JPH0348786Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a magnetic tape cassette, and more specifically, to a new compact cassette used for audio equipment of the same size or smaller than the Phillips type. It is.

(Prior art) In recent years, cassette tape recorders have become smaller and lighter, and the magnetic tape cassettes used in these have also become smaller and more popular.In the audio field, it is becoming more and more popular to use high-quality tape over long periods of time. In addition, a magnetic tape cassette that can be adapted to high-density recording and reproduction is strongly desired. Unlike analog methods, digital methods such as pulse code modulation (PCM), which record and reproduce input signals by converting them into pulses, are known as suitable for meeting these demands. As for those using this method, large-sized video tape cassettes, which have a wider recording frequency band than compact audio tapes, are generally popular because the recording frequency band needs to be about five times wider than that of conventional audio tapes.

This video cassette, except for special ones, is compatible with the rotating head system.
Its structure includes a guard panel that closes an opening provided in front of the cassette and can be rotated above the cassette to open the opening. That is,
When using a digital system, recording and reproducing in a high-density, wide-frequency band with a shorter recording wavelength than conventional audio compact cassettes requires a cassette structure with sufficient dust-proofing and tape protection measures. do.

A magnetic tape cassette that meets the above requirements, that is, the subject of the present invention, can be applied to audio systems that use a relatively wide frequency band recording and reproducing method, similar to the video tape cassette.
This is an extremely small magnetic tape cassette whose size is comparable to or smaller than a conventional audio compact cassette. Therefore, it is expected that this magnetic tape cassette will be carried and used outdoors as frequently as, or even more than, conventional audio compact cassettes.
There is a need for a structure that can reliably prevent tape jamming caused by tape loosening caused by vibrations applied to the cassette during transportation or the like.

(Purpose of the invention) The present invention was devised in view of the above-mentioned problems, and is small in size and has a locking member that prevents unexpected rotation of a hub wrapped with magnetic tape when storing a cassette. An object of the present invention is to provide a magnetic tape cassette for digital audio that ensures the following.

(Structure of the invention) That is, the above-mentioned object of the invention is to include a pair of hubs around which magnetic tape is wound, an opening for allowing the magnetic tape to be pulled out in front of the cassette, and a hub on the front side of the opening. A rotatable guard panel having a generally U-shaped horizontal cross section and an upper end portion extending in the left-right direction of the cassette along the inner surface of the upper half case, and cassette side walls at both ends of the upper end portion in the left-right direction of the cassette. The leg pieces standing upright along the guard panel each have an overhang piece extending toward the front side of the cassette to engage with both left and right end pieces of the guard panel, and overhanging pieces toward the rear side of the cassette so as to lock the hub at the upper end portion. In the magnetic tape cassette, the magnetic tape cassette includes a locking member having a pair of pointed protrusions, which is slidable in the front-rear direction of the cassette, and which is biased toward the rear of the cassette. , the tip of the overhanging piece is configured to engage with a claw portion protruding in the left and right outward direction of the cassette by rotation of the guard panel, and the lower edge of the tapered surface is on the inward side of the cassette. The magnet is characterized in that the surface of the claw portion on the rear side of the cassette that engages with the tapered surface is formed into an inclined surface that extends toward the rear of the cassette toward the tip of the claw portion. This is accomplished with a tape cassette.

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

The magnetic tape cassette 1 shown in FIG.
It is about the same size or smaller than a compact cassette used for audio etc. The magnetic tape cassette 1 includes a pair of flangeless type hubs 4 in which a magnetic tape T is wound inside a cassette case consisting of upper and lower half cases 2 and 3, and a friction sheet 5 for smoothing the rotation of the hubs 4. and a locking member 6 for preventing unexpected rotation of the hub 4, a guard panel 8 that closes the front side of the opening 10 at the front of the cassette case, and a slide that closes the lower side of the opening 10. A guard 20 is attached.

The hub 4 has an outer peripheral edge 4 that protrudes concentrically with the tape winding surface so that the pair of pointed protrusions 7 provided on the lock member 6 can engage with each other.
It forms a.

