JPS6052391B2 - Manufacturing method for decorative plates for watches - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a decorative plate for a timepiece, which has a synthetic resin on the upper part and a metal substrate on the lower part.

Conventionally, the dial has the function of hiding the movement from the outside and making the time readable, and also has the function of adding to the decorative beauty of the entire watch. For this reason, attempts are being made to increase the diversity of designs as much as possible by applying various colors, patterns, and shapes to the dial surface. Among these, so-called laminated dial plates have been devised and implemented since ancient times, in which a transparent or translucent synthetic resin plate is provided on the upper part and a metal substrate is provided on the lower part.

The pattern and color on the board surface of this laminated dial board looks three-dimensional and unique, but since a flat synthetic resin board is generally pasted onto a flat board, the variety is slightly different.
It has become low. For this reason, efforts are being made to expand the diversity of designs by attaching small parts such as typesetting and marks to synthetic resin plates. However, if you think about manufacturing, you will need laminating technology.

There are problems such as the need to drill small holes to attach small parts, and it is often difficult to commercialize the product. In addition, as a type of dial plate made by another method, a dial plate made by injecting synthetic resin for casting onto the surface of a metal substrate and solidifying it, and then removing unnecessary synthetic resin, has been devised.

This dial is made by forming a prominent uneven pattern on the surface of the substrate, and by injecting and solidifying synthetic resin to fill in this pattern.
Although it is possible to obtain a three-dimensional effect and diversity compared to the above-mentioned laminated dial, it is not suitable for mass production as it takes time and effort to inject the synthetic resin, and it is necessary to prevent air bubbles from forming in the synthetic resin when it solidifies. However, this also poses a problem in practical use.

The present invention has been made in view of the above-mentioned drawbacks of the prior art.
This project aims to provide a method for manufacturing letters and dials that allows the completed dials to have a three-dimensional appearance, a sense of luxury, and rich diversity, while significantly reducing manufacturing costs. The present invention is characterized in that after a conductive film is formed and a metal is electroformed on the conductive film to form a metal substrate, the convex portion of the metal substrate is removed to the extent that a portion of the plastic matrix remains.

Embodiments of the present invention will be described below with reference to the drawings.

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view of a dial completed according to the present invention, and the second is a sectional view taken along a line in FIG. 1.

3 to 7 are cross-sectional views of parts in the manufacturing method of the present invention. First, FIGS. 1 and 2 will be explained.

The electroformed metal substrate 1 has a movement mounting foot 1a at the lower part, and a convex part 1b corresponding to an index, mark, etc. at the upper part and a surface part 1c forming a surface pattern.
A conductive film 2, which also serves as a decorative color, is provided on c. 1d is a center hole through which the pointer shaft is inserted.

The synthetic resin portion 3 covers the surface of the substrate 1 with the conductive treatment film 2 interposed therebetween. The upper surface of the convex portion 1b of the substrate 1 and the synthetic resin portion 3 coincide with each other, and a mirror finish is applied to enhance the sense of luxury. Next, the manufacturing method of the present invention will be described.

First, Bs. A plastic molded metal 4 is manufactured using a material such as Cu.

The convex portion 4b of the plastic molded metal 4 in Fig. 3 is an indicator of the completed dial plate.
This becomes a convex portion such as a mark, and the surface portion Ac becomes a surface portion of the surface pattern of the completed dial. Therefore, the convex portion 4 of the plastic molding die 4
b and the surface portion 4c are each given a predetermined finish. Using this plastic molded metal 4, a plastic mother mold 5 is then molded. (Fig. 4) The plastic matrix 5 is made of transparent, translucent, or colored transparent material. Next, the plastic matrix 5 is subjected to conductive treatment to form the conductive film 2, and then the metal 6 is electroformed.

(FIG. 5) The conductive film 2 is made of silver or gold because it will be the finishing color on the completed dial plate, and is adhered to the plastic matrix by vapor deposition. The metal electrodeposited is copper.
Next, unnecessary portions of the electroformed metal 6 are removed by cutting.

(FIG. 6) This electroformed metal 6 that is not removed will become the metal substrate 1 later. Next, the protrusions 6b of the electroformed metal 6 are removed to the extent that a portion of the plastic matrix 5 remains.

(FIG. 7) This plastic matrix 5 that is not removed will later become the synthetic resin part 3. In the removal procedure, first rough finishing is performed by cutting, and then a diamond cutting tool is used. Furthermore, wrap finishing is performed and the process is completed. Since this removal work is performed to expose the convex portions 6b on the surface, the finished surface may be finished to a diamond cut finish, or may be finished to a cutting finish. The dial plate manufactured in this manner is provided with a center hole 1b, a mounting foot 1a fixed therein, and finish plating to complete the dial plate as shown in FIGS. 1 and 2.

FIG. 8 shows a dial manufactured according to the present invention, in which the convex portions 1b of the electroformed metal substrate are arranged in a ripple pattern to diversify the pattern.

FIG. 9 shows a dial plate of a digital watch manufactured according to the present invention, and FIG. 10 shows a dial ring for an analog watch.

As described above, the present invention has a structure in which the protrusions of the electroformed metal are removed within the range where a portion of the plastic matrix remains, so the plastic matrix used only during the manufacturing process can be used as it is for the substrate. It can be constructed as a synthetic resin part, and manufacturing costs can be significantly reduced.

In addition, the adhesion between the synthetic resin part and the substrate is much better than conventional casting or laminating methods, and together with the three-dimensional pattern created by the combination of the convex parts and surface parts of the board, it creates a high-quality finish. It is possible to create high-quality dials, parting boards, dial rings, etc. that are confusing.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a dial completed according to the present invention, FIG. 2 is a sectional view taken along the line -- in FIG. 1, FIGS. 3 to 7 are sectional views showing the steps of the present invention, and FIG. Figures 1 to 10 are plan views of other decorative plates for watches completed according to the present invention. DESCRIPTION OF SYMBOLS 1... Metal substrate, 1b... Convex part, 1c... Surface part, 2... Conductive film, 3... Synthetic resin part, 4... Plastic mold, 4b... Convex part Part, 4c...Surface part, 5...
・Plastic matrix, 6...Electroformed metal.

Claims (1)

[Claims] 1. After a conductive film is formed on the surface of a plastic matrix having convex portions and a metal is electroformed on the conductive film to form a metal substrate, a part of the plastic matrix remains. A method for producing a decorative plate for a watch, characterized in that the convex portion of the metal substrate is removed within a certain range. 2. The method for producing a decorative plate for a watch according to claim 1, wherein the plastic matrix is made of transparent, translucent, or colored transparent synthetic resin.