JPH065040A - Container made of resin - Google Patents

Abstract

PURPOSE:To provide a tape cassette, whose tape winding diameter can be readily confirmed and appearance is excellent. CONSTITUTION:Tape-cassette halves 3a and 3b have transparent windows 13 in opaque parts. Each transparent window continues from the edge of, one side wall 7 to the edge of a side wall 7 at the opposite side through a main plate part 4. Thus, a tape cassette 3 has the transparent windows 13 along the entire outer surface. Therefore, defective molding and the like can be prevented by dividing the primary-side cavity for the opaque part into two parts at the time of dichroic molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin container used as a tape cassette or the like.

[0002]

2. Description of the Related Art For example, in an audio cassette tape, as shown in FIG. 6, a magnetic tape 2 wound around a pair of rotatable hubs 1 is a cassette 3 which is a resin container.
It is stored inside. This tape cassette 3 is generally a cassette half 3a, which is a pair of box-shaped resin containers,
It is composed by combining 3b. This cassette half 3a,
In 3b, the side walls 5, 6 and 7 are bent substantially vertically in the same direction from each side of the rectangular main plate portion 4 which is the bottom wall. Also,
A bulging portion 8 is provided at the center of the front side of the main plate portion 4, and in the bulging portion 8, a front tooth portion (not shown) for pressing the exposed portion of the tape is provided on the front side wall 5. Further, in the central portion of the main plate portion 4, there are a pair of left and right hub receiving portions 10 for rotatably supporting the hub 1. Further, in the cassette tape, generally, the tape winding diameter can be seen through from the outside. Therefore, in the conventional tape cassette 3 shown in FIG. 6, the main plate portion 4 has a space between the hub receiving portions 10. A small transparent window 11 is provided at the position. However, with such a small transparent window 11, the visibility is poor and it is difficult to confirm the tape winding diameter. On the other hand, conventionally, there is also a tape cassette 3 which is made entirely transparent, but with this, it is not good to look at because it can see unnecessary things such as internal ribs and guide rollers. On the other hand, as shown in FIG. 7, conventionally, there is also a tape cassette 3 in which a large transparent window 12 including both hub receiving portions 10 is provided in the main plate portion 4.

By the way, the cassette halves 3a and 3b having the transparent windows 11 and 12 as described above are molded in two colors, for example.
In two-color molding, first, a primary side cavity in the shape of a cassette half 3a, 3b excluding a transparent window is formed between mold members, and the primary side cavity is filled with an opaque primary side resin. To do. Next, a secondary side cavity having the shape of the transparent windows 11 and 12 is formed between the mold member and the primary side resin solidified in the primary side cavity, and a transparent cavity is formed in the secondary side cavity. Fill the secondary resin. The gate for pouring the molten resin into the cavity is the main plate 4 and the transparent window 1
It may be provided as a direct gate in which spears and valves are provided on the surfaces of 1 and 12, but, for example, if a gate mark is formed on the surface of the main plate portion 4, the external appearance deteriorates. There is also one in which the side gate is a tunnel gate to a position corresponding to the front tooth portion of the front side wall 5. However, if the primary side gate is provided only at the position corresponding to the front tooth portion, filling of the primary side resin with the primary side cavity will be hindered especially when the transparent windows 11 and 12 are large as shown in FIG. The molded cassette halves 3a and 3b may be warped. When such warpage occurs, the tape may be inclined with respect to the head, which may adversely affect the reproduction characteristics. Therefore, in order to prevent the occurrence of warpage, secondary gates, which are tunnel gates, are provided at the positions corresponding to the rear portions of the left and right side walls 7 and the rear side walls 6 in addition to the front teeth. However, providing a large number of tunnel gates, which is troublesome to process, is disadvantageous in die manufacturing. In addition, in the case of a tunnel gate, even if there are manifolds and spears, the resin in the sub-runner from this spear or valve gate to the tunnel gate is wasted. There is a lot of waste. Further, when a plurality of gates are provided for one cavity, a weld line is formed at the confluence of the resin flow from these gates, and the appearance is impaired. Moreover,
If the plurality of gates are located in a biased position, the weld line may be displaced from the center of the cassette halves 3a and 3b or may be obliquely formed, further impairing the appearance.

[0004]

As described above, in the conventional tape cassette, since the transparent window is provided only in the main plate portion, there is a problem that the visibility is poor and it is difficult to confirm the tape winding diameter. On the other hand, conventionally, there is a tape cassette which is made entirely transparent, but this has a problem in that it looks unnecessarily, such as internal ribs and guide rollers, which is not good to look at. Further, when the tape cassette half is molded in two colors, for example, by providing the transparent window as described above, there are problems in molding failure and mold manufacturing.