The guard panel 8 has a U-shaped horizontal cross section as in the case of a conventional video cassette, and has end pieces 1 disposed at the left and right ends of the front wall 17.
Rotating shafts 9 facing each other are protruded from the inside of 7a. The guard panel 8 has the rotary support shaft 9 rotatably inserted into a hole 16 formed in the side wall 15 of the lower half case 3 when the upper and lower half cases 2 and 3 are stacked on top of each other. The guard panel spring 28 is attached to the guard panel and is always biased in a direction to close the opening 10.

Further, the guard panel 8 has left and right end pieces 17.
a is cut out on the lower side of the rotational support shaft 9 and is formed narrower than the front wall 17, and furthermore, the lower edges of both end edges 17a extend in the front and back direction of the cassette when the opening 10 is closed. It is provided on a tapered surface 21 that is formed almost along the cassette and is sloped so that the wall thickness gradually becomes thinner toward the bottom of the cassette (slanted as if the outer surface of the case was largely chamfered) (see Fig. 2). Further, a notch 18 is formed at the center of the lower edge of the front wall 17 of the guard panel 8, so that when loading the magnetic tape cassette 1 into a recording/reproducing apparatus, the cassette is not inserted in the front-back direction by mistake. has been done. That is, the protrusion for preventing incorrect insertion provided on the bucket, which is the cassette receiving part of the cassette insertion part of the recording/reproducing apparatus, corresponds to the notch 18, so that the magnetic tape cassette 1 can be inserted normally in the front-rear direction. It is designed so that it can be loaded into a recording/reproducing device only when the

The locking member 6 has an upper end portion 30 that is slidable in the cassette front-rear direction along the inner surface of the upper half case 2, and is arranged along the side wall 15 of the lower half case 3, forming both left and right ends of the upper end portion 30. The vertical cross-sectional shape of the leg piece 19 is substantially U-shaped, and an overhang piece 19a extending from below the leg piece 19 toward the front of the cassette is provided.

A claw portion 24 is formed at the tip of the projecting piece 19a and is slightly bent toward the left and right direction of the cassette, and when the locking member 6 is placed at a fixed position in the cassette, the projecting piece 19a 1
9a and the claw portion 24 are provided so as to slightly protrude from the side wall 15 of the lower half case 3 toward the outside of the cassette.

Further, as shown in FIG. 2, the claw portions 24 of the locking member 6 are configured to come into sliding contact with the tapered surfaces 21 formed on the left and right end pieces 17a of the guard panel 8 when the guard panel 8 rotates. The surface 24a of the claw portion 24 on the rear side of the cassette, which is in sliding contact with the tapered surface 21, extends toward the rear of the cassette toward the tip of the claw portion, and is provided in a tapered shape to suitably mesh with the tapered surface 21. ing.

Returning to FIG. 1, the upper end portion 30 of the locking member 6 has a thinned step portion 30a at the front side of the cassette at the center thereof.
A spring locking shaft 31 slightly protrudes upward on the top surface of the
is provided. Further, a pair of pointed protrusions 7 are provided on the edge of the upper end portion 30 on the rear side of the cassette to extend toward the rear of the cassette and come into contact with the hub 4 to prevent rotation of the hub 4.

Note that the lock member 6 has its spring locking shaft 31.
A locking member spring 29 is fitted in the cassette, and one end 29a of the spring 29 is brought into contact with the locking member 6, and the other end 29b is brought into contact with the front inner wall surface of the upper half case 2, so that the cassette is always urged rearward. .

Hereinafter, each of the other constituent elements will be explained in order.

In FIG. 1, the lower half case 3 includes:
The hub 4 is similar to the conventional video tape cassette.
A pair of reel shaft insertion holes 14 corresponding to the opening 10 are provided therethrough, and tape draw-out ports 11 are provided at both left and right ends of the opening 10 to allow the magnetic tape T to be pulled out to the front of the cassette. Further, the bottom of the cassette between the tape draw-out openings 11 is formed such that its side walls retract toward the rear of the cassette, so that when the magnetic tape cassette 1 is loaded into a recording/playback apparatus, the tape drawer of the recording/playback apparatus is opened. The member is constructed so that it can be inserted into the cassette from below.

