MACROCYSTALLINE WATCH DIAL
United States Patent 3863439
A watch dial has an outer surface consisting of metal crystals large enough to be seen by the naked eye. Such crystals are formed by annealing of the metal and may have been treated by etching, coloring, dyeing, coating, oxidation or sulphuration.
US Patent References:
Decorative aluminum surface
Mostovych et al. - June 1960 - 2941930
POLYCHROMATIC WATCH DIAL PLATE
Shibanai - October 1973 - 3763647
CRYSTAL SKETCHING
Pond - November 1973 - 3773576
Decorative aluminum surface
Mostovych et al. - June 1960 - 2941930
POLYCHROMATIC WATCH DIAL PLATE
Shibanai - October 1973 - 3763647
CRYSTAL SKETCHING
Pond - November 1973 - 3773576
Inventors:
Kasai, Kazutomo (Shimosuwa-machi, JA)
Koizumi, Shuzo (Suwa, JA)
Koizumi, Shuzo (Suwa, JA)
Application Number:
05/390290
Publication Date:
02/04/1975
Filing Date:
08/21/1973
View Patent Images:
Export Citation:
Assignee:
Kabushiki Kaisha Suwa Seikosha (Tokyo, JA)
Primary Class:
Other Classes:
968/156, 428/632, 427/283, 428/935, 428/66.500, 428/433, 428/631, 428/641, 428/672, 428/553, 428/927, 428/601, 428/673, 428/450, 428/626, 428/666, 428/469, 428/667, 428/546, 428/687, 428/464, 428/621, 428/665
International Classes:
G04B19/12; G04B19/06; G04B19/10
Field of Search:
58/127R 117/107 25/200 148/31.5,31 175/123R,175R 204/153,35R 29/195M,195Y,196,199
Primary Examiner:
Rutledge, Dewayne L.
Assistant Examiner:
Steiner, Arthur J.
Attorney, Agent or Firm:
Blum Moscovitz Friedman & Kaplan
Claims:
What is claimed is
1. A watch dial having an outer face consisting essentially of metal crystals large enough to be visible to the unassisted eye, said metal selected from the group consisting of iron, tin, copper and alloys thereof.
2. The watch dial as defined in claim 1 wherein said crystals are in the annealed state.
3. The watch dial as defined in claim 1, wherein said crystal face is in the annealed, etched and polished state.
4. The watch dial as defined in claim 1 wherein said face further comprises indicia thereon and a lacquer coating on said face and said indicia.
5. The watch dial as defined in claim 1 wherein said metal crystals are embedded in a metallic binder.
6. The watch dial as defined in claim 5, wherein said metallic binder is of a contrasting color with respect to said crystals.
7. The watch dial as defined in claim 1 wherein said outer surface has thereon a metallic oxide coating of thickness such that the pattern of said large metal crystals is visible to the unassisted eye.
8. The watch dial as defined in claim 1, wherein said outer face has thereon a coating of a member selected from the group consisting of chromium, silicon, tungsten and glass.
9. The watch dial as defined in claim 1, wherein said outer face is in the dyed state.
10. The watch dial as defined in claim 1, wherein said outer face has thereon a coating of a sulfide of at least one of said members of said group.
11. The watch dial as defined in claim 1, wherein said outer face has thereon a plated metal selected from the group consisting of silver and gold, said plated metal being of a thickness such that the pattern of said metal crystals is visible to the unassisted eye.
1. A watch dial having an outer face consisting essentially of metal crystals large enough to be visible to the unassisted eye, said metal selected from the group consisting of iron, tin, copper and alloys thereof.
2. The watch dial as defined in claim 1 wherein said crystals are in the annealed state.
3. The watch dial as defined in claim 1, wherein said crystal face is in the annealed, etched and polished state.
4. The watch dial as defined in claim 1 wherein said face further comprises indicia thereon and a lacquer coating on said face and said indicia.
5. The watch dial as defined in claim 1 wherein said metal crystals are embedded in a metallic binder.
6. The watch dial as defined in claim 5, wherein said metallic binder is of a contrasting color with respect to said crystals.
7. The watch dial as defined in claim 1 wherein said outer surface has thereon a metallic oxide coating of thickness such that the pattern of said large metal crystals is visible to the unassisted eye.
