US 2958642 A
Description (OCR text may contain errors)
Nov. 1, 1960 w. E. BELKE 2,958,642
ELECTROPLATING RACK Original Filed May 26. 1955 -nite irais ELECTROPLATING RACK William E. Eelke, Chicago, Ill., assigner to Eelke Manufacturing Co., Chicago, Ill., a corporation of Illinois @riginal application May 26, 1955, Ser. No. 511,264,
now Patent No. 2,820,757, dated Jan. 21, 1958. Divided and this application Sept. 27, 1957, Ser. No. 686,616
1 Claim. (Cl. 21M- 297) The present invention relates to plating racks and methods of racking articles for electroplating, and is particularly concerned with the provision of improved structures and methods for meeting the electroplating requirements of an ininite number of different articles, while preserving useful rack parts in classified arrangement for use in meeting future requirements.
The present application is a division of my prior application, Ser. No. 511,264, iiled May 26, 1955, on Plat ing Racks and Methods of Racking Articles for Electroplating, Patent No. 2,826,757, issued January 21, 1958.
One of the objects of the invention is the provision of an improved method of assembling rack parts of the type which can be disassembled and reused, in such Inanner that a low resistance electrical connection is assured between the rack parts by cutting into the metal of one part with the other and exposing a new bright surface for effecting the electrical connection each time the parts are assembled.
Another object of the invention is the provision of an improved method of assembly which includes the cutting of a new bright surface for engagement between rack parts, in which provision is automatically made for covering and sealing these clean connecting surfaces against the ingress of electrolyte for maintaining good electrical connection and preventing erosion of the conducting metal.
Another object of the invention is the provision of improved rack structures including rack sections and rack tips which are adapted to be so assembled that a new bright conducting surface is cut for engagement between them whenever they are assembled to provide the low electrical resistance connection between the parts every time the parts are reassembled.
Another object of the invention is the provision of improved rack `and tip structures which are protected against the action of acid throughout, except at the point where the rack hangs and the tip supports articles to be electroplated and `at the connection between the rack and tip, the latter connection being automatically sealed by assembly of the parts after cutting and assuring new bright engaging surfaces between the tip and rack.
Another object of the invention is the elimination of the methods yand structures of the prior art in which racks have been provided for -an infinite number of types ofarticles to be electroplated and the racks have been discarded after use or stored in such manner that they are not likely to be found, even if the same articles are to be electroplated again, and the racks have represented a loss because of the lack of system in their assembly and storage.
m i l E@ Another object of the invention is the provision of improved electroplating racks and methods in which the racks can be assembled after coating, and disassembled Without injury to the parts or insulation, and having the following advantages:
(l) Damaged tips can be replaced quickly and economically.
(2) Tips are easily replaced with dilferent tip designs for plating different articles.
(3) Spacing olf tips can be changed.
(4) Spacing `of rack members can be changed.
(5) When no longer needed, racks can be disassembled and the parts reused in racks of similar or diiferent design.
(6) Rack parts can be stored systematically in a small fraction of the space required for assembled racks.
(7) Systematic storage makes any part or tip instantly available and easy to use.
Other objects and advantages of the invention will be apparent yfrom the following description and the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.
Referring to the drawings accompanying the specification, of which there are four sheets,
Fig. l is a view in perspective of an electroplating rack assembly with various exemplary plating tips;
Fig. 2 is a sectional viefw, taken on the plane of the line 9--9 of Fig. 1;
Fig. 3 is a View in perspective of the cruciform plate 81 of Figs. l and 2.
The present application relates particularly to the tip 24 of Fig. 1.
Referring to Fig. 1, this is a View in perspective which is exemplary of an iniinite number of rack assemblies, which may be made up out of one or more spine niembers 20, yand one or a multiplicity of tip members 21, 22, 23 or 24.
The tip members selected are merely exemplary of a yfew types, of which there are an infinite number of forms for meeting lan equal number of electroplating requirements of different articles.