At the upper edge of the side wall 15 of the lower half case 3,
A stepped portion 32 is provided which forms a slit along the front-rear direction of the cassette when the cassette is assembled.

Further, the lower half case 3 has its left and right side walls 1
5 is formed on a partition wall 15a slightly shifted inward of the cassette near the front of the cassette, and the side wall 15
The protruding piece 19a of the lock member 6 that moves along the side wall 15 is fitted through an opening 33 formed by the side wall 15 and the partition wall 15a.

The slide guard 20 is plate-shaped, and its left and right end portions are formed into side pieces 26 that stand up at right angles along the side wall 15, and its vertical cross-sectional shape is approximately U-shaped. The upper edges of the side pieces 26 face each other to form a projecting portion 27 that slightly extends into the cassette case. Further, the slide guard 20 has a transparent hole 23 corresponding to the reel shaft insertion hole 14 on a surface corresponding to the bottom of the lower half case 3.
and an engaging protrusion 22 that is received in the notch 18 and is abutted by a slide guard spring 25 that urges the slide guard 20 forward of the cassette.

The front portion of the upper half case 2 is configured such that, when combined with the lower half case 3, the upper half case 2 forms the tape outlet 11 together with the lower half case 3, similar to a conventional video tape cassette. . Further, although not shown, means for regulating the rotational position of the hub 4 is provided on the inner surface of the upper half case 2.

When assembling the magnetic tape cassette 1,
First, the slide guard 20 is attached to the lower side of the lower half case 3. At this time, the step portion 32 provided on the side wall 15 of the lower half case 3 is attached.
The upper edge of the slide guard 20 and the overhanging portion 2 of the slide guard 20
Fit it so that it engages with the lower surface of 7.

Further, the slide guard 20 is configured such that the slide guard spring 25 has one end fitted onto the locking pin 13 formed on the lower half case 3 and the other end engaged with the engagement protrusion 22. , the cassette is biased forward and the cassette is slidable in the front and rear directions.

Thereafter, the hub 4 with the magnetic tape T wound thereon is placed on the friction sheet 5 laid on the inner surface of the lower half case 3, so as to correspond to the reel shaft insertion hole 14, and the magnetic tape The T is mounted between the left and right tape guides 12 in such a way that it comes out of the cassette from the tape draw-out port 11. Cover it with Frixion sheet 5,
The lock member 6 is disposed above it, and the spring 29 urges the cassette rearward. Next, when the upper half case 2 is placed on the guard panel 8, the rotation support shaft 9 is rotatably inserted into the hole 16, and the guard panel 8 is urged in the closing direction by the guard panel spring 28. It is installed like this.

After finally covering the upper half case 2,
The magnetic tape cassette 1 is assembled by fastening the upper and lower half cases 2 and 3 with screws or the like.

When the magnetic tape cassette 1 assembled in this manner is stored, the guard panel 8 and the slide guard 20 close the opening 10, and the outer peripheral edge 4a of the hub 4 and the The pointed protrusion 7 of the locking member 6 comes into contact with the hub 4 to prevent it from rotating.

The materials of the upper and lower half cases 2, 3, the guard panel 8, and the lock member 6 may be conventionally used plastic resins such as polyacetal resin, ABS resin, and PS resin. Constructed from plastic resin. Note that the slide guard 20 is
For example, the cassette body may be made of metal such as stainless steel, but since the cassette body is made of plastic resin, the cassette body will be scraped by repeated sliding operations of the slide guard. Therefore, it is desirable that the upper and lower half cases 2 and 3 be made of a plastic resin that is resistant to wear.

The magnetic tape T may be a ferromagnetic iron oxide or chromium dioxide tape, but preferably one suitable for high-density recording and reproduction, such as a metal tape or a vapor-deposited tape.

