JPH0713110Y2 - 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, except for special ones, uses a rotating head system. Since the magnetic tape is protected and recording / reproduction is performed in a high density wide frequency band, a movable guard panel is provided above the cassette in order to prevent the influence of dust on various characteristics of the recording / reproduction.

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. Also, it is expected that the magnetic tape cassette for digital audio will be used frequently outdoors like the conventional audio cassette, 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, in addition to a guard panel that can be opened above the cassette like the above video tape cassette, a slide that slides in the cassette front-rear direction along the outer surface of the cassette bottom to close the lower side of the opening in front of the cassette. There is a guard.

However, the magnetic tape cassette for the digital audio is smaller and lighter than the video tape cassette, and additionally includes various members such as the slide guard,
Moreover, since a biasing means such as a spring for activating these members is incorporated, the cassette structure becomes relatively complicated, and there is a problem in cassette assembly. In view of the above situation, the magnetic tape cassette for digital audio needs to have a structure with more reliable tape protection and dustproof function than the conventional video tape cassette. Especially, in the slide guard, the operation can be performed smoothly. A device was desired.

(Purpose of the Invention) The present invention has been made in view of the above problems, and is a magnetic tape configured to have a reliable dustproof function and tape protection, good assembling ability, and reliable slide guard operation. The purpose is to provide a cassette.

(Construction of the Invention) An object of the present invention is to incorporate a pair of hubs 4 around which a magnetic tape T is wound, and have an opening 10 that allows the magnetic tape T to be pulled out to the front of the cassette. In a magnetic tape cassette comprising a rotatable guard panel 8 closing the front side of 10 and a slidable slide guard 20 closing the lower side of the opening 10, the slide guard 20 extends along the outer surface of the bottom of the cassette case. It is slid and is biased toward the front of the cassette by a spring 30 that engages with an engaging protrusion 40 that is provided on the inside of the front edge side of the engaging protrusion 40. Is formed by intersecting a pair of tapered surfaces 41, 43 that rise and fall.
This is achieved by a magnetic tape cassette characterized in that the spring is locked at the intersection 42 of the tapered surfaces 41, 43.

Hereinafter, the present invention will be described in detail based on 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 includes a pair of flangeless hubs 4 each having a magnetic tape T wound in a cassette formed of upper and lower half cases 2 and 3, and a friction sheet 5 for smoothly rotating the hub 4. 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 slide for closing the lower side of the opening 10. Guards 20 and are attached.

Each of the hubs 4 is formed with an annular portion 4a which is concentrically projected with the tape winding surface so that it can be engaged with the locking member 6.

The guard panel 8 has a horizontal cross section shaped like a letter as in the case of a conventional video tape cassette.
Rotating support shafts 9 facing each other are projectingly provided on the left and right end pieces. The guard panel 8 has a hole 1 formed when the upper and lower half cases 2 and 3 are overlapped.
6, or the rotation support shaft 9 is rotatably fitted into a hole (not shown) formed in either one of the upper and lower half cases 2 and 3. 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 rod-shaped spring 30 for urging the slide guard 20 in a desired direction is mounted. Further, the wall surface of the cassette bottom between the tape outlets 11 is formed so as to recede to the rear of the cassette, and when the magnetic tape cassette 1 is loaded into the recording / reproducing apparatus, the tape drawer member of the apparatus is set to the cassette. It is configured so that it can be inserted into the cassette from below.

The spring 30 comprises an arm portion 32, a fulcrum portion 31, and a hooking portion 33, and is attached to the lower half case 3 so that the fulcrum portion 31 fits into the slit 13a. On the other hand, the tip of the arm portion 32 is engaged with the engagement protrusion 40 formed on the slide guard 20. Therefore, the slide guard 20 is urged forward of the cassette.

As shown in FIG. 3, the engaging projection 40 has a vertical cross section on the rear side of the cassette formed in a dogleg shape. That is, a taper surface 41 that slopes upward toward the rear of the cassette is formed in the upper portion on the rear side of the cassette, and a taper surface 43 that slopes downward toward the rear of the cassette is formed in the lower portion. These tapered surfaces 41 and 43 are formed so as to intersect with each other, and the linear intersecting portion (taper surface boundary line) is the spring receiving portion.
42, the tip of the arm portion 32 of the spring 30 is locked. The inclination angles of the tapered surfaces 41 and 43 are not particularly limited,
The inclination angle does not have to be highly accurate.

