US3118545A - Anodizing rack structure - Google Patents

Description

Jan. 21, 1964 E. B. ROSNER 3,118,545

ANODIZING RACK STRUCTURE Filed Dec. 17, 1962 IN VENTOR.

ERNEST B. ROSN ER ATT'YS United States Patent 3,118,545 ANODIZING RACK STRUCTURE Ernest B. Rosner, 131 N. Green St., Chicago, Ill. Filed Dec. 17, 1962, Ser. No. 244,981 7 Claims. (Cl. 211-117) This invention relates in general to rack equipment used to hold piece parts during plating and similar processes and is more particularly concerned with a new and unique universal rack especially amenable to use during anodizing processes.

Protective finishes such as plating and the like are applied to finished piece parts rather than to the material from which the piece parts are fabricated because in most instances the protective coating would be damaged or ruptured during the fabrication process. The result is that the articles or piece parts requiring protective finishes have an infinite variety of sizes and shapes. Accordingly, the racks employed to hold the piece parts during the processes used to apply the protective coatings have similarly assumed many different sizes and shapes. In fact the racks used have in the past been custom made for almost each part.

This need for custom made racks is especially true of racks used during electrofinishing processes, such as electroplating and anodizing, where the piece parts are used as one of the electrodes in an electrolytic cell. The racks, consequently, must be capable not only of securely holding a plurality of articles properly spaced apart but must also provide a low impedance current path and make good contact with the parts being held.

Accordingly, racks known in the art are comprised of heavy and complicated frames supporting matrices of furcated resilient members made to hold particular piece parts. When different sized or shaped piece parts require finishing other racks are needed. The result is that a large inventory of racks has to be maintained consuming useful storage space. Even with a large inventory of such racks, new ones are needed when there is any improvement in the final products that requires new and difierently shaped piece parts or any new products that require such new and differently shaped piece parts. These new racks add materially to the costs of such improvements or new piece parts.

The problem of providing custom made racks for each article to be finished is even more acute in anodizing than in electro-plating. In electro-plating the articles to be plated are used as the cathodes of the electrolytic cells. They are immersed in an electrolytic solution which contains the metal with which they are to be plated. The metal is caused to be deposited on the cathode by the electric current passing through the cells. On the other hand, in anodizing, the articles are used as the anode in the electrolyic cell. The electrolyte used instead of being a relatively non-corrosive metallic solution is usually a highly corrosive acid, such as sulphuric acid in the case of aluminum anodizing. The current passing through the electrolytic solution releases oxygen at the anode and forms an oxidized layer on the articles. Thus in addition to rack specifications that require good current carrying capacity; the strength and rigidity to simultaneously hold a plurality of articles; and the ability to make good electrical contact with the anticles while holding them so that only a minimum surface area of the articles is shielded from the electrolyte, the racks used in anodizing should ideally be impervious to the corrosive environment in which they are used. Also, the racks should be fabricated from a similar type metal since the use of different metals is detrimental in the electrolytic environment.

It has been found that titanium is an ideal material from which to make the anodizing racks. Titanium has the strength necessary for holding a plurality of piece Patented Jan. 21, 1984 2 parts, it has the required current carrying capacity and it is extremely corrosion resistant. Also, titanium is immune to the oxidation efiects of the anodizing process and consequently does not require expensive and time consuming stripping treatment normally required by other metals used for anodizing racks.

The major drawback to the use of titanium for anodizing racks is that it is very expensive. Therefore, it is economically impossible to use titanium racks if they must be custom built for each of the vast variety of shapes and sizes of piece parts. In addition it is economically not feasible to construct racks from titanium with complicated support structures.

The primary object of this invention is to provide a new and novel universal rack which will securely hold and make good electrical contact with articles to be anodized, which will conduct SllfilClBIl't current to efficiently anodize the articles and which will be readily adjustable to accommodate the many different sizes and shapes of articles requiring anodizing.

Another object of the invention is to provide a rack structure that can economically be fabricated from metals such as titanium.

A further object of this invention is to provide an adjustable rack comprising a few basic parts that can be assembled readily in different spatial arrangements thereby substantially reducing the number of racks previously required.

Still another object of this invention is to provide, in an adjustable rack, novel means for instantaneously and securely fastening the parts together and for readily modifying the rack arrangement.

Since the racks are eventually consumed, the invention teaches how to fabricate a rack which is extremely economical to manufacture being simple and without complexity in structure. Economy in the amount of metal used is extremely important in permitting the use of titanium and like expensive metals. The economical structure herein not only permits the use of such material but provides a structure wherein the minimum amount of material will support a wide variety and weight of articles. The objects of the invention contemplate the provision of just such a compact and efiicient structure.

