US 2831808 A
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April 1953 G. J. ESSEFF ETAL ARTICLE SUPPORTING RACK Filed 001;. 14, 1955 INVENTOBS GEd. [SSEFF URC'E United Sitates Patent 2,831,808 ARTICLE SUPPORTING RACK George J. Esseif, Fort Belvoir, Va., Sidney Levine, Washington, D. C., and Woodrow Thurston, Fort Belvoir,
Application October 14, 1955, Serial No. 540,656 5 Claims. (Cl. 204-297) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
This invention relates to an article supporting rack and more particularly to a rack for supporting articles in an electrolytic bath in an anodic oxidation process, as in an electroplating process or the like.
In an anodic oxidation process, the article to be anodized is submitted to an electric current while immersed in an electrolytic fluid whereby an ionic transference causes an even coating to be deposited on the exposed surfaces of the article. One important consideration in this and related processes is that an unrestricted flow of electrolyte be permitted around the whole of the article upon which the transference is to take place. This is so whether the article is to be coated with an insulating oxide as in the anodic oxidation process, or with a metallic coat as in the electroplating process, or where the article is to be treated chemically in the absence of an electric current. Implicit in this problem is the consideration of contact areas. In all such processes, the article to be worked upon must in some way be suspended in the fluid. Obviously, where physical means of suspension or support are used, there will be areas on the article which will not come in contact with the fluid. In an anodic oxidation process or electroplating process these areas of contact are generally identical with the areas of electrical contact as well as areas of support or suspension. At the point where the flow of current passes to the article, no oxidation or transference takes place. It is therefore desirable in such processes that these areas be as small as possible and in non-critical locations. At the same time, in processes involving electricity, good contact is essential for complete success. The problem then resolves itself into obtaining maximum electrical contact and support for the article with a minimum of unexposed surface area. Generally, the rack is electrically conductive and transmits the current to the held article at contact points. These contact points in an anodic oxidation process eventually become unusable and require replacement because the oxide coating formed is an eifec tive insulator and as the points themselves become coated, the necessary flow of current is diminished. Accordingly, it is desirable to be able to remove and replace such contact points easily and inexpensively. The rack itself in an anodic oxidation process will also become coated with oxide. Where it is constructed of aluminum, magnesium or the like, it is stripped of such oxide prior to re-use by dipping it in an alkali bath as is well-known in the art. Where the rack is constructed of titanium, the slight oxide film that forms does not materially effect the operation of the anodic oxidation process and the rack and associated parts can be re-used time after time with out stripping. Where different shapes and sizes of articles to be worked upon are contemplated, the problems of immersion, good current flow (where applicable), and minimum contact area are multiplied.
moval-and inexpensive replacement of the contact points as necessary.
A further object is to provide support means which can also be used as electrical contacts where needed.
A further object is to provide support means which assure adequate spacing between the rack and the article to be treated.
A further object is to allow complete encompassing of through the use of the article to be treated by the fluid the open frame structure of the rack.
A further object is to provide adjustable contact and'.
support means so that the inevitable bare spots on the treated article can be localized to predetermined noncritical areas.
A further object of this invention is to minimize thesize of the contact areas and at the same time assures good electrical contact where necessary between the rack and the treated article.
Following is a more which Fig. 1 isa perspective view of the rack shown sus-- pended in a bath and supporting an article to be treated;
Fig. 2 is a vertical longitudinal section on the line 2-2.
of Fig. 1;
Fig. 3 is a transverse section on 1, showing the head of a the interconnecting slots Fig. 4 is a transverse 1, showing the heads of the contact pins in relation to the flange openings whereby easy insertion and removal. of the pins into the frame is effected; and
Fig. 5 is an enlarged View of the contact pin assembly, showing the relative positions of the head, threaded base, locking collar, shank, and locking nut.
The rack shown in Fig. 1 is especially adapted for supporting articles in a standard anodizing bath, such as a solution of sulphuric, chromic or other acid. It is shown of the frame;
connected to an electrical source through conductors 16 v and suspended in-a tank 14 for containing an electrolytic bath with a cathode 15. of aluminum, titanium, or any light metal alloy." It consists of a suspension bar'2 and interconnecting channels 3 forming an open frame. The channels have inwardly-directed flanges 4 on a side forming slots 5. Spaced at each intersection of the channels'is an opening 6 in the side of the flange which has sufiicient clearance for the head 7 of the contact pin 8. As shown in Fig. 1, the head 7 of the contact pin 8 can be inserted into the slots 5 at openings 6, and the pin moved to any part of the frame where it can be fastened into place by the locking collar 9 and lock nut 10 operating in conjunction with the threaded portion 11 of the shank 12. The article 13 to be anodized or the like is held in place variously by the pins 8 as shown in Fig. 1, where the two lower pins support the base while the two upper pins act in a pincer-type relation. The contact pins 8 are constructed of an electrically conductive material such as aluminum, titanium or any light metal alloy as are the locking collar 9 and lock nut 10, which are integral parts of the contact pin unit designated generally as 8. As can be seen, the areas of contact between the pins 8 and the article 13 are very small yet good electrical contact is assured at predetermined points.
