JPS59178385A - Cover glass for timepiece and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a cover glass for a timepiece high in quality and inexpensive by blanking a transparent or opaque organic resin plate into a desired shape to form. CONSTITUTION:A polycarbonate plate or a methacryl resin plate undergoes a surface treatment by offset printing, screen printing or the like to form a pattern 2 for a timepiece. An organic resin plate 1 is cut off by a shearing or the like to make a blank 1' and then the blank is blanked with a die having a desired shape to complete a cover glass for timepiece. The blanking is done by a press, coining or the like, the product is looked plushy with an excellent smoothness of the surface while the time of the surface treatment and forming of the desired shape can be reduced thereby providing a very inexpensive cover glass for timepiece.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a watch glass made of an organic resin and a method for manufacturing a watch cover glass.

Traditionally, glass for watches made of organic resin was made by injection molding or by rolling a plate into the desired shape and then completing it by surface treatment such as printing.Injection molding Cover glasses for watches that are molded by molding do not have a smooth surface due to sink marks during molding, resulting in poor appearance, difficulty in subsequent surface treatment, and poor surface treatment quality. In addition, the glass for watches made by the cut method in which the sheet material is mechanically cut into the desired shape is compared to the glass for watches made by the above-mentioned injection molding method. do,
Although it is possible to create a very smooth surface, it has the disadvantage that it is difficult to cut and has a high manufacturing cost, and is only used for special items that require precision in subsequent surface treatment.

The above-mentioned watch glass made of organic resin is mainly used in low-priced watches, but in recent years the cost of low-priced watches has been significantly reduced, and as a result, the cost of watch cover glasses has also decreased significantly. There is a need for down and high quality products. Therefore, the current method of applying surface treatment to each watch cover glass formed by injection molding or cutting methods has reached its limits in terms of cost and quality. .

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and aims to provide a cover glass for a watch that is of high quality and is also very inexpensive.

The gist of the invention is as described in the claims.

Next, the present invention will be explained based on examples.

FIG. 1 is a diagram showing a method of manufacturing a watch cover glass according to an embodiment of the present invention. Transparent or translucent organic resin board 1
For example, a polycarbonate plate or a methacrylic resin plate is surface-treated by printing, such as offset printing or screen printing, to form the watch pattern 2. The organic resin plate 1 may be of any size as long as it can be easily subjected to surface treatment such as printing, and a large number of patterns may be formed as shown in the figure, as long as the spacing allows for punching. Next, the organic resin plate 1 is cut into a shape that is easy to punch out using a shear cylinder or the like to produce a punched material 1. The punching material 1' may have any shape as long as it is easy to punch out, and may be in the shape of a band or a square. The punched material 1' made in this manner is punched out using a die having a desired shape to complete a watch cover glass.

Punching is performed by pressing, coining, or the like. For those that do not require surface treatment, the transparent or semi-transparent organic resin plate 1 may be cut into punched materials 1', and then punched into the desired shape using a press. The watch cover glass ♂ completed in this way has a smoother surface compared to conventional ones and has a luxurious feel, while at the same time reducing the time for surface treatment and molding into the desired shape, making it extremely streamlined. You can get inexpensive cover glasses for watches.

FIG. 2 is a cross-sectional view of a press showing an embodiment of the present invention and illustrating a method for chamfering the outer periphery of a watch cover glass punched into a desired shape.

In a press composed of a punch 10, a stripper 12, a die 1, a knockout 11, and a spring 14, a slope clearance 15 is provided inside the cutting edge 10a of the punch 10 having a desired shape, and the punched material 1' described above is It is placed between the punch 10 and the die 16, and the punch 10 is struck down. The watch cover glass 3 punched out in this way is
As shown in FIG. 3, a chamfer 17 is formed at the same time as punching. If either the top or bottom surface of the watch cover glass B is chamfered, a sloped portion may be provided on the cutting edge of either the punch 10 or the knockout 13. Punching can be performed not only by pressing but also by coining or the like. Further, depending on the type of organic resin, it is easier to form a chamfer and some are difficult to form a chamfer, but in order to form a chamfer or improve the surface condition of a punched cross section, the mold may be heated. When the organic resin is polycarbonate, as shown in Figure 4, the cross section on the die 1 bottom side sag or sag in a circular shape, so a chamfer 17 is formed only on the punch 10 side, and a sag is not formed on the die 1 bottom side. By forming the surface 18, it is also possible to provide the watch cover glass 6 with a chamfer with an unprecedented texture. The size of the sagging surface 18 can be freely shaped depending on the clearance 15 between the punch 10 and the die 1.

