JPH04173576A - Magnetic tape cassette storage case - Google Patents

Abstract

PURPOSE:To suppress the transmission of vibration to a stopper considerably by absorbing outside vibration at a multi-layer structural part by a method wherein for a cover at a range which at least contains a pair of stoppers, materials with different elastic moduli are combined into a multi-layer structure. CONSTITUTION:A cover 3 of a magnetic tape cassette storage case 1 engages with engaging parts 10, 10' of a pair of hubs 8, 8' when a magnetic tape cassette is contained, and it is equipped with a pair of stoppers 5, 5' which stop the rotation of the pair of hubs 8, 8'. A part of the cover 3, which contains the pair of stoppers 5, 5' is constituted by combining materials with different elastic moduli in two layers. The part of the cover 3 consists of two layers of a high elastic modulus material P1 which has a comparatively high elastic modulus and a low elastic modulus material P2 which has a comparatively low elastic modulus. By this method, the transmission of outside vibration to the stoppers 5, 5' can be suppressed.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is a magnetic tape cassette, which is made up of a housing housing a pair of hubs around which magnetic tape is wound, and is widely used for audio applications. The present invention relates to a magnetic tape cassette storage case that accommodates small-sized magnetic tape cassettes.

(Prior Art) A small magnetic tape cassette widely used for audio and the like has a housing containing a pair of hubs around which magnetic recording tape is wound.

The pair of hubs is formed into a substantially ring shape, and has an engaging portion on its inner circumferential surface that engages with a rotating member on the tape deck side that rotates the hubs when loading the tape deck. Further, the housing of the magnetic tape cassette is provided with a pair of insertion holes into which the rotating member on the tape deck side is inserted, at positions facing the engaging portions of the pair of hubs.

When not in use, this magnetic tape cassette is stored and protected in a dedicated magnetic tape cassette storage case. This magnetic tape cassette storage case consists of a substantially planar cassette receiving portion and a cover portion rotatably provided on the cassette/receiving portion, and forms a substantially thin rectangular parallelepiped in the stored state.

The cover portion is provided with a pair of stoppers that engage with the engaging portions of the pair of hubs of the magnetic tape cassette/slot to stop rotation of the pair of hubs.

Conventionally, the magnetic tape cassette storage case and the stopper have been integrally molded from the same synthetic resin material.

(Problem to be Solved by the Invention) However, in the conventional magnetic tape cassette storage case, external vibration is transmitted to the hub of the magnetic tape cassette through the stopper, and this vibration causes the magnetic recording tape wound around the l\b to be damaged. There was a problem that sagging easily occurred. Some devices have devised the shape of the stopper to prevent this sag, but it is not possible to suppress the vibration itself - 1° If the magnetic recording tape sag, when the magnetic tape cassette is loaded into the tape deck, the tape Preventing this sagging is considered to be a very important issue because it causes various problems such as not running properly.

In view of these points, the present invention aims to provide a magnetic tape cassette storage case that suppresses external vibrations transmitted to a portion of the stopper and prevents the magnetic recording tape wound around the hub from sagging. This is the purpose.

(Means for Solving the Problems) In order to solve the above problems, in the magnetic tape cassette storage case according to the present invention, the cover portion in a range including at least the pair of stoppers is made of multiple layers of materials having different moduli of elasticity. Preferably, the pair of stoppers is approximately S.
It is characterized by being formed into a letter shape.

That is, the cover part near the installation position of the pair of stoppers is characterized by having a multilayer structure, for example, made of a layered combination of a material with a relatively large elastic modulus and a material with a relatively small elastic modulus, and preferably further includes the above-mentioned material. The shape of the pair of stoppers is approximately S-shaped.

Here, the shape of the pair of stoppers is approximately S-shaped means that the shape of each of the pair of stoppers is approximately S-shaped when the magnetic tape cassette storage case is viewed from the cover side when magnetic tape cassettes are stored. It means having a mold,
When you look at it like this, the stopper has an approximately inverted S-shape (8
This also includes cases where it is formed in the form of an inverted character.

(Operations and Effects) As described above, in the magnetic tape cassette storage case according to the present invention, the cover portion including at least the pair of stoppers is configured by combining materials with different moduli of elasticity in multiple layers. Since external vibrations can be absorbed by this multilayer structure and transmission of the vibrations to the stopper can be considerably suppressed, sagging of the magnetic recording tape wound around the hub can be prevented.

