JPH04314513A - Holding case for magnetic tape cassette and its manufacture and device - Google Patents

Abstract

PURPOSE:To provide a holding case for cassette of two-color molding, which has high wear-resistance and strength and is superior in a cassette protective function and capable of observing visually the held cassette from the outside, and a manufacture, which can avoid complication in its molding step even if it is the two-color molding and is superior in productivity, and a device enabling the manufacture. CONSTITUTION:The first slide core 4 demarcating the inside of a lid part is provided movably freely in the direction corresponding to a taking-in-and-out direction of a cassette and the second slide core, which can move within the first slide core 4 by meeting almost at right angles with a moving direction of the core, is provided, in a manufacture manufacturing a holding case for a magnetic tape cassette and a device executing the manufacture. A fitting part bet the second slide core 5 and a driving device 20 moving the core is fitting allowing a movement of the first slide core, the second slide core and first slide core are moved in appropriate order and a plurality of resin are injected. Then this is the holding case for the magnetic tape cassette molded by the manufacture.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cassette storage case, its manufacturing method, and an apparatus, and more particularly to improvements in a magnetic tape cassette storage case used for storing magnetic tape cassettes such as audio equipment, its manufacturing method, and apparatus. It is something.

0002

2. Description of the Related Art Magnetic tape cassettes used for audio and the like are normally stored in a magnetic tape cassette storage case (hereinafter simply referred to as a "cassette storage case") made of plastic. This cassette storage case has a cassette front opening into which a magnetic head, etc. is inserted when the magnetic tape cassette (hereinafter referred to as "cassette") is loaded into a recording/reproducing device, and has a cassette that extends across the front opening. Since the magnetic tape is mounted on the cassette, it prevents dust from entering the cassette through the front opening, protects the magnetic tape located in the front opening, and protects the entire cassette. It is used for the purpose of protection.

To describe the basic structure of the cassette storage case, as is well known, the cassette storage case includes a lid portion provided with a pocket in which one end of the cassette is stored, and a lid portion pivotally attached to the lid portion and shaped like a door. It consists of a casing part that can be opened and closed, and the lid part and the casing part are integrally molded from synthetic resin.

[0004] General purpose polystyrene (GPPS), which has high transparency and is inexpensive, is often used as the synthetic resin for molding the storage case. That is, most conventional cassette storage cases are molded from transparent resin. This type of highly transparent synthetic resin is often used because it makes it easy to see the cassettes stored in the storage case.

[0005]

[Problem to be solved by the invention] However, GPP
Although the storage case molded from S has the advantage of high transparency, it has low hardness and low surface strength. For this reason, the pivot portion and the fitting and locking portion may wear out as the storage case is opened and closed, or may rub against the stored cassette during storage or transportation, resulting in the production of shavings. Since the shaving powder is a fine powder, it easily spreads unpredictably inside the storage case and adheres to the surface of the magnetic tape exposed on the opening side of the cassette. As a result, recording and playback are no longer performed at the locations on the magnetic tape where the shavings have adhered, resulting in so-called signal dropouts, resulting in poor recording and reproduction.
There is a problem that playback may not be possible.

[0006] Furthermore, in order to prevent the generation of shavings as described above, for example, if the storage case is molded using a resin with high wear resistance or a resin with good sliding properties, such resins have low transparency. However, there is a problem in that the index cards stored in the storage case cannot be viewed from outside the case.

[0007] Therefore, it appears that the problem can be solved by partially constructing the storage case from resin with high transparency and resin with high wear resistance. However, in such a storage case with partially changed performance, productivity would be extremely low if, for example, each part was molded separately and then assembled by gluing or the like.

On the other hand, although it appears that molding can be easily done by two-color molding, it was extremely difficult to mold the lid portion, as will be described below with reference to FIG. FIG. 6 is a sectional view of the mold for forming the lid. In FIG. 6, the lid portion 5
To explain the state of injection molding No. 2, the cavity (injection space) of the lid part 52 is molded by one fixed mold 70 and two movable molds 71 and 72 (72 is a slide core).

[0009] After the cavities formed by the respective molds are filled with a desired resin, the resin is suitably solidified, and then the movable molds 71 and 72 are replaced with the fixed mold 70.
The lid portion 52 is molded by being moved in the mold release direction (direction A and direction B in FIG. 6). When releasing the mold, the molded product cannot be released from the mold unless the mold 72 is slid in the direction B so as to pull out the portion located inside the pocket portion.

Since such a configuration is required, for example, if the center portion A of the lid portion 52 and the other shaded portion B are molded with different resins, the center portion A A structure is required in which another slide core corresponding to the above can be slid within the mold 72. However, since the mold 72 slides in the direction B, it is extremely difficult to drive another slide core. In other words, when the mold 72 is moved, the inner slide core is moved away from the mold 72. A structure for pulling it out is required, or the connection between the slide core and its driving means must be released. Therefore, even if the slide core can be moved, there is a problem in that the method for moving the mold and the molding steps become complicated.