As described above, according to the present invention, it is possible to speed up the production of a cover glass for a watch, and to produce a cover glass of high quality at a much lower cost than in the past.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention and shows a method of manufacturing a cover glass for a watch. FIG. 2 is a sectional view of a press showing an embodiment of the present invention and showing a punching method. 5 and 4 are cross-sectional views of a watch cover glass showing an embodiment of the present invention. 1.Organic resin board, 1' punching material, 2. pattern,
6 ・Completed watch cover glass, 10-punch,
10a... Punch cutting edge, 10b, 11b... Slope part,
11...knockout, 11a...knockout cutting blade,
12 Stripper, 13・Die, 13' Die cutting blade, 14.16・Spring, 15・Clearance, 17...
- Chamfer, 18, sagging surface. 20 No. 3 Z' l Figure 4 Supplementary IF document for procedures (Method) Kazuo Wakasugi, Commissioner of the Special Agency, Indication of workability 1981 Patent Application No. 0532'74 2 Name of invention Cover glass for watches and for watches Cover glass manufacturing method 3, person making the amendment＼-1/′ 4゜Date of amendment order 6th day, 28th, 1982 (Date of dispatch) Procedures Ministry of amendment (spontaneous)] Indication of the case 1982 Patent application No. 0532'24 No. 2, Title of invention Cover glass for watches and method for manufacturing watch cover glasses S3 Relationship with the case of the person making the amendment Patent applicant Telephone: 0555-3-1231 5 Number of inventions increased by amendment 6. Subject of amendment (1) "Applicable Articles" section of the application (2) "Number of inventions stated in the scope of claims" of the application
Section and number 7, contents of amendment (1) Adding "A patent application pursuant to the provisions of the subtitle to Article 38 of the Patent Act" after the patent application in the application. The number of inventions described in the scope of claims... 2" is added.

Claims (1)

[Scope of Claims] (1) A transparent or translucent organic resin plate having a desired shape vC
A watch glass characterized by having J'J cut out. (2) A watch cup (-glass) according to claim (1), characterized in that it is formed by subjecting a transparent or translucent organic resin plate to a surface treatment and then punching it into a desired shape. 3) Cut transparent or translucent organic resin plate into desired shape +]
A cover glass for a watch according to claim 1, characterized in that the cover glass is subjected to surface treatment after being punched. ”The term t j as set forth in claim (1), characterized by a chamfer on the outer periphery of at least one side of the machine resin.
l'l no J bar glass. (5) A transparent or translucent organic resin punched into a desired shape, one side of which has a chamfer on its outer periphery, and the other side of which has a sag due to punching. The watch cover glass described in (1). (6) A method for manufacturing a watch cover glass, characterized in that a transparent or translucent organic resin plate, or an organic resin plate treated with Table M1 is punched into a desired shape. - A beveled surface corresponding to a chamfer is provided on at least one of the cutting edges of the mold and the lower mold, and a transparent or translucent organic resin plate or a surface-treated organic resin plate is used as described above. A method for producing a watch cover glass according to claim (6), characterized in that, at the same time as punching with a die, a chamfer is formed on the outer periphery of at least one side of the punched organic resin. (8) At the cutting edge of either the upper mold or the lower mold having the desired shape, the inclined surface corresponding to the chamfer is formed by using a transparent or translucent organic resin plate, or a surface-treated organic resin plate. Punching with a die (at the same time, chamfering is formed locally on one side of the punched organic resin, and a sagging surface due to punching is formed on the outer periphery of the other side) Claim (6) 2. Method for manufacturing a watch cover glass as described in Section 1.