The present invention is intended to solve such a problem and has a novel design, and when used in, for example, a tape cassette, the visibility of the tape winding diameter is maintained without deteriorating the appearance. It is an object of the present invention to provide a resin-made container capable of increasing the molding cost and eliminating molding defects and problems in mold production when molding two colors.

[0006]

The present invention is intended to achieve the above object, and the invention of claim 1 provides a resin container having a side wall bent from the periphery of the bottom wall to the same side.
In the opaque portion, there is a transparent portion that continues from the leading edge of one side wall to the leading edge of the side wall that penetrates the bottom wall and faces the one side wall.

The invention of claim 2 includes a pair of claims 1
The resin container described is butted against the tip edge of the side wall,
It has a transparent portion that extends over both sides and extends over the entire circumference.

[0008]

In the resin container according to the present invention, the transparent portion is provided in the opaque portion, the transparent portion being continuous from the leading edge of the side wall to the leading edge of the side wall facing the one side wall. It is a design that is novel and has high utility value. Further, in the case of two-color molding, the opaque portion in the resin container is completely divided into two by the transparent portion, so that a gate is provided in each of the two cavities for the opaque portion formed in one resin container. Although it must be provided, the complete separation of the opaque portions on both sides of the transparent portion makes it unlikely that molding defects will occur.

Further, the resin container according to the invention of claim 2 is
A pair of the resin containers according to claim 1 are butted against each other at the leading edges of the side walls, and a transparent portion is provided over the entire circumference so as to have a novel and highly useful design. . For example, when used as a tape cassette, the visibility of the tape winding diameter can be increased without deteriorating the appearance.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the resin container of the present invention will be described below with reference to the drawings. The resin container of this embodiment is a tape cassette 3 used for a cassette tape as shown in FIG. 1 and a pair of cassette halves 3a and 3b constituting the tape cassette. Since the cassette tape shown in FIG. 1 has the same configuration as the cassette tape shown in FIGS. 6 and 7 described above, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted. In the cassette halves 3a and 3b shown in FIG. 1, the transparent window 13 which is a transparent portion penetrates the cassette halves 3a and 3b in the longitudinal direction. That is, the transparent window 13 is continuous from the leading edge of the left and right side walls 7 through the main plate portion 4 to the leading edge of the side wall 7 facing the one side wall 7, and the pair of hub receiving portions is provided. Contains 10. And a pair of cassette halves 3a,
The tape cassette 3 in which 3b is abutted and joined at the leading edges of the side walls 5, 6, 7 has a transparent window 13 that extends over the entire circumference and extends over both cassette halves 3a, 3b. The parts other than the transparent window 13 in the tape cassette 3 and the cassette halves 3a and 3b are opaque parts.

Next, an example of a mold used for two-color molding of the cassette halves 3a and 3b will be described with reference to FIGS. This mold includes a fixed mold 21 and a movable mold 22 that move in the vertical direction in the drawing to open and close. Fixed type
Reference numeral 21 forms the outer surface of the box-shaped cassette halves 3a, 3b, and the movable die 22 forms the inner surface of the cassette halves 3a, 3b. The movable mold 22 is a movable mold body.
23, a first movable core member 24 and a pair of second movable core members 25 are incorporated. The first movable core member 24
Is a movable body 23 driven by a hydraulic cylinder device.
With respect to the cavity formed in the mold, the part that corresponds to the transparent window 13 of the main plate part 4 of the cassette halves 3a and 3b is closed by moving up and down with respect to the fixed mold 21.
Further, both the second movable core members 25 move up and down independently of the first movable core member 24 with respect to the movable die main body 23 by the driving of the hydraulic cylinder device or the like, and the first movable core members 24 Of the cavities formed in the mold, by sliding on both side surfaces of the
The portions corresponding to the transparent window 13 on both side walls 7 of the cassette halves 3a and 3b are closed. That is, the movable core members 24 and 25 form the inner surface of the transparent window 13, and in particular, the second movable core member 25 forms both the leading edges of the transparent window 13. A pair of pins 26 for forming the hub receiving portion 10 of the cassette halves 3a and 3b are provided on the movable die 22 side. These pins 26 are integral with the movable main body 23 and slide with respect to the first movable core member 24. Then, FIG. 2A and FIG.
As shown in (a), the fixed mold 21 and the movable mold 22 are clamped together, and the movable core 22 and the movable core 22 are pressed against each other in a state where the movable core members 24 and 25 are abutted against the fixed mold 21. After the primary side cavity 27 is formed in the core, and the primary side cavity 27 is filled with the primary side resin, the movable core members 24 and 25 are fixed as shown in FIGS. 2B and 3B. Separated from mold 21, fixed mold
A secondary side cavity 28 is formed between 21, the movable die 22, and the primary side resin P1 solidified in the primary side cavity 27. In particular, one for one cassette half 3a, 3b
The secondary cavity 28 is completely divided into two by the movable core members 24 and 25. In addition, the fixed mold 21 has a plurality of primary side gates 29 respectively opening to the divided primary side cavities 27 and the secondary side cavities.
A secondary side gate 30 opening to 28 is formed. The primary-side gate 29 is a tunnel gate that opens from the sub-runner 31 formed between the fixed mold 21 and the movable mold body 23 to a position corresponding to the side wall 5, the side wall 6, or the side wall 7 during mold clamping. There is. On the other hand, the secondary gate 30 is a direct gate having a spear or a valve built therein, and is opened to a position corresponding to the center of the main plate portion 4.

