JPH08235819A - Tape cassette - Google Patents

Abstract

PURPOSE: To reduce the failure in combining a cover half and a base half at the time of assembling a cassette and to improve the productivity by setting the dimension of the space part at the cover half side larger than that of the space part at the base half side. CONSTITUTION: A pair of hubs, i,e, a hub 6 at the supply side and a hub at the take-up side are rotatably housed inside a cassette casing corresponding to left/right ports 4a, 4b and 5a, 5b for hub driving shafts formed respectively on the cover half 2 and the base half 3. Inside the cassette casing 1, pins 10a, 10b positioned at the left/right sides of an opening part 9 are projectingly provided at the side of base half 3, and also with supporting shafts 11a, 11b projectingly provided adjacent thereto, guide rollers 12a, 12b are pivotally supported so as to be rotatable. At this time, the dimension (a) of the space part 21 at the side of the cover half 2 for inserting a shield plate is set larger than that of the space part 22 at the side of the base half 3 for inserting the shield plate 16.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a tape cassette,
In particular, it relates to the structure of the built-in portion of the shield plate.

[0002]

2. Description of the Related Art First, the construction of a general tape cassette will be described with reference to FIGS. The tape cassette illustrated here is a compact cassette for audio that is widely used at present, and the cassette housing 1 of this tape cassette has a pair of upper and lower plastic halves, that is, a cover half 2 and a base formed in a substantially symmetrical shape. The cover half 2 and the base half 3 are fixed to each other in a combined state by screwing or welding.

Inside the cassette housing 1, a pair of hubs, ie, supply-side hubs, are provided corresponding to the left and right hub drive shaft insertion holes 4a, 4b and 5a, 5b formed in the cover half 2 and the base half 3, respectively. 6. The take-up hub 7 is rotatably housed, and the magnetic tape 8 is wound around the supply hub 6 and the take-up hub 7 with both ends thereof fixed.

An opening 9 for exposing the internal magnetic tape 8 is provided on the front side of the cassette housing 1. Pins 10a and 10b are provided on the side of the base half 3 so as to project inside the cassette housing 1 located on both the left and right sides of the opening 9, and a support shaft 11a that is provided adjacent to the pins 10a and 10b.
Guide rollers 12a and 12b are rotatably supported by 11b, respectively, and the magnetic tape 8 drawn out from the supply-side hub 6 passes through the opening 9 via the guide pin 10a and the guide roller 12a, and then the guide roller 12a. 12b
A tape running path is formed so as to be wound around the winding-side hub 7 via the guide pin 10b.

Furthermore, inside the cassette housing 1, liner sheets 13a and 13b for smoothing the rotation of the hubs 6 and 7 and for preventing the winding disorder of the magnetic tape 8 sandwich the hubs 6 and 7 from above and below. It is located in.

The central portion of the opening 9 through which the magnetic tape 8 is exposed serves as a head insertion portion 9a into which the magnetic head is inserted, and the magnetic head inserted into this head insertion portion 9a slides on the magnetic tape 8. Recording or reproduction is performed by contact.

In the head insertion portion 9a, a lease spring 15 which fixes the pad 14 to the central portion and a shield plate 16 made of a metal plate are incorporated. When the magnetic head is inserted into the head insertion portion 9a, the lease spring 15 is provided with the magnetic tape 8 via the pad 14.
Is to be pressed onto the magnetic head. The shield plate 16 has a function of magnetically blocking between the magnetic head inserted into the head insertion portion 9a and the magnetic tape 8 wound around the hubs 6 and 7.

The structure of the built-in portion of the shield plate 16 in the head insertion portion 9a is shown in detail in FIGS.
The cover half 2 and the base half 3 have partition walls 17 and 18 for separating the head insertion portion 9a and the magnetic tape storage portion, respectively.
Further, the support walls 19 and 20 which are located in front of the partition walls 17 and 18 and project from the left and right sides of the head insertion portion 9a are formed symmetrically.

