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Publication numberUS3453185 A
Publication typeGrant
Publication dateJul 1, 1969
Filing dateFeb 20, 1967
Priority dateFeb 20, 1967
Publication numberUS 3453185 A, US 3453185A, US-A-3453185, US3453185 A, US3453185A
InventorsNakagawa Shigesabura
Original AssigneeNakagawa Shigesabura
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Process of manufacturing jewelry chains using electroplating
US 3453185 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)



PROCESS OF MANUFACTURING JEWELRY CHAINS USING ELECTROPLATING Filed Feb. 20, 1967 Sheet 2 of 2 kw lab .1 INVENT OR BY Y5 United States Patent U.S. Cl. 204-24 9 Claims ABSTRACT OF THE DISCLOSURE The disclosure describes a method for processing jewelry chains by applying or imparting various ornamental configurations and then suitably finishing the chains.

This invention relates to'the art of jewelry chain manufacture.

Heretofore jewelry chains whether made by machinery or by hand have all involved mechanical steps to deform or remove metal. Such steps include cutting, grinding, bending, punching, stamping, hammering, rolling, filing, drawing, and polishing. Where electroplating has been used, it has only been to impart a glossy metallic finish to the links of the chain. Electroforming might have been tried to form individual links. However, it requires supplementary mechanical steps to complete the chains made from these links, and the resulting chains look like chains made entirely by mechanical methods mentioned above.

The object of the present invention is to provide method for producing a chain having a novel appearance, with links having unusual irregular surfaces and configurations not possible of attainment by conventional mechanical steps heretofore employed.

In the present invention an ordinary machine made chain of links of precious or base metal is subjected to an electrochemical forming process in which the links are thickened and distorted by electrochemically deposited metal. The metal is deposited non-uniformly so as to result in rough, porous, granular surfaces. Heretofore such electroplated surfaces have been scrupulously avoided in jewelry manufacture because this has been regarded as defective electroplating. Electroforming processes have been used heretofore in the metal working arts to produce moulds, irregularly shaped machine parts, and other mechanical forms. In all cases the processes have been directed at producing hard, dense, uniform deposits. There as in the jewelry manufacturing arts, granular surfaces and irregularities of deposits were considered defects and work having such defects was regarded as spoiled and treated as waste and scrap. In the present invention, by contrast, the electroforming process is especially pursued in such manner as to produce the rough granular, irregular, porous surfaces and configurations heretofore universally avoided in the prior art. The deposited metal is so applied to the chains that flexibility or relative movement between links is retained sufficiently to enable ends of the chain to be brought together. Thus the resulting structure can be worn as a chain necklace, bracelet, anklet or the like. As a result of the electroforrning step, the links of the chain are rough, granular and coarse in appearance. They may then be finished in a variety of ways.

The invention will be better understood from the following detailed description taken in conjunction with the drawing wherein:

FIGS. 1-4 are side views of a chain in successive stages of a process according to the invention.

FIGS. 1A-4A are end views of the chain in the successive stages shown in FIGS. 1-4 respectively.

3,453,185 Patented July 1, 1969 "ice FIGS. 58 are side views of another chain in successive stages of the process according to the invention.

FIGS. 5A8A are end views of the chain in the successive stages shown in FIGS. 5-8 respectively.

FIG. 9 is a similar view to FIG. 8, showing a further development of the invention.

