JPH0718073Y2 - Magnetic tape cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a magnetic tape cassette, and more specifically,
The present invention relates to a new compact cassette for audio, which is of the same size as or smaller than the Philipps type.

(Prior Art) In recent years, the miniaturization and weight reduction of cassette tape recorders have progressed, and the magnetic tape cassettes used for them have also been miniaturized, and it is strongly possible to adapt to high-quality and high-density recording and reproducing for a long time It has come to be desired. As a device that responds to such a demand, a digital system such as a pulse code modulation (PCM) that converts an input signal into a pulse and performs recording and reproduction is known.
Currently, with this system, a video tape cassette is widely used because it is necessary to widen the recording frequency band to about 5 times that of the conventional audio tape.

This video tape cassette adopts the rotary head system except for special ones, and protects the magnetic tape and records / reproduces in a high-density wide-frequency band.To prevent dust from affecting the characteristics of the recording / reproduction, the cassette is used. An openable guard panel is provided above.

The magnetic tape cassette to which the present invention is applied is a magnetic tape cassette for digital audio which adopts a recording / reproducing system of a relatively wide frequency band similarly to the video tape cassette, and is the same as or smaller than a conventional compact cassette for audio. It is extremely small with a size smaller than that. Further, it is expected that the magnetic tape cassette for digital audio will be frequently used outdoors like the conventional cassette for audio, and that it is often carried and used without a storage case.

Under such circumstances, various magnetic tape cassettes for digital audio have been proposed. This magnetic tape cassette has a slide guard that slides in the cassette front-rear direction along the outer surface of the cassette bottom to block the lower side of the opening in front of the cassette in addition to the guard panel that can be opened above the cassette like the video tape cassette. Is provided. The structure provided with the slide guard and the guard panel has a high protection effect and a dust prevention effect on the magnetic tape, and the effect of preventing deterioration of the recording / reproducing apparatus can be enhanced.

However, the magnetic tape cassette for the digital audio is smaller and lighter than the video tape cassette, and in addition, since various components such as the slide guard are provided, the cassette structure becomes relatively complicated and the cassette assemblability is improved. I had a problem.

(Purpose of the Invention) The present invention has been made in view of the above problems, and an object thereof is to provide a magnetic tape cassette having a structure that is reliably dust-proof and tape-protected, and has an excellent assembling property. is there.

(Construction of the Invention) An object of the present invention is to incorporate a pair of hubs around which a magnetic tape is wound, have an opening through which the magnetic tape can be pulled out to the front of the cassette, and connect the front side of the opening to the front side. In a magnetic tape cassette comprising an upper half case and a close guard panel and a slide guard closing the lower side of the opening, the slide guard is slidable in the front-rear direction of the cassette along the outer surface of the lower half case, The side walls of the cassette, which have substantially vertical flat surfaces on both right and left sides, are raised so as to face each other with a flat surface, and the upper portion thereof is bent toward the inside of the case. And is attached to cover the plurality of screw holes arranged on the bottom surface of the lower half case by being urged to the front of the cassette by urging means. Has an engaging recess for receiving the tip of the holding means arranged outside the cassette from the outer surface thereof and for moving the entire slide guard by a predetermined distance with respect to the cassette by an external force transmitted from the holding means. A magnetic device, comprising a locking portion, wherein the holding means and the locking portion are engaged with each other to move the slide guard, thereby enabling a screw to be screwed into the screw hole. Achieved by tape cassette.

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

The magnetic tape cassette 1 shown in FIG. 1 is of the same size as or smaller than a compact cassette used in conventional audio or the like. The magnetic tape cassette 1 comprises a pair of flangeless hubs 4 each having a magnetic tape T wound in a cassette case composed of upper and lower half cases 2 and 3, and a friction sheet for smoothly rotating the hubs 4. 5 and a lock member 6 for preventing unexpected rotation of the hub 4, a guard panel 8 for closing the front side of the opening 10 in front of the cassette case, and a lower side of the opening 10 for closing. A slide guard 20 and is attached.

It should be noted that each of the hubs 4 has an annular portion 4a which is concentrically projected with the tape winding surface so as to be engaged with the lock member 6.
Are formed.