That is, an object of the present invention is to solve the above-mentioned problems, and to provide a two-color molded cassette storage case that has an excellent cassette protection function and allows the stored cassettes to be viewed from the outside. However, it is an object of the present invention to provide a manufacturing method that avoids the complication of the molding step and has excellent productivity, and furthermore, to provide an apparatus that enables the manufacturing method of this cassette storage case.

0012

[Means for Solving the Problems] One of the above-mentioned problems of the present invention is that a lid portion provided with a pocket into which a portion of a magnetic tape cassette is inserted and a casing portion corresponding to the lid portion are pivotally connected to each other so as to be freely openable and closable. In the storage case for magnetic tape cassettes, at least the lid portion is molded in two colors using a mold using a slide core that is movable substantially perpendicular to the moving direction of the slide core for pocket molding. This can be solved by using a storage case for magnetic tape cassettes.

One of the above-mentioned problems of the present invention is to provide a magnetic tape cassette in which a lid portion provided with a pocket into which a portion of the magnetic tape cassette is inserted and a casing portion corresponding to the lid portion are pivotally connected to be openable and closable. In the manufacturing method of the storage case, the first slide core defining the inner wall surface of the molding space of the lid part is provided so as to be slidable in the cassette insertion direction, and the first slide core is provided so as to be movable substantially perpendicular to the moving direction of the first slide core. The first resin is injected with the second slide core protruding from the first slide core into the injection space, and then,
After injecting the second resin into the new space formed by retreating the second slide core, slide the first slide core together with the second slide core to a position where the inner portion forming the pocket is removed. This problem can be solved by a method for manufacturing a storage case for magnetic tape cassettes, which is characterized in that the lid part is taken out from a molding die.

Another object of the present invention is to provide a storage for magnetic tape cassettes, in which a lid portion provided with a pocket into which a portion of the magnetic tape cassette is inserted and a casing portion corresponding to the lid portion are pivotally connected to be openable and closable. In an apparatus for manufacturing a case, a first slide core defining an inner wall surface of an injection space of the lid part is provided to be movable in a direction corresponding to a cassette loading/unloading direction, and the first slide core is provided within the first slide core to be movable in a direction corresponding to a cassette loading/unloading direction. A second slide core movable in a direction substantially perpendicular to the moving direction of the slide core is provided, and the engagement portion between the lower end of the second slide core and the drive means for moving the second slide core is A core-side engaging portion having a sliding engaging surface along the moving direction of the first slide core and a driving-side engaging portion having an opposing engaging surface that engages with the sliding engaging surface are slidably fitted. The present invention is solved by an apparatus for manufacturing a storage case for magnetic tape cassettes, which is characterized by the following features:

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that FIG. 5 is a perspective view of the magnetic tape cassette storage case and the magnetic tape cassette. The magnetic tape cassette storage case 51 has a pocket 5.
4 and a casing part 53 having a pair of anti-rotation protrusions 55, and a support shaft 56 protruding inside the left and right side walls 33a of the casing part 53.
and fitting holes provided in the left and right side walls 54a of the pocket 54 are fitted, so that the lid part 52 and the casing part 53 can be opened and closed like a door.

The pocket 54 is for storing the thickened portion (opening portion 62 side) of the magnetic tape cassette 61, and the pair of anti-rotation protrusions 55 are for storing the thickened portion of the magnetic tape cassette 61 (opening portion 62 side).
The magnetic tape T is inserted through the shaft insertion hole 63 and engaged with the hub to prevent the magnetic tape T from sagging.

Further, a protrusion 57 is provided on the left and right side wall portions 54a.
are formed, and the left and right side wall portions 53 corresponding to the projections 57
An engagement recess 58 is formed in a. Therefore, when the lid portion 52 and the casing portion 53 are closed, the engagement recess 58 engages with the protrusion 57 to hold the lid portion 52 and the casing portion 53 in a closed state.

Furthermore, the flat plate portion of the lid portion 52 facing the upper and lower surfaces of the magnetic tape cassette 61, other than the edge portion B, a portion A is molded from a transparent GPPS resin as a first resin; The edge B indicated by diagonal lines in FIG. 5 was molded from a resin obtained by adding silicone oil to high-impact polystyrene (HIPS), which has high sliding properties, as a second resin.

