US2333907A - Apparatus for electrodepositing metals - Google Patents

Description

1943- i R. WERRETT' 2,333,907

APPARATUS FOR ELECTRODEPOSITING METALS Filed Jan. 28, 1942 3 Sheets-Sheet l Nov. 9, 1943. R! WERRETT 2,333,907

APPARATUS FOR ELECTRODEPOSITING METALS Filed Jan. 28, 1942 3 Sheets-Sheet Nov. 9, 1943. R. WERRETT APPARATUS FOR ELECTRODEPOSITING' METALS Filed Jan. 28, 1942 3 sheets sheet 3 Patented Nov, 9, 1943.

APPARATUS FOR ELE METALS Roy Werrett, Cam, England, assignor to R. A.

c'rnonnrosrrmc Lister & Company Limited, Dursley, Gloucestershire, England, a British-company Application January 28, 1942, Serial No. 428,520 In Great Britain December 5, 1940 1 Claim.

This invention relates to the electrodeposition of metals on articles of the type (hereinafter referred to as the type described) having inner and outer faces, and apparatus therefor. Such articles may be tubular, or cylindrical, or may have 5 the form of acontainer.

' It is sometimes desirable to deposit a metal on the entire outer surface as well as on the entire inner surface of an article of cylindrical form, or on part of the outer surface and the entire inner surface, or on part of the inner surface and the entire outer surface, or on parts of both surfaces, and an important object of the present invention is to facilitate and expedite such electroplating operations, and to provide an improvedconstruction of electroplating aparatus for that purpose.

According to the invention, there is provided apparatus for electrodepositing metal on an arcomprising a jig constituting a cathode, an inner anode. arranged to lie within, andan outer anode arranged to' lie surrounding the butsideof the article for use simultaneously in plating its inner and outer surfaces, which jig is a structure of U- shape having an aperture in the middle ofthebase section thereof, means extending through said aperture for suspending the inner anode from and insulating it from the upper partlof the jig,

means for suspending the outer anode from and insulating it from the lower part of the jig, an

annular block constituting a combined continuity and supporting member, on the upper side of which the article to be plated can be seated,

and suspension "means for securing said block to ing one form of electroplating apparatus accord- 46 ing to the invention;

Figure 2 is an elevation thereof, partly in section, as viewed from the left-hand side of Figure 1, but with one vertical wall of the jig removed,

and, 50

Figure 3 is an under plan view of the apparatus. Like reference character 'designate like parts throughout the several views. Referring to the drawings, an article to be plated is suspended in the electrolyte or an elec- 5s troplatingbath by means or a device known in the trade as a jig which functions as a cathode, which Jig is a U-shaped structure that is designated generally 42, and is rectangular in plan and hastwo vertical walls 44,46 and a bottom wall 48 having a rectangular aperture 50 in the middle thereof. The article to be electroplated may be a one-piece cylinder or a cylinder divided axially into two or more parts. As illustrated, the article 52 is a cylindrical journal-bearing that is divided longitudinally into two halves d h an external flange 54 at its upper end, which cylinder is supported, as described hereinafter, by the jig 42. In order to plate the inside and outside peripheral surfaces of the body of the two-part cylinder evenly and simultaneously, a two-diameter inner anode 56, 58 extends into the cylinder, and a second anode 60 surrounds. the outside of it. ticle havinginner and outer faces to be plated, 20

- The inner anode 56, 58 is circular as viewed in plan, its part 56 of larger diameter constituting the head lying wholly within the article 52, and the part 58 of lesser diameter extending upwards from the head through the aperture 58. to restrict its freecross-sectional area, the lower end 62 .of the head being bevelled. This inner anode I6, 5! is carried by a stem 64 having four radially arranged ribs or fins 86, which are shouldered at the top and seated on a rectangular piece of insulation 88 that is carried by the walls 48 of the jig at the top thereof. These walls have each a perforated lug 10 for connection to through a radial arm I8 of the outer anode 60.

