JPH056621Y2 - - 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. 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. Digital methods such as pulse code modulation (PCM), which record and reproduce input signals by converting them into pulses, are known to be suitable for these demands, unlike analog methods.
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 must 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 in the direction of 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 to release the bub lock, 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 present invention is to solve the above problems, and to provide a magnetic tape cassette having a structure that not only improves cassette assembly ease 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, claws at the tips of both arms of the locking member protruding in front of the cassette protrude inwardly of the cassette. Engagement hooks are provided inside the side walls at both ends and are formed to be located inward of the cassette from the arm section, and when the guard panel is opened, the engagement hook engages with the claw section and locks the lock member. This is achieved by a magnetic tape cassette characterized in that the cassette is configured to be slid forward.

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

FIG. 1 is a perspective view showing the 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 portions 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 urging the locking member 1 toward the rear of the cassette is attached, and arm portions 10 are formed at both left and right ends to project forward of the cassette along the side walls of the cassette. or,
A claw portion 10a facing inward of the cassette is formed at the tip of both arm portions 10.

The guard panel 15, which opens and closes the opening in front of the cassette, is built into the guard panel 15 so as to rotate about a rotating shaft 17 provided on the side walls 16 at both ends thereof. Engagement hooks 18 are each formed to protrude appropriately.

The lock member 1 and guard panel 15 described above are
When assembling the cassette, the cassette is attached to the upper half case 2 and assembled onto the lower half case into which a pair of hubs wrapped with magnetic tape, a friction sheet, etc. are incorporated. 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 is attached to the guard panel 15 attached to the front part of the upper half case 2. Twist spring 9
The cassette can be assembled into the lower half case while being slid toward the front side against the rearward biasing force of the cassette. That is, as shown in FIG. 2, the lock member 1 and the guard panel 15 are
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 claw portion 10 of the arm portion 10, so that the lock member 1 slides toward the front of the cassette. has been done.

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 does not engage with the hub, and the hub is prevented from accidentally engaging with the sharp protrusion 6. The ease of assembling the cassette is improved without causing misalignment due to misalignment. By simplifying the assembly of the cassette in this way, assembly using an automatic machine becomes possible, and productivity can be further improved.

Further, the operation of the lock member 1 constructed as described above when it is assembled 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 lock member 1 slides toward the front of the cassette due to the engagement between the engaging hook 18 and the claw portion 10a 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, as shown in FIG.
and the engaging hook 18, troubles such as disengagement between the claw portion 10a and the engaging hook 18 can be avoided, and reliable operation of the locking member 1 can be guaranteed.

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 so as to hook the claw portion 10a and slide the locking member 1 forward in the cassette when the guard panel 15 is opened, the position and shape of the engaging hook 18 can be changed. is not particularly limited and can be changed in various ways.

(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.

Furthermore, the engagement between the lock member and the guard panel according to the present invention is such that the arm portion of the lock member is sandwiched between the side wall of the guard panel and the engagement hook, and the lateral movement of the cassette is restricted. Therefore, it is possible to completely prevent troubles such as the engagement hook and the pawl becoming disengaged, and reliable operation of the lock member can be guaranteed.

[Brief explanation of the drawing]

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. FIG. 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 part, 10a... Claw part, 11...
... Convex portion, 12 ... Prism body, 13 ... Front wall of upper half case, 15 ... Guard panel, 16 ...
Side wall, 17... Rotating shaft, 18... Engagement hook.

Claims (1)

[Scope of claims for utility model registration] 1) Having a pair of hubs wrapped with magnetic tape,
In a magnetic tape cassette, the magnetic tape cassette includes a slidable locking member that is biased by a spring and locks the hub, and a rotatable guard panel that opens and closes an opening at the front of the cassette. Claws at the tips of both arms protrude inward from the cassette, and engaging hooks are provided inside the side walls at both ends of the guard panel so as to be located inward from the cassette from the arm portions. A magnetic tape cassette, characterized in that the engagement hook engages with the pawl when the guard panel is opened, causing the lock member to slide forward of the cassette. 2) The magnetic tape 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 both end side walls. Cassette.