JPH0538450Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a magnetic tape cassette, and more particularly to a magnetic tape cassette having a structure in which recording and reproduction are performed by pulling out a magnetic tape toward the front of the cassette.

(Prior Art) In recent years, high-density recording has been performed using magnetic tape. A typical example is a magnetic tape cassette (video cassette) such as the VHS system or the β system.

This type of magnetic tape cassette usually has a structure in which the magnetic tape is pulled out from an opening at the front of the cassette for recording and reproduction. That is, it has a rotatable guard panel that opens and closes the opening, and this guard panel closes the opening when the cassette is stored (when not in use), prevents dirt from entering the cassette, protects the tape, and During recording and playback, the magnetic tape is opened to release the opening, and the tape pull-out member provided in the recording and playback device enters the back side of the tape (non-magnetic side) and pulls out the magnetic tape as appropriate. . In addition, for cassette storage, for example, Utility Model Application No. 55-57184,
As disclosed in Japanese Patent No. 141485, the outer periphery of the flange of a tape wrapping body around which a magnetic tape is wound is formed into a tooth shape, and a reel brake that engages with this tooth shape is used to wind the tape. It is designed to prevent unexpected rotation of the body, and to prevent the magnetic tape from loosening or tape jamming. The reel brake is released by a brake release lever that enters into the cassette through a hole in the bottom of the cassette.

To further describe the reel brake, its structure generally consists of a locking portion that engages each flange, and a release portion that transmits the action of the brake release lever to the locking portion. When the cassette is stored, the release part faces a hole formed in the bottom of the cassette, and also has a dustproof function that closes the hole to some extent and prevents dirt from entering the cassette. There is.

However, since the release member comes into contact with the brake release inserted through the hole and moves to open along the bottom surface of the cassette, the contact surface needs to be tilted to some extent, so that the hole cannot be completely blocked. It was extremely difficult to do so.

On the other hand, magnetic tape cassettes are designed so that the reel wrapped with magnetic tape can move slightly inside the cassette along the bottom of the cassette, in order to deal with subtle differences in dimensions between recording and reproducing devices. It is set in.

Therefore, when the reel moves slightly during storage of the cassette, the locking part that engages with the flange is moved, and the release part is moved in the direction of opening the hole, so that the hole is not completely closed. I made it.

In particular, in recent years, various research and development efforts have been made in many fields to achieve higher quality recording and playback than ever before, and as part of this, magnetic tape cassettes (video tape cassettes) such as those mentioned above are being developed to be even better than before. There is a strong need for a highly reliable structure that can accommodate high-density recording and reproduction.

(Purpose of the invention) The present invention was made in view of the above-mentioned problems, and the purpose is to provide a magnetic tape cassette that can completely close the holes under any circumstances and is compatible with high performance. It is something.

(Structure of the invention) The object of the invention is to include a pair of tape winding bodies around which magnetic tape is wound, and a reel brake for preventing rotation of the tape winding bodies;
In a magnetic tape cassette having a hole in the cassette wall into which a brake release lever for releasing the reel brake is inserted, the hole is covered with a flexible dustproof material divided to allow insertion of the brake release lever. This is achieved by a magnetic tape cassette characterized in that it is configured to be

Hereinafter, embodiments of the present invention illustrated in the drawings will be described in detail.

FIG. 1 is a perspective view showing the back side of the magnetic tape cassette 1 of this embodiment, and FIGS. 2 and 3 are perspective views and exploded views of the reel brake 13 provided in the magnetic tape cassette 1 shown in FIG. Although not a perspective view, FIG. 4 is a perspective view of a sheet-shaped dustproof material 19 that is a feature of the present invention, and FIGS. 5 to 7 illustrate the operating states of the reel brake 13 and the dustproof material 19. FIG.

