JPH071621B2 - Tape cassette and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention a. TECHNICAL FIELD The present invention relates to a tape cassette and a manufacturing method thereof.

B. 2. Description of the Related Art A conventional tape cassette, for example, a video tape cassette of a type called S-VHS, has a pair of left and right reel hubs 42 and 43 (tape reels) around which a magnetic tape 41 is wound, as shown in FIGS. ) Is accommodated in the lower half 5 and the upper half 4 to which the leaf springs 55 for pressing and holding the reel hubs are fixed are joined together. In the figure, 9 and 10 are a pair of left and right transparent windows, and 60 and 61 are tape guides. An opening / closing lid 20 called a lid is attached to the front surface of the cassette. However, the lid 20 is omitted in FIG. 9 showing the lower half 5 side (cassette bottom side).

In this tape cassette 1, a narrow groove 11 (which can serve as a guide for preventing erroneous insertion when the cassette is inserted into the tape deck) is provided on the back side of the lower half 5. A release pin insertion hole 12 for the tape reel rotation preventing claw is formed at an intermediate position of the groove 11, and an S-VHS mode (that is, a luminance signal is separated from a color signal and the A detection hole 13 for detecting a high frequency band) is formed. This detection hole 13 is
Although it is formed as shown in the figure and the detector is inserted from the tape deck side, it is the same as the S-VHS system except that this detection hole 13 is not present in the normal VHS type tape cassette. It is configured.

To manufacture the tape cassette 1 for S-VHS,
Use a mold as shown in FIG. That is, this mold is
Movable type 15 with movable side insert 14, fixed side insert 16
Each has a fixed mold 19 with a
A cassette half molding space 20 is formed between 16 parts. Here, the resin injection gate, ejector pin, and the like are omitted from the drawing. In this mold, the fixed-side insert 16 has a pin-shaped protrusion until it contacts the movable-side insert 14.
Since 21 is integrally provided, the above-mentioned detection hole 13 is formed at the position of this protrusion 21.

However, when this mold is used for normal VHS type cassette molding, as shown in FIG.
As a fixed side nest, a protrusion 22 lower than the pin-shaped protrusion 21
It is necessary to prepare another nesting 23 having the above and replace it with the nesting 16. However, producing two kinds of nests in this way is costly and the replacement work is complicated.

C. OBJECT OF THE INVENTION It is an object of the present invention to provide a tape cassette in which different types of tape cassettes can be molded easily and at low cost, and workability is greatly improved, and a method for manufacturing the same.

D. Configuration of the Invention That is, according to the present invention, in a tape cassette configured to detect the type of a tape cassette by the presence or absence of a detection hole, in the state where the detection hole does not exist, traces of replacement pins at the time of molding on the surface of this area The present invention relates to a tape cassette characterized in that

Further, according to the present invention, when the first pin and the second pin are exchangeably incorporated into the main mold to form a corresponding cassette half, the tape cassette is selected by selecting the first pin and the second pin. The present invention also provides a method for manufacturing a tape cassette, in which the presence or absence of a detection hole for detecting the type is determined.

E. Examples Hereinafter, examples of the present invention will be described. However, in this embodiment, parts common to those in FIGS. 8 to 12 are designated by common reference numerals, and description thereof may be omitted.

First, the tape cassette 71 according to this embodiment will be described with reference to FIGS.

1 and 2 show an S-VHS type tape cassette 71.
However, the detection hole 13 similar to that described above has the groove 11
Is formed at the end of. However, this detection hole 13 is formed by a pin that is incorporated in the mold in a replaceable manner as described later, and this point is fundamentally different from the conventional cassette.

3 and 4 show a normal VHS tape cassette 7
1 and the above-mentioned detection hole 13 is not formed. However, in this case, it is characteristic that the trace 70 of the end face of the pin, which will be described later, remains in a substantially circular shape on the bottom surface of the groove 11.

As described above, both the S-VHS type cassette and the ordinary VHS type cassette are manufactured by selecting the pins to be used at the time of molding, so that they are easy to mold and are very advantageous in terms of mass productivity and cost. is there.

Next, a method for manufacturing the above tape cassette 71 will be described.

First, as shown in FIG. 5, molds composed of various molds are assembled. That is, this mold has a movable mold 15, a movable mold 14, a fixed mold 19, and a fixed mold 76, and a pin 72 of a predetermined length is inserted through the mold 76. This pin 72
Is set so that its tip surface 72a is brought into contact with the insert 14 as shown. Therefore, the above-described detection hole 13 by the pin 72 is formed in the cassette half 5 obtained by the resin injection. This cassette half is used for S-VHS.