8. The watch dial as defined in claim 1, wherein said outer face has thereon a coating of a member selected from the group consisting of chromium, silicon, tungsten and glass.
9. The watch dial as defined in claim 1, wherein said outer face is in the dyed state.
10. The watch dial as defined in claim 1, wherein said outer face has thereon a coating of a sulfide of at least one of said members of said group.
11. The watch dial as defined in claim 1, wherein said outer face has thereon a plated metal selected from the group consisting of silver and gold, said plated metal being of a thickness such that the pattern of said metal crystals is visible to the unassisted eye.
Description:
BACKGROUND OF THE INVENTION
In recent years, in addition to the principal function of showing the time correctly, watches have become regarded more and more as decorative accessories or costume jewelry. A particularly important part of a watch regarded in this way is the watch dial. In general, colored watch dials are preferred to those of conventional colors such as the yellow of gold or the white of silver.
Where color has been used to enhance the appearance of watch dials, solid colors have usually been used. Consequently, the effect, while pleasant, has not been as striking as might be. Color patterns have been used to some extent but these have been distracting to the eye, and of relatively limited attractiveness.
In view of the extremely competitive market situation with respect to watches, any enhancement of the appearance of the watch dial can contribute markedly to an increase in sales.
SUMMARY OF THE INVENTION
In a watch dial, at least the outer surface thereof consists essentially of a metal. After heating in an atmosphere inert to the particular metal, as well as to the substance of which the watch dial is made, crystals of the metal are formed which are large enough to be seen by the unaided eye. In general, the crystals are polished and etched, as by acid or electrolytic anodization, as a result of which the crystal pattern becomes evident. The dial, in final form, is lacquered for protection and has indicia marked thereon.
Accordingly, an object of the present invention is a watch dial, at least the surface of which consists essentially of crystals large enough to be seen by the unaided eye.
Another object of the present invention is a watch dial of improved appearance having a macrocrystalline structure visible to the unaided eye.
A further object of the present invention is a watch dial of improved appearance wherein macrocrystals have been up-graded in appearance by polishing, etching, oxidation, dyeing, or sulphuration.
Yet another object of the present invention is a process for manufacturing a watch dial of improved appearance by forming macrocrystals.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the article possessing the features, properties, and the relation of elements, which are exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is well known, metals, whether elementary or alloys, display various types of characteristic crystal patterns when properly etched. In general, the size of the crystals is such that the pattern is not visible to the unassisted eye, making it necessary to use a low-power microscope for observation or study of the pattern. This process has been in use for years as a means of identifying metals with respect to their composition and as an indication of treatment to which they may have subjected.
In order to make such patterns visible to the unassisted eye, it is necessary that the crystals be enlarged. An example of the way in which this can be done is provided by 70-30 brass which may be employed in an embodiment of the present invention. The crystals of brass in this composition when heated at 850°C for 10 hours are substantially enlarged so that when polished, the crystal pattern becomes quite visible. It should be noted that the temperature of heat treatment is below the melting point of the material. Consequently, such heat treatment may appropriately be termed annealing.
In the embodiment presented above, the entire dial may be of brass or just the outer surface may be of this material. The brass may be applied to a suitable substrate, the only requirement being that the substrate have a melting point at least as high as that of the brass. Where the outer surface is a layer on a substrate, the layer may be applied by electrodeposition or by vacuum evaporation or by sputtering. Another method is to make the substrate and the outer surface as a bimetal or a clad metal.
After annealing and polishing the surface of a watch-dial in accordance with the present invention, the crystal pattern may be over-plated with silver or gold. The crystal pattern becomes very evident as the result of minute differences in the way the silver or gold is deposited on the surfaces of the crystals themselves and at the interfaces. Where the plating is of silver it is desirable that lacquer be applied over same to prevent corrosion.
The polishing process generally consists of a combination of mechanical polishing with fine abrasives and etching with acids, but either mechanical or chemical polishing with acid etchants may be used alone. A preferred etchant is 5 percent nitric acid.
The crystal pattern may also be enhanced by oxidation of metals or evaporation of oxides onto the surface. Where oxides are evaporated characteristic colors are obtained. For instance, tungsten oxide when evaporated gives a deep blue color and the color changes in accordance with the angle of light falling on the surface. Surprisingly where an inorganic glass is evaporated onto the surface of the dial, the dial appears more metallic.