An insulating sleeve is arranged between this arm 18 and'the base 48 of the jig, anda second insulating sleeve 82 is provided around the bolt ll above the lug II at a hole .03 in the wall of the is secured to the top of the bolt 14 by a nut I, a

, collar 88, and awasher ilbeingprovided between the top of the sleeve 82 and the lead-in member I. By tightening the nut '8 at the top of the bolt I4 and a nut 82 at'the bottom thereoLthe arm 18 of the outer anode can be firmly secured in position and good electrical contact can be made between it and the. lead-in member 84. The

secured to the wall 08 by a stud I02.

outer anode 60 has. also two additional radial arms 04, 00, each of which is secured to, but insulated from, the bottom wall 48 of .the Jig by a nutequipped stud 90 secured in the lower end of an insulating sleeve I00, whereof the upper end is I Asviewed in plan the three arms 10, 04 and 90 of the outer anode are arranged in the form of a Y and firmly detachably secure the outer anode 00 in spaced relation with the article 52. This anode 60 may be cylindrical, but as illustrated it has at its upper end an inwardly-directed flange I04 which extends toward the article 52.

The article 52 to be plated may be suspended from the Jig l2 constituting the cathode in any convenient manner so as to be in electrical connection with the jig. As illustrated, the suspension means comprises an annular member I06" which constitutes not only a supporting member, but also a continuity member for the article 02. This member I06 has its top face levelwith the bottom face of the outer anode, has a chamferedlower end I08, and is suspended by metal arms or pins II 0 from an annular metal block I I2, preferably composed of lead, having a rectangular aperture III, which may be secured to the base 40 in any convenient manner; a rebated spacing piece Ill having a rectangular aperture H is shown provided between the rebated upper portion of the:

block I I2 and the base 48, and the lead block H2 is welded or soldered to the spacing piece I I4; the block III may be bolted and soldered in position, two studs being shown at I I1, so that mechanical strength and good electrical conductivity are provided. The block II! is provided with'any convenient number of substantially vertical circulation ducts or gashole IIB that extend from a chamfered face I I8 at the lower end thereof to the top face at a situation outside the spacing piece Ill, which ducts serve for the circulation of the electrolyte, as the gas released by the current risesinside or outside surfaces of the hearing. The chamfer I08 at the lower end of thecontinuity member I08 is preferably 45; its function isto deflect the flow of electrolyteto the outside rather than to the inside of the article It so as to maintain an even rate of deposit on both the inside and the outside. Due to the construction of the apparatus as described, there is a greater obstruction in the flow of electrolyte to the outer surface of the article I52 than to the inner surface, so that this chamfer plays an important role.

The apparatus described above the anodes are provided with separate terminals by means of which current can be supplied from independent variable resistances, so that the rate of deposit may be varied and the actual thickness of the deposit controlled on either surface, the deposition taking place simultaneously on both surfaces from the same electrolyte. P

- The article to be plated may be of various shapes, for example'its surfaces on which the deposits are to be made may be flat/concave,

' convex or angular.

I claim:

Apparatus for electrodepositing metal on an article having inner and outer faces to be plated, comprising a jig constituting a cathode, an inner anode arranged to ie within.. and an outer anode arranged to lie s rounding the outside of the article for use simultaneously in plating its inner and outer surfaces, which Jig is a structure of U-shape having. an aperture in the middle of the base section thereof, means extending through said aperture for suspending the'inner anode from and insulating it,from the upper part of the jig, means for suspending the outer anode from and insulating it from the lower part of the Jig, an annular block constituting a combinedcontinuity and supporting member, on the upper side of which the article to be plated can be seated, the outer lower edge of which continuity member is chflm'fered and uspension means for securing said continuity member to the base section with the upper en d of the article in electrical contact with the cathode, which suspension means comprises metal supporting arms that are attached to the around the outer surface of the article supported on said continuity member.

' ROY WERRE'I'I.

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