Referring first to FIGS. 1 and 1A, there is shown a chain 10A of round links 12 disposed perpendicular to each other. This is generally known as a cable chain. The chain can be made wholly or partially by hand or by metal working machinery of some known type. Starting with this chain the present manufacturing process begins. The chain of any desired length is supported at ends 13, 14 and is immersed in an electroplating bath and electroplated. A suitable electroplating solution my contain:

Grams per liter Cuprous cyanide Free cyanide 7-10 Potassium sodium tartrate 10 Electroplating is performed at approximately 60 C. at 5 volts D.C. The electroplating proceeds rapidly and a rather rough, porous, granular thickening of the links occurs at all points. When removed from the bath after an hour or more the chain 10B will have an appearance somewhat as shown in FIGS. 2 and 2A. The pores and irregularities 15 in the thick deposited coatings 16 are plainly visible. The chain is now less flexible than before but still retains sufiicient flexibility so that opposite ends can be brought together. Thus, the chain is practical for wear as a jewelry chain. Uncoated points 13, 14 are at the ends of the chain where the chain was supported by suitable supports in the bath. These ends of the chain can serve for attachment of appropriate clasp members.

At the end of the electroforming step, as illustrated by FIGS. 2 and 2A, the original round, fiat form of the links is distorted and is now only suggested but not clearly defined. The copper or other metal enlargements can now be finished by electroplating a thin base coating of nickel and a thin finish coating of gold, silver, rhodium or the like. These fine, bright finish coatings are applied by conventional electroplating methods well known in the art.

While the finished chain 10B may have the link configurations shown in FIGS. 2 and 2A, other finished shapes may be desirable. The chain 10B can be subjected to mechanical treatment before applying the bright, precious metal finish. As one example, opposite sides 17, 17 and 18, 18' of alternate pairs of links 20, 21 can be ground to form fiat or concave lands as shown in FIGS. 3 and 3A. The remaining alternate pairs of links 23, 24 are not ground. The chain after selective grinding has been completed can now be subjected to a finishing electroplating process to present a gold, silver or other bright metallic appearance. The chain 10C as shown in FIGS. 3 and 3A has a novel configuration not obtainable by any prior known method. Links 23, 24 have rough, coarse, porous surfaces 25 on all sides. The other links 20, 21 have smooth surface portions 17, 17, 18, 18' and coarse, porous surface portions 26. All surfaces may be bright finished, or they may have a matte finish produced by suitable treatment with a fine brush.

If a different chain configuration 10D shown in FIGS. 4, 4A, is desired, the chain 10B shown in FIGS. 2 and 2A can be entirely ground fiat on one pair of opposite sides 27, 27 or on both pairs of opposite sides 27, 27' and 28, 28'.

On each link adjacent the smooth portions or lands 30 are coarse, granular or porous recessed surface portions 32. This presents a very novel and attractive appearance. The chain 101) as shown in FIGS. 4 and 4A can then be finish plated with a nickel base coat and a bright gold,

silver, rhodium or other precious metal coat. The final finish coat can have a matte surface if desired.

FIGS. 5 and 5A show another conventional type of chain E known as a curb chain in which the links 40 are twisted to a general figure eight confiuration in end view.

FIGS. 6 and 6A show the chain 10F after it is heavily encrusted with an electrochemically deposited metal. The twisted shape of the links 40 is basically retained by links 40A. The chain is sufficiently flexible to bring free ends 13, 14 together.

FIGS. 7 and 7A show chain 106 after all four sides 45, 46, 47 and 48 of chain 10F have been partially ground flat or concave to form smooth lands 50 on each link 40B. Recessed areas 52 all around the ground flats or lands 50 remain coarse and granular in appearance.

FIGS. 8 and 8A show chain 10H after chain 106 has been further processed by grinding side 45' further to reduce the thickness of the encrustation at this side, left side. Bevels 54 and 56 are ground off the encrustations at the intersection of sides 46, 47, and 47, 48 opposite from side 45. The chain is now generally trapezoidal cross section with smooth lands 60-67 on the links 40C. Recessed areas 52 adjacent the smooth lands may still be rough, coarse, or may have smooth surfaces.

The chains 10F, 106 or 10H may each be regarded as a complete jewelry piece. Opposite ends 13', 14 of the original end links are exposed for attachment of jewelry clasp members. After mechanical treatment by grinding, suitable bright metal finishes can be applied to each of chains 10F, 10G or 10H if the chain is not to be ground down further.

