JP2000011589A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape cassette capable of easily and surely fixing a reel spring to an upper cassette half. SOLUTION: In this magnetic tape cassette 10, boss parts 19 and a clear piece control rib 18 are provided on the inside surface 12a of the upper cassette half 12. A leaf spring 20 for urging the reel is provided with a pair of arm parts 21 and a base end part 22 connecting the arm parts 21, and through-holes 23 are arranged on the base end part 22. Then, the positioning is made in such a manner that the base end part 22 is engaged with the clear piece control rib 18 which is the part of the upper cassette half 12 other than the boss parts 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cassette such as a digital video cassette (DVC) in which a pair of tape reels around which a magnetic tape is wound are rotatably supported in a cassette case composed of upper and lower cassette halves. More specifically, the present invention relates to a magnetic tape cassette characterized by a reel biasing leaf spring that biases each tape reel to a predetermined side.

[0002]

2. Description of the Related Art In general, in audio equipment, video equipment and the like, a magnetic tape cassette for recording / reproducing a magnetic tape wound around a pair of tape reels so as to be able to run in a cassette half is often used. . FIG.
3 shows a magnetic tape cassette for VC. The magnetic tape cassette 50 includes an upper cassette half 52 and a lower cassette half 5.
In the lower cassette half 53, a pair of tape reels 51 around which a magnetic tape 65 is wound are rotatably supported.

An outer lid 61, an upper lid 62, and an inner lid 63 that cover an opening 54 of the lower cassette half 53 are attached to the upper cassette half 52 so as to be freely opened and closed.

[0004] The upper cassette half 52 is provided with a pair of leaf urging leaf springs (hereinafter referred to as reel springs) 70.
It is provided for each tape reel 51. Reel spring 70
Are arm portions 71 formed by bending a band-shaped metal plate.
And a base end 72. The boss is welded in a state where the through-hole 73 formed in the base end 72 is inserted into a boss (not shown) of the upper cassette half 52. As a result, each reel spring 70 is cantilevered by the upper cassette half 52, and the arm portion 71 urges the corresponding tape reel 51 to a predetermined side.

On the other hand, the lower cassette half 53 is provided with a tape reel lock member 66 having a tape reel locking arm 67 at the back in the figure. The tape reel lock member 66 is urged by a compression coil spring 68 to engage the tape reel locking arm 67 with an engagement tooth 51 a formed on the outer periphery of each tape reel 51. Prevent unexpected rotation. Thereby, loosening of the magnetic tape 65 and the like are prevented.

Tape guides 55 are provided on both sides of the opening 54 on the near side in the drawing of the lower cassette half 53. Each tape guide 55 is connected to one of the tape reels 5.
1 guides the magnetic tape 65 that is sent out from the first tape reel 51 and wound on the other tape reel 51, and the magnetic tape 65 is
4 at a predetermined position.

When the magnetic tape cassette 50 is loaded in a recording / reproducing apparatus or the like, a tape end provided on the recording / reproducing apparatus side is detected at the opening 54 side in the longitudinal center portion of the lower cassette half 53. An opening 56 into which a light source (not shown) is inserted. In order to keep the magnetic tape cassette 50 dustproof, a transparent clear piece 64 that does not block the light from the light source is mounted in the opening 56.

FIG. 6 is a diagram showing the inner side surface 52a of the upper cassette half 52 in the magnetic tape cassette 50.
On the inner side surface 52a, a boss portion 59 to be inserted into each through hole 73 of the pair of reel springs 70, and a reel spring 7
And a reel spring restricting rib 57 for clamping the base end 72 of the zero and restricting the displacement of the reel spring in the planar direction. In addition, when the upper and lower cassette halves are assembled, the upper and lower cassette halves are brought into contact with the upper surface of the clear piece 64 shown in FIG. Are provided.

FIG. 7 is an enlarged view of the vicinity of the reel spring 70 in FIG. The solid line in FIG. 7 shows the reel spring 70 before being fixed to the inner side surface 52a of the upper cassette half. The arm portion 71 of the reel spring 70 before being fixed has its inner surface 5
2a, and the base end 72 is lifted from the inner side surface 52a. Then, by melting the top of the boss portion 59 by ultrasonic vibration, the base end portion 72 comes into contact with and is fixed to the inner side surface 52a, and as a result, as shown by a two-dot chain line in FIG. It rises from the inner side surface 52a.

In the above-described magnetic tape cassette 50 having a pair of reel springs 70, since it is necessary to separately assemble each reel spring 70 into the upper cassette half 52, the assembling operation is complicated, and improvement is desired. I was Before the reel spring 70 is fixed to the inner surface 52a of the upper cassette half, the base end 72 of the reel spring floats from the inner surface 52a. As a result, the base end 72 may come off the boss 59.