The gaps 21 and 22 between the partition walls 17 and 18 and the support walls 19 and 20 serve as the insertion portions of the shield plate 16, that is, the shield plate 16 has the gaps 21 and 22.
The structure is such that it is sandwiched between the cover half 2 and the base half 3 in a state of being inserted into the head insertion portion 9a and is accommodated in a predetermined position in the head insertion portion 9a. In addition, the support walls 19 and 20 have chamfered inwardly inclined surfaces 1 for allowing the shield plate 16 to be smoothly inserted into the gaps 21 and 22.
9a and 20a are formed.

In the built-in portion of the shield plate 16, conventionally, the dimension a of the shield plate insertion gap 21 on the cover half 2 side and the dimension b of the shield plate insertion gap 22 on the base half 3 side are set. , The shield plate 16 is formed to have a size value slightly larger than the thickness t of the shield plate 16 (a = b).
> T, at actual size t = 0.4 to 0.8 mm, a = b = t +
(0.05-0.2) mm).

[0011]

By the way, in assembling the tape cassette as described above, first, the hubs 6 and 7 having the internal parts, that is, the magnetic tape 8 on the base half 3, the guide rollers 12a and 12b, the liner sheet 13a, and the like. Thirteen
b, the leaf spring 15 and the shield plate 16 are assembled, and then the cover half 2 is covered and fixed to the base half 3 (this assembly is automatically performed by an automatic assembly machine).

At this time, in the built-in portion of the shield plate 16, the shield plate 16 is slightly inclined as shown in FIG. 5 due to the above dimensional relationship (b> t), and the cover half 2 is There may be a state where the ridge line portion of the upper end of the shield plate 16 and the inviting inclined surface 19a of the support wall 19 of the cover half 2 come into contact with each other due to the positional accuracy deviation of the automatic assembling machine when covering the base half 3 (Fig. The part surrounded by A).

Here, originally, the inclining slope 1 of the support wall 19
9a is used as a guide surface to guide the shield plate 16 into the gap 21. However, when the inclining inclined surface 19a is not smooth due to the influence of so-called hot water wrinkles during molding or the surface roughness of the mold, and the shield plate When the ridge line portion of 16 is sharp, the cover half 2 is caught by the shield plate 16 and the cover half 2 cannot be covered with the base half 3, which may result in a defective combination.

If such a combination failure occurs, the assembly line is stopped and the productivity is lowered, resulting in an unfavorable result.

The present invention has been made in view of the above circumstances, and provides a tape cassette in which a shield plate is incorporated, which can effectively prevent a defective combination of the cover half and the base half during assembly. The purpose is to

[0016]

In order to achieve the above-mentioned object, the present invention has a shield plate incorporated in a cassette housing formed by combining a cover half and a base half.
This shield plate is a tape cassette having a structure that can be inserted into the shield plate insertion gap provided in each of the cover half and the base half so as to fit in a predetermined position. The size is set to be larger than the clearance for inserting the shield plate on the base half side.

[0017]

In the tape cassette of the present invention, the above-mentioned dimensional relationship is set in the assembling portion of the shield plate, so that the shield plate is attached to the base half side in the state of being assembled to the base half side first during assembly. When the cover half is put on, it is possible to stochastically reduce the possibility that the cover half is caught by the shield plate.

[0018]

Embodiments of the present invention will be described below. The structure of the basic part of the tape cassette according to the present invention is the same as that of the conventional example shown in FIGS.

That is, the cassette housing 1 of the tape cassette according to the present invention comprises a plastic cover half 2 and a base half 3 which are formed in a substantially symmetrical shape as shown in FIGS. Base half 3
And are fixed in a combined state by screwing or welding.

