US 2462968 A
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Description (OCR text may contain errors)
March 1, 1949. G. B. HoGABooM, JR., ET AL 2,462,968
ANODE Filed Febp22, 1945 Y 2 sheets-sheet 1 March 1, 1949. G. B. HoGABOoM, JR., ET AL. 2,462,958
ANODE 2 Sheets-Sheet 2 Filed Feb. 22, 1945.
Patented Mar. 1949 AN ODE George B. Hogaboom, Jr., Kenilworth, N. J., and Nathaniel R. Hall, Brooklyn, N. Y.
Application February 22, 1945, Serial No. 579,288
This invention relates to improvements in anodes for use in electroplating operations, and the invention has reference, more particularly, to anodes especially adapted for use in chromium plating.
The invention has for an object to provide, in an anode of given selected length and width, a novel construction of body so formed as to provide a multiplicity of projections extending from its front or Work opposing face, whereby to obtain a maximum amount of surface area, including a maximum extent of free edge portions, and thereby facilitate the discharge of electric current therefrom, and thus increase the electrical efficiency of the anode; the novel anode body being additionally formed to provide, adjacent said projections, through opening-s which not only contribute to the extent of current discharging free edge portions, but which also provide, adjacent to said projections, passages for solution movement through the anode from front to back thereof, whereby to redu-ce tendency of gas bubbles to collect and unduly blanket the front face of the anode, thus aiding in keeping the current discharging surfaces and edges free from obstructing gas bubbles, and better assuring adeq uate and uniform current flow from the anode to the object being plated.
Another object of the invention is to provide the anode body with novel means for suspending the saine from and in good electrical contact with a current delivery anode rod of an electroplating tank; said means comprising hanger stud means fixedly molded into the anode body so as to project from the upper end thereof as a permanent part thereof, together with a separable clamp hook means having a clamp screw adapted to cooperate with said anode rod, and operative to engage terminal parts of said hanger stud means in direct and positive electrical contact with said anode rod. Said hanger stud means and clamp hook means for best eiciency should, in practice, be made of corrosion resistant metal.
The invention has for a further object to provide in combination with the anode body, a novel construction and arrangement of insulator shield related to the rear face thereof so as to be interposed between the anode and the wall-s and interior fittings of an electroplating tank in which the anode is used, whereby to prevent secondary electrical current iiow between the anode and said tank wall and/or interior fittings.
Other objects of this invention, not at this time more particularly enumerated, will be understood from the following detailed description of the same.
An illustrative embodiment of this invention is shown in the accompanying drawings, in which:
Fig. 1 is a transverse vertical section of an electroplating tank equipped with anodes made according to this invention.
Fig. 2 is a front or work opposing face view of an anode according to this invention; Fig. 3 is a longitudinal sectional view thereof, taken on line 3-3 in Fig. 2; Fig. 4 is a rear face View thereof; and Fig. 5 is a transverse sectional view thereof, taken on line 5-5 in Fig. 2.
Similar characters of reference are employed in the above described views, to indicate corresponding parts.
Referring to the drawings, the novel anodes according to this invention are adapted to be suspended in the electrolyte content l!) of a lead lined piating tank Il', adjacent to opposite walls of the latter and in opposition to each other and to the work W immersed in said electrolyte intermediate the thus opposed anodes. The anodes are suspended from and in electrical contact with current delivery anode rods I2 with which the tank is provided, and the work W is likewise suspended, by suitable electrically conductive suspension means I3, from and in electrical contact with a current discharging cathode rod it, all in the conventional manner well-known to the industry.
The novel anode according to this invention, when used in the process of chromium plating, comprises a body formed from lead or an alloy of lead. When used in depositing other metals or other materials, the anode body may, of course, be formed from any other appropriate metals, or alloys or materials, either soluble or insoluble.
The anode body comprises a main plate i5 of suitable length, width and thickness, having along the longitudinal sides thereof, to project outwardly from its front or work opposing face, marginal reenforcing ribs I6, whereby to stiien the plate l5 against distortion. Said ribs I6 are of polygonal cross-'sectional -shape whereby to provide sharp inner edges l1 and sharp outer edges i8, which edgesfurnish a considerable length or extent of discharge lines for outflow of current from the anode to the electrolyte solution. Formed integrally with the main plate i5, to also project outwardly from the front or work opposing face thereof, are a multiplicity of truncated pyramidal projections I9. These projections I9 are preferably arranged in spaced staggered relation one to another throughout the major part of the area of `said front or work opposing face of the main plate l5. By reason of their truncated pyramidal form, said projections I9 provide side edges 20 at the intersections of their side faces, and end edges 2i' at the intersections of their side faces with the end faces thereof. These free edge portions 20 and 2|, in the aggregate, provide a considerable additional extent of discharge lines for outflow of current from the anode to the electrolyte solution.