Next, two-color molding using the mold will be described. When molding the tape cassette halves 3a and 3b, first, as shown in FIGS. 2 (a) and 3 (a),
The fixed die 21 and the movable die 22 are clamped, and the movable core member 2
Butts 4 and 25 to fixed mold 21. In this state, the transparent window 13
The secondary side cavity 28 portion corresponding to the movable core member 24,
It is blocked by 25, and between the fixed mold 21 and the movable mold 22, 1
A primary side cavity 27 divided into two is formed for each cassette half 3a, 3b. And the primary gate 29
Then, the opaque primary resin P1 is injected and filled into the primary cavity 27. As a result, parts of the cassette halves 3a and 3b other than the transparent window 13 are molded. Then, after the primary resin P1 filled in the primary cavity 27 is solidified, as shown in FIGS. 2B and 3B, the movable core member 24, Lower 25 as shown.
At this time, the first movable core member 24 is moved by the thickness of the main plate portion 4 as indicated by arrow A, and the second movable core member 25 is moved by the height of the side wall 7 as indicated by arrow B. Move only a minute. In this state, the transparent window 13 is provided between the fixed mold 21, the movable mold 22, and the primary resin P1 solidified in the primary cavity 27.
The secondary side cavity 28 having the shape of is formed. In addition,
The pin 26 remains in contact with the fixed mold 21. And
A transparent secondary resin is injected and filled from the secondary gate 30 into the secondary cavity 28. Thereby, the transparent window 13 is formed. Then, the 2 filled in the secondary side cavity 28
After the secondary resin has solidified, the fixed die 21 and the movable die 22 are opened, and the formed tape cassette halves 3a and 3b are released and taken out.

In this way, the cassette halves 3a, 3b having the transparent window 13 extending from the one side wall 7 to the other side wall 7 through the main plate portion 4 as shown in FIG. As a result, the tape cassette 3 having the transparent window 13 over the entire circumference can be obtained.
In this way, the tape cassette 3 having the transparent window 13 extending over the entire circumference has excellent visibility of the tape winding diameter, and can be used, for example, in a dark place such as the inside of a vehicle or when viewed obliquely.
You can easily and surely check the tape winding diameter. At the same time, unnecessary things such as internal ribs and guide rollers are not visible and it looks good. Moreover, the design is novel. In addition, since the primary side cavity 27 for one cassette half 3a, 3b is completely divided into two with the transparent window 13 sandwiched between them, both primary side cavities 27 have a unified shape. Resin can be smoothly filled into the primary cavities 27 from the primary gates 29, respectively. As a result, the molded cassette halves 3a and 3b are less likely to warp,
It is possible to prevent deterioration of reproduction characteristics. At the same time, it suffices to provide only one primary gate 29 for each primary cavity 27. Therefore, it is possible to prevent the generation of weld lines, and it is also advantageous in manufacturing a mold and saving resin.

Next, another example of a mold for molding the cassette halves 3a and 3b in two colors will be described with reference to FIG. In this mold, the cassette half 3 of the cavity
The pair of second movable core members 35 for closing the portions of the side walls 7 of a and 3b corresponding to the transparent window 13 are replaced with those which move in the horizontal direction in the figure with respect to the movable mold body 23. That is, the second movable core member 35 slides on the lower surface of the fixed die 21 in the drawing and opens and closes with respect to the first movable core member 24. The first movable core member 24 forms the inner surface of the transparent window 13, while the second movable core member 35 forms the outer surface of the transparent window 13 of the side walls 7. At the time of molding, first, as shown in FIG. 4A, the fixed die 21 and the movable die 22 are clamped, and the first movable core member 24 is abutted against the lower surface of the fixed die 21 shown in the drawing. , Both second movable core members 35 are provided on both side surfaces of the first movable core member 24.
Are abutted against each other to form the primary side cavity 27. The primary cavity 27 is filled with an opaque primary resin P1 to mold the cassette halves 3a and 3b other than the transparent window 13. Then, as shown in FIG.
The movable core members 24 and 25 are moved with respect to the movable main body 23. At that time, as shown by an arrow A, the first movable core member 24 is moved downward in the figure by the thickness of the main plate portion 4, that is, the fixed mold 21
Away from the second movable core member 35.
Is moved in the direction away from the first movable core member 24 by the thickness of the side wall 7 along the lower surface of the fixed mold 21 as shown by the arrow C. In this way, the secondary side cavity 28 is formed, and the transparent secondary side resin is filled in the secondary side cavity 28 to form the transparent window 13. In the mold shown in FIG. 2, the thickness of the second movable core member 25 is the same as the thickness of the side wall 7 and is very thin, but the mold shown in FIG. Since it can be made thick to some extent, it is advantageous in strength. On the other hand, the mold shown in FIG. 4 has the second movable core member 35, the fixed mold 21, and the first movable core member 24 in the mold manufacturing process.
Since the positioning of and is complicated, the configuration of the mold shown in FIG. 2 is advantageous in that respect.