Further, the height of the spring receiving portion 42 from the bottom surface of the slide guard is the same as the wall thickness h of the lower half case 3, but this is so that the biasing force of the spring 30 works only in the horizontal direction. It is the structure.

A step portion 15a is formed on the upper edge of the side wall 15 of the lower half case 3 so that when the cassette is assembled, the projecting portion 27 of the slide guard 20 forms a slit that can enter the cassette. Has been done.

The slide guard 20 is plate-shaped, and has a through hole 23 corresponding to the reel shaft insertion hole 14, a engaging projection 40, and a notch 18 in the guard panel 8 on a wall surface corresponding to the bottom surface of the cassette. A projection 21 is formed to be received by
Side pieces 26 on both left and right sides that rise along the cassette side wall 15
Further, each of the upper edges of the side pieces 26 is formed with the projecting portion 27 protruding so as to slightly enter the cassette case.

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 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 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. It is mounted between the left and right tape guides 12 so that T is taken out of the cassette through the tape outlet 11. Further, another friction sheet 5 is placed on the lock sheet 6, and the lock member 6 is arranged on the friction sheet 5.
Is attached and the upper half case 2 is covered.

In addition, as described above, the spring 30 has the fulcrum portion 31 and the boss.
It is mounted so as to be pushed in or dropped into the slit 13a of 13 and the tip end portion of the arm portion 32 is engaged with the engaging projection 40. At this time, since the tapered surfaces 41 and 43 are formed, the tip portion of the arm portion 32 easily and reliably enters the spring receiving portion 42. That is, when the spring 30 is locked to the engagement protrusion 40, the spring 30
By locating the tip of the arm portion 32 of the above in the gap formed by the tips of the tapered surfaces 41 and 43, the tip of the arm portion 32 is guided to the spring receiving portion 42 by either of the tapered surfaces 41 and 43. The work of locking the spring 30 is extremely easy.

In the guard panel 8, when the upper half case 2 is covered, the rotation support shaft 9 is rotatably fitted in the hole 16, and the guard panel spring 28 is also attached.
It is attached so as to be biased in the closing direction.

In this way, the magnetic tape cassette 1 is assembled by assembling the upper and lower half cases 2 and 3 and then fastening them with screws or the like.

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 engagement between the annular portion 4a of each hub 4 and the lock member 6 is performed. The abutment portion 7 comes into contact with the hub 4 to prevent the hub 4 from rotating unexpectedly.

The material of the upper and lower half cases 2, 3, the guard panel 8, and the lock member 6 may be a plastic resin such as polyacetal resin, ABS resin, PS resin or the like which has been conventionally used, and the slide guard 20 is not particularly limited. However, it is preferable to use the same resin as the above-mentioned plastic resin because it can be manufactured at low cost.

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. 2). 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 annular portion 4a and the engaging portion 7 is released. as a result,
The magnetic tape T can be pulled out from the opening 10 to 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 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.

Since the spring 30 can determine the projecting direction of the arm portion 32 such that the fulcrum portion 31 fits into the slit 13a of the boss 13, the biasing force thereof can be easily set to an appropriate strength. Is.

In the above-mentioned embodiment, the intersection of the tapered surfaces 41, 43 formed on the engaging projection 40, that is, the boundary line is formed in a straight line, but the present invention is not limited to such a shape. For example, it can be changed as shown in FIG. 4 and FIG.

The engaging projection 50 shown in FIG. 4 has a vertical cross-section of a portion into which the spring 30 is inserted, which has a dogleg shape. That is, the boundary portion between the upper tapered surface 54 and the lower tapered surface 53 has a curved structure such that the central portion thereof bulges to the rearmost side of the cassette. Therefore, the spring receiving portion 52, which is the contact portion with the spring 30, is always in point contact with the spring 30 and is always in a substantially constant position.

The engaging projection 60 shown in FIG. 5 is also constructed so that the vertical cross-section of the engaging projection 60 has a dogleg shape like the engaging projection 50. In this case, the spring receiving portion 62 is composed of points, and three tapered surfaces including the lower tapered surface 63,
Three tapered surfaces including the upper tapered surface 64 are configured to extend from the spring receiving portion 62.

The spring receiving portions 52 and 62 are configured so that the distance from the bottom surface of the slide guard is h, as in the above embodiment.