The guard panel 8 has a U-shaped horizontal cross section as in the case of the conventional video tape cassette.
Rotating support shafts 9 facing each other are projectingly provided on the left and right side pieces. The guard panel 8 has a bearing hole 16 formed when the upper and lower half cases 2 and 3 are superposed on each other, or a bearing hole formed in either one of the upper and lower half cases 2 and 3 (shown in the drawing). No.), the rotary support shaft 9 is attached so as to be rotatably inserted.
Further, the guard panel 8 is biased by the guard panel spring 28 in the direction of closing the opening 10.

Notches 18 are formed on both the left and right sides of the lower edge of the front wall 17 of the guard panel 8 to prevent the magnetic tape cassette 1 from being inserted by mistake in the front-rear direction of the cassette when it is loaded in the recording / reproducing apparatus. It is configured. That is,
The protrusion for preventing incorrect insertion provided in the bucket which is the cassette receiving portion of the cassette insertion portion of the recording / reproducing device has the notch 18
The magnetic tape cassette 1 can be loaded into the recording / reproducing apparatus only when the magnetic tape cassette 1 is properly inserted in the front-rear direction.

The lower half case 3 is provided with a pair of reel shaft insertion holes 14 corresponding to the hub 4 similarly to a conventional video tape cassette, and has the opening so that the magnetic tape T can be pulled out to the front of the cassette. Tape outlets 11 are formed at both left and right ends of the portion 10. Further, a boss 13 having a slit 13a is provided in the vicinity of the tape outlet 11 (on the right side in the figure). The boss 13 is a portion on which a spring 30 for urging the slide guard 20 in a desired direction is mounted. Further, screw bosses 24 are formed at both rear corners of the cassette, and the tape guide 12 on the front side of the cassette is configured to also function as a screw boss. Further, the wall surface of the bottom of the cassette between the tape guides 12 is formed so as to recede behind the cassette,
When the magnetic tape cassette 1 is loaded into the recording / reproducing apparatus, the tape pull-out member of the apparatus can be inserted into the cassette from below the cassette.

Also, a step portion 15 is provided on the upper edge of the side wall 15 of the lower half case 3.
a is provided. That is, when the cassette is assembled, a slit is formed so that the overhanging portion 27 of the slide guard 20 can enter the cassette.

The spring 30 includes an arm portion 32 that engages with the slide guard 20 and a coil-shaped fulcrum portion 31 that is fitted to the boss 13.

The slide guard 20 is a plate-shaped one,
The wall surface corresponding to the bottom surface of the cassette is received by the through hole 23 corresponding to the reel shaft insertion hole 14, the engaging projection 33 with which the spring 30 is engaged, and the notch 18 of the guard panel 8. Protrusions 21 are formed, and the left and right ends are formed as side pieces 26 that rise up along the cassette side wall 15.
A circular hole 25, which is a locking portion with which a holding means 40 described later is engaged, is provided at substantially the center of the, and each of the upper edges thereof has a
A protruding portion 27 is formed so as to slightly enter the cassette case. The hole 25 does not have any relation to the operation of the slide guard 20 when the cassette is used.

When the upper half case 2 is combined with the lower half case 3 like a conventional video tape cassette,
The front portion is formed so as to form the tape withdrawing port 11 together with the lower half case 3. Further, although not shown, means for restricting the rotational position of the hub 4 and a screw boss into which the screw 22 (screw) is screwed are 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 outer surface of the bottom of the lower half case. At this time, the slide guard 20 is mounted so that the projecting portion 27 enters the cassette from the step portion 15a. Then, the hub 4 having the magnetic tape T wound thereon is arranged on the flexion sheet 5 laid on the inner surface of the lower half case 3 so as to correspond to the reel shaft insertion holes 14, respectively. The T is mounted between the tape guides 12 so that T is taken out of the cassette through the tape outlet 11. Further, another fricsion sheet 5 is placed on the upper half case 2, and the locking member 6 is disposed on the fricsion sheet 5, and a locking member spring 29 is attached to cover the upper half case 2.