Yet an additional object of the invention is to provide an adjustable rack structure which precludes the necessity of complex support members.

A further object of the invention is to provide a rack structure which does not interfere with the circulation of said chemical solution and thereby also increases the available surface for anodization and improves upon the control of said process. Thus a more uniform coating thickness is provided which is essential to specification compliance and/or color match.

In accordance with this invention there is provided an adjustable rack structure having a standard comprising two slotted vertical members. The vertical members support horizontal members having spring finger plates arranged so that opposing fingers will hold the articles to be plated. The horizontal members have discs permanently attached at both ends thereof. The discs have a threaded stud protruding respectively from their centers and four lugs which are punched or upset from the back to protrude on the same side as the stud. The lugs are rectangular in shape with their longer side being slightly smaller than the Width of the slots. The lugs are arranged degrees apart and in a circle whose diameter is slightly larger than the width of the vertical members, with the stud at the center of the circle. Thus when the stud is passed through the slot of the vertical member the two side lugs straddle the member and the top and bottom lugs seat in the slot. When a nut is tightened over the stud, a rigid, securely locked connection is obtained. The

U horizontal members can be turned through 90 degrees and still be rigidly connected and can also be readily adjusted up and down in the slot to accommodate differently sized and shaped piece parts.

With the foregoing and other objects in view as will appear as the description proceeds, the invention consists of certain features of construction, arrangement and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportion, size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

-Referring now to the drawings:

FIG. 1 is a perspective view of the rack combination constructed in accordance with the invention and having three horizontal members with spring finger plates attached thereto suitable for supporting a variety of types of articles.

FIG. 2 is a perspective view of a single horizontal member showing discs at each end and having a spring finger plate attached thereto.

FIG. 3 is a perspective view of a single horizontal memher without the spring finger plate.

FIG. 4 is an enlarged perspective View showing in dejtail how the horizontal member with the end discs is simply attached to the slotted vertical members.

FIG. 5 is a view showing how the discs are attached to the ends of the horizontal member.

FIG. 6 is an enlarged cross-sectional view taken at line 65 on FIG. 1 showing the horizontal member attached to the vertical member.

There is illustrated in FIG. 1 an anodizing rack designated generally by the reference character It said rack adapted to be hung from an overhead busbar or the like,by means such as hook member 11 shown in broken outline, and immersed in a chemical anodizing bath contained in a tank; the walls of which act as the cathode of an electrolytic cell. The articles secured to the rack act as the anode of the cell. The entire rack is preferably formed of titanium but may also be of many other metals, such as but not limited to, aluminum, tantalum, zirconium and others of this family and their alloys. If the hook member 11 is made of a conductive material other than the material comprising rack member it must not be immersed in the chemical anodizing bath.

The rack 10 comprises a standard having two similar vertical members 12a, 12b each having a slot 13 down the center length thereof. The vertical members are shown :spaced apart by horizontal member assemblies 16, 17 and 18 attached to the vertical members. The spacing between the horizontal member assemblies can be readily varied to accommodate different sized piece parts.

A horizontal member assembly is shown in detail in FIG. 2. It comprises a horizontal member 21 to which is attached a spring finger plate 22 with means such as screw and nut 23a, 23b. The spring finger plate comprises a base section 25 from both sides of which protrude resilient tines or finger like members such as finger 26. "To aid their resiliency, the fingers are bent from the base :at an angle which may vary for different plates. The tips of the fingers such as .27 are bent sharply and have 'slots therein such as slot 27a the shape of which may also vary from plate to plate. The spring finger plates are de- :signed to hold the piece parts between fingers arranged in opposition either on different plates or on the same plate.

A horizontal member 29 is shown at FIG. 3. It comprises similarly shaped bars or rods 36, 31 arranged spaced apart and parallel to each other. The two bars are both permanently attached, as by welding, at both the space between the two bars is the slot 35 through which fasteners are passed to conveniently attach the horizontal member to the springfinger plates.