More preferably, in the magnetic tape cassette storage case according to the present invention, in addition to the above structure, the pair of stoppers is formed in a substantially S-shape, so that external vibrations that cannot be absorbed by the multilayer structure are transmitted to the stoppers. Even when the hub vibrates, the ratchet effect suppresses the rotation of the hub and produces remarkable effects such as suppressing sagging of the magnetic recording tape.

Incidentally, the magnetic tape cassette storage case according to the present invention can sufficiently exhibit its effect even if the shape of the stopper is not substantially S-shaped, just by having the multilayer structure as described above.

(Example) Details of the magnetic tape cassette storage case according to the present invention will be described below based on an example.

FIG. 1 is a perspective view showing the overall structure of an embodiment of a magnetic tape cassette storage case according to the present invention, FIG. 2 is a detailed cross-sectional view showing the structure of the cover part, and FIG. 3 is a view when the magnetic tape cassette is stored. FIG. 3 is a plan view showing a state of engagement between the stopper and the hub.

As shown in FIG. 1, the magnetic tape cassette storage case 1 of this embodiment consists of a substantially flat cassette receiving part 2 and a cover part 3 rotatably provided on the cassette receiving part 2. As shown in FIG.

When storing the magnetic tape cassette 4, move the magnetic tape cassette 4 in the direction of the arrow as shown in FIG.
First, the cassette is placed in the cassette receiving portion 2, and then the cover portion 3 is rotated in the direction of arrow B to be stored.

As shown in FIG. 3, the magnetic tape cassette 4 includes a pair of hubs 8.8', around which a magnetic recording tape 7 is wound, housed in a housing 6. A pair of hubs 8.8' are provided on the inner peripheral surface,
An engaging portion 10.1 consisting of a plurality of convex portions 9, 9' that engages with a rotating member on the tape deck side when loading a magnetic tape cassette.
0'. Also, as shown in Figure 1, the housing
The ring 6 has a pair of insertion holes 11.1 into which the rotating member on the tape side is inserted, at a position facing the pair of hubs 8, 8'.
1'.

On the other hand, as shown in FIG. m1 and FIG.
a pair of stoppers 5. engaged with the hubs 8.8' to lock rotation of the pair of hubs 8.8';5' Lie.

This embodiment has two features. Its characteristics will be explained below.

The first point is that the cover part 3, as shown in FIGS. 1 and 2,
The portion including the pair of stoppers 5, 5' is constructed by combining two layers of materials with different moduli of elasticity. As shown in FIG. 2, the cover portion 3 is made up of two layers: a high elastic modulus material P1 having a relatively high elastic modulus and a low elastic modulus material P2 having a relatively low elastic modulus. Thereby, transmission of external vibrations to the stopper 5.5' can be suppressed. This method of suppressing vibration by combining two layers of materials with different moduli of elasticity is known as the non-constraint type (extension type) damping method, and its principle is to reduce vibration energy by elongating the low elastic modulus material Pz. It is something that absorbs.

The degree to which vibration can be suppressed is expressed by the loss coefficient ratio η/η2. Here, η is the loss coefficient of the entire two layers, η
2 is the loss coefficient of the low elastic modulus material P2. Loss factor ratio η/
η2 takes a value from 0 to 1, and the closer it is to 1, the more vibration can be suppressed. The loss coefficient ratio η/η2 is the elastic modulus ratio E, /E between the elastic modulus E1 of the high elastic modulus material Pl and the elastic modulus Ez of the low elastic modulus material Pz, and the elastic modulus ratio E, /E of the high elastic modulus material P shown in Fig. 2. Thickness ratio h2/ of thickness hl and thickness h2 of low elastic modulus material P2
It is determined using hl as a parameter.

FIG. 4 is a diagram for determining the loss coefficient ratio η/η2 from the thickness ratio h2/h1 and the elastic modulus ratio E2/E1.

- As an example, GP-PS resin "Idemitsu US-308J (elastic modulus E, -32, (l1) Okg
f/c12, thickness hl -0.5mm), low elastic modulus member P2imPS two-layer last? -rTUFTECHIO
31" (elastic modulus E2 - 1,000 kgf/am2, h2
-1.0■) was used to investigate its damping effect. In that case, the elastic modulus ratio Ez / El -3Xl0-2, h2/h
From 1-2, loss coefficient ratio η/ηz'-0,6 from Figure 4.
Therefore, it was possible to suppress vibration considerably.

The second feature of this embodiment is that the stopper 5 is shaped like an S and the stopper 5' is shaped like an inverted S as shown in FIGS. 1 and 3.
It was formed into a letter shape. Here stopper 5.5'
3, the shape of the magnetic tape cassette storage case 1 when the magnetic tape cassette 4 is stored is viewed from the cover part 3 side. In FIG. 1, the shape seen from the opposite direction is shown, so each shape is reversed.