In FIG. 9 chain 10H is shown to be connected to a conventional ornament 10K which is also produced in accordance to this invention.

Although only two different types of chains have been illustrated as subjected to the present process, the process is applicable to many other different types of jewelry chains, for example: double cable, jack, triangular, barley corn, scroll, etc. etc.

It 'will be apparent that regardless of the original form of links, they will retain their basic original form even though they appear distorted after they are enclosed in the rough coarse, porous, granular heavy encrustations. The resulting chains after final finishing treatments will be most unusual and attractive in appearance.

What is claimed is:

1. The method of making a jewelry chain from a chain of links having any smooth, regular original shape, comprising the basic steps of rapidly electroplating a metal on the links to deposit a heavy, porous, granular, rough encrustation on each link, said incrustation being nonuniformly deposited so that each link appears externally distorted; and stopping the electroplating step after the links are externally deformed while the original shape of the links is still discernible and while the chain is still sufficiently flexible so that opposite ends of the chain can be brought together.

2. The method as recited in claim 1, further comprising the step of applying a bright metal finish to the encrusted links.

3. The method as recited in claim 1, further comprising the step of grinding away selected portions of selected links to form smooth lands, leaving the remainder of the surfaces of the links in a porous, granular, rough state.

4. The method as recited in claim 3, further comprising the step of applying a bright metal finish to the encrusted links.

5. The method as recited in claim 1, wherein the opposite ends of the chain are so supported during the electroplating step that said ends of the chain are free of said encrustation, so that jewelry clasp members can be attached to the free ends of the chain.

6. The method as recited in claim 1, further comprising the step of grinding away opposite sides of each encrusted link of the chain to form smooth lands thereat, with each land surrounded by a recessed porous, granular, rough surface.

7. The method as recited in claim 6, further comprising the step of applying a bright metal finish to the external surfaces of the encrusted links.

8. The method as recited in claim 6, further comprising the step of grinding away one corner at the intersection of two adjacent lands on each encrusted link to form a beveled land on each link.

9. The method as recited in claim 6, further comprising the step of grinding away a plurality of corners at the intersections of a plurality of pairs of adjacent lands on each encrusted link to form at least two beveled lands on each link.

References Cited UNITED STATES PATENTS 835,659 11/1906 Beckwith 204-36 1,886,277 11/1932 Winkler 204-206 1,949,131 2/1934 Shields 204-23 3,397,134 8/1968 Rinker et al. 20424 FOREIGN PATENTS 244,487 5/ 1927 Great Britain.

JOHN H. MACK, Primary Examiner.

T. TUFARIELLO, Assistant Examiner.

US. Cl. X.R. 20418

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US835659 *Sep 11, 1903Nov 13, 1906Arthur K BeckwithProcess for finishing metals.
US1886277 *Apr 17, 1930Nov 1, 1932Alfred WinklerMethod and apparatus for galvanizing fancy chains and the like
US1949131 *Nov 14, 1932Feb 27, 1934Shields Thomas PRhodium plating
US3397134 *Jun 28, 1965Aug 13, 1968Sel Rex CorpDevice for holding and moving chains for liquid treatment thereof
GB244487A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4348861 *Sep 28, 1979Sep 14, 1982Nakagawa CorporationJewelry chains by electro-forming
US4419193 *Aug 31, 1982Dec 6, 1983Chen Juei LungMethod for making hollow pendants
US4543803 *Nov 30, 1983Oct 1, 1985Mark KeyaskoLightweight, rigid, metal product and process for producing same
US4787229 *Mar 26, 1987Nov 29, 1988Fuji Tekko Co., Ltd.Method of rolling a pipe by flat cutters
U.S. Classification205/120, 205/222, 63/4, 205/150
International ClassificationC25D7/00
Cooperative ClassificationC25D7/00
European ClassificationC25D7/00