JPH0262775A - Tape cassette - Google Patents

Abstract

PURPOSE:To form a transparent window easily and surely even if it is of a complicated shape by applying insert molding to the transparent window molded in advance with a required shape so as to form cassette halves and coupling the cassette halves. CONSTITUTION:A tape cassette 1 is formed by coupling cassette halves 2 which is molded by inserting the required shape of transparent window 4 molded formed in advance at the molding of a cassette half main body 3. Thus, the coupled face between the main body 3 and the transparent window 4 is formed to have a complicated cross section thereby ensuring excellent adhering strength with various kinds of materials and attaining nearly complete integration. Moreover, the generation of a defective cassette halves caused by a trace of gate is reduced and the molding die does not give damage to the window molding face by chip of gate and the tape cassette 1 integrated with the main body 3 having the transparent window 4 is easily obtained.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a tape cassette with a transparent window.

[Summary of the invention]

The present invention is a tape cassette having a transparent window through which a stored magnetic tape can be seen, and the cassette half is formed by inserting a pre-molded transparent window having a desired shape when molding the cassette half main body. By doing so, the transparent window can be neatly formed without bleeding or deforming at the boundary with the main body, and a tape cassette with an excellent appearance can be obtained.

[Conventional technology]

Conventionally, in a tape cassette, the transparent S part through which the stored magnetic tape can be seen is formed by gluing or welding a molded product or a plate-shaped window member to the main body part to form a cassette half.

In addition, the cassette half is molded using a core bank type two-color molding method, in which resin is injected and filled into the main body molding cavity, and when the resin begins to solidify, the slide core is retreated to create a window molding space. A cassette half with a transparent window integrally formed in the main body is formed by injecting and filling a transparent molding resin into this space and cooling and solidifying it.

Furthermore, the cassette half is molded using a rotary type two-color molding method, that is, the window part is molded by primary injection of transparent resin, the mold is opened, and the movable core is molded into the secondary molding with the window part molded product attached. A molding cavity for the main body is formed around the window molded product by rotating it to the side, and secondary injection of resin is performed to mold the main body, creating a cassette half in which the main body and the transparent window are integrated. It was known that it could be molded.

[Problems to be Solved by the Invention] In the conventional technology described above, in which a transparent window member is joined to the main body of a cassette half, there is a need for adhesion, welding, etc. between the main body and the window member. Therefore, there are many restrictions on the design, and when changing the design, it is necessary to change the mold for forming the main body as well as the window member, resulting in an increase in cost.

In addition, in the case of two-color molding using the core-back type, what is the shape of the joint surface between the main body and the window? jl Due to the difficulty of sloping, the strength of the joint may be insufficient depending on the molding material.
When molding this window, the resin is injected from the surface side, so the gate marks are exposed, resulting in poor appearance.
In addition, there are problems such as the possibility that this gate debris may mIM the inner surface of the mold, and when changing the design of the window, there are cost issues such as changing the mold or requiring large-scale remodeling. But it was at a disadvantage.

Furthermore, in the case of rotary type two-color molding, the rotary type two-color molding machine is large and equipment costs increase, and if the cross-sectional shape of the window is complicated, the mold structure becomes complicated, which further increases equipment costs. There were problems such as high costs.

The present invention has been made in view of these problems of the conventional technology, and its purpose is to:
It is an object of the present invention to provide a tape cassette in which the transparent window part can be easily and reliably formed even when the shape is complicated, and the tape cassette is excellent in appearance.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a tape cassette having a transparent window through which the stored magnetic tape can be seen.
The cassette halves are formed by inserting a pre-molded transparent window body having a desired shape into the cassette half main body when molding the cassette half body.

[Effect]

The tape cassette constructed in this way is formed by inserting a transparent window into the cassette half body, so that the window can be reliably joined with the required boundary without the peripheral surface melting into the main body. A tape cassette that is integrated with the main body and has a transparent window can be easily obtained.

Furthermore, since the transparent window body is injection molded from the side, no injection gate marks are exposed on the front and back surfaces, and the appearance is not impaired.

(Example〕 Embodiments of the present invention will be described below with reference to the drawings.

FIG. ) shows the whole tape cassette, (2) is the cassette half, (3) is the main body, and (4) is the transparent window.

The transparent window body (4) is molded from transparent resin, and is provided with a pair of reel shaft insertion holes (5a) and (5b), and both outer ends (4a) and (4b) are formed into a sharp point. and the respective tips and insertion holes (5a), (
Grooves (6a) and (6b) are formed between the insertion holes (5b), and grooves (6c) and (6d) are formed at equal intervals between the insertion holes (5a) and (5b), alternately on the front and back sides.
, (6e), (6f), and (6g) are formed.

This transparent window body (4) is molded by injecting transparent resin into the cavity of the mold from the side end surface side, and as a result, gate marks g remain and protrude on the side end surface of the transparent window body (4). Become.

