JPH028563B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a plastic storage case for storing magnetic tape cartridges, and relates to a manufacturing method that enables the case body to be molded out of plastic without causing any partial deformation. .

1 and 2, the storage case for a Philips type magnetic tape cartridge has a front side wall 2 and left and right side walls 3, 3 erected on three sides of a rectangular bottom wall 1, and the bottoms of the left and right side walls 3, 3. Pivot shafts 4, 4 are provided on the inner surfaces of the portions 3a, 3a extending rearward from the wall 1.
A plastic case body 5 with a protruding
and a lid made of transparent plastic, in which a pocket 7 for inserting and supporting a magnetic tape cartridge 6 is formed at the inner base, and pivot holes 9, 9 are formed in the outer surfaces of the left and right side walls 8, 8 of the pocket 7. It consists of 10,
The basic structure is such that each pivot shaft 4 of the case body 5 is fitted into each pivot hole 9 of the lid body 10, and the lid body 10 is rotatably supported on the case body 5 so as to be freely openable and closable.

However, when manufacturing the case body 1,
Conventionally, as shown in FIG. 6, a plurality of inner and outer molds 11a, 11b, and 11c are used to mold the bottom wall 1, the front wall 2, the left and right side walls 3, 3, and the inner and outer surfaces of the bottom wall 1, the front wall 2, the left and right side walls 3, and the magnetic tape cartridge positioning rib 12. A method is adopted in which the locking pawl 13 for preventing rotation of the tape hub and the like are molded, and the inner surfaces of the rear extending portions 3a, 3a of the left and right side walls 3, 3 are molded using slide molds 14, 14 that move in the left-right direction. It was getting worse.

In this conventional method, the inside of the rear extending portions 3a, 3a of the left and right side walls 3, 3 was molded entirely using the slide molds 14, 14, so a plastic material was injected between the molds and cooled. After that, when the molds are removed, when the slide molds 14, 14 are moved inwardly, the rear extending portions 3a, 3a of the left and right side walls 3, 3 are moved inwardly, as shown in FIG. It tended to deform into a bent state. This is because the left and right side walls 3, 3 contract in the front and back direction when the mold is cooled, and the pivot shafts 4, 4 strongly bite into the molding recesses 15, 15 of the slide molds 14, 14, making it difficult to remove them. However, since the slide molds 14, 14 move inward from this state, the cantilevered extending portions 3a, 3a are dragged and deformed.

This invention has been proposed to solve these problems during molding, and the details thereof will be explained below based on the drawings.

In FIGS. 3 and 4, the rear end of each left and right slide mold 14 is set slightly (approximately 0.5 mm) shorter than the rear end of each left and right side wall 3, and the rear mold 11c is made shorter by that amount. The mold 11c is extended forward to locally mold the rear end edges of the inner surfaces of the left and right side walls 3 over the entire upper and lower widths. In this case, even when the slide molds 14, 14 move inward, the rear mold 11c abuts and locks the rear ends of the left and right side walls 3, 3 from the inside, so that the rear extending portions 3a, 3a The pivot shafts 4, 4 move into the molding recesses 1 of the slide molds 14, 14 without being dragged inward and deformed.
5 and 15, respectively.

In addition, the reference numeral 16 in the figure indicates the cover body 10 on the case body 5.
In order to maintain the closed state when closed,
These are projections provided on the inner surfaces of the rear extending portions 3a, 3a, respectively, and this projection 16 is connected to the pivot shaft 4.
It is also molded using a slide mold 14. Incidentally, when the lid body 10 is closed, the recessed holes 17, 17 formed on the outer surfaces of the left and right side walls 8, 8 of the pocket 7 fit into the protrusions 16, 16.

FIG. 5 shows another embodiment of the present invention, in which the rear ends of the slide molds 14, 14 are connected to the rear ends of the left and right side walls 3, 3, as in the conventional example shown in FIG. Match. However, the slide mold 14,
The upper end of 14 is connected to the rear extending portion 3 of the left and right side walls 3, 3.
The upper end of the upper mold 11d is set slightly lower than the upper end of the upper mold 11d. With this, when the slide molds 14, 14 are moved inward, the rear extending portions 3a, 3a near the upper ends are partially supported by the upper mold 11d, and the rear extending portions 3a, 3a are partially supported by the upper mold 11d. 3a is not dragged inward and deformed.

According to the method of the present invention as described above, by only adding a slight shape deformation to the mold, the case body 5 can be
The cantilevered rear extending portions 3a, 3a of the left and right side walls 3, 3 can be effectively molded into plastic without being deformed when the molds are separated.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing an example of a storage case to which the present invention is applied, and FIG. 2 is a partially cutaway plan view of the storage case in a closed state. FIG. 3 is a plan view showing an example of the implementation of the method of the present invention, and FIG. 4 is a sectional view taken along the line A--A in FIG. 3. FIG. 5 is a longitudinal sectional front view of the main parts showing another embodiment of the method of the present invention. FIGS. 6 and 7 are plan views illustrating the conventional method, respectively. 1...Bottom wall, 2...Front wall, 3, 3...Left and right side walls, 4, 4...Pivot shaft, 5...Case body, 6...
...Magnetic tape cartridge, 7...Pocket,
8, 8... Left and right side walls of the pocket, 9, 9... Pivot hole, 10... Lid body, 11a, 11b, 11c,
11d...Mold, 14,14...Slide mold,
16, 16... protrusion, 17, 17... recessed hole.

Claims (1)

[Claims] 1. A front side wall 2 and left and right side walls 3, 3 are erected on three sides of a rectangular bottom wall 1, and the left and right side walls 3, 3 have rear extensions extending to the rear side of the bottom wall 1. A case body 5 made of plastic from which pivot shafts 4, 4 are formed protruding from the inner surfaces of the parts 3a, 3a, and a pocket 7 for inserting and supporting a magnetic tape cartridge 6 are formed at the inner base, and the left and right sides of the pocket 7 are formed. It consists of a lid body 10 made of plastic in which pivot holes 9, 9 are formed on the outer surfaces of side walls 8, 8, and each pivot shaft 4 of the case body 5 is fitted into each pivot hole 9 of the lid body 10. In the method for manufacturing a magnetic tape cartridge storage case in which a lid 10 is rotatably supported on a case body 5 so as to be freely openable and closable, when molding the case body 5, the left and right side walls 3,
Slide mold 1 that is movable in the left-right direction on the inner surface including the pivot shafts 4, 4 of the rear extending portions 3a, 3a of 3.
4 and 14, and a part of the rear end side of the inner surface of the rear extending portions 3a and 3a is molded using a mold 11c or 11d that does not move in the left-right direction. A method for manufacturing a storage case for magnetic tape cartridges.