All of the tip members and racks have in common the fact that they are coated with an initially' plastic layer of electrical insulation 25, covering every part of the rack and tips, which is immersed in the electrolyte or subjected to its fumes, excepting the upper V-shaped hook Z6 of the rack 20, which hook is electrically connected to the conducting rod on which it is supported, and excepting the eXtreme end surfaces 27 of the tips on that side where the tips engage the electroplated articles.
Thus the tips 21 may have the insulation ground off at 27 on the bottom and top of the extreme ends of these tips, because they are intended to engage an article by spreading action, being inserted into an aperture or cavity in the article to effect an electrical conducting connection between the rack and article.
ln some embodiments of the invention the hook 26 may also be coated, except its lower surface 28, which actually engages the rod, serving as a bus bar,
The rack member 20, which is sometimes called a spine, comprises an elongated metal bar of substantial thickness `and width of conducting metal, such as copper, provided with the hook at one end and with the insulating coating 25, and a plurality of cylindrical apertures Y 3 extending through the coating and copper for attachment of the various types of tips.
For example, the tip 21 is a round wire spring contact tip employing a threaded copper bolt 29, with a pair of wire members 3i) and 3l, which have a pair of converging portions 40, arranged on opposite sides of the shank of the bolt 29, adjacent its head.
The wires are bent outwardly at fit1 on each side of the bolt to bring their parallel body portions 4l into a spread condition, and are bent inwardly again at 42 to provide `shoulders that may engage the body to be electroplated just outside an aperture, limiting the movement of the body toward the spine 20.
The tip `is provided with extreme end portions 43 which may `be straight and parallel for insertion into the aperture of the subject, and the adjacent wires 3G, 3l are in each case given an initial tension away from each other, so that they may be forced together and inserted in the aperture in the subject, spreading resilient-ly to bring the bare surfaces 27 into engagement with the subject inside said aperture.
The bent formations 4d, 4l, 4Z increase the resiliency of this wire tip. The wire tip so far described is cornr pletely covered with a thick layer of plastic insulation, leaving the bolt shank 29 bare, and leaving the surfaces 27 bare.
Referring to tip 2.3 of Fig. l, this is exemplary of one type of rugged fiat spring tip, the structure of which is shown in Fig. 5. In this case the tip includes a pair of relatively at copper springs 6l, 62, the central bodies of which are provided with registering apertures 63.
The bodies of springs 6l, 62 are riveted together at 64, 64, and formed with the otuwardly turned obtuse angles at 65, so that their end portions 66 diverge. These end portions may be completely covered with the plastic insulation, which may be ground ofi wherever the tips are intended to have conducting engagement with a subject to be electroplated.
The same cutting bushing 46 may be employed, but 1t is provided with a non-circular head 67 for engagement with two of the flanges 68 of a metal clip 69, which has an aperture 70 for the screw bolt 7l.
The clip 69 has oppositely extending ilanges 72, '72, engaging the edges of the at springs 61 and 62, and preventing the flat springs from rotating relative to the cutting bushing, which is to be lixed on the spine 20, as previously described.
The screw bolt 71 extends into the threaded bore 73, but it leaves suiiicient room in the threaded bore 73 for the shank 7 4 of another screw bolt without a head but having a kerf 75 in its end. The tapered nut 51 is threaded on the shank 74, drawing the parts into tight electrical conducting relation with the spine 20, as previously described, and the nut l is covered by a similar insulating cap 56, sealing this end of the assembly.
The flat spring tip Z3 is again covered over all with insulation 76, terminating in the tapered circular sealing ange 77, which engages and seals against the insulating covering 25.
Referring to the rugged flat spring tip 24 of Fig. 1, the structure of this member is shown in Figs. 2 and 3, and this spring tip being adapted to support heavier subjects, it is provided with a twin mounting.