As a solution, it is conceivable to use a reel spring in which a pair of reel springs for urging each tape reel supported in the lower cassette half are integrated (hereinafter, referred to as an integral reel spring). In this way, by integrating the pair of reel springs, the assembling operation can be simplified and the base end can be stabilized. Such a configuration is implemented in a VHS video cassette, an 8 mm video cassette, and the like.

As shown in FIG. 8, an integral reel spring 8 in a magnetic tape cassette 90 for a VHS video cassette is used.
Reference numeral 0 denotes a pair of arm portions 81 connected by a connection base end portion 82. Two through holes 83 are provided in the connection base end portion 82, and two boss portions 99 provided on the inner side surface 92 a of the upper cassette half 92 are fitted into the respective through holes 83. By melting the tops of these bosses 99, the connection base end 82 is fixed to the inner surface 92a.

[0013]

In the magnetic tape cassette 90 having the integral reel spring 80, the integral reel spring 80, the through hole 83, and the upper cassette half 9 are provided.
The difference between the hole diameter of each through-hole 83 and the outer diameter of each boss 99, that is, the play, is determined by allowing the through-hole 73 of the ordinary reel spring 70 and the boss It was set larger than the play with 59.
As a result, the integral reel spring 80 may be fixed to the upper cassette half 92 at a position shifted from the normal position in the plane direction. Even if the structure relating to the integral reel spring 80 in the magnetic tape cassette 90 is applied to the magnetic tape cassette 50 shown in FIGS. 5 and 6, the same problem occurs, and further improvement has been desired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic tape cassette capable of easily and reliably fixing a reel spring to an upper cassette half.

[0015]

SUMMARY OF THE INVENTION The object of the present invention is to support a pair of tape reels around which a magnetic tape is wound, rotatably supported in a cassette case comprising upper and lower cassette halves, a base end and an arm. And a through hole formed in the base end portion is fixed to the upper cassette half by welding the boss portion in a state where the through-hole formed in the base end portion is inserted into the boss portion of the upper cassette half. In the magnetic tape cassette provided with a reel biasing leaf spring that biases each of the tape reels toward the lower cassette half side, the base end portion is
A magnetic tape cassette is characterized in that a pair of arms for urging each tape reel is connected, and is positioned by engaging with an upper cassette half other than the boss.

Here, the play at the engaging portion between the base end of the reel spring and the upper cassette half other than the boss portion is set smaller than the play between the through hole of the reel spring and the boss portion. Is preferred. According to the magnetic tape cassette having such a configuration, the positioning of the reel spring with respect to the upper cassette half can be easily and reliably performed, and the reel spring can be fixed to a correct position of the upper cassette half.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to FIGS. The members and the like already described are denoted by the same reference numerals or corresponding reference numerals in the drawings to simplify or omit the description.

FIG. 1 shows an upper cassette half 12 of a magnetic tape cassette 10 as a first embodiment. On the inner surface 12a of the upper cassette half, two bosses 19 are provided.
It is provided closer to the longitudinal center of the inner side surface 12a than the position of the conventional boss portion.
2 are provided near both sides of the opening 14. No conventional reel spring regulating rib is provided. A clear piece regulating rib 18 is provided on the side of the opening 14 at the center in the longitudinal direction of the inner side surface 12a.

The pair of arms 21 and the arms 2
An integral reel spring 20 having a connecting base end portion 22 for connecting the first and second connecting members 1 is fixed to the inner side surface 12a. Connection base end 22
Has through holes 23 at both ends into which the boss portions 19 are inserted. The connecting base end portion 22 has an engaging portion 2 that engages with the clear piece regulating rib 18 at the longitudinal center portion thereof.
4 is provided. The engaging portion 24 is provided to protrude from the connection base end portion 22 on the opening 14 side and has a concave portion into which the clear piece regulating rib 18 can be fitted.

FIG. 2 is an enlarged perspective view of the integral reel spring 20. FIG. 2 shows the integral reel spring 20 before being fixed to the inner side surface 12a of the upper cassette half. in this way,
In the integral reel spring 20, the weight of the connection base end 22 and the engaging portion 24 is heavier than the weight of the pair of arms 21. The arm portion 21 is in contact with the inner surface 12a and floats from the inner surface 12a.

FIG. 3A is an enlarged view of a portion A in FIG.
The state where the clear piece regulating rib 18 is fitted into the concave portion of the engaging portion 24 of the integral reel spring is shown. Also, FIG.
5 is an enlarged view of a portion B in FIG. 5, showing a state in which the boss portion 19 is inserted into the through hole 23 of the reel spring. As shown in these figures, the play between the concave portion of the engaging portion 24 of the integral reel spring and the clear piece regulating rib 18 is set smaller than the play between the through hole 23 and the boss portion 19 of the integral reel spring. Have been.