Formed in the main plate l5 in alignment with and below the projections I9 are through openings 22. The free edges 23, which border these openings in the plane of the front or work cp*- posing face of the anode, provide a further extent of discharge lines for outiiow of current from the anode to the electrolyte solution. The openings 22 provide passages for solution movement through the anode from front to back thereof as an aid in preventing gas bubbles from blanketing the front or Work opposing face of the anode with likelihood of obstructing and thu-s diminishing free and full how of current from the anode to the electrolyte solution and toward the work W.
At its upper end, the main plate l5 is provided with an integral thickenedv head portion 24. Moldedv into said head portion 2d, so as to be nonremovably imbedded therein, are the enlarged anchor butts 25 of one or more hanger studs or rods 2S which project exteriorly from the upper extremity of said head portion, so as to extend vertically or longitudinally upward therefrom. The upper free ends of said hanger studs or rods 2S are screw-threaded to receive fastening nut means for separably attaching thereto a metallic clamp hook` means operative to engage a current delivering anode rod l2, whereby to mechanically suspend the anode therefrom an-d electrically connect said anode thereto.
Said clamp hook means comprises a base nange 2l from one side of which extends an upstanding leg 28. Said leg 28 terminates in an angular hook portion 29 which is spaced above said base flange so as to overhang the same. Said hook portion 29 terminates in a bill-portion 3@ which is angularly opposed to the leg 28. Threaded through the bill-portion Sil is a manipulatable clamp-screw 3 I. Threaded onto the hanger studs or rods 26 are suitably positioned stop nuts 32. The upper free end portions of the hanger studs or rods 26, which project above said stop nuts 32, are passed through openings with which the base flange 2l of the'clamp hook means is provided for their reception; said base flange being stopped against said stop nuts 32. Threaded onto the extremities of said hanger studs or rods 26 are nuts 33, preferably in the form of cap nuts, the same being adapted to bear against the upper surface of said base flange 2l, thus xedly, but nevertheless separably, attaching the clamp hook means to said hanger studs or rods 2E.
To suspend the anode from an anode rod l2, when thus equipped with the clamp hook means, said clamp hook means is engaged over the anode rod with its leg 28 stopped against the inner face of the latter, whereupon the clampscrew 3| is turned home against said anode rod. The effect of thus turning down the clamp-screw is to draw upward the clamp hook means so as to cause the cap nuts 33 or hanger stud or rod ends, as the case may be, to directly abut and bear upon the anode rod, in tight and non-movable contact therewith, thus assuring a direct and positive electrical contact between the anode rod and the suspended anode, which is unaffected by vibration or shocks.
By reason of the separable or detachable connection of the clamp hook means with an anode to be served thereby, the former may be readily and quickly removed from said anode when the latter is worn out in use, and said clamp hook means may then be reemployed by application to a new or replacement anode. As a result of this, the clamp hook means may be economically used over and over again, since the anodes may be easily replaceably connected therewith, such replacement anodes requiring only the provision of therelatively inexpensive hanger studs,` or rods 26. Not only'therefore'is the clamp honk means, by reason of its described construction and mode of operation, adapted to assure good and stable electrical connection of the anode equipped therewith with a current delivered anode rod, but also, by reason of its detachability and consequent capability of transfer to replacement anodes, provides afeature of economy of no little advantage.