An orange color may be imparted to a brass plate if it is soaked in an alkaline solution of copper carbonate. Appropriate conditions are the use of a solution containing 25g of NaOH and 50g of CuCO 3 in contact with the surface for a few minutes at 70°C.
A film of chromic oxide may be formed on the surface of the dial by conventional procedure. It can subsequently be dyed blue or red using organic dyestuffs.
Clear lacquer is a preferred means of preventing corrosion. However, colored lacquer may also be used to obtain special effects.
Chromium may be evaporated onto the surface of the dial, after which heating at 700°C in a controlled oxidizing atmosphere results in the production of a green color. Alternatively, silicon may be evaporated onto the surface and then oxidized to a controlled extent, as the result of which interference colors such as a bright blue may be obtained.
Where the crystalline surface has been plated with silver, this may be sulphurized to produce an aged effect, which can then be protected by lacquering.
An excellent effect is obtained by annealing brass as described above until a macrocrystalline pattern is formed, then electroplating with silver to a thickness of about 2μ and covering with clear lacquer to protect the silver from corrosion. In comparison with conventional silver-plated dials, this particular construction is extremely metallic in appearance and due to the variation in color caused by light scattering seems to be 3-dimensional.
Evaporation of cobalt to produce a film of about 1μ in thickness on a copper dial which has been annealed to make it macrocrystalline and subsequent treatment for 3 hours at 850°C in an atmosphere wherein the oxygen pressure is held at a low level but not so low that oxidation cannot take place, yields a characteristic and distinct blue color. The color tone is particularly attractive due to the fact that the dial shows the crystalline pattern of the copper.
A brass plate, annealed as described above may be coated with tin by immersion in the molten metal. A coating thickness of about 130μ is suitable. The coating is then mechanically polished and is etched by electrolysis in perchloric acid and acetic acid solution. An attractive pattern may also be obtained without prior annealing of the brass.
A further embodiment of the present invention is produced by mixing 93 parts by weight of iron and 7 parts by weight of copper, both materials being in the size range of 100 - 200μ, pressing into the form of a disc and sintering for 4 hours at about 1000°C in an inert atmosphere. The surface is then mechanically polished after which it is etched with dilute HCl. The iron grains will be from 0.3 to 0.8 mm in size. A dial prepared in this way can then be overcoated in any of the ways already noted.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and, since certain changes may be made in carrying out the above process and in the article set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
In recent years, in addition to the principal function of showing the time correctly, watches have become regarded more and more as decorative accessories or costume jewelry. A particularly important part of a watch regarded in this way is the watch dial. In general, colored watch dials are preferred to those of conventional colors such as the yellow of gold or the white of silver.
Where color has been used to enhance the appearance of watch dials, solid colors have usually been used. Consequently, the effect, while pleasant, has not been as striking as might be. Color patterns have been used to some extent but these have been distracting to the eye, and of relatively limited attractiveness.
In view of the extremely competitive market situation with respect to watches, any enhancement of the appearance of the watch dial can contribute markedly to an increase in sales.
SUMMARY OF THE INVENTION
In a watch dial, at least the outer surface thereof consists essentially of a metal. After heating in an atmosphere inert to the particular metal, as well as to the substance of which the watch dial is made, crystals of the metal are formed which are large enough to be seen by the unaided eye. In general, the crystals are polished and etched, as by acid or electrolytic anodization, as a result of which the crystal pattern becomes evident. The dial, in final form, is lacquered for protection and has indicia marked thereon.
Accordingly, an object of the present invention is a watch dial, at least the surface of which consists essentially of crystals large enough to be seen by the unaided eye.
Another object of the present invention is a watch dial of improved appearance having a macrocrystalline structure visible to the unaided eye.
A further object of the present invention is a watch dial of improved appearance wherein macrocrystals have been up-graded in appearance by polishing, etching, oxidation, dyeing, or sulphuration.
Yet another object of the present invention is a process for manufacturing a watch dial of improved appearance by forming macrocrystals.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the article possessing the features, properties, and the relation of elements, which are exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is well known, metals, whether elementary or alloys, display various types of characteristic crystal patterns when properly etched. In general, the size of the crystals is such that the pattern is not visible to the unassisted eye, making it necessary to use a low-power microscope for observation or study of the pattern. This process has been in use for years as a means of identifying metals with respect to their composition and as an indication of treatment to which they may have subjected.