Here, the play between the recess of the engaging portion 24 and the clear piece regulating rib 18 is caused by the gap S1 between one side of the recess and one side of the clear piece regulating rib 18, and the other side of the recess and the clear piece. It refers to the length obtained by adding the gap S2 to the other side surface of the regulating rib 18, and the gap S3 between the bottom surface of the concave portion and the tip end surface of the clear piece regulating rib 18. The play between the through hole 23 and the boss 19 refers to a length obtained by subtracting the outer diameter D2 of the boss 19 from the hole diameter D1 of the through hole 23.

In the magnetic tape cassette constructed as described above, the connecting base end 22 of the integral reel spring 20 is
Since the boss portion 19 is used to fix the upper cassette half 12 to the upper cassette half 12, the connecting base end portion 22 can be securely fixed without providing a reel spring regulating rib or the like on the upper cassette half 12. Further, the connecting base end portion 22 includes an engaging portion 24 having a concave portion that can be fitted to the clear piece regulating rib 18. The play between the concave portion of the engaging portion 24 and the clear piece regulating rib 18 is an integral reel. Spring through hole 23 and boss 19
It is set smaller than the play with. Therefore, the two boss portions 19 can be easily inserted into the two through holes 19 of the integral reel spring 20, respectively, and the integral reel spring 20 is reliably positioned.

In addition, since the connecting base end portion 22 of the integral reel spring 20 is in contact with the inner side surface 12a even before being fixed,
The connecting base end portion 22 does not come off the boss portion 19 due to vibration or the like accompanying the conveyance of the magnetic tape cassette 10.

FIG. 4 shows an upper cassette half 32 of a magnetic tape cassette 30 as a second embodiment. On the inner surface 32a of the upper cassette half, two clear piece regulating ribs 38 are provided in parallel. The connecting base end 42 of the integral reel spring 40 has an engaging portion 34 that engages with the clear piece regulating rib 38 at the longitudinal center portion thereof.
It has. The engaging portion 34 protrudes from the connection base end portion 42 on the opening 34 side, and is fitted between the two clear piece regulating ribs 38.

It should be noted that the magnetic tape cassette of the present invention is not limited to the above-described embodiment, and appropriate modifications and improvements can be made. For example, in the above-described embodiment, the connection base end includes the engagement portion that engages with the clear piece regulating rib. However, a recess or the like is provided in the connection base end to directly connect the connection base end. The clear piece regulating rib may be engaged. Further, the planar shapes of the boss portion and the through hole may be other than circular.

In the above-described embodiment, the integral reel spring is engaged with the clear piece regulating rib of the upper cassette half to position the integral reel spring. It is also possible to engage the integral reel spring with the projection or the recess.

[0028]

According to the magnetic tape cassette of the present invention, the base end of the reel spring connects the pair of arms for urging each of the pair of tape reels, and the clear piece provided on the upper cassette half. It is positioned by engaging with the regulating rib. Therefore, the positioning of the reel spring with respect to the upper cassette half is easily and reliably performed, and the reel spring can be fixed to a correct position of the upper cassette half.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a main part of the first embodiment of the present invention.

FIG. 3 is a diagram showing a main part of the first embodiment of the present invention.

FIG. 4 is a diagram showing a second embodiment of the present invention.

FIG. 5 is an exploded perspective view of a conventional magnetic tape cassette.

FIG. 6 is a diagram showing an inner surface of an upper cassette half in FIG. 5;

FIG. 7 is a view showing a mounting structure of a reel spring in FIG. 6;

FIG. 8 is a view showing a conventional magnetic tape cassette.

[Explanation of symbols]

 10, 30 Magnetic tape cassette 12, 32 Upper cassette half 18, 38 Clear piece regulating rib 19, 29 Boss 20, 40 Integrated reel spring (leaf biasing leaf spring) 21, 41 Arm 22, 22, 42 Connecting base end (Base end) 23, 43 Through hole 24, 34 Engagement part

Claims (1)

[Claims] 1. A pair of tape reels each having a magnetic tape wound thereon are rotatably supported in a cassette case composed of upper and lower cassette halves, have a base end and an arm, and are formed at the base end. With the through hole inserted into the boss of the upper cassette half, the boss is welded to the upper cassette half, and the tape reel is attached to the lower cassette half by the arm. In a magnetic tape cassette provided with a biasing reel biasing leaf spring, the base end portion connects a pair of arm portions for biasing each tape reel and relates to an upper cassette half portion other than the boss portion. A magnetic tape cassette characterized by being positioned together.