A feature of this invention can be seen by perusing each of the figures and noting that the end discs attached to the horizontal members each have a set of four lugs punched or upset from the back of the disc and set degrees apart. This is best illustrated in FIG. 4 where an end disc such as disc 32 is shown in detail. The lugs are rectangular in shape with vlugs 36a, 36b shown at the top and the bottom of the disc with their longer sides being parallel to each other. Lugs 37a and 371) are at the opposite sides of the discs. The length of the lugs is arranged to be slightly smaller than the width of slot 13 and the distance between the opposite lugs is slightly greater than the width of the vertical members 12a, 12b. The threaded stud 38 is at the center of the lugs and is permanently fastened to the disc. To assemble the rack, the threaded stud '38 is passed through slot 13 and fastened with nut 3811. As can be seen in HQ. 6, two of the lugs will seat in the slot and the other two lugs will straddle the vertical member thereby providing a solid and secure assembly. The horizontal member can be rotated 90 degrees and the secure assembly will still be maintained since two of the lugs 37a and 37b will seat within slot 13 and the other two lugs 36a and 36b will straddle the member providing the same stabilization originally obtained.

The finger plates may be used in opposing pairs as shown in the horizontal member assemblies 16, 17 of FIG. 1 or a single finger plate may be used on a horizontal member that is rotated 90 degrees with relation to those shown in FIG. 1. In such a case the angle at which the fingers are bent away from the base would be increased so that a pair of opposing fingers from opposite sides of the base could be used to hold the piece parts. Additionally, two sets of spring fingers may be mounted back to back on a single horizontal member as shown in assembiy 17 of FIG. 1.

Thus a great many parts may be mounted in a simple manner by means of the horizontal member assemblies described. Also because of the ease of adjust-ability of the horizontal members they may be positioned at varying points along the vertical members so as to accommodate articles of varying length on the same rack yet remaining securely clamped in position to hold the articles tightly between opposing fingers throughout the anodizing process. The rack of the invention accomplishes this without depending on any additional supporting member that would limit the range of size and space allotment available and interfere with the circulation of the electrolyte.

Because of the ease of assembling and adjusting the inventive rack, it could serve to hold a great variety of piece parts without having to prepare new racks for each different shaped piece part. Once assembled, the inventive rack is locked securely even though it does not have the complex heavy permanently attached standards found in racks presently incommon use. This secure locking is obtained Without complicated clamps, special spacers or washers. Since all parts of the assemblage 1% are preferred not to be manufactured from dissimilar metals, the elimination of additional parts results in a substantial cost saving to the user of an expensive material such as titaniurn, the like above mentioned metals and/ or their alloys.

Also because of the ease of dismantling, storage space formerly required with priordevices can be released for more profitable purposes.

While the invention is principally directed to a structure useful in the anodizing process, the same is not limited thereto, but is equally applicable to various electroplating and electropolishing processes wherein a large number of articles are required to be suspended in electrochemical baths and have electric current passing through the same. Other processes which require the support or suspension of members in baths and solutions irrespective of whether or not current passes through the members may advantageously use the invention with superior results and with great economy.

It is believed that this invention, its mode of construction and assembly, and many of its advantageous advantages should be readily understood frmo the foregoing without further description, and it should be also manifest that, while a preferred embodiment of the invention has been shown and described for illustrative purposes, the specific details are nevertheless capable of wide variation within the purview of this invention as defined in the appended claims.

What is claimed is:

1. A rack structure for supporting articles in a bath comprising a pair of slotted vertical members, at least one horizontal member assembly for holding said articles, said horizontal member assembly having a disc at each end thereof, each of said discs having at least two lugs protruding from one side thereof, and arranged 90 degrees apart tangential to an arc Whose radius is slightly larger than one-half the width of said vertical members, means for fastening one of the said discs to each of the said vertical members so that at least one of said lugs seat Within the slot of said vertical member and at least one other of said lugs abuts an outer edge of said vertical member whereby said horizontal member assembly is rigidly connected between said vertical members.

2. A rack structure for supporting articles in a bath comprising a pair of slotted vertical members, at least one horizontal member assembly for holding said articles, a disc attached at each end of said horizontal assembly, each of said discs having at least two lugs protruding from one side thereof and arranged 90 degrees apart and tangential to an arc whose radius is slightly larger than onehalf the width of said vertical members, said lugs being rectangular in shape and having a longest side slightly shorter than the width of said slot, and means for fastening one of the discs to each of the said vertical members so that at least one of said lugs seat Within the slot of said vertical member and at least one other of said lugs abuts the outer edge of said vertical member whereby said horizontal member assembly is rigidly connected between said vertical members.

3. A rack for supporting articles in a bath comprising a pair of vertical members each having a slot running the length thereof, at least one horizontal assembly for holding said articles, a disc at each end of said horizontal assembly, each of said discs having four lugs protruding from one side thereof arranged 90 degrees apart, and tangential to a circle whose diameter is slightly larger than the width of said vertical members, means for fastening one of the said discs to each of the vertical members so that at least two of said lugs seat within the slot of said vertical member and the other two of said lugs each abut an opposite outer edge of said vertical member whereby said horizontal assembly is rigidly connected between said vertical members.