The spring 30 is attached at an appropriate stage after the slide guard 20 is attached. Also, the guard panel 8 is
The rotation support shaft 9 is rotatably inserted into the bearing hole 16, and the guard panel spring 28 is also attached to the rotation support shaft 9 so that the opening 10 is biased in the closing direction. To be

The magnetic tape cassette 1 is composed of the upper and lower half cases 2,
After the three are superposed, the assembly of the cassette is completed by screwing the screw 22 into a predetermined position, but the insertion hole 22a of the screw 22 inserted into the tape guide 12 is ( (See FIG. 2), usually the slide guard 2
It is located inside 0. Therefore, as shown in FIG. 2, the screw 22 that fastens the front side of the cassette is moved rearward (in the direction of arrow E) by the holding means 40 in which the slide guard 20 is engaged with the hole 25. After that, the lower half case 3 is screwed in.

Further, by engaging the holding means 40 with the hole 25, it is possible to prevent the cassette from being unassembled before being screwed.

When the magnetic tape cassette 1 is stored, the opening 10 is closed by the guard panel 8 and the slide guard 20, and the annular projections 4a of the hubs 4 and the engaging projections 7 of the locking member 6 are stored. And abut each other, and the unexpected rotation of the hub 4 is prevented.

The material of the upper and lower half cases 2, 3, the guard panel 8, the lock member 6 and the like may be conventionally used plastic resin such as polyacetal resin, ABS resin, PS resin, etc., and the material of the slide guard 20. Is not particularly limited, but it is more advantageous in terms of price to be composed of the same plastic resin as described above.

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

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

When the magnetic tape cassette 1 is loaded in the cassette insertion portion of the recording / reproducing apparatus, it is pushed in with the opening 10 side facing forward (in the direction of arrow A shown in FIG. 3). During this pushing operation, the slide guard 20 slides rearward of the cassette (in the direction of arrow B) against the biasing force of the spring 30 by the protrusion 21 abutting a protrusion for preventing erroneous insertion in the cassette insertion portion, for example. ), The lower side of the opening 10 is opened, and the through holes 23 are aligned with the reel shaft insertion holes 14 so that the hub shaft driving reel shaft can be inserted.

After that, the magnetic tape cassette 1 moves downward (direction of arrow C) in a direction perpendicular to the pushing direction. During this downward movement, the guard panel 8
For example, a guard panel opening means provided in the interior of the cassette insertion portion is brought into contact with a lower edge of the guard panel opening means so as to open above the cassette case about the rotation support shaft 9 (arrow D).
Direction).

Further, when the guard panel 8 is opened, the left and right end pieces of the guard panel 8 hook the tip portions of the left and right projecting pieces 19 of the lock member 6 to slide the lock member 6 forward of the cassette. Accordingly, the hub 4 is disengaged from the engaging portion 7 of the locking member 6 and is in a rotatable state.

In this way, the loading of the magnetic tape cassette 1 is completed by the pushing operation and the downward movement, and the opening 10 is completely opened by the slide of the slide guard 20 and the opening of the guard panel 8. The contact between the outer peripheral edge 4a and the engaging portion 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, so that the recording / reproduction can be performed by the rotary head system.

When the magnetic tape cassette 1 is taken out from the recording / reproducing apparatus, the magnetic tape cassette 1 moves with a stroke opposite to that at the time of loading, and first, the guard panel 8 is released from the contact with the guard panel opening means and the guard panel 8 is released. The front side of the opening 10 is closed by the urging force of the panel spring 28. Then, when the magnetic tape cassette 1 is pulled out, the slide guard 20 is released from contact with the erroneous insertion preventing projection, so that the slide guard 20 is slid forward by the urging force of the spring 30 and the opening 10 is opened. Is completely occluded.

Further, since the guard panel 8 is rotated so as to close the opening 10, the engagement between the left and right end pieces of the guard panel 8 and the tip end portion of the projecting piece 19 is released. As a result, the locking member 6 is slid rearward of the cassette by the urging force of the locking member spring 29, and the engaging portions 7 abut the annular portion 4a so that the hub 4 is not rotated. To do. Further, since the slide guard 20 slides so as to close the lower side of the opening 10, the positions of the transparent hole 23 and the reel shaft insertion hole 14 are displaced, and the reel shaft insertion hole 14 is closed. To be done.

