US 3582523 A
Description (OCR text may contain errors)
June 1, 1971 P. LINNHOFF 3,582,523
ELECTROPLATING BARREL Filed Dec. 12, 1968 2 Sheets-Sheet 1 "W t Yd) 42-1 ATTORNEY June 1,1971
Filed Dec. 12,. 1968 P. LINNHOF'F ELECTROPLATING BARREL 2 Sheets-Sheet INVENTOR Mm, bloul m r.
ATTORNEY United States Patent 3,582,523 ELECTROPLATING BARREL Paul Linnholf, Iserlohn, Germany, assignor to Wilhelm Linnhotr' oHG, Hemer, Germany Filed Dec. 12, 1968, Ser. No. 783,347 Claims priority, application Germany, Dec. 13, 1967, P 16 21 104.4 Int. Cl. C23b 5/78 US. Cl. 204-213 Claims ABSTRACT OF THE DISCLOSURE A rotary electroplating barrel wherein the shell is provided with polygonal openings for removable one-piece plastic inserts. The inserts are formed with perforations for the passage of electroplating fluid.
BACKGROUND OF THE INVENTION The present invention relates to improvements in electroplating apparatus. More particularly, the invention relates to improvements in electroplating containers or barrels which are used for electroplating of small and extremely small articles, such as needles, minute screws, components of electronic parts or the like.
The shell of a conventional electroplating barrel is normally provided with perforations or orifices of a size which depends on the size of articles to be electroplated. The orifices are of circular or other than circular outline. A drawback of such barrels is that the orifices which are provided directly in the shell are often long so that they offer excessive resistance to the passage of electroplating fluid. It was therefore proposed (see Pat. No. 3,159,560) to form the shell of the barrel with relatively large openings and to employ a woven plastic fabric of relatively fine mesh (40-300 per square inch) which overlies the large openings. The cost of such electroplating barrels is rather high and the sharp edges or tips of articles to be electroplated are likely to be caught in the interstices of the fabric. Moreover, the fabric undergoes considerable wear and the means for securing the fabric in the barrel includes a large number of parts.
SUMMARY OF THE INVENTION One object of my invention is to provide a novel and improved electroplating container or barrel, particularly for electroplating of minute articles, which overcomes the drawbacks of aforediscussed conventional containers and whose useful life is much longer than that of presently known barrels.
Another object of the invention is to provide a barrel which can be readily converted for electroplating of differently dimensioned articles.
A further object of the invention is to provide an electroplating barrel which offers relatively low resistance to the flow of electroplating fluid.
An additional object of the invention is to provide an electroplating barrel which can be used in presently known electroplating apparatus.
The improved container or barrel comprises wall means defining chamber means for articles to be electroplated and provided with a plurality of relatively large and preferably polygonal openings, and a plurality of preferably plastic inserts of chemically inert material each of which is preferably removably accommodated in one of the openings and has a finely perforated relatively thin wall portion extending across the respective opening. The thickness of each wall portion may be a small fraction of the thickness of wall means and the perforations in such wall portion may be of circular, polygonal, oval or other outline. Since the inserts are removable from 3,582,523 Patented June 1, 1971 the respective openings, they can be replaced with inserts having larger or smaller perforations so that the flow of electroplating fluid through the perforations may be selected at will in dependency on the size of articles which are to be electroplated.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved electroplating container itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary transverse sectional view of an electroplating container which embodies one form of my invention;
FIG. 2 is an enlarged sectional view of a detail in the structure of FIG. 1, substantially as seen in the direction of arrows from the line IIII of FIG. 3;
FIG. 3 is a plan view as seen in the direction of arrow III in FIG. 2; and
FIG. 4 is a fragmentary transverse sectional view of a second electroplating container.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The electroplating barrel or container of FIG. 1 comprises two end walls 3 (only one shown) connected to each other by axially parallel tie rods 2 which support the marginal portions of intermediate Walls 1. The walls 1 and the tie rods 2 together form a polygonal shell which surrounds a chamber for reception of articles to be electroplated. In accordance with a feature of my invention, the intermediate walls 1 are provided with polygonal openings 4 for substantially cap-like one-piece inserts 5 of chemically inert synthetic plastic material. In the illustrated embodiment, the openings 4 are of hexagonal outline (see FIGS. 2 and 3). Each insert 5 comprises a hexagonal portion which is press-fit or tight fit in the respective opening 4 and a concavo-convex wall portion 7 Which is provided with fine perforations or orifices 8 for the passage of electroplating fluid. The wall portions 7 are located at the inner sides of the respective intermediate Walls 1 and their convex sides face the interior of the container. Each wall portion 7 is provided with a marginal portion or flange 6 which is sealingly received in an annular recess surrounding the inner end of the respective opening 4. FIG. 3 shows that the openings 4 are disposed in several rows which extend lengthwise of the respective intermediate walls 1 and that the openings of certain rows are staggered with reference to the openings in the other rows. Such distribution of openings 4 renders it possible to mount a large number of inserts 5 in each of the intermediate walls 1.