Inside the cassette housing 1, a pair of hubs, ie, supply-side hubs are provided corresponding to the left and right hub drive shaft insertion holes 4a, 4b and 5a, 5b formed in the cover half 2 and the base half 3, respectively. 6. The take-up hub 7 is rotatably housed, and the magnetic tape 8 is wound around the supply hub 6 and the take-up hub 7 with both ends thereof fixed.

On the front side of the cassette housing 1, there is provided an opening 9 through which the internal magnetic tape 8 is exposed. Pins 10a and 10b project on the side of the base half 3 inside the cassette housing 1 located on both the left and right sides of the opening 9, and support shafts 11a projecting adjacent to the pins 10a and 10b. 1
Guide rollers 12a and 12b are rotatably supported by 1b, respectively, and a magnetic tape 8 drawn out from a supply side hub 6 passes through an opening 9 through a guide pin 10a and a guide roller 12a, and then a guide roller. A tape running path is formed so as to be wound around the winding-side hub 7 via 12b and the guide pin 10b.

Further, inside the cassette housing 1, liner sheets 13a and 13b for smoothing the rotation of the hubs 6 and 7 and for preventing the winding disorder of the magnetic tape 8 sandwich the hubs 6 and 7 from above and below. It is located in.

The central portion of the opening 9 through which the magnetic tape 8 is exposed serves as a head insertion portion 9a into which the magnetic head is inserted, and the magnetic head inserted into this head insertion portion 9a slides on the magnetic tape 8. Recording or reproduction is performed by contact.

In the head insertion portion 9a, a lease spring 15 which fixes the pad 14 in the central portion and a shield plate 16 made of a metal plate are incorporated. The tape cassette according to the present invention is characterized by the structure of the built-in portion of the shield plate 16. A first embodiment thereof is shown in FIG. 6 and a second embodiment thereof is shown in FIG.

As shown in the embodiments of FIGS. 6 and 7, the basic structure of the built-in portion of the shield plate 16 is the same as that of the conventional example. That is, partition walls 17 and 18 and supporting walls 19 and 20 are symmetrically formed on the cover half 2 and the base half 3, respectively.
The shield plate 16 is inserted into the gaps 21 and 22 between the shield plate 20 and the gap 20, so that the shield plate 16 can be set at a predetermined position. Also branch wall 1
The shield plate 16 is smoothly attached to the gaps 9 and 20.
Chamfer-shaped inclining-in inclined surfaces 19a, 20a are formed so that they can be inserted into 1, 22.

Here, the tape cassette according to the present invention is different from the conventional example in the dimensions of the gap 21 for inserting the shield plate on the cover half 2 side and the gap 22 for inserting the shield plate on the base half 3 side. Have a relationship. That is, as is apparent from the embodiments shown in FIGS. 6 and 7, the dimension a of the shield plate insertion gap 21 on the cover half 2 side is smaller than the dimension b of the shield plate insertion gap 22 on the base half 3 side. Is also set large (a> b).

Further, in the first embodiment of FIG. 6, the dimension b of the gap portion 22 for inserting the shield plate on the side of the base half 3 is
The shield plate 16 is formed to have a size slightly larger than the thickness t (a>b> t). In the second embodiment of FIG. 7, the dimension b of the gap 22 for inserting the shield plate on the side of the base half 3 is shown.
Is formed to have a dimension substantially equal to the thickness t of the shield plate 16 (a> b≈t).

For reference, the actual size of the embodiment is t
= 0.4 to 0.8 mm, a = t + (0.2 to 0.5) m
m, b = t + (0.05 to 0.2) mm (in the case of the first embodiment).

By setting a> b as in these embodiments, the base half 3 can be assembled with the shield plate 16 first attached to the base half 3 side when the cassette is assembled.
When the cover half 2 is covered with the cover half 2 even if the shield plate 16 is slightly inclined or the positional accuracy of the automatic assembly machine is slightly displaced, the ridge line portion of the upper end of the shield plate 16 and the support half 2 are supported. Invitation slope 19a of wall 19
It is possible to avoid or reduce contact with the cover half 2, that is, the probability that the cover half 2 is caught on the shield plate 16 can be reduced stochastically. Therefore, the incidence of defective combination of the cover half 2 and the base half 3 is significantly reduced as compared with the conventional case, and the productivity is improved.