It is to be understood that this rack would be equally eflicacious where purely chemical treatment of articles detailed description of the inven-- tion taken in conjunction with the appended drawings, in.
the line 33 of Fig. contact pin in position in one of section on the line 44 of Fig.
The rack 1 can be constructed was desired in the absence of electro-stimulation. In such a case, the rack and the pins could be constructed of any material desired including inexpensive light-weight plastics. Moreover, the rack itself could be of any design, such as a grid, or even circular, so long as the principle of interconnecting channels is maintained.
Having thus described our invention, what we claim as new and wish to secure by Letters Patent is:
1. A workholder rack for supporting articles to be treated in a chemical bathvcomprising a frame, means for supporting said frame, said frame having a plurality of continuous interconnecting channels having inwardlydirected mutually spaced flanges along their edges forming guide and retention tracks, a plurality of fastening members slidably mounted in said tracks, each of said fastening members having a shank element including a threaded portion and terminating in an enlarged head retained in said tracks by the inwardly-directed flanges thereof, the shank elements extending outwardly through the uninterrupted space between the flanges, and projecting forward of the frame for fastening the work away from said frame, locking collars overlying and engaging oppositely directed flanges of said tracks, lock nuts threadedly mounted on the threaded portions of said fastening members for clamping the locking collars and e the heads of the fastening members against opposite sides of the flanges of said tracks thereby locking the fastening members in adjusted position with respect to the frame.
2. A workholder for supporting articles to be treated in a chemical bath comprising a frame, means for supporting said frame, said frame including a plurality of continuous interconnecting channels having inwardlydirected mutually spacedflanges along their edges forming guide and retention tracks, a plurality of fastening members slidably mounted in said tracks, each said fastening member having a shank and an adjacent threaded portion terminating in an enlarged head retained in said tracks by the inwardly-directed flanges thereof, the shank portions extending outwardly through the uninterrupted space between the flanges, and projecting forward of the frame whereby the work may be fastened in position away from the frame, locking collars overlying and engaging the oppositely directed flanges of said tracks, lock nuts engaging the threaded portions of said fastening members for clamping the locking collars and the heads of the fastening members against said flanges for locking the fastening members in adjusted position with respect to the frame, and a plurality of openings in said flanges for removing said fastening me ibers from said tracks.
3. A rack for supporting a plurality of variable-shaped articles. in an electrolytic bath comprising a frame of electrically-conducting material, said frame having a plurality of continuous interconnecting channels formed by inwardly-directed mutually spaced flanges along their edges defining guide and retention tracks, a plurality of article-supporting, electrically-conducting pins slidably mounted in said tracks for movement to any part of the frame within the interconnecting guide and retention tracks, each said pin including a partially threaded shank element and having an end thereof terminating in an enlarged head, the heads of said pins being positioned in said tracks beneath said flanges, said shank elements projecting outwardly through the uninterrupted spaces between the flanges for supporting variably-shaped articles at a spaced relationship from the frame, locking collars overlying and engaging the oppositely directed flanges of said tracks, lock nuts threadably mounted on the threaded portions of the pins for clamping the locking collars and the heads of the pins to said flanges thereby locking the pins in adjusted position with respect to the frame, and means for supporting said frame.
4. A rack as recited in claim 3 wherein said flanges have a plurality of openings for removing said pins from said channels.
5. A rack for supporting variably-shaped articles in an electrolytic bath comprising a sectionalized frame of electrically conductive material, said frame formed of continuous interconnecting channels having inwardlydirected, mutually spaced flanges, said flanges forming an unbroken slot throughout the entire frame, a plurality of electrically conductive pins, each of said pins having an enlarged head riding in said interconnecting channels, a threaded portion extending outwardly through said unbroken slot and terminating in a shank element projecting outwardly from said slot, and a locking piece for said threaded portion for fixing the pin at any point along the unbroken slot, said plurality of pins collectively supporting variably-shaped articles in spaced relation from said sectionalized frame to insure good flow of electrolytic bath solution around the articles to be plated, a plurality of openings in the channel sections to permit said enlarged heads of said pins to enter said continuous interconnecting channels, and means for supporting said frame.
References Cited in the file of this patent UNITED STATES PATENTS 1,427,875 Weeks Sept. 5, 1922 1,503,396 Voigt July 29, 1924 1,534,918 Claybouin Apr. 21, 1925 2,637,689 Myers May 5, 1953 FOREIGN PATENTS 986,289 France July 30, 1951 549,777 Germany Apr. 14, 1932