JPH10241325A - Tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of abnormal sound at the time of rotation of a guide roller by reducing the contact area with the end surface of the guide roller in the manner of arranging a recessed part on a guide roller receiving surface of a cassette half and further forming a recessed part so that a protrusion generated due to the force-fitting of a guide pin is not brought into contact with the guide roller. SOLUTION: On the tape guide receiving surface of a boss part 15 of the lower half 2, the 1st recessed part 18 is formed, which is made by one step digging down the circumference of a mounting hole 12 remaining the part of a specified width from the outer periphery, to reduce the contact area with the lower end surface of the guide roller 10, thereby the generation of abnormal sound at the time of rotation of the guide roller 10 is reduced. Further, the protruding part 16 is formed on the tape guide receiving surface of the boss part 15 of the lower half 2 by force-fitting the guide pin 13 into the mounting hole 12. To prevent the effect of this protrusion, the 2nd recessed part 19 digged down deeper than the 1st recessed part 18 is formed at the position of the protruding part 16. By this arrangement, the lower end surface of the guide roller 10 is not brought into contact with the protruding part 16 generated on the circumference of the mounting hole 12 by the force-fitting of the guide pin 13, and the prevention to the generation of abnormal sound at the time of rotation of the guide roller 10 is attained accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette, and more particularly to a tape cassette having a structure in which a guide pin for supporting a guide roller for guiding a tape is attached to a cassette half by press-fitting.

[0002]

2. Description of the Related Art First, a conventional example will be described with reference to FIGS. FIG. 1A shows an upper cassette half (hereinafter referred to as an upper half) of a so-called beta type video tape cassette.
1B, while FIG. 1B shows a lower cassette half (hereinafter, referred to as a lower half) 2, and the upper half 1 and the lower half 2 are combined and fixed with screws to form a cassette housing. Is done. The upper half 1 and the lower half 2 constituting the cassette housing are both formed of a resin such as ABS.

A lower half 2 is provided inside the cassette housing.
A pair of tape reels around which a tape (magnetic tape) 3 is wound, that is, a supply-side tape reel 4 and a take-up-side tape reel 5, are rotatably accommodated. Tape guides 7 and 8 are attached to the front and left and right sides of the inside of the cassette housing, and the tape 3 led out from the supply-side tape reel 4 is exposed to the front of the cassette through the tape guide 7. Then, a tape running path is formed so that the tape travel path is wound on the winding-side tape reel 5 through the tape guide 8.

Further, in the middle of the tape running path, the tape located inside the cassette housing is located between the supply-side tape reel 4 and the tape guide 7 and between the take-up-side tape reel 5 and the tape guide 8. A guide roller 10 for guiding the roller 3 is rotatably mounted.

[0005] Focusing on the guide roller 10, the structure of the mounting portion of the guide roller 10 is shown in FIG.
It is shown as follows. That is, mounting holes 11 and 12 are formed at positions corresponding to each other on the inner surface sides of the upper half 1 and the lower half 2, respectively.
A round bar-shaped guide pin 13 is attached between the upper half 1 and the lower half 2 in a state of being inserted into the cylindrical guide 12, and a cylindrical guide roller 10 is rotatably supported by the guide pin 13. Here, the guide pin 13 is formed of metal, for example, stainless steel (SUS304), and the guide roller 10 is formed of a resin material, for example, POM.

Bosses 14 and 15 are provided around the mounting holes 11 and 12, respectively, and the guide roller 10 is rotatable in a state in which it can move up and down within a clearance between the bosses 14 and 15. Attached to.

The mounting hole 11 on the upper half 1 is formed in a round hole as shown in FIG. 3, while the mounting hole 12 on the lower half 2 is formed in a square hole as shown in FIG. I have.

The mounting hole 11 on the upper half 1 side is formed to have an inner diameter slightly larger than the outer diameter of the guide pin 13. Therefore, as shown in FIG. The guide pin 13 is inserted and supported with a clearance, that is, the guide pin 13 is simply supported by the mounting hole 11 to prevent it from falling down.

On the other hand, the mounting holes 12 on the lower half 2 side
Is formed slightly smaller than the outer diameter of the guide pin 13 so that when the guide pin 13 is inserted into the mounting hole 12, the mounting hole 12 is pushed in as shown in FIGS. It is press-fitted so as to spread out, so that the guide pin 13 is firmly fixed and supported in the mounting hole 12.

[0010]

At the mounting portion of the guide roller 10 in the tape cassette constructed as described above, the guide roller 10 is moved by the tape running.
If the guide roller 10 moves up and down while rotating within the clearance between the bosses 14 and 15 of the upper and lower halves 1 and 2 when the is rotated, there is a problem that abnormal noise is generated. That is, when the guide roller 10 moves upward, the upper end surface of the guide roller 10 comes into contact with the boss portion 14 on the upper half 1 side, and the sliding contact noise becomes abnormal.
When 0 moves downward, the lower end surface of the guide roller 10 comes into contact with the boss 15 on the lower half 2 side, and the sliding contact noise becomes abnormal.

Here, actually, when the upper end surface of the guide roller 10 comes into contact with the boss portion 14 on the upper half 1 side, noise is small, and the problem is that the lower end surface of the guide roller 10 is located on the lower half 2 side. This is an abnormal noise when contacting the boss portion 15 of FIG.

