JPH056620Y2 - - 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 in the audio field, too, they have to be used for long periods of time at high temperatures. There has been a strong demand for magnetic tape cassettes that are of high quality and can be adapted to high-density recording and reproduction. 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 video tape cassettes, which have a wider recording frequency band than compact audio cassettes, 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 is such that an opening provided in front of the cassette is closed and a guard panel that can be opened is provided above the cassette. In other words, when using the digital method, recording and playback is performed in a high-density, wide-frequency band with a shorter recording wavelength than in conventional audio compact cassettes, so sufficient tape protection measures have been taken to increase reliability. A cassette structure was required.

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 that is intended for use with devices that are comparable in size to conventional audio compact cassettes or smaller in size. 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. A structure is required that can reliably prevent tape jamming caused by tape loosening.

One of the magnetic tape cassettes proposed to meet this condition is a hub wrapped with magnetic tape.
Some devices are equipped with locking members that lock and release when not in use and when in use.
This lock member is always biased toward the hub by a spring, and when not in use, the protrusion on the lock member comes into contact with the hub to prevent rotation of the hub, and when in use, the protrusion separates from the hub. It is structured like this. However, as cassettes become smaller, these components are also made smaller, making it difficult to assemble them.Also, the locking member is assembled while being biased by a spring, making it difficult to handle and making assembly work easier. It was a factor that led to the decline of

Furthermore, the locking member is constantly biased toward the hub (towards the rear of the cassette) in order to lock the hub.
When the guard panel is engaged when opening, the cassette slides forward and unlocks the hub, so the locking member may bend at this time, making the engagement with the guard panel uncertain and reducing its reliability. There was also a problem.

(Purpose of the invention) Therefore, the purpose of the invention is to solve the above-mentioned problems, and to provide a magnetic tape cassette having a structure that not only improves the ease of assembling the cassette but also enables highly reliable hub locking and release. It is about providing.

(Structure of the invention) The object of the invention is to have a pair of hubs wrapped with magnetic tape, a built-in slidable locking member that is biased by a spring and locks the hubs, and a locking member located at the front of the cassette. In a magnetic tape cassette equipped with a rotatable guard panel for opening and closing an opening of the magnetic tape cassette, the ends of both arm parts of the locking member projecting in front of the cassette are provided with a bag-shaped engaging part that opens at least upwardly, and Engagement hooks are provided on the inside of the side walls at both ends of the guard panel, and are formed to protrude in a substantially L-shape so that their tips can be inserted into the engagement portion. This is achieved by a magnetic tape cassette characterized in that the mating hook is engaged to slide the locking member forward of the cassette.

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

FIG. 1 is a perspective view showing a state before the lock member 1 is attached to the upper half case 2. As shown in FIG. A window member 3 is fixed to the upper half case 2 by, for example, ultrasonic welding. This window member 3 has a pair of receiving parts 4 that hold the upper edge of a hub (not shown) on the rear side of the cassette.
For example, a pair of protrusions 11 that protrude long in the front-rear direction of the cassette are formed at a position closer to the front of the cassette than the receiving part 4, and a pair of protrusions 11 that extend to the tape outlet on the front side of the cassette are formed. A prism body 12 is formed on each piece. On the other hand, the locking member 1 includes a flat part 5 that makes sliding contact with the window member 3, a pair of recesses 7 that fit into the convex part 11, and a pair of pointed protrusions that abut against the outer circumferential edge of the hub and lock the hub. 6. A protrusion 8 is formed to which a spring 9 for biasing the locking member 1 toward the rear of the cassette is attached, and arm portions 10 are formed at both left and right ends of the cassette and project toward the front of the cassette along the side walls of the cassette. or,
At the tips of both arm parts 10, for example, an engaging part 20 having a bag-shaped receiving part 21 opened above the cassette is formed. Note that since the arm portion 10 has a relatively small width l ₁ in the cassette left-right direction, it is desirable that the width l ₂ of the engaging portion 20 is large so that the receiving portion 21 can be easily formed.

On the other hand, the guard panel 15 that opens and closes the opening in front of the cassette is built in so as to rotate around a rotating shaft 17 provided on the side walls 16 at both ends thereof. Appropriately protruding engagement hooks 18 are formed approximately parallel to each other.

When assembling the cassette, the lock member 1 and guard panel 15 described above are attached to the upper half case 2, and then assembled into the lower half case in which a pair of hubs wrapped with magnetic tape and a friction sheet are incorporated. Make it. At this time, the lock member 1 is held slidably in the cassette front and back direction along the upper half case 2 by fitting the recess 7 and the protrusion 11, and the guard panel attached to the front part of the upper half case 2 15, the cassette can be assembled into the lower half case in a state where it is slid toward the front side of the cassette against the biasing force of the spring 9 toward the rear of the cassette. That is, as shown in FIG. 2, the lock member 1 and the guard panel 1
5, when the guard panel 15 is rotated in the direction of arrow A, the engagement hook 18 formed on the rotating shaft 17 engages with the engagement part 20 of the arm part 10, so that the lock member 1 is moved forward of the cassette. It is configured to slide.