In order to make such patterns visible to the unassisted eye, it is necessary that the crystals be enlarged. An example of the way in which this can be done is provided by 70-30 brass which may be employed in an embodiment of the present invention. The crystals of brass in this composition when heated at 850°C for 10 hours are substantially enlarged so that when polished, the crystal pattern becomes quite visible. It should be noted that the temperature of heat treatment is below the melting point of the material. Consequently, such heat treatment may appropriately be termed annealing.
In the embodiment presented above, the entire dial may be of brass or just the outer surface may be of this material. The brass may be applied to a suitable substrate, the only requirement being that the substrate have a melting point at least as high as that of the brass. Where the outer surface is a layer on a substrate, the layer may be applied by electrodeposition or by vacuum evaporation or by sputtering. Another method is to make the substrate and the outer surface as a bimetal or a clad metal.
After annealing and polishing the surface of a watch-dial in accordance with the present invention, the crystal pattern may be over-plated with silver or gold. The crystal pattern becomes very evident as the result of minute differences in the way the silver or gold is deposited on the surfaces of the crystals themselves and at the interfaces. Where the plating is of silver it is desirable that lacquer be applied over same to prevent corrosion.
The polishing process generally consists of a combination of mechanical polishing with fine abrasives and etching with acids, but either mechanical or chemical polishing with acid etchants may be used alone. A preferred etchant is 5 percent nitric acid.
The crystal pattern may also be enhanced by oxidation of metals or evaporation of oxides onto the surface. Where oxides are evaporated characteristic colors are obtained. For instance, tungsten oxide when evaporated gives a deep blue color and the color changes in accordance with the angle of light falling on the surface. Surprisingly where an inorganic glass is evaporated onto the surface of the dial, the dial appears more metallic.
An orange color may be imparted to a brass plate if it is soaked in an alkaline solution of copper carbonate. Appropriate conditions are the use of a solution containing 25g of NaOH and 50g of CuCO 3 in contact with the surface for a few minutes at 70°C.
A film of chromic oxide may be formed on the surface of the dial by conventional procedure. It can subsequently be dyed blue or red using organic dyestuffs.
Clear lacquer is a preferred means of preventing corrosion. However, colored lacquer may also be used to obtain special effects.
Chromium may be evaporated onto the surface of the dial, after which heating at 700°C in a controlled oxidizing atmosphere results in the production of a green color. Alternatively, silicon may be evaporated onto the surface and then oxidized to a controlled extent, as the result of which interference colors such as a bright blue may be obtained.
Where the crystalline surface has been plated with silver, this may be sulphurized to produce an aged effect, which can then be protected by lacquering.
An excellent effect is obtained by annealing brass as described above until a macrocrystalline pattern is formed, then electroplating with silver to a thickness of about 2μ and covering with clear lacquer to protect the silver from corrosion. In comparison with conventional silver-plated dials, this particular construction is extremely metallic in appearance and due to the variation in color caused by light scattering seems to be 3-dimensional.
Evaporation of cobalt to produce a film of about 1μ in thickness on a copper dial which has been annealed to make it macrocrystalline and subsequent treatment for 3 hours at 850°C in an atmosphere wherein the oxygen pressure is held at a low level but not so low that oxidation cannot take place, yields a characteristic and distinct blue color. The color tone is particularly attractive due to the fact that the dial shows the crystalline pattern of the copper.
A brass plate, annealed as described above may be coated with tin by immersion in the molten metal. A coating thickness of about 130μ is suitable. The coating is then mechanically polished and is etched by electrolysis in perchloric acid and acetic acid solution. An attractive pattern may also be obtained without prior annealing of the brass.
A further embodiment of the present invention is produced by mixing 93 parts by weight of iron and 7 parts by weight of copper, both materials being in the size range of 100 - 200μ, pressing into the form of a disc and sintering for 4 hours at about 1000°C in an inert atmosphere. The surface is then mechanically polished after which it is etched with dilute HCl. The iron grains will be from 0.3 to 0.8 mm in size. A dial prepared in this way can then be overcoated in any of the ways already noted.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and, since certain changes may be made in carrying out the above process and in the article set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.