JPH08304564A - Molded structure of clock dial plate and molding method thereof - Google Patents

Abstract

PURPOSE: To obtain a molding structure of a clock dial plate and a molding method thereof which dispense with a bonding process of the dial plate, enable large power-saving of operating processes and reduction of the cost, further enable the attainment of complete flatness of the dial plate due to integration thereof with a clock front plate after fusing and, moreover, enable the prevention of peeling-off. CONSTITUTION: In a structure wherein a dial plate 2 is fitted on a clock front plate 1, the dial plate 2 is formed of paper or synthetic resin, while the clock front plate 1 is formed of synthetic resin. The whole rear side of the dial plate 2 is fusion-bonded to the resin at the time of molding of the clock front plate 1. The clock front plate 1 is formed by insert molding wherein the resin for forming a base is poured into a mold, and the dial plate 2 is fitted in a recessed part la in the front of the front plate 1. The dial plate 2 is shaped like a disk and a round hole 2a for the insertion of a hand shaft and a notch for positioning at the time of setting inside the mold are provided in the central part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for attaching a dial to a watch front plate made of synthetic resin and a method for forming the dial.

[0002]

2. Description of the Related Art In a timepiece, a dial is generally attached to a front plate of the timepiece for displaying the time. Conventionally, when attaching a dial to a front plate of a watch, (1) the dial is formed of a metal thin plate such as aluminum, and a locking claw piece is provided in a projecting manner at an appropriate position. When mounting the dial, insert it into the mounting hole of the front plate and bend and fix it (2)
A method is known in which a dial made of paper or synthetic resin is attached to the timepiece front plate via a double-sided tape on the back surface thereof.

[0003]

In the case of the above (1) in which the claw pieces are projected on the dial plate, it is necessary to form the claw pieces, so that the forming die is enlarged correspondingly and the material can be taken. This results in a high cost, and there is the inconvenience of requiring a separate mounting step called so-called foot bending for bending the claw pieces.

In the case of (2), which is attached to the back surface of the dial plate via the double-sided tape, since the double-sided tape is arranged at a plurality of places, material cost and labor are required, and wrinkles and twists are generated after joining. In addition, there is an inconvenience of causing deformation due to heat, humidity and the like.

The present invention has been made in view of the above circumstances, and has been inspired by the fact that many case members such as a front plate of this type of watch are molded by pouring resin into a mold. The present invention proposes a structure in which a dial is fused at the same time as resin molding of a front plate and a molding method thereof.

[0006]

According to a first aspect of the present invention, in a case where a dial is attached to a timepiece front plate, the dial is made of paper or synthetic resin, and the timepiece front plate is made of synthetic resin. The molding structure of a timepiece dial has a structure in which the entire back surface of the dial is fused to a resin when the timepiece front plate is molded.

The invention according to the second aspect of the present invention is a method of mounting a dial on a watch front plate, wherein after a dial formed of paper or synthetic resin is mounted in a mold for molding the watch front plate, This is a method of molding a timepiece dial in which a resin for forming a front plate is poured into a mold and the dial is fused to the resin when the front plate of the timepiece is molded.

[0008]

With this construction, the dial plate made of paper or synthetic resin is fused to the resin during the molding process of the timepiece front plate, thus greatly reducing the labor of the working process and reducing the cost. In addition, the dial plate after fusion can be integrated with the timepiece front plate to obtain perfect flatness, and peeling can be prevented, so that the quality can be improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiments.

The molding structure of the timepiece dial of this embodiment is shown in FIG.
As shown in FIG. 3, in the case of attaching the dial 2 to the timepiece front plate 1, the dial 2 is made of paper or synthetic resin, and the timepiece front plate 1 is made of synthetic resin. The entire back surface is fused with resin when the timepiece front plate 1 is molded.

When the entire back surface of the dial 2 is fused with the resin in this way, when the dial 2 shrinks, the entire dial shrinks integrally with the resin and does not peel off, and wrinkles do not occur. The result is obtained.

The timepiece front plate 1 is formed by insert molding in which a resin for forming a base is poured into a mold, as will be described later, and the dial 2 is mounted in the front recess 1a of the front plate 1. . As shown in FIG. 2, the dial 2 has a disk shape, and is provided with a circular hole 2a for inserting a pointer shaft (not shown) in the center and a notch 2b for positioning when mounted in a mold. ing.