As shown in FIGS. 4 and 5, the engaging protrusions 50, 60 are provided.
Since the spring guard 30 and the spring 30 are configured to make point contact with each other, the biasing force and biasing direction of the spring 30 are relatively stable even when the slide guard 20 moves in the cassette front-rear direction. Becomes

In the embodiment, the spring 30 includes the arm portion 32.
Although the fulcrum portion 31 and the fulcrum portion 31 are appropriately bent, the present invention is not limited to such a shape.
For example, a portion corresponding to the fulcrum portion 31 may be formed in a coil shape and wound around the boss 13.

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 40 that engages with the arm portion 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 40. It can also be configured as follows.

(Effect of the Invention) As described above, the magnetic tape cassette 1 of the present invention is used.
During storage, the guard panel 8 and the slide guard 20 completely close the opening 10, and the slide guard 20 also closes the reel shaft insertion hole 14. The magnetic tape T mounted on 10 has a very excellent protection effect and a dust prevention effect, and has an extremely excellent effect of preventing the deterioration of the recording / reproducing characteristics.

Further, according to the present invention, since the engaging protrusions 40, 50, 60 have the tapered surfaces 41, 43, 53, 54, 63, 64, the spring 30
When the spring is assembled, the tip portion of the spring 30 is
It can be easily and securely installed at 42, 52, 62.
Further, since the spring receiving portions 42, 52, and 62 are configured to have a height corresponding to the thickness of the cassette from the bottom surface of the slide guard, a force inclined in the vertical direction of the cassette acts on the slide guard 20. Can be suppressed, the slide guard 20
The above-mentioned operation can be made smooth, and the effect of facilitating the setting of the biasing force of the spring 30 is exerted. Further, in the present invention, since the pair of tapered surfaces 41, 43, 53, 54, 63, 64 are formed to intersect with each other and the spring 30 is locked at the intersecting portion 42, the pair of tapered surfaces 41, 43, 53, 54 , 63, 64, it is not necessary to form another spring locking portion, and since the taper surfaces 41, 43, 53, 54, 63, 64 are not required to have a high degree of accuracy, the engaging projection 40, Five
It is extremely easy to make 0, 60, and even a magnetic tape cassette.

It was stated at the beginning that the present invention was applied to a magnetic tape cassette for a digital audio, which is about the same size as or smaller than a conventional compact cassette for audio, but it is not necessarily limited to this, and it is not limited to this. It can also be applied to 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 an assembled state of the magnetic tape cassette shown in FIG. 1, and FIG. 3 is a schematic view of the embodiment shown in FIG. FIG. 4 is an enlarged perspective view of a part, and FIGS. 4 and 5 are perspective views of main parts showing a modified example of the present invention. 1 ... Magnetic tape cassette, 2 ... Upper half case, 3
...... Lower half case, 4 ...... Hub, 4a ...... Ring part, 5 ...
... Frixion sheet, 6 ... Lock member, 7 ... Engagement part, 8 ... Guard panel, 9 ... Rotating spindle, 10 ... Opening part, 11 ... Tape outlet, 12 ... Tape guide, 13
...... Boss, 13a ... Slit, 14 ... Reel shaft insertion hole, 15 ... Side wall, 15a ... Step, 16 ... Hole, 17 ... Front wall, 18 ... Notch, 19 ... Overhanging piece , 20 …… Slide guard, 21 …… Protrusion, 23 …… Transparent hole, 26 …… Side piece, 27
...... Overhanging part, 28 ...... Spring for guard panel, 29 ...... Spring for locking member, 30 ...... Spring, 31 …… Support point part, 32 …… Arm part, 33 …… Hooking part, 40,50, 60: engagement protrusion, 41
...... Tapered surface, 42,52,62 ...... Spring receiving part, 43,53,54,63,
64 ... Tapered surface.

Claims (1)

[Scope of utility model registration request] 1. A pair of hubs (4) around which a magnetic tape (T) is wound are built-in, and an opening (10) for allowing the magnetic tape (T) to be pulled out to the front of the cassette is provided. Department (1
0) A magnetic tape cassette comprising a rotatable guard panel (8) closing the front side and a slidable slide guard (20) closing the lower side of the opening (10). ) Slides along the outer surface of the bottom of the cassette, and is urged toward the front of the cassette by a spring (30) that engages with an engaging projection (40) provided on the inside of the front edge of the cassette. On the cassette rear side of the portion (40), there are a pair of tapered surfaces (41), (43) that rise and descend toward the rear of the cassette from the height where the end of the spring (30) to be locked is located. A magnetic tape cassette characterized in that it is formed so as to intersect in a V-shape in cross section, and the spring is locked at the intersection (42) of the tapered surfaces (41), (43).