In this way, the magnetic tape cassette 61
The parts that easily rub when stored, the fitting part between the support shaft 56 and the fitting hole, and the fitting part between the protrusion 57 and the engaging recess 58, which are easily scraped, are molded from synthetic resin with good sliding properties. Therefore, not only the storage case 1 but also the magnetic tape cassette 61 is not scraped, and the generation of scraping powder can be reduced. Further, since the area A excluding the edge B corresponding to the outer circumferential portion of the magnetic tape cassette 61 is transparent, the label of the stored magnetic tape cassette 61 and the description on the index card can be visually observed.

The magnetic tape cassette storage case 1 as described above is molded from two types of synthetic resins, and this type of molding can be performed by a two-color molding method using the molding die described below. .

The apparatus 1 shown in FIG. 1 is a mold apparatus for molding the lid part 52 of the storage case 51. Note that illustration of each injection gate is omitted for convenience. In the mold shown here, a cavity (injection space) is formed by a fixed mold 2, a movable mold 3, and a first slide core 4. A second slide core 5 that slides within the first slide core 4 is provided within the first slide core 4 .

The first slide core 4 defining the inside of the lid portion 52 is provided so as to be movable in a direction corresponding to the cassette loading/unloading direction (direction of arrow C in the figure). The second slide core 5, which is slidably disposed within the first slide core 4, is moved by a drive means 20, which is constituted by, for example, a hydraulic cylinder. This direction of movement is substantially perpendicular to the direction of movement of the first slide core 4 (direction of arrow D). The driving means 20 and the second slide core 5 are connected via a connecting member 8, for example.

The engagement portion between the lower end of the second slide core 5 and the connection member 8 has a slidably movable fitting structure. That is, at the lower end of the second slide core 5, there is a core-side engagement portion 6 in the shape of a widening groove that has a slide engagement surface 7 along the moving direction (direction of arrow C) of the first slide core 4. On the other hand, the connecting member 8 is provided with a substantially T-shaped drive-side engaging portion 9 having an opposing engaging surface 9a that slidably engages with the sliding engaging surface 7. There is.

Furthermore, the sliding movement of the first slide core 4 involves a movement distance (a movement distance of at least distance L or more) until the end portion 4a of the first slide core 4 comes out from the portion corresponding to the pocket 54. It is configured to be mobile. Further, the engagement portion between the lower end portion of the second slide core 5 and the connection member 8 is formed when the first slide core 4 is moved rightward in the figure (the state shown in FIG. 3).
If the engagement is maintained, backward movement (movement to the left in the figure) can be performed more smoothly than in a structure where engagement and disengagement are repeated each time.

A molding process using the mold apparatus 1 constructed as described above will be described. First, as shown in Figure 1,
The first resin is injected from a gate (not shown) with the second slide core 5 protruding from the first slide core 4 into the injection space. Note that the second slide core 5 can be positioned in this state by abutment between the step portion 4b of the first slide core 4 and the shoulder portion 5a of the second slide core. After this first resin is appropriately solidified, the second slide core 5 is moved backward (moved downward in the figure) to form a new space. The setting of this retraction distance h is based on the step surface 3 of the movable mold 3 that constitutes the movement space 10 of the second slide core 5, as shown in FIG.
This can be determined by the contact between a and the lower end surface 5b of the second slide core 5. That is, the dimension h in FIG.
The case is set to be thick.

After injecting the second resin into this new injection space from another gate and solidifying the resin appropriately, the first slide core 4 and the second slide core 5 are inserted from the pocket 54 to the end. The portion 4a is slid to the pulling position by a driving means connected to the connecting portion 22. Thereafter, the movable mold 3 is moved in the direction A (downward in the figure) and the lid portion 52 is taken out from the mold.

The casing part 53 is molded so that the edge B and the other area A are made of the same resin as the A part and B part of the lid part 52, respectively. The slide core in this case may have a mold structure that includes a slide core that moves in the thickness direction of the storage case.

Note that in the above embodiment, the cassette opening 62
Although the above description has been made regarding the type of case that is inserted into the pocket 54, the present invention naturally applies to a thin storage case, that is,
The present invention can also be appropriately applied to a storage case in which the rear or side portion of a cassette is stored in a pocket.

Furthermore, the engagement structure between the second slide core and its driving means in the present invention is not limited to the engagement structure as shown in FIG. can also be modified in various ways. Furthermore, it goes without saying that the structure may include a plurality of second slide cores. That is, the storage case according to the present invention is not limited to the form shown in FIG. 5, but can take various forms.

[0030]

As described above, the present invention makes the first slide core defining the inside of the lid part movable in the cassette loading/unloading direction, and allows the first slide core to move within the first slide core. A second slide core movable in a direction perpendicular to the direction is provided, and an engagement portion structure between the second slide core and a driving means of the second slide core allows the first slide core to move. Therefore, even if the first slide core moves, the connection structure between the second slide core and its driving means does not become complicated. Further, due to this connection structure, the molding step is relatively simple even though the second slide core moves in two stages, which is a complicated movement, and the size of the mold is avoided. According to the present invention, even in two-color molding, it is possible to avoid complication of the molding step and provide a manufacturing method with excellent productivity, and furthermore, it is possible to provide a manufacturing apparatus for this cassette storage case.

