JPS63128285A - Manufacture of outer package parts for portable timepiece - Google Patents

Abstract

PURPOSE:To reduce manhours for assembling a button, and also, to decrease the unit price of a product by using materials whose mold shrinkage factors are different, and which are not welded to each other, and forming a middle and the button as one body. CONSTITUTION:First of all, a middle 1 having a button hole 1a is formed by using a plastic material, and subsequently, by using a plastic material which is not welded each other to the middle 1, a button 2 is formed as one body in the button hole 1a. The material of the button 2 has a difference in mold shrinkage factor, therefore, the button 2 becomes smaller than the button hole 1a in the diameter direction. Therefore, a clearance 3 is generated between the button hole 1a and the button 2, the button 2 can be operated easily, and its function can be performed. Also, after the forming has been ended, the middle 1 and the button 2 are completed in an already assembled state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for molding a case and a button or case of a watch case.

[Summary of the invention]

The present invention utilizes two-color plastic molding technology to integrally mold the body and button using materials that do not fuse with each other, so that separate parts can be processed at the same time.

[Conventional technology]

Traditionally, the body and buttons, which are both molded from plastic, are processed and assembled separately. − [Problems to be solved by the invention] However, when the buttons are in several places, the number of assembly steps increases, the processing cost of the product increases, and even though cheap materials are used and mass production is possible, Regardless, this was a factor that prevented product prices from falling.

[Means for solving problems]

In order to solve the above problems, the present invention utilizes two-color plastic molding technology to integrally mold the body and button using materials that have different molding shrinkage rates and do not fuse together. I processed it and combined it.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, the body l has a buttonhole 1a and is molded using a plastic material, and then a button 2 is integrally molded in the buttonhole 1a using a plastic material that does not fuse with the body. Since the material of the button 2 has a molding shrinkage rate, the button 2 becomes smaller in the radial direction than the button hole 1a. This creates a gap 3 between the buttonhole 1a and the button 2, allowing the button 2 to operate easily and fulfill its functions. Further, when the molding is completed, the body 1 and the button 2 are already assembled. Therefore, in the case of a watch with a keyboard type and many buttons as shown in FIG. 2, the number of man-hours required for assembling the button 2 can be significantly reduced.

〔Effect of the invention〕

As explained above, this invention uses different plastic materials for the body and button and integrally molds them using two-color molding, thereby significantly reducing the number of man-hours required to assemble the button, and as a result, the unit price of the product is significantly reduced. There is an effect that can be done.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a button portion of the invention, and FIG. 2 is a perspective view showing an embodiment of the invention. ■...Body 1a...Button hole or screw hole 2...Button 3...Gap or more

Claims (1)

[Claims] An exterior part for a portable watch, wherein the body and the button are made of a synthetic resin material that does not fuse with each other, and the button part is subjected to insert injury molding after the body injury molding. Production method.