The transparent window body (4) thus formed is molded into a cassette half (2), and as shown in FIG.
11) and the movable mold (12) at a predetermined position in the cavity (13), and is pushed out when the mold is clamped. In this state, game 1-(
Inject the main body molding resin from 13g). In this resin injection, the resin is filled not only into the space of the cavity (13) but also into each of the grooves (6a) to (6g) of the transparent window body (4).

After holding this state for a predetermined time to cool and solidify the filled resin, the mold is opened and the molded product, that is, the cassette half molded body, is ejected with an ejector bin without ejecting the cassette half (2
) is obtained.

In this way, a cassette half (2) is obtained in which the transparent window body (4) is insert-molded into the main body part (3), and this cassette half (2) is inserted into the concave groove (6a) of the transparent window body (4).
) to (6g) are filled with the molding resin of the main body part (3) and integrated with the main body part (3), so the transparent window part is a transparent part around the reel shaft insertion holes (5a) and (5b), and both ends are transparent. There is a triangular shaped part that indicates the running direction of the tape.
Further, linear portions are formed at a predetermined interval between the insertion holes (5a) and (5b), and a portion for sensing the amount of tape is formed in each portion.

In this way, in the tape cassette of this example, that is, the cassette half (2), the transparent window (4) is securely inserted and integrated into the main body (3), and the transparent window (41) has various types of The gate marks g during molding of the transparent window body (4) itself remain and protrude from the side end surface, but the gate marks g remain on the main body part (3) of the transparent window body (4).
) is buried within the thickness of the main body (3) and is not exposed on the surface side, so that the appearance of the cassette half (2) is not impaired.

Next, FIGS. 4 and 5 show other embodiments, FIG. 4 is a plan view of the tape cassette on the other side, and FIG. 5 is a cross-sectional view of the center of the cassette half. 21)
The cassette half (22) is formed by inserting an elliptical transparent window (24) into a main body (23).

This transparent window body (24) is molded from transparent resin in the same manner as in the above-mentioned embodiment, and has a pair of reel shaft insertion holes (24).
5a) and (25b) are provided, and the outer peripheral surface is formed as an uneven surface (24a), and the molding of this transparent window body (24) also involves injecting transparent resin into the cavity of the mold from the side end surface side. As a result, gate marks remain and protrude on the side end surfaces of the transparent window body (24).

When this transparent window body (24) is inserted into the cavity of the mold during molding of the cassette half (22) and the main body molding resin is injected, this injected resin is transferred to the transparent window body (24).
), the body part (23) is molded by inserting the transparent window body (24) into the cassette half (22). In the cassette half (22) formed in this way, the main body (23) and the transparent window (24) have a complex cross-section with concave and convex shapes at the boundary between them, as shown in an enlarged view in FIG. 5B. This increases the bonding strength and allows them to be integrated.

Furthermore, in this example as well, the gate marks of the transparent window body (24) remain and protrude from the side end faces, so that they are buried within the thickness of the main body (23) and are not exposed on the surface side. The appearance of the cassette half (22) is not impaired.

Although the present invention has been described in detail above, the present invention is not limited to these embodiments, and can be modified in various ways without departing from the spirit of the present invention. In particular, the transparent window body may have various shapes. It is something that can be used interchangeably.

〔Effect of the invention〕

As described above, according to the present invention, a cassette half of a tape cassette having a transparent window is molded by inserting a transparent window of an arbitrary shape into the main body, so that the joint surface between the main body and the transparent window is formed. By creating a complex cross-sectional shape, it is possible to ensure good bonding strength with various materials, allowing for almost complete integration, and it is also possible to set the molding gate marks on the transparent window body in areas that are not exposed on the surface side. Therefore, it is possible to reduce the occurrence of defective products due to gate marks without damaging the appearance, and the mold has a longer service life because the window molding surface is not damaged by gate marks.Moreover, it is possible to change the window design. On the other hand, since the mold for the main body part is common and only the window molding mold can be changed, it is advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an example of a tape cassette according to the present invention;
Figure 2 is a cross-sectional view of the tape cassette during cassette half molding, Figure 3 is a perspective view of the transparent window used in the tape cassette, Figure 4 is a plan view of the other side of the tape cassette, and Figure 5. 4A is a cross-sectional view of a cassette half forming the tape cassette shown in FIG. 4, and FIG. 4B is an enlarged view of a portion of FIG. 4A. In the figure, (1) and (21) are tape cassettes, (2+
, (22) is a cassette half, (31, (23)
is the main body, (4). (24) is a transparent window. Preliminary drawing of a conventional tape cassette Figure 4 21: Tape 77 cot

Claims (1)

[Scope of Claims] A tape cassette comprising a transparent window through which a stored magnetic tape can be seen, the cassette comprising a pre-molded transparent window having a desired shape and insert molding when molding a cassette half body. A tape cassette formed by forming two halves and combining these cassette halves.