te will be consistently applied to more t an fifty percent of the surface of the roll at all times. Initial electroplating will take place while the current is flowing from the anode, 29, to the cathode cylinder, 2l. A sustained electro lating action will take place after the sur ace of the cylinder has passed above the level of the electrolyte solution. This action will be produced between a supplemental anode member, 36, and the cylinder, as the electrolyte is carried along the passageway 35 between the shroud 33 and the cylinder.

It will be found that by this method the agitation of the electrolyte, as produced by therotating cylinder, and the manner in which the electrolyte is caused to envelope the cylinder in its rotation, insures that a Amuch higher current density may'be emgiven amount of metal upon the cylinder# It is also true that the rotation of the cylinder i the electrolyte Iand the manner in whiplt is enveloped by the electrolyte during its' igh speed of rotation causes the electro lating action to be carried on with fresh an agitated electrolyte at all times, and will also act to'insure that the thickness of the electroplatin will be uniform and that its texture will die line and solid, and that its surface` will be smooth.

While I have shown the preferred form of my invention as now known to me, it will be understood that various changes might be made in the combination, construction and arrangements of parts by those skilled in the art without departing from the spirit of the invention as claimed.

Having thus described my inventionxwhat I claim as new and desire to secure by Letters Patent isl K 1. An apparatus of the class described, comprisingV a tank within which an electrolyte is adapted to be placed, bearings in the opposite end of the tank for receiving the trunnions of a rotogravure cylinder and supporting it with its lower portion submerged in theelectrolyte, means attachable to the trunnions for rotating the same, an anodel plate submerged in the electrolyte and confdrmng to the submerged surface of the cylinder,

means for creating a flow of electricity from the anode plate through the, electrolyte andl comprising a vat adapted to contain an elecy trolyte, bearings in the opposite ends thereof and adapted to recelve the end trunnions of a rotogravure cylinder, casings for the bearings which casings are impervious to the electrolyte, said bearings supporting the cylinder to rotate on its horizontal axis and with its lowermost portion submerged in the electrolyte, an arcuate anode plate submerged in the eleotrolyte beneath the cylinder and forming an electrolyte passageway of uniform width between the surface of the cylinder and the anode plate, a shroud member enclosing the portion of the cylinder above the surface of the electrolyte and forming a continuing passageway for the electrolyte which is carriedv up with the cylinder as it rotates, and means for establishing a iiow of electric current through the anode plate and the cylinder to produce an electroplating action.

3. Am apparatus of the class described, comprising a vat adapted to contain an ele"c`\ tmlyte, bearings in the opposite ends thereof and adapted to receive the end trunnions of a rotogravure cylinder, casings for the bearings which casings are impervious to the electrolyte, said bearings supporting the cylinder to rotate on its horizontal axis and with its lowermost portion submerged in the electrolyte, an arcuate anode plate submerged in the` electrolyte beneath the cylinder and forming an electrolyte passageway of uniform width between lthe surface of the cylinder and the^ anode plate, a shroud member enclosing the portion of the cylinder abovefthe surface of' the electrolyte and forming a continuing passageway^ for the electrolyte whichL is carried up with the cylinder as it rotates, means for establishing a flow of electric current through the anode plate and the cylinder to produce an electroplat-ing action, and means for rotating the cylinder at av speed of rotation siiiciently high to cause some of the electrolyte to be carried upwardly by the submerged portion of the cylinder and to be carried along the electrolyte passagewayv between the anode plate, the shroud, and the cylinder, whereby the rotating cylinder will be substantially enveloped -in the electrolyte.

` 4. An apparatus of the class demribed,

l comprising a vat adapted to contain an electrolyte, bearings in the oplposite ends thereof and adapted to receive t e end trunnipns of -a rotogravure cylinder, casings for th bearings which casings are impervious to the electrolyte, said bearmgssupporting the cylinder to rotate on its horizontal axis and with its lowermost portion submerged in the electrolyte, an arcuate anode plate submer ed in the electrolyte beneath the cylinder an formin Y `an electrolyte passagewa of uniform wid between the` surface of t e cylinder and the anode plate, a shroud member enclosing the portion of the cylinder above thesurface ofthe electrolyte and forming a continuing pasassam rent through the anode plateynd the cylinder to produce an electroplating action, means for rotating the cylinder at a speed of rotation suiciently high to cause the electrolyte to be sageway for the electrolyte some of which is carried up with the cylinder as it rotates, means for establishing a ow of electric cur- CERTIFICATE or CORRECTION. f

,ment No. 1,884,512, Y omber z5, 1932.

yERNEST s.A BALLARD.

lt is 'hereby certified lthat the above nn-mbered patent was erroneously issued v to "Ballard Process Co., of San Francisco, l(Jalifomia, a copartnership consist ling of Russell B. Leech, of San Francisco, California, and Colvin M. Reed, of

Burlingame, California", .whereas saidpatent should have been issued to "Standard l Process Corporation, of Chicagmlllinois, a corporation of Delaware", as aseignee by mesne assignments of the entire interest in said invention, as shown by the records of assignments in this office; and that the said Letters Patent should be read with this correction therein that `the same may conform `to the record of the case inthe Patent Officer f signed and Ysealed :his 6th day of Iecember, A. D. 1932n (Seal) v Acting Connissionerfof Patents.

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