Therefore, when assembling the cassette, when the upper half case 2 is placed over the lower half case, the sharp protrusion 6 of the locking member 1 will not engage with the hub, and the hub will not be exposed to the unexpected contact of the sharp protrusion 6. The ease of assembling the cassette is improved without causing displacement due to engagement. By simplifying the assembly of the cassette in this way, assembly using an automatic machine is particularly easy, and productivity can be further improved.

Further, the operation of the lock member 1 constructed as described above when it is installed in a cassette case will be explained. When the cassette case is loaded into the recording/reproducing apparatus and the guard panel 15 on the front of the cassette case rotates, the locking member 1 slides toward the front of the cassette due to the engagement between the engaging hook 18 and the engaging portion 20 of the arm portion 10. , unlock the hub. This sliding is performed against the biasing force of the spring 9 in contact with the front wall 13 of the upper half case toward the rear of the cassette. Therefore, when the lock member 1 slides forward of the cassette and when the hub is unlocked, a tensile force is applied to the lock member 1 between the tip of the arm portion 10 and the protrusion 8. However, due to this force, for example, the lock member 1 is subjected to a force that deforms.
As shown in FIG. 2, since the engaging hook 18 is positioned so as to fit into the engaging portion 20 of the arm portion 10, troubles such as disengagement between the engaging portion 20 and the engaging hook 18 are avoided. This can ensure reliable operation of the locking member 1.

In addition, in this embodiment, the lock member 1
was held by fitting the concave part 7 provided in the flat part 5 and the convex part 11 provided in the window member 3, but other than that,
For example, the planar portion 5 of the locking member 1 may be slidably held between the window member 3 and the upper half case 2, and various other configurations are possible.

In the embodiment described above, the engaging hook 18 is provided on the rotating shaft 17, but the present invention is not limited to this embodiment. That is, if the engaging hook 18 is formed on the inner surface of the side wall 16 in order to hook the engaging portion 20 and slide the locking member 1 forward in the cassette when the guard panel 15 is opened, the formation position and The shape is not particularly limited and can be changed in various ways.

Furthermore, the engagement portion 20 in the present invention is not limited to that shown in FIG. 2, but as shown in FIG.
The engagement hook 18 is formed in a U-shape or V-shape.
Needless to say, a configuration in which the cassette is inserted from the left and right sides is included within the technical scope of the present invention.

(Effects of the invention) As described above, in the magnetic tape cassette of the invention, the locking member attached to the upper half case and biased toward the rear of the cassette is deflected toward the front of the cassette by the guard panel. Since it can be reliably maintained, the locking member does not come into contact with the hub at all when assembling the cassette, and problems such as misalignment of the hub can be avoided and the difficulty of the assembly process can be reduced. Therefore, it is possible to easily mechanize cassette assembly and improve productivity.

Further, the engagement between the lock member and the guard panel according to the present invention is such that the engagement hook is inserted into the engagement portion at the tip of the arm portion of the lock member.
For example, due to the bending of the arm part and the engagement hook,
It is possible to completely prevent troubles such as the engagement hook and the arm becoming unlatched, and ensure reliable operation of the lock member.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing the upper half case, lock member, and guard panel of a magnetic tape cassette according to an embodiment of the present invention, and Fig. 2 is an enlarged view of the main parts to show the engaged state of the lock member and the guard panel. The perspective view and FIG. 3 are enlarged perspective views of essential parts showing a modification of the present invention. 1...Lock member, 2...Upper half case, 3
...Window member, 4...Receiving portion, 5...Plane portion, 6...
... Pointed protrusion, 7... Recess, 8... Protrusion, 9... Spring, 10... Arm, 11... Convex, 12...
Prism body, 13... Upper half case front wall, 1
5...guard panel, 16...side wall, 17...rotating shaft, 18...engaging hook, 20...engaging portion, 2
1...Ukebe.

Claims (1)

[Scope of claims for utility model registration] 1) Having a pair of hubs wrapped with magnetic tape,
In the magnetic tape cassette, the magnetic tape cassette includes a slidable locking member that is biased by a spring and locks the hub, and is equipped with a rotatable guard panel that opens and closes an opening at the front of the cassette. The tips of both arm portions projecting forward are provided with bag-shaped engagement portions that open at least upward, and protrude in a substantially L-shape inside the side walls at both ends of the guard panel, so that the tip portions can fit into the engagement portions. An engaging hook formed as shown in the figure is provided, and when the guard panel is opened, the engaging hook engages with the engaging portion and slides the locking member forward of the cassette. Magnetic tape cassette. 2) The magnetic tape cassette according to claim 1, wherein the engaging hook is configured to protrude from the tip of the rotating shaft of the guard panel along the side walls at both ends. .