As shown in FIG. 3, the shapes of the stoppers 5 and 5' are approximately S-shaped and approximately inverted S-shaped, respectively, so that the hubs 8° and 8' are
The magnetic recording tape 7 can be rotated only in the direction in which it is wound (in the direction of the arrow X in the figure), and cannot be rotated in the opposite direction, and the winding becomes tighter but not looser. Due to this ratchet effect, even if there is external vibration that cannot be absorbed by the vibration damping structure, the magnetic recording tape 7 can be prevented from sagging.

Although the details of the magnetic tape cassette storage case according to the present invention have been described above based on one embodiment, the magnetic tape cassette storage case according to the present invention is not limited to this embodiment.

For example, in this embodiment, the shape of the pair of stoppers is approximately S.
The shape of this pair of stoppers can be either the generally used approximately cross shape or the approximately S shape.
It may also be in the form of a letter.

Further, although the cover part has a two-layer structure in this embodiment, it can also have a three-layer structure. This method is known as a constraint-type vibration damping method, and its principle is to absorb vibration energy by shear deformation between three layers, but the basic idea is the same as in this example. be.

Further, in this embodiment, only a part of the cover part has a two-layer structure, but the entire cover part may have a two-layer structure.Also, although the material of the stopper is a low elastic modulus material, it may be a high elastic modulus material.

Hereinafter, details of other embodiments will be explained with reference to the drawings.

FIG. 5A, FIG. 5B, and FIG. 5C are detailed cross-sectional views showing the structure of a cover portion according to another embodiment.

As shown in FIG. 5A, the cover portion 3 may have a two-layer structure of a high elastic modulus material P1 and a low elastic modulus material P2, and the stopper 5 may be formed of the high elastic modulus material P1.

Further, as shown in FIG. 5B, the cover portion 3 may be arranged with a high elastic modulus material P1 and a low elastic modulus material P2, contrary to FIG. 5A.

Furthermore, as shown in FIG. 5C, the entire cover portion 3 may have a three-layer structure in which a low elastic modulus material P2 is sandwiched between high elastic modulus materials P1.

FIGS. 6A, 6B, and 6c are plan views showing the shapes of stoppers according to other embodiments.

As shown in FIG. 6A, the shapes of the stoppers 5 and 5' may be approximately S-shaped.

Further, as shown in FIG. 6B, the stopper 5 may be shaped only at both ends of a substantially S-shape, and the stopper 5' may be shaped only at both ends of a substantially S-shape.

- Furthermore, as shown in FIG. 6C, the shapes of the stoppers 5° and 5' may be substantially cross-shaped.

As described above, the magnetic tape cassette storage case according to the present invention can be modified in various ways without impairing its effects.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the overall structure of an embodiment of a magnetic tape cassette storage case according to the present invention, FIG. 2 is a detailed cross-sectional view showing the structure of the cover portion thereof, and FIG. FIG. 4 is a diagram for determining the loss coefficient ratio; FIGS. 5A to 5C are detailed cross-sectional views showing the structure of the cover portion of other embodiments; ! 6A6A and 6C are plan views showing the shape of the stopper. 1...Magnetic tape cassette storage case-2...Cassette receiving part 3...Cover part 4...Magnetic tape cassette 5.5'...Stopper 6...Housing 7.
...Magnetic recording tape 8,8'...Hub 9.9'
...Convex portion 10.10'...Engagement portion 11,
11'...Insertion hole Pl...High elastic modulus material Pl...Low elastic modulus material Fig. 2 Fig. 3 Fig. 4 N"' /hr Fig. 5A Fig. 5c Fig.

Claims (1)

[Scope of Claims] 1) In order to accommodate a magnetic tape cassette in which a pair of hubs on which magnetic recording tape is wound are housed in a housing, the housing has substantially the same shape as the bottom surface of the magnetic tape cassette and is in contact with the bottom surface. In a magnetic tape cassette storage case comprising a substantially flat cassette receiving part in contact with the cassette receiving part, and a cover part rotatably provided on the cassette receiving part and covering the entire magnetic tape cassette together with the cassette receiving part, on the back surface of the cover part. is provided with a pair of stoppers that lock the pair of hubs when the magnetic tape cassette is housed, and the cover portion in a range including at least the pair of stoppers is made of a multilayer combination of materials having different moduli of elasticity. A magnetic tape cassette storage case characterized by: 2) The magnetic tape cassette storage case according to claim 1, wherein the pair of stoppers are formed in a substantially S-shape.