On the other hand, in the case of an ordinary VHS type tape cassette, as shown in FIG. 6, it is only necessary to replace the above-mentioned pin 72 with another slightly shorter pin 82 and attach it to the nest 76. That is, the pin 82 is positioned with a constant gap 80 between the tip surface 82a of the pin 82 and the nest 14. Therefore, the above-described detection hole 13 is not formed in the cassette half obtained by molding. However, when the product (molded product) is removed from the fixed mold, specifically, the insert 76, the shape of the tip end surface 82a of the pin 82 is transferred, and this trace 70 (see FIG. 3) is left on the half surface.

As can be understood from the above method, different types of tape cassettes, that is, the S-VHS system and the VHS system are connected to the pins 72 and 82.
Molding can be performed only by exchanging with, and in this exchanging, since the insert 76 can be used in common as it is, the cost of the mold can be greatly reduced as compared with the conventional method. Moreover, since only the pins need to be replaced, the work becomes easier and the workability is significantly improved.

FIG. 7 shows a mold which is a further improvement of the above mold. 7th A
Although the mold shown is used for S-VHS, the above-mentioned pin 72 is connected to the outside of the insert 76 by the mold plates 90 and 91.
And a mounting plate 93 for fixing the pin 72 are fixed to the outer surface of the mold plate 92 for pressing the pin 72 in order. A stopper plate 94 is fixed between the plates 90-91-92. Note that A, B, and
C, D, E, and F are simplified illustrations of fixing bolts. Further, 95 is an ejector pin used when taking out the product, but only one is shown for simplification of the drawing.

When the mold shown in Fig. 7A is used, the work of exchanging pins becomes very easy. That is, as shown in FIG. 7B, first, the bolt A is removed, the bolt D is removed, and the plate 94 is rotated about the bolt E in the direction of the arrow 97 to change the position to the movable die 15 side.
Tighten the bolt D here, the plates 91, 90, nesting
The 76 is supported on the movable mold 15 side, and the plate 92 is
And 93 are removed. Then, in this state, insert the pin 72 into the insertion hole.
When it is removed from 96, another pin 82 is newly inserted into the insertion hole 96, so that the pin can be easily replaced, and the mold can be easily assembled by the operation reverse to the above.

Therefore, when the mold shown in FIG. 7 is used, it is not necessary to dismount the mold from the molding machine (when the pin is replaced, the entire fixed side of the mold is disassembled), and disassembly can be performed only once. Become.

Although the present invention has been illustrated above, the above-described example can be further modified based on the technical idea of the present invention.

For example, the shapes and sizes of the pins 72 and 82 described above may be variously changed, and the mold configuration may be changed to other types.

F. As described above, according to the present invention, the presence or absence of the type detection hole of the tape cassette is determined by the replacement pin at the time of molding (when there is no detection hole, the trace of the pin remains). Since the molds other than the above can be used in common as they are, the manufacturing cost can be greatly reduced. Moreover, since only the pins need to be replaced, the work becomes easier and the workability is significantly improved.

[Brief description of drawings]

1 to 7 show an embodiment of the present invention. FIG. 1 is a rear view of a part of an S-VHS type tape cassette (lower half), and FIG. 2 is II of FIG. -II line sectional view, FIG. 3 is a rear view similar to FIG. 1 of a normal VHS tape cassette, and FIG. 4 is a IV-IV line sectional view of FIG. 3, FIG. 5, and FIG. Fig. 7A is a sectional view of a part of a mold used for cassette half molding, Fig. 7A is a sectional view of an improved mold, and Fig. 7B is a sectional view of a mold partially disassembled when a pin is replaced. 8 to 13 show a conventional example, FIG. 8 is a plan view of a tape cassette, FIG. 9 is a rear view of the same tape cassette, and FIG. 10 is a line XX of FIG. An enlarged sectional view, FIG. 11 is an enlarged sectional view taken along line XI-XI of FIG. 9, and FIGS. 12 and 13 are sectional views of a part of a mold used for cassette half molding. In the reference numerals used in the drawings, 4, 5 ... Cassette half 11 ... Groove 13 ... Detection hole 14 ... Movable side nest 15 ... Movable type 16, 23, 76 ... Fixed side nest 19 ... Fixed Mold 20 …… Molding space 70 …… Trace 72, 82 …… Pins 90, 91, 92, 93, 94 …… Plate 95 …… Ejector pins A, B, C, D, E, F …… Bolts.

Claims (2)

[Claims] 1. A tape cassette constructed so that the type of tape cassette can be detected depending on the presence or absence of a detection hole, and when the detection hole is not present, traces of replacement pins for molding remain on the surface of this region. A tape cassette characterized by that. 2. A tape cassette type according to the selection of the first pin and the second pin when molding the corresponding cassette half by incorporating the first pin and the second pin in the main mold in a replaceable manner. A method for manufacturing a tape cassette, in which the presence or absence of a detection hole for detection is determined.