The storage case for magnetic tape cassettes of the present invention includes a side wall of the lid member and the casing member, including a flat plate portion and a pivoting portion of the lid member and the casing member, which face the thickened portion of the magnetic tape cassette to be stored. This part is molded from a resin that has better sliding properties than the other parts, which are molded from a resin that can be seen from outside the case. Therefore, the parts that are easily rubbed when the magnetic tape cassette is stored and the parts that are easily scraped during opening and closing operations can be molded with synthetic resin with good sliding properties, which can reduce the generation of shavings that impede good recording and playback of the magnetic tape cassette. In addition, since the area for viewing the label of the stored magnetic tape cassette and the writing on the index card is molded from a transparent synthetic resin, there is no possibility that these writings will become invisible from outside the case.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a mold for molding a storage case for a magnetic tape cassette according to the present invention, and is a sectional view showing a state at a first stage during injection molding.

FIG. 2 is a cross-sectional view of a main part of a mold for molding a magnetic tape cassette storage case according to the present invention, and is a cross-sectional view showing a second stage state during injection molding.

FIG. 3 is a cross-sectional view of a main part of a mold for molding a magnetic tape cassette storage case according to the present invention, and is a cross-sectional view showing a third stage of injection molding.

FIG. 4 is a cross-sectional view of a portion taken along line E-E in FIG. 1.

FIG. 5 is a perspective view of an embodiment of a magnetic tape cassette storage case and a magnetic tape cassette according to the present invention.

FIG. 6 is a sectional view of a mold for molding a conventional magnetic tape cassette storage case.

[Explanation of symbols]

1 Mold equipment 2 Fixed mold 3 Movable side mold 3a Stepped surface 4 First slide core 4a End 4b Stepped section 5 Second slide core 5a Shoulder 5b Lower end surface 6 Core side engaging part 7 Slide engagement surface 8 Connecting member 9 Drive side engagement part 9a Opposing engagement surface 10　Movement space 20 Driving means 21 Piston 22 Connecting part 51 Storage case for magnetic tape cassette 52 Lid 53 Casing part 53a Left and right side walls 54 Pocket 54a Left and right side walls 55 Anti-rotation protrusion 56 Support shaft 57 Protrusion 58 Engagement recess 61 Magnetic tape cassette 62 Increased thickness part 63 Shaft insertion hole

Claims (3)

[Claims] 1. A storage case for a magnetic tape cassette, in which a lid portion provided with a pocket into which a portion of the magnetic tape cassette is inserted and a casing portion corresponding to the lid portion are pivotally connected to be openable and closable, wherein at least the lid portion is A storage case for magnetic tape cassettes, characterized in that it is molded in two colors using a molding die that uses a slide core that can move almost orthogonally to the direction of movement of the slide core for pocket molding. 2. A method for manufacturing a storage case for magnetic tape cassettes, in which a lid part provided with a pocket into which a part of the magnetic tape cassette is inserted and a casing part corresponding to the lid part are pivotally connected to be openable and closable, wherein the lid part A first slide core that defines the inner wall surface of the molding space is provided so as to be slidable in the cassette insertion direction, and a second slide core that is provided so as to be movable substantially orthogonally to the first slide core moving direction is attached to the first slide core. The first resin is injected in a state in which the slide core protrudes into the injection space, and then the second resin is injected into a new space formed by retracting the second slide core, and then the first resin is injected into the injection space. A method for manufacturing a storage case for a magnetic tape cassette, characterized in that the core is slid together with the second slide core to a position where the inner part forming the pocket is pulled out, and then the lid part is taken out from the mold. 3. An apparatus for manufacturing a storage case for magnetic tape cassettes, in which a lid part provided with a pocket into which a part of the magnetic tape cassette is inserted and a casing part corresponding to the lid part are pivotally connected to be openable and closable, A first slide core that defines the inner wall surface of the injection space of the lid part is provided to be movable in a direction corresponding to the cassette loading/unloading direction, and a first slide core is provided within the first slide core with respect to the moving direction of the first slide core. A second slide core movable in a substantially orthogonal direction is provided, and an engaging portion between a lower end of the second slide core and a driving means for moving the second slide core is arranged in a direction in which the first slide core moves. A magnetic device characterized in that a core-side engaging portion having a sliding engaging surface along the same direction and a driving-side engaging portion having a facing engaging surface that engages with the sliding engaging surface are slidably fitted together. Manufacturing equipment for storage cases for tape cassettes.