4. A rack for supporting articles in a bath comprising a pair of vertical members having a slot running the length thereof, at least one horizontal assembly comprising spring finger plate means having spaced opposed resilient fingers for holding said articles, said horizontal member assembly having a disc at each end thereof, each tof said discs having at least two parallel spaced apart rectangular lugs protruding from one side thereof, said 'lugs being separated by a distance that is slightly larger than the width of said vertical member, said lugs having a length that is slightly smaller than the width of the slot in said vertical member, means for securing said discs of a horizontal assembly respectively; to each of the said vertical members in one of two positions, the first in which said lugs seat within the said slot and the second in which the said lugs abut the outer edges of said vertical member whereby said horizontal assembly is rigidly connected between said vertical members in either of said two positions, albeit in different rotational aspects.

5. A rack structure for suspending articles in a bath comprising a pair of vertical members each having a slot running the length thereof, horizontal assembly means comprising a horizontal member, said horizontal member terminating in a disc at each end thereof, said discs each having a plurality of lugs and a threaded stud protruding outward therefrom, and said threaded stud adapted for fastening one of the said discs to each of the said vertical members with at least one of said lugs seated within the slot of said vertical member and at least one other lug abutting an outer edge of said vertical members whereby said horizontal assembly is rigidly connected between said vertical members.

6. A rack structure for supporting articles in a bath comprising a pair of vertical members each having a slot running the length of said vertical member, a plurality of horizontal assembly means each comprising a horizontal member having a slot running the length thereof, each of said horizontal members terminating in a disc at each end thereof, each disc having a plurality of lugs protruding outwardly therefrom, at least one spring finger plate attached along the length of each of said horizontal members, said spring finger plate comprising a base section having a plurality of resilient tines extending outwardly from both sides of the length of said base, said tines at opposite sides of said base being bent toward each other at the junction of the tines and the base, and means for fastening one of said discs at each end of said horizontal iernbers to each of said vertical members with at least one of said lugs seated within the slot of said vertical member and at least one other of said lugs abutting an outer edge of said vertical members whereby each of said horizontal assemblies is rigidly connected between said vertical members and said tines on adjacent horizontal assemblies are adjusted opposite each other to hold said articles therebetween.

7. In a plating rack structure which includes a pair of slotted vertical members for mounting horizontal assemblies therebetween, said horizontal assemblies comprising means for supporting articles in a bath, the herein invention which comprises means for mounting said horizontal assemblies between said vertical members, comprising a disc at each end of said horizontal member, said disc having a plurality of lugs thereon arranged degrees apart and tangential to a circle Whose diameter is slightly larger than the width of said vertical member, means comprising a threaded stud attached to said disc at the center of said circle for securing said horizontal assemblies to said vertical member with at least one of said lugs seated within the slots of said vertical members and at least one of said lugs abutting one of the outer edges of said vertical members.

References Cited in the file of this patent UNITED STATES PATENTS 1,044,210 Lynne Nov. 12, 1912 1,427,876 Weeks Sept. 5, 1922 1,749,953 Lichtman Mar. 11, 1930 2,737,268 Smith Mar. 6, 1956 2,999,802 Gault Sept. 12, 1961

Claims (1)

1. A RACK STRUCTURE FOR SUPPORTING ARTICLES IN A BATH COMPRISING A PAIR OF SLOTTED VERTICAL MEMBERS, AT LEAST ONE HORIZONTAL MEMBER ASSEMBLY FOR HOLDING SAID ARTICLES, SAID HORIZONTAL MEMBER ASSEMBLY HAVING A DISC AT EACH END THEREOF, EACH OF SAID DISCS HAVING AT LEAST TWO LUGS PROTRUDING FROM ONE SIDE THEREOF, AND ARRANGED 90 DEGREES APART TANGENTIAL TO AN ARC WHOSE RADIUS IS SLIGHTLY LARGER THAN ONE-HALF THE WIDTH OF SAID VERTICAL MEMBERS, MEANS FOR FASTENING ONE OF THE SAID DISCS TO EACH OF THE SAID VERTICAL MEMBERS SO THAT AT LEAST ONE OF SAID LUGS SEAT WITHIN THE SLOT OF SAID VERTICAL MEMBER AND AT LEAST ONE

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