The operation of each member when the magnetic tape cassette 1 constructed as described above is loaded into a recording/reproducing apparatus will be described below.

When the magnetic tape cassette 1 is loaded into a cassette insertion section of a recording/reproducing apparatus, the opening 1
It is pushed in with the 0 side facing forward (in the direction of arrow A shown in FIG. 3). During this push-in operation, the engaging protrusion 22 comes into contact with, for example, a protrusion for preventing incorrect insertion in the cassette insertion portion, so that the slide guard 20 slides rearward of the cassette (in the direction of arrow B) and inserts the opening 10 into the opening 10. The lower side of the reel shaft is opened, and each of the through holes 23 is aligned with the reel shaft insertion hole 14, so that a reel shaft for driving the hub can be inserted.

Thereafter, the magnetic tape cassette 1 moves in a direction perpendicular to the pushing direction, that is, downward (in the direction of arrow C). During this downward movement,
For example, the guard panel 8 opens upwardly of the cassette case using the rotational shaft 9 as a fulcrum when its lower edge comes into contact with a guard panel opening means (not shown) provided deep within the cassette insertion section. (in the direction of arrow D). As the guard panel opens, as shown in FIG. 4, the tapered surface 21 of the guard panel 8 (actually, the lower edge portion 21a of the tapered surface 21) comes into contact with the claw portion 24 so as to catch it. The lock member 6 slides toward the front of the cassette against the urging force of the lock member spring 29. The tapered surface 21 has a surface 24a on the rear side of the cassette that engages with the claw portion 24.
As mentioned above, since the tapered structure is such that the cassette protrudes rearward toward the tip of the nail, for example, the lower edge portion 21a of the tapered surface 21 is located near the tip of the surface 24a as shown in FIG. When engaged, the contact force F of the opening movement causes the lower edge portion 21a of the tapered surface 21 and the claw portion 24 to shift so as to engage more deeply (arrow f in FIG. 4). I can do it. Furthermore, by forming the tapered surface 21, the end piece 1
The position where the lower edge of 7a engages with the claw portion 24 can be made as deep as possible toward the base of the claw portion 24 in view of its thickness.

When the lock member 6 is slid toward the front of the cassette, its sharp protrusion 7 touches the outer peripheral edge 4 of the hub 4.
When the hub 4 is released from the hub 4, the lock is released and the hub 4 can be opened freely.

In this way, loading of the magnetic tape cassette 1 is completed by the pushing operation and downward movement, and the opening 10 is completely opened by sliding the slide guard 20 and opening the guard panel 8. The engagement between the outer peripheral edge 4a and the pointed protrusion 7 is released. As a result, the magnetic tape T can be pulled out from the opening 10 toward the front of the cassette, and the hub 4 can be rotated, making it possible to perform recording and reproduction using a rotary head system.

When the magnetic tape cassette 1 is taken out from the recording and reproducing apparatus, it moves with a stroke opposite to that when it was loaded, and first, the guard panel 8 is disengaged from the guard panel opening means, and the guard panel 8 is disengaged from the guard panel opening mechanism. Due to the biasing force of the panel spring 27, the opening 1
Close the front side of 0. Subsequently, when the magnetic tape cassette 1 is pulled out, the slide guard 20 is released from contact with the protrusion for preventing incorrect insertion, and the cassette is slid forward by the biasing force of the slide guard spring 25, thereby closing the opening. Section 10 is completely occluded.

Further, by rotating the guard panel 8 so as to close the opening 10, the tapered surface 21 of the guard panel 8 and the claw portion 2 of the locking member 6 are closed.
4 is released. As a result, the locking member 6 is slid toward the rear of the cassette by the biasing force of the spring 29, and the pointed protrusion 7 is moved toward the outer peripheral edge 4.
a to lock the hub 4 from rotating. Further, as the slide guard 20 slides to close the opening 10, the positions of the reel shaft insertion hole 14 and the transparent hole 23 are shifted, and the reel shaft insertion hole 14 is closed.