FIG. 4 illustrates a portion of a modified electroplating container or barrel wherein the intermediate walls 9 are of substantially U-shaped cross-sectional outline and each thereof comprises three mutually inclined panels 9a, 9b, 90. Each of these panels is formed with at least one row of openings for the inserts 5. In this Way, a very large number of inserts can be installed in each of the intermediate walls 9 to insure more intensive galvanizing action upon the articles which are accommodated in the internal chamber of the container.
Certain more important advantages of my electroplating container can be summarized as follows: The inserts 5 can be mass-produced at a low cost and in such a Way that the dimensions of all inserts are exactly the same. This renders it possible to replace a damaged insert with a fresh one. The inserts 5 can be mass-produced by injecice tion molding or by resorting to any other well known simple technique. Since the wall portions 7 of the inserts can be readily formed with pronounced convex exposed surfaces, the likelihood of non-uniform electroplating of small flat articles is reduced to a minimum because such articles can not adhere to the inserts. The exposed surfaces of the wall portions 7 are sufliciently smooth to prevent certain types of articles from getting caught in the perforations 8. The size of perforations and the strength of inserts 5 can be chosen at will so that the designer can readily select an optimum combination of such factors to insure satisfactory flow of electroplating fluid and long useful life of inserts. The size of each insert 5 can also be selected at will, i.e., the container can be provided with relatively large inserts to insure satisfactory fluid-drawing action when the container is set in rotary motion.
The improved container is susceptible of many additional modifications without departing from the spirit of my invention. For example, the tie rods 2 and intermediate walls 1 or 9 can be replaced by a single cylindrical wall which is provided with suitably distributed openings for reception of inserts 5 or analogous inserts. Also, the thin wall portions 7 of the inserts 5 can be provided with circular, polygonal, oval or otherwise configurated perforations and the container can be furnished with two or more sets of inserts each having wall portions formed with differently dimensioned and/ or distributed perforations. Since the thickness of wall portions 7 is a small fraction of the thickness of intermediate walls 1 or 9, the perforations 8 offer a relatively low resistance to the flow of electroplating fluid. However, the thickness of such wall portions 7 invariably sufiicies to insure that the inserts 5 can stand longer use than a fabric of fine mesh which is used in certain types of conventional electroplating containers. Finally, it is equally possible to provide the intermediate walls 1 or 9 with openings 4 of circular, oval or other outline and/ or to employ intermediate Walls having two or more difierent types of openings.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:
1. An electroplating container, comprising wall means defining chamber means for articles to be electroplated, said wall means being provided with a plurality of openings; and a plurality of one-piece molded plastic inserts each received in one of said openings and each insert comprising a rigid, finely perforated wall portion extending across the respective opening, and holding wall portions integral with said finely perforated wall portions and engaging said wall means of said container for retaining said inserts in the corresponding openings.
2. A container as defined in claim 1, wherein each of said inserts is removably accommodated in the respective opening.
3. A container as defined in claim 1, wherein each of said inserts consists of a single piece of synthetic plastic material.
4. A container as defined in claim 3, wherein a portion of each of said inserts in a press-fit in the respective openmg.
5. A container as defined in claim 1, wherein said wall means comprises annular recesses each surrounding one of said openings and wherein each of said inserts comprises a flange sealingly accommodated in the respective recess.
6. A container as defined in claim 1, wherein said wall means has an inner side and an outer side and said wall portions are adjacent to said inner side.
7. A container as defined in claim 6, wherein each of said wall portions has a convex side facing the interior of the container.
8. A container as defined in claim 1, wherein said wall means comprises a pair of end walls and a plurality of intermediate walls extending between said end walls, said openings being provided in said intermediate walls.
9. A container as defined in claim 8, wherein each of said intermediate walls is of substantially U-shaped cross sectional outline and has three mutually inclined panels, said openings being provided in at least one panel of each of said intermediate walls.
10. A container as defined in claim 1, wherein said openings are arranged in a plurality of rows and wherein the openings of at least some rows are staggered with reference to the openings of the other rows.
References Cited UNITED STATES PATENTS 1,030,053 6/1912 Catlin 2042l3 1,376,052 4/1921 Taylor et a1. 204213 3,159,560 12/1964 Belke 204-213 3,337,442 8/1967 Kiefer et a1 204213 FOREIGN PATENTS 39,935 9/ 1932 France.
HOWARD S. WILLIAMS, Primary Examiner T. TUFARIELLO, Assistant Examiner U.S. Cl. X.R 25989