Anodes suspended in the electrolyte solution content of a plating tank discharge current primarily to the work W to be plated. Some current, however, is discharged from thel back of the anode toward the adjacent tank wall, when the tank or its lining is conductive; such current thence passing by Way of the tank bottom and ends through the electrolyte solution to the work W, thus establishing a secondary path of current iiow. This is objectionable, since yit not only applies an uncontrolled amount of current to the work, but additionally causes undesirable deposition of metal on the tank walls. Furthermore, at points where such secondary current leaves tank walls, said points become anodic, and thus subject to break down attack, e. g. at the bottom and ends of the tank. To prevent these objectionable occurrences, the anode per se may be further provided with means operative to obstruct .and substantially prevent secondary current liow. To this end, the anode is provided, as a unitary part thereof, with an insulator shield means so related thereto as to be spaced from the back or rear iace of the anode in a plane parallel thereto. Such insulator shield means may be made of any suitable non-conductive material which will not be deleterlously affected by the electrolyte solution, when immersed in the latter. In an exemplifying form thereof, said insulator shield means comprises a glass plate 35 substantially corresponding in length .and width to the length and width of the anode main plate. Said glass plate 35 is preferably of the wire glass type, so as to be less'liable to breakage and disintegration. To mount said insulator shield plate 35 in assembled relation to the anode, upper and lower supporting brackets or blocks 36 and 3l' are provided, each having attachment Shanks 38 to engage in openings 3Q provided in the anode end portions for their reception. Said shanks 38 are provided with screw-threaded bores into which may be threaded fastening bolts 40 which, with their washers di, abut the front face of the anode, thus functioning to securely connect said supporting blocks with the anode. Said supporting blocks are preferably made of non-conductive material, such e. g. as ceramic or plastic materials, glass, or the like. The opposed faces of said supporting blocks are provided with transverse channels or grooves ft2 to respectively receive and embrace the respective ends or the insulator shield plate 35, whereby to support said shield plate in fixed parallel offset relation to the back face of the anode.
Provision of the anode with the described insulator shield plate 35 is of especial advantage in cases where the plating tank interior is provided along its side walls with coils i3 for circulation of either a heating or cooling uid for controlling the temperature of the electrolyte solution content of the plating tank, since such shield plate 35 substantially prevents secondary ilow of current from the anode to said coils, and
thus prevents the latter from either becoming anodic or of being quickly corroded.
It will be understood that in its broader aspects the instant invention primarily and broadly involves the novelty of the anode per se irrespective of whether equipped with said insulator shield plate or not, but secondarily or more specifically involves the combination of the insulator shield means with the anode body.
Having now described our invention, We claim:
An electroplating anode comprising a main body plate of selected width, length and thickness, said plate having stiffening ribs of polygonal cross sectional shape projecting from its Work opposing iace along its longitudinal marginal portions, said plate having a multiplicity of solid truncated pyramidal projections integral therewith and distributively spaced both laterally and longitudinally over the work opposing face thereof, said projections being of polygonal cross sectional shape to provide sharp edges at the junctures of its faces, said body plate having through openings in longitudinally aligned contiguous relation to and beneath said projections, said openings being of inverted pyramidal form and of polygonal cross sectional shape, with faces thereof extending in common plane with coincident faces of said projections, whereby side and end bordering sharp edges of said projections and free edges of said openings and of said stifrening ribs provide, in the aggregate, a considerable extent of current discharge lines distributed throughout the area of said body plate, said projections on the anode front face being adapted to prevent gas blanketing of said front face while the contiguous through openings cause some gas ow to move through the anode to the back thereof, an impervious shield attached to the anode body plate in rearwardly offset spaced relation to the back thereof, said shield being :nadeof non-conductive material and corresponding in area to the back face area of the anode body plate, hanger rod means affixed to the upper end portion of said plate body to extendrexteriorly upward therefrom, and clamp hook means afxed to said hanger rod means whereby to suspend the anode from a current delivering anode rod in electrical connection therewith.
GEORGE B. HOGABOOM, JR.
NATHANIEL R. HALL.
REFERENCES CITED The following references are of record in the rlle of this patent:
UNITED STATES PATENTS Number Name Date 1,152,772 Wheeler Sept. 7, 1915 1,297,157 Harris Mar. 11, 1919 1,368,011 Allen Feb. 8, 1921 1,484,194 Servis Feb. 19, 1924 1,738,515 Belke Mar. 31, 1927 1,771,091 Lawaczeck July 22, 1930 1,856,663 Smith May 3, 1932 2,194,138 Crawford Mar. 19, 1940 2,319,624 Olsen May 18, 1943 FOREIGN PATENTS Number Country Date 16,057 Great Britain July 20, 1896 480,547 Great Britain Feb. 24, 1938 18,391 Australia Feb. 13, 1929 279,253 Germany Oct. 13, 1914