FIG. 5 shows another embodiment of the present invention.
The cassette halves 3a and 3b of this embodiment are provided with two layers of an opaque primary resin P1 and a transparent secondary resin P2 on both sides of the transparent window 13. For the cassette halves 3a and 3b having such a two-layer portion, for example, a die in which a die member for closing a portion of the main plate portion 4 corresponding to the transparent window 13 in the cavity is vertically movably incorporated into the fixed die side is used. It can be molded by The secondary side gate may be, for example, a movable core member as shown in FIG. 2 which is a mold member that closes a portion of the side wall 7 of the cavity corresponding to the transparent window 13, and then the side wall of the secondary cavity from the fixed mold. The side gate may be opened to a position corresponding to 7.

The present invention is not limited to the above embodiment, but various modifications can be made. For example,
The structure of the mold for molding the two halves of the cassette halves 3a and 3b is not limited to that of the above embodiment. Further, in the above embodiment, the resin container is the cassette halves 3a, 3b for the audio cassette tape, but the present invention is applicable to the resin container for the magnetic recording medium other than the audio cassette tape, or another resin container. Can also be applied. Further, in the above-described embodiment, the transparent portion and the opaque portion are integrally formed by two-color molding, but the transparent portion and the opaque portion may be separately formed and then joined together.

[0017]

The resin container according to the first aspect of the present invention has, in the opaque portion, a transparent portion that is continuous from the leading edge of one side wall to the leading edge of the side wall that passes through the bottom wall and faces the one side wall. , Has a design that is novel and has high utility value. Further, when two-color molding is performed on such a resin container, the cavity for the opaque portion is completely divided into two, so that molding defects can be prevented and it is also advantageous in manufacturing a mold.

Further, the resin container according to the invention of claim 2 is
A pair of resin containers according to claim 1 are butted against each other at the leading edges of the side walls, and a transparent portion is provided over the entire circumference extending over the both sides, which is a novel and highly useful design. For example, when used as a tape cassette, the visibility of the tape winding diameter can be increased without deteriorating the appearance.

[Brief description of drawings]

FIG. 1 is a perspective view of an entire cassette tape showing an embodiment of a resin container of the present invention.

FIG. 2 is a sectional view taken along the longitudinal direction of the cassette half showing an example of a two-color molding die for a tape cassette half which is a resin container, and FIG.
(B) shows the formation of the secondary side cavity.

FIG. 3 is a cross-sectional view of the same cassette half taken along the lateral direction, in which (a) shows the formation of the primary side cavity and (b) shows the formation of the secondary side cavity.

FIG. 4 is a cross-sectional view taken along the longitudinal direction of the cassette half showing another example of the two-color molding die for the tape cassette half, (a) showing the formation of the primary side cavity, and (b) showing the secondary cavity. It shows the formation of the side cavity.

FIG. 5 is a partial cross-sectional view of a cassette half according to another embodiment of the present invention.

FIG. 6 is a perspective view showing an example of a conventional cassette tape.

FIG. 7 is a perspective view showing another example of a conventional cassette tape.

[Explanation of symbols]

 3 Tape cassette (resin container) 3a, 3b Tape cassette half (resin container) 4 Main plate part (bottom wall) 5 Side wall 6 Side wall 7 Side wall 13 Transparent window (transparent part)

Claims (2)

[Claims] 1. A resin container having a side wall that is bent from the periphery of the bottom wall to the same side, in the opaque portion, from the leading edge of the one side wall to the leading edge of the side wall that penetrates the bottom wall and faces the one side wall. A resin container having a continuous transparent portion. 2. A resin container comprising a pair of the resin containers according to claim 1 butted against each other at a front edge of a side wall thereof, and having a transparent portion extending over the entire circumference thereof.