Further, in the first embodiment, b> t is set, so that when the shield plate 16 is assembled to the base half 3, the shield plate 16 can be easily inserted into the gap 22.

In the second embodiment, b.apprxeq.t. Therefore, when the shield plate 16 is assembled to the base half 3, the shield plate 16 is inserted into the gap portion 22 in a close-fitting manner, so that it may tilt. Absent. Therefore, the dimension a of the gap portion 21 on the cover half 2 side may be set in consideration of only the positional accuracy of the automatic assembly machine, so that the dimension a can be made smaller than that in the first embodiment.

As an effect peculiar to the second embodiment, the shield plate 16 is closely inserted into the gap 22 on the base half 3 side, and the dimension a of the gap 21 on the cover half 2 side. By making it relatively small, it is possible to minimize rattling of the shield plate 16 in the cassette housing after the cassette is completed.

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the structures of these embodiments.

[0034]

As is apparent from the above description, according to the present invention, the shield plates are incorporated in the cassette housing formed by combining the cover half and the base half, and the shield plates are provided on the cover half and the base half, respectively. In the tape cassette having a structure that fits in the predetermined position while being inserted in the gap, by setting the gap on the cover half side to be larger than the gap on the base half,
The defective combination of the cover half and the base half when assembling the cassette is reduced, and the productivity is improved. Further, in the present invention, the size of the gap on the base half side is formed slightly larger than the thickness of the shield plate, so that the shield plate can be easily inserted. Further, in the present invention, by forming the size of the gap portion on the base half side substantially equal to the thickness of the shield plate, rattling of the shield plate can be suppressed.

The present invention can be realized by slightly changing the size of the gap for inserting the shield plate, which requires only a slight change in the mold for the cover half or the base half, and is therefore extremely inexpensive. It can be implemented.

[Brief description of drawings]

FIG. 1 is a perspective view of a tape cassette (audio compact cassette).

FIG. 2 is an exploded perspective view of the same.

FIG. 3 is a plan view of a shield plate incorporating portion of a cover half (or a base half) in a tape cassette.

FIG. 4 is an explanatory view of a conventional example and is a vertical cross-sectional side view of a shield plate built-in portion in a tape cassette.

FIG. 5 is an explanatory diagram showing a state in which the cover half is hooked on the shield plate during assembly in the conventional tape cassette.

FIG. 6 is an explanatory view of the first embodiment of the present invention and is a vertical cross-sectional side view of a shield plate built-in portion in the tape cassette.

FIG. 7 is an explanatory view of the second embodiment of the present invention and is a vertical cross-sectional side view of a shield plate built-in portion in the tape cassette.

[Explanation of symbols]

 1 Cassette Box 2 Cover Half 3 Base Half 16 Shield Plate 21 Gap for Shield Plate Insertion (Cover Half Side) 22 Gap for Shield Plate Insertion (Base Half Side)

Claims (3)

[Claims] 1. A shield plate is incorporated in a cassette housing formed by combining a cover half and a base half,
This shield plate is a tape cassette having a structure that can be set at a predetermined position while being inserted into the shield plate insertion gaps provided in the cover half and the base half, respectively. A tape cassette characterized in that the gap is set to have a size larger than the gap for inserting the shield plate on the base half side. 2. The tape cassette according to claim 1, wherein the space for inserting the shield plate on the side of the base half is formed to have a size slightly larger than the thickness of the shield plate. 3. The tape cassette according to claim 1, wherein a gap portion for inserting the shield plate on the base half side is formed to have a size substantially equal to a thickness of the shield plate.