In the above-described embodiment, the engaging portion of the holding means 40 is formed in the circular hole 25, but the present invention is not limited to such a shape, and for example, the lower portion 25 may be replaced with the lower portion. A concave portion having no protruding surface may be formed on the surface facing the half so that the holding means 40 can be engaged.

In the embodiment, the slide guard 20
The backward sliding of the cassette was performed by contacting the projections 21 for preventing erroneous insertion with the projections 21 formed on the left and right of the front edge of the slide guard, but the present invention is not necessarily limited to such a configuration. For example, the engagement protrusion 33 that engages with the arm 32 of the spring 30 is provided at the front edge of the slide guard, and the guard panel 8 is also provided with a notch for receiving the engagement protrusion 33. It may be configured as follows.

(Effects of the Invention) As described above, since the magnetic tape cassette 1 has the hole 25 in the slide guard 20, when the screw is tightened at the final stage of the cassette assembly, the holding means 40 is extremely simple. The slide guard 20 can be easily moved to fasten the screw, and at the same time, the slide guard 20 can be pressed so as not to cause the collapse of the cassette before the screw is fastened, which is excellent in cassette assembly.

It was stated at the beginning that the present invention was applied to a magnetic tape cassette for digital audio of a size equal to or smaller than that of a conventional compact cassette for audio. However, the present invention is not limited to this, and it is not limited to this. It can also be applied to cassettes and various other magnetic tape cassettes.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention, FIG. 2 is a perspective view showing a final stage of assembly of the magnetic tape cassette shown in FIG. 1, and FIG. 3 is shown in FIG. It is a perspective view for showing operation of a magnetic tape cassette. DESCRIPTION OF SYMBOLS 1 ... Magnetic tape cassette, 2 ... Upper half case, 3 ... Lower half case, 4 ... Hub, 4a ... Ring part, 5 ... Friction sheet, 6 ... Lock member, 7 ... Engagement part, 8 ... Guard panel, 9 … Rotating spindle, 10… Opening, 11… Tape outlet, 12… Tape guide, 13… Boss, 13a… Slit, 14
… Reel shaft insertion hole, 15… Side wall, 15a… Step, 16…
Bearing hole, 17 ... Front wall, 18 ... Notch, 19 ... Overhanging piece,
20 ... Slide guard, 21 ... Protrusion, 22 ... Screw, 22a ... Insertion hole, 23 ... Through hole, 24 ... Screw boss, 25 ... Hole, 26 ... Side piece, 27
... Overhang part, 28 ... Guard panel spring, 29 ... Lock member spring, 30 ... Spring, 31 ... Support point part, 32 ... Arm part, 33 ...
Engaging protrusions, 40 ... Holding means.

Claims (1)

[Scope of utility model registration request] 1. A guard panel having a pair of hubs around which a magnetic tape is wound, having an opening for allowing the magnetic tape to be pulled out to the front of the cassette, and closing the front side of the opening, and the opening. In a magnetic tape cassette comprising upper and lower half cases with a slide guard closing the lower side of the lower half case, the slide guard is slidable in the front-rear direction of the cassette along the outer surface of the lower half case and has a substantially vertical shape on both left and right sides thereof. It rises up so as to face the cassette side wall having a flat surface with a flat surface and bends the upper part toward the inside of the case, and has a side piece whose vertical cross section is substantially U-shaped, and by the biasing means. It is biased toward the front of the cassette and mounted so as to cover the plurality of screw holes arranged on the bottom surface of the lower half case, and the side pieces are arranged outside the cassette. It comprises a locking portion having an engaging concave portion for receiving the tip end portion of the holding means from the outer surface thereof and moving the entire slide guard with respect to the cassette by a predetermined distance by an external force transmitted from the holding means. A magnetic tape cassette, wherein the holding means and the locking portion are engaged with each other to move the slide guard, thereby enabling a screw to be screwed into the screw hole.