JPH038186A - Shell for disk containing cassette - Google Patents

Abstract

PURPOSE:To improve the productivity by providing a pin gate position for injection molding on two parts in the vicinity of a side edge part of a shell, and forming the thickness of a storage disk containing part of the shell and the thickness of a corner part of its periphery to the same. CONSTITUTION:Thickness T0 of a disk containing part 11 of a shell 1 is formed to almost the same as thickness T1 of a corner part 12 of the periphery. As for the shell 1, a die which has a sprue 6 and a runner 7, and provided with two pieces of pin gates 8 in the vicinity of en edge part of a shutter insertion side of the shell 1 is used so that three set of upper and lower shells 1, that is, total six pieces of shells 1 can be brought to injection molding simultaneously, and the shell 1 which generates no recessed part on the surface of the shell 1 and whose external appearance is satisfactory can be manufactured. In such a way, many sets of shells whose external appearance is satisfactory can be manufactured simultaneously by a simple die structure, and the productivity can be improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to upper and lower shells constituting a disk storage cassette that stores storage disks such as floppy disks so that they can be rotatably driven and recorded/played from the outside, and in particular, This invention relates to a shell that prevents the appearance from being damaged by dents on the surface of the shell during injection molding.

(Prior art and its problems) As shown in an exploded perspective view in FIG. 4, a conventional disk storage cassette has a magnetic disk 2 mounted on the inner surface of two upper and lower plastic shells 1 via a nonwoven fabric liner (as shown). It is constructed by combining.

Reference numeral 3 denotes a shutter, which is attached to the cassette and prevents dust and the like from entering the cassette when the cassette is not in use.

Conventionally, the upper and lower shells 1 constituting the disk storage cassette are manufactured by injection molding plastic, but in this case, as shown in FIG. 4, the injection molding pin gate position 4
In order to prevent particles from forming on the surface of the shell 1, two injection molding pin gate positions 4 were provided near the edge of the insertion side of the shutter 3 during injection molding. There is a problem in that an air pocket is generated at the opposite side edge location 5 near the insertion side edge 3, and a dent is created in the location 5, which impairs the appearance.

As a result of various studies, we found that in the conventional shell 1, the flow of plastic was partially different. The thickness to is thinner than the thickness tl of the surrounding corner 12, and the plastic easily flows in the thicker corner 12, so the plastic flows earlier than the thinner disk storage part 11. It was discovered that this caused an air pocket to form at a location 5 near the side edge on the opposite side of the pin gate position 4.

(Means for Solving the Problems) The present invention has been made based on the above findings, and includes:
The feature is that two pin gate positions for injection molding are provided near the side edges of the shell, and the thickness of the storage disk storage part of the shell is injection molded to be almost the same as the thickness of the surrounding corners.

(Example) The present invention will be explained below with reference to the drawings.

Fig. 1 is a sectional view of a shell for a disk storage cassette according to the present invention, and Fig. 2 is a sectional view of a conventional shell (■-■ in Fig. 4).
Figure 3 shows three sets (six shells) of the shells of the present invention.
FIG. 4 is an exploded perspective view showing a conventional disc storage cassette. In the figure, the same parts as in the conventional example are denoted by the same reference numerals.

The shell 1 of the present invention differs from the conventional shell 1 shown in FIG. 2 in that the thickness TO of the disk storage portion 11 is
The thickness is approximately the same as the thickness T1 of No. 2. In this case, the surface of the shell 1 may be partially uneven.

As shown in FIG. 3, the shell 1 of the present invention has a sprue 6 and a runner 7, and a pin gate 8 has two thin metal plates near the edge of the shutter insertion side of the shell 1. Using a mold, three sets of upper and lower shells 1, that is, a total of six shells 1, are injection molded at the same time.
It is possible to manufacture a shell 1 with a good appearance without any dents on the surface of the shell 1. With the mold arrangement shown in Figure 3, using ABSI resin as the plastic, injection resin temperature 280°C, mold temperature 40°C, injection time 0.4
When the shell 1 was injection molded in seconds, no dents were observed on the surface of the injection molded shell 1, and the appearance was good.

(Effects of the Invention) As described above, according to the present invention, despite the fact that there are two pin gate positions for injection molding, there is no dent caused by air pockets on the shell surface near the shell side edge on the opposite side to the pin gate position. Compared to conventional injection molding pin gates formed at four positions, this mold structure is simpler and has a larger number of shells with a better appearance. can be manufactured at the same time, which has advantages such as excellent productivity.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a shell for a disk storage cassette according to the present invention, Fig. 2 is a sectional view of a conventional shell (cross-sectional view taken along the line -■ in Fig. 4), and Fig. 3 is a sectional view of three sets of shells of the present invention ( FIG. 4 is an exploded perspective view showing a conventional disk storage cassette. In the figure, 1 is the upper and lower shells, 11 is a disk storage section, 12 is a corner, 2 is a storage disk, and 4 is a pin gate position.

Claims (1)

[Claims] A shell for a disk storage cassette consisting of an upper and lower shell for storing a storage disk, wherein two injection molding pin gate positions are provided near the side edges of the shell, and the thickness of the storage disk storage portion of the shell and the surrounding corners thereof are A shell for a disk storage cassette characterized by being injection molded to have almost the same thickness.