A magnetic tape cassette 1 shown in FIG. 1 has a pair of tape winding bodies (hereinafter referred to as "reels") wound with magnetic tape rotatably built into a cassette case consisting of upper and lower half cases 2 and 3. in,
Its general structure is almost the same as that of a conventional VHS video tape cassette, but the hole 8 for inserting the brake release lever is on the front side of the cassette, and the structure of the hole 8 is different from that of the conventional one. Different. The reason why the hole 8 is provided on the front side of the cassette is that by providing a light detection means such as a light source at the tip of the brake release lever, the lever can have a tape end detection function. It is. Further, the mouth portions 7a and 7b at the front of the cassette are provided with lid members that are slidable in the front and rear directions of the cassette in order to improve dust resistance.

Below, regarding the magnetic tape cassette of the present invention,
The structure will be explained step by step.

The reel brake 13 shown in FIG. 2 is provided approximately in the center of the cassette case and on the front side of the case, and is inserted into the case through a hole 8 provided in the lower half case 3 (see FIG. 1). By appropriately operating the reel brake release lever 30, the lower flanges 11a and 11b of the reel are released.
The gear parts 12a and 12b are disengaged from each other.

That is, the reel brake 13 is attached to a brake support shaft 14 which is protruded from the lower half case 3 of the cassette.
It is provided as a combination of two brake members 15, 20 that are fitted into and rotate around the support shaft, and the body portions 16, 21 through which the support shaft 14 passes through.
In addition, the engaging claws 17, 22 that protrude in the direction of the flanges 11a, 11b and engage with the flanges, and the operating protrusions 18, 23 that protrude in the direction of the hole 8 into which the brake release lever 30 enters are integrally constructed. be. The brake members 15 and 20 are constantly biased by a torsion spring 25,
When the engaging claws 17, 22 are engaged with the flanges, the actuating protrusions 18, 23 abut each other to close the hole 8.

On the other hand, in order to release the brake, the brake release lever 30 is moved from the lower part of the cassette to the operating projection 18,
Press 23 and move these in the left and right direction (arrow C direction)
By spreading the brake member 1
5 and 20 rotate to engage the engaging claws 17 and 22.
This can be achieved by separating them from the gear parts 12a and 12b.

A feature of the present invention is that the reel brake 13 configured as described above moves toward the hole so that the reels approach each other, and the engaging claws 17 and 22 that engage the reels are moved. When the pushing action is applied, the body parts 16 and 21 rotate, and the working protrusions 18 and 23 that close the hole 8 move away from each other, creating a gap, causing the hole to close slightly. A dustproof material 19, which will be described later, is provided so that the hole can always remain closed even if the hole is opened.

That is, as shown in FIG. 4, the hole 8 into which the brake release lever 30 enters is formed in a stepped portion 31 in which the lower half case 3 is slightly recessed at its periphery inside the cassette. The dustproof material 19 is flexible and has slits.
are glued together in a shape that allows them to fit together.

Note that it is desirable that the bottom surface of the cassette be configured to have a uniform height when the dustproof material 19 is provided.

The dustproof material 19 has a peripheral edge 19a that contacts the stepped portion 31, is bonded to the stepped portion 31, is fixed to the cassette half 3, is ruptured (slit) toward the center of the hole 8, and has elasticity. It has a substantially disk-like shape in which a plurality (four) of swinging pieces 19b having force are formed.

The dustproof material 19 may be made of a material having a small surface friction coefficient, such as polyethylene terephthalate, so as not to interfere with the insertion of the brake release lever 30.

Figure 5 shows how the cassette is stored.
Operating projections 18 and 23 of the reel brake 13
are in contact with each other, and the dustproof material 19 fixed to the cassette also closes the hole 8.

The state shown in FIG. 6 is a case where the reel moves during the storage of the cassette described above and a gap is created between the operating projections 18 and 23. However, the hole 8 is covered with the dustproof material 19 and remains closed.

FIG. 7 shows the brake release lever 30 starting to enter the cassette from below.
First, it comes into contact with the swinging piece 19 and pushes it apart. Then, as described above, the brake release lever 30 further advances and presses the actuating protrusions 18 and 23 to spread them apart in the left and right direction (in the direction of arrow C), thereby releasing the brake (the third (See Figure 2).