For this purpose a pair of iiat spring members 7 S and 7 9 having their central iiat body portions secured with a pair of rivets 80 to a cruciform supporting member 81, having rivet apertures S2. The cruciforrn member 81 has its upwardly and downwardly extending portions 83 provided with apertures 84, large enough to receive the cylindrical end portions 85 on the cutting bushings 86.
The cutting bushing has an annular shoulder 87, and a threaded end portion S8 for receiving a nut 89, which clamps the cutting bushing to the cruciform member in each case at a spacing suitable for causing the cutting bushing to register with the apertures 90, 91 in the spine 20.
'I'he spring tip 24 is again bent outwardly at an obtuse angle at 92, 92, providing the spreading ends 93. All parts of the tip assembly on the right side of Fig. 9, except the cutting edges 48 of the cutting bushings 86, are covered with the insulating compound 94, which terminates about the cutting bushings in the circular, tapered thin sealing flanges 95 for engaging the insulation 25.
Threaded bolt 29 in each case carries a tapered nut 51 centering the threaded bolt 29 in the aperture of the spine and drawing the cutting bushing 86 into the aperture 90 or 91. The nut 51 in each case is covered by a Lucite cap 65 rotating about the nut 5I, but having a threaded bore so that the nut 65 may be threaded on the end of bolt 29. Nut 65 engages in the insulation on the spine and eifects a liquid-tight seal, excluding electrolyte.
Thus a connection of high electrical conductivity and rigidity is provided although the parts may be disassembled, stored and reused over and over again. An ample clearance is provided between the end of the tapered nut and the end of the cutting bushing, so that there is always room for them to be drawn into tight engagement in the same or other aperture in a supporting rack.
It will thus be observed that I have invented an improved electroplating rack structure and improved methods of assembly, whereby an acid-tight seal is automatically provided, surrounding and enclosing newly cut and bright engaging surfaces between the parts of the tip and the parts of the supporting spine.
My method has the advantage that damaged tips can be replaced quickly and economically, and the racks can be kept at full production.
While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claim.
Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:
An electroplating rack comprising an elongated vertically extending metal spine comprising a flat body formed at its upper end with a downwardly open V shaped hook, said body being covered over all except at its hook with an initially plastic layer of electric insulation, the said body being provided with a plurality of transversely extending apertures spaced from each other, and each aperture being provided with a tip structure for supporting articles to be electroplated, one of said apertures being provided with an electrically conducting bushing having a tapered end and a threaded bore, the said tapered end being 1ongitudinally grooved and provided with converging sharp edges bordering its grooves and adapted to cut a new bright contacting surface in the aperture in said body when the tapered end is forced into said aperture, a threaded shank in the bore of said bushing and extending through the bushing and through the aperture of said body and projecting from the other side of said body, an elongated non-circular nut having a threaded bore receiving said shank on which it is threaded, and said nut having a frusto-conical end engaging the adjacent side of said body and centering said shank in said aperture, said nut drawing the nut and the bushing into said aperture to effect a tight electrical connection, said shank projecting beyond said nut with its threaded end, and having an insulating cover nut provided with a threaded bore for receiving the threaded end of the shank, and having a counterbore large enough to rotate about said tapered nut, the said cover nut engaging the plastic insulation on said body and excluding electrolyte from engagement with the tapered nut and threaded shank at this side, said spine having two adjacent apertures, each aperture having one of said bushings, threaded Shanks, nuts, and cover nuts, and the bushings being provided with reduced threaded extensions, said eX- tensions extending through apertures in the vertically extending arm of a cruciform plate, nuts clamping said plate on said bushings, the said cruciform arm having a horizontal portion provided with apertures containing rivets sscuring a pair of laterally projecting flat springs to said cruciform plate, the flat springs having diverging end portions for supporting subjects to be electroplated, and the at springs, plate, and clamping nuts being covered over 6 References Cited in the le of this patent UNITED STATES PATENTS Belke Ian. 21, 1958 OTHER REFERENCES all with plastic insulation, excluding the electrolyte except 10 18- at the ends of the at springs, where they are adapted to support a subject to be electroplated.