Next, a method of molding a timepiece dial in which the entire back surface of the dial 2 is fused with resin will be described.

FIG. 3 is a cross-sectional view showing the fixed mold A and the movable mold B. The resin flowing through the secondary sprue 11 flows into the cavity portion formed by these molds A and B. Thus, the timepiece front plate 1 is molded. The gate portion 12 is provided at a portion where the pointer shaft is just inserted, that is, at the center portion of the timepiece front plate 1.

The dial 2 is mounted in the molds A and B for molding the timepiece front plate 1. In this embodiment, a dial plate 2 made of paper is put in contact with the fixed mold A side, and then a resin is poured into the mold so that the dial plate 2 is made into resin when molding the timepiece front plate 1. Fusing and molding. That is, the resin poured into the mold is solidified by heat dissipation, but in this process, the dial 2 is fixed to the timepiece front plate 1 by heat and pressure.

As described above, the gate portion 12 has the dial 2
Since it is provided at the central portion of the, the resin flows and is filled in the direction in which the dial 2 is pressed. Therefore, the dial does not peel off during molding. In addition, 13 is a holding pin, and an appropriate number of them are arranged on the movable mold B. The pin 13 is provided so that the dial 2 is not pressed and the dial is not displaced or peeled off.

Further, the fixed mold A is provided with a protruding portion 14 corresponding to the cutout 2b of the dial plate 2. This protrusion 1
By engaging 4 with the notch 2b, the dial plate 2 is positioned when it is mounted in the mold.

The positioned dial plate 2 is fused at the same time when the timepiece front plate 1 is molded, and the protruding portion 1b of the timepiece front plate 1 corresponding to the gate portion 12 is removed after the resin is solidified.
A hole 1c for inserting a pointer shaft is formed in this portion. The hole 1c corresponds to the circular hole 2a of the dial 2.

As described above, according to the molding method of this embodiment, since the gate portion 12 is provided at the central portion of the dial 2, the resin flows and is filled in the direction in which the dial 2 is pressed, Therefore, the dial does not peel off during molding. Further, since the entire back surface of the dial 2 is fused to the resin when the front dial 1 is molded, if the dial shrinks due to temperature change after molding, the entire dial is integrated with the resin. Since it is a target, it shrinks together with the resin. Therefore, even if it shrinks, it does not peel off and wrinkles do not occur.

In the above-mentioned embodiment, the dial plate is made of paper, but it is preferable to use a dial plate having heat resistance. Further, not limited to paper, synthetic resin may be used.

Further, in the present embodiment, the dial plate is used in the shape of a disk, but the invention is not limited to this.
It may be used in a rectangular shape, a curved shape, or any other shape.

[0022]

Since the present invention is constructed as described above, the paper or synthetic resin dial plate is fused to the resin during the molding process of the timepiece front plate, and therefore the separate character plate is used. The plate bonding process can be eliminated, resulting in significant labor savings and cost reductions. Furthermore, the fused dial plate is integrated with the watch front plate for perfect flatness. And the peeling can be prevented, so that the quality of the product can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a timepiece front plate having a dial plate fused thereto according to the present invention.

FIG. 2 is a front view showing a dial.

FIG. 3 is a cross-sectional view of a state in which a movable mold and a fixed mold are combined.

FIG. 4 is a cross-sectional view showing a notch of a dial plate and a protruding portion of a movable mold engaging with the notch.

[Explanation of symbols]

 1 Clock Front Plate 1a Front Recess 1b Projection 1c Hole 2 Dial 2a Circular Hole 2b Notch 11 Secondary Sprue 12 Gate Part 13 Presser Pin 14 Projection A Fixed Mold B Movable Mold

Claims (2)

[Claims] 1. A dial for attaching a dial to a watch front plate, wherein the dial is made of paper or synthetic resin, and the watch front plate is made of synthetic resin. A molding structure for a timepiece dial, characterized in that it is fused to a resin when molding the timepiece front plate. 2. A method of attaching a dial to a watch front plate, comprising: mounting a dial made of paper or synthetic resin in a mold for molding the watch front plate, and then forming the front plate in the mold. A method of molding a timepiece dial, comprising pouring a resin and fusing the dial to the resin at the time of molding the timepiece front plate.