Further, when the brake release lever 30 is retracted from the cassette, the operating protrusions 18 and 23 that come into sliding contact with the lever 30 are connected to the torsion spring 25.
The sheet material 19 returns to the closed state due to the urging force thereof, and on the other hand, the sheet material 19 returns to the closed direction due to its elastic force.

In addition, in order to make it easier for the actuating projections 18 and 23 to generate a force that moves in the left and right direction when the brake release lever 30 is pressed, at least the surface facing the bottom surface of the cassette should be sloped as shown in the figure. is desirable. For this reason, in the prior art, in addition to the case where the hole is opened by the movement of the reel during storage of the cassette, the above-mentioned operating projections 18,
However, the arrangement of the dust-proofing material 19 prevents the opening of the hole that occurs on the inclined side surface between the holes 8 and 23. However, the arrangement of the dust-proofing material 19 prevents this from happening and completely closes the hole. It completely prevents it from entering the cassette.

8 and 9 show modified examples of the dustproof material 19. FIG.

That is, in the case of FIG. 8, in order to prevent the dustproof material 50 from becoming sagging due to repeated rocking, a rib 51 is formed at the base of the dustproof material 50 where the dustproof material 50 is rocked, and a rib 51 is formed on the opposite side of the rib 51. A recess is formed to form a hinge part that is resistant to fatigue. Further, in FIG. 9, the dustproof material 60 is fixed to the cassette not by pasting with adhesive or double-sided tape, but by caulking. That is, a caulking boss 32 is formed in the stepped portion 31 of the hole formed in the lower half case 3, and a through hole 61 is formed in the corresponding position of the dustproof material 60, so that the dustproof material 60 is inserted into the boss 32 and fixed by caulking.

In the embodiment described above, a slit is provided to divide the dustproof material into four parts, but the present invention is not limited to this, and the number of divisions can be changed as appropriate. It is not necessary to do so, and it is also possible to construct a structure in which a plurality of sheets are stacked one on top of the other to further enhance the dust-proofing effect.

The present invention is not limited to the embodiment described above, but can be widely applied to any magnetic tape cassette provided with the hole 8.

(Effects of the invention) As described above, according to the invention, the hole into which the brake release lever is inserted is covered with a flexible dust-proof material that allows the insertion of the brake release lever. Regardless of the structure of the brake, the dustproof performance is not affected by the structure of the leaf brake, and a high-performance magnetic tape cassette with a perfect dustproof effect can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a magnetic tape cassette which is an embodiment of the present invention, FIGS. 2 and 3 are perspective views and exploded perspective views of a leaf brake provided in the magnetic tape cassette shown in FIG. The figure is a perspective view showing a sheet-like dustproof material, FIGS. 5 to 7 are sectional views of main parts of a cassette explaining the operating state of the dustproof material, FIG. 8 is a sectional view showing a modified example of the dustproof material, and FIG. The figure is a perspective view showing another modification of the dustproof material. DESCRIPTION OF SYMBOLS 1... Magnetic tape cassette, 2... Upper half case, 3... Lower half case, 4... Reel shaft insertion hole, 6... Opening, 7a, 7b... Mouse part, 8... Hole, 10... Support shaft, 11a, 11b...
...lower flange, 12a, 12b...gear part, 13
... Reel brake, 14 ... Brake spindle, 1
5, 20... Brake member, 16, 21... Body, 17, 22... Engaging claw, 18, 23... Operating overhang, 19, 50, 60... Dust-proof sheet material,
19a... Periphery, 19b... Rocking piece, 25... Torsion spring, 30... Brake release lever, 3
1... Step portion, 32... Boss, 51... Rib, 6
1...Through hole.

Claims (1)

[Scope of utility model registration request] It contains a pair of tape winding bodies around which magnetic tape is wound, and has a reel brake that prevents the rotation of the tape winding bodies, and a brake release lever that releases the reel brake is inserted. A magnetic tape cassette having a hole in the cassette wall, characterized in that the hole is covered with a flexible dustproof material divided to allow insertion of the brake release lever.