(Effects of the Invention) As described above, when the magnetic tape cassette 1 of the present invention is stored, the guard panel 8 and the slide guard 20 completely close the opening 10, and the slide guard 20 completely closes the opening 10. Since the reel shaft insertion hole 14 is also closed, the magnetic tape T mounted in the opening 10 has an extremely excellent protection effect and dustproof effect, and is extremely effective in preventing deterioration of recording and reproducing characteristics. can have.

Further, in the present invention, the abutting surfaces of the lock member 6 and the guard panel 8 are provided in a suitable interlocking structure, so that the lock member 6 can be reliably engaged with the guard panel 20 and slid. . Further, since such engagement means are provided at both the left and right ends, the sliding operation is made stable and the operation by the locking member 6 is ensured.

Although it was mentioned earlier that the present invention is applicable to magnetic tape cassettes that are the same size or smaller than conventional audio compact cassettes (Philips type), it is not necessarily limited to this, and can be applied to conventional video cassettes. Alternatively, it can be applied to various other magnetic tape cassettes.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing one embodiment of the present invention, Fig. 2 is a sectional view of essential parts of the magnetic tape cassette shown in Fig. 1, and Fig. 3 is an assembled state of the magnetic tape cassette shown in Fig. 1. FIG. 4 is a sectional view of a main part taken along the front and back surfaces of the cassette, showing a state in which the end piece of the guard panel and the claw part of the locking member are engaged with each other. Code 1 in the figure... Magnetic tape cassette, 2...
Upper half case, 3... Lower half case, 4...
Hub, 4a... Outer peripheral edge, 5... Friction seat, 6... Lock member, 7... Sharp protrusion, 8...
Guard panel, 9... Rotation shaft, 10... Opening, 11... Tape outlet, 12... Tape guide, 13... Locking pin, 14... Reel shaft insertion hole, 15... Side wall, 15a ...Bulkhead, 1
6... Hole, 17... Front wall, 17a... End piece, 1
8... Notch, 19... Leg piece, 19a... Projection piece, 20... Slide guard, 21... Tapered surface, 22... Engaging protrusion, 23... Transparent hole, 24...
...Claw portion, 25...Slide guard spring, 26...
...Side piece, 27... Overhanging portion, 28... Spring for guard panel, 29... Spring for lock member, 30...
...Top end, 31...Spring locking shaft, 32...Step,
33...Opening.

Claims (1)

[Scope of utility model registration request] It houses a pair of hubs 4 around which magnetic tape is wound, and has an opening 10 that allows the magnetic tape to be pulled out to the front of the cassette. It is provided with a guard panel 8 in the shape of a letter, and an upper end portion 30 extending in the left-right direction of the cassette along the inner surface of the upper half case 2, and leg pieces that stand upright along the side walls of the cassette at both ends of the upper end portion 30 in the left-right direction of the cassette. 19,
Reference numeral 19 denotes left and right end pieces 17a of the guard panel 8,
It has projecting pieces 19a, 19a extending toward the front side of the cassette to engage with the hub 17a, and has a pair of pointed protrusions 7 extending toward the rear side of the cassette so as to lock the hub 4 to the upper end portion 30. In the magnetic tape cassette, the left and right end pieces 17a, 1 are provided with a locking member 6 which is slidable in the front and back direction of the cassette and is biased toward the rear of the cassette.
The tapered surface 21 formed on the lower edge of the guard panel 7a is configured to engage with the claw portion 24 provided at the tip of the overhanging pieces 19a, 19a in a direction protruding in the left-right outward direction of the cassette when the guard panel 8 is rotated. The tapered surface 21 is inclined so that its lower edge portion 21a is located inward of the cassette, and the surface of the claw portion 24 on the rear side of the cassette that engages with the tapered surface 21 is located on the cassette rear side. A magnetic tape cassette characterized in that it has an inclined surface 24a that extends toward the rear of the cassette toward its tip.