One of the causes is a difference in the contact area of the boss 14 on the upper half 1 and the boss 15 on the lower half 2 with the guide roller 10. That is, FIG.
As shown in FIG. 4, the guide roller receiving surfaces of the boss portions 14 and 15 of the upper and lower halves 1 and 2 are indicated by hatching lines, respectively, so that the boss portion 1 on the lower half 2 side with respect to the boss portion 14 on the upper half 1 side.
5 has a larger contact area with the guide roller 10 (in the actual area, the boss portion 14 on the upper half 1 side is about 5.8 m).
m ² , the boss 15 on the lower half 2 side is about 16.7 m
m ² ), the amount of abnormal noise generated when the guide roller 10 rotates is correspondingly large.

Further, since the guide pin 13 is press-fitted into the mounting hole 12 on the lower half 2 side, after the press-fitting, the protrusion 16 as shown in FIG.
Will occur. If the protrusion 16 is large, the lower end surface of the guide roller 10 comes into contact with the protrusion 16 as shown in FIG. 8, thereby causing the guide roller 10 to vibrate up and down when the guide roller 10 rotates, resulting in abnormal noise. Occur.

For reference, a normal tape running (P
The rotation number of the guide roller at the time of (LAY) is 400 to 500.
r. p. m, the number of rotations of the guide roller at the time of fast forward (FF) and rewind (REW) is up to 14000 to 1500
0r. p. m and the number of revolutions at which abnormal noise occurs is about 400
0r. p. m. From this, the number of rotations of the guide roller was set to 4000 rpm. p. m or less can solve the problem of abnormal noise, but in this case the guide roller and the tape are slipping,
It is not realistic because it may cause tape damage or cause magnetic powder to fall off the tape.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a tape cassette which has a simple structure and can effectively suppress generation of abnormal noise when the guide roller rotates. I do.

[0016]

According to the present invention, there is provided a tape cassette having a structure in which a guide pin for supporting a guide roller for guiding a tape is mounted on a cassette half by press-fitting. The guide roller receiving surface of the half forms a first concave portion for reducing the contact area with the end surface of the guide roller, and further prevents the protrusion generated by press-fitting the guide pin from contacting the end surface of the guide roller. Second
Characterized in that it has a structure in which the concave portion is formed.

According to the present invention, the contact area of the cassette half with the guide roller is reduced, so that the amount of abnormal noise generated when the guide roller rotates is suppressed. Since the guide rollers do not come into contact with each other, generation of abnormal noise is prevented.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. In this embodiment, the so-called beta type video tape cassette shown in FIG. 1 will be described as an example.

FIG. 1A shows an upper half 1 of a beta type video tape cassette, while FIG. 1B shows a lower half 2 thereof, and the upper half 1 and the lower half 2 are combined and fixed with screws or the like. This constitutes a cassette housing. The upper half 1 and the lower half 2 constituting the cassette housing are both formed of a resin such as ABS.

A lower half 2 is provided inside the cassette housing.
A pair of tape reels around which a tape (magnetic tape) 3 is wound, that is, a supply-side tape reel 4 and a take-up-side tape reel 5, are rotatably accommodated. Tape guides 7 and 8 are attached to the front and left and right sides of the inside of the cassette housing, and the tape 3 led out from the supply-side tape reel 4 is exposed to the front of the cassette through the tape guide 7. Then, a tape running path is formed so that the tape travel path is wound on the winding-side tape reel 5 through the tape guide 8.

Further, in the middle of the tape running path, the tape located inside the cassette housing between the supply-side tape reel 4 and the tape guide 7 and between the take-up tape reel 5 and the tape guide 8 A guide roller 10 for guiding the roller 3 is rotatably mounted.

If attention is paid to this guide roller 10, the structure of the mounting portion of this guide roller 10 is shown in FIG.
It is shown as follows. That is, mounting holes 11 and 12 are formed at positions corresponding to each other on the inner surface sides of the upper half 1 and the lower half 2, respectively.
A round bar-shaped guide pin 13 is attached between the upper half 1 and the lower half 2 in a state of being inserted into the cylindrical guide 12, and a cylindrical guide roller 10 is rotatably supported by the guide pin 13. Here, the guide pin 13 is formed of metal, for example, stainless steel (SUS304), and the guide roller 10 is formed of a resin material, for example, POM.

The portions around the mounting holes 11 and 12 are bosses 14 and 15, respectively, and the guide roller 10 is rotatable in the clearance between the bosses 14 and 15 so that it can move up and down. Attached to.

The mounting hole 11 on the upper half 1 is formed in a round hole as shown in FIG. 3, while the mounting hole 12 on the lower half 2 is formed in a square hole as shown in FIG. I have.

The mounting hole 11 on the upper half 1 side is formed to have an inner diameter slightly larger than the outer diameter of the guide pin 13, and therefore, as shown in FIG. The guide pin 13 is inserted and supported with a clearance, that is, the guide pin 13 is simply supported by the mounting hole 11 to prevent it from falling down.

On the other hand, the mounting holes 12 on the lower half 2 side
Is formed so that the dimension of one side thereof is slightly smaller than the outer diameter of the guide pin 13, so that when the guide pin 13 is inserted into the mounting hole 12, the mounting hole 12 is pushed out as shown in FIG. By press-fitting, the guide pin 13 is fixedly supported by the mounting hole 12. The press-fitting of the guide pin 13 is easier than the round hole because the mounting hole 12 has a polygonal shape.

In particular, in this embodiment, a novel structure is employed in a portion around the mounting hole 12 on the lower half 2 side. That is, as shown in FIG. 9 and FIG.
On the tape guide receiving surface of the boss portion 15 on the side, a first concave portion 18 is formed, which is dug down one step around the mounting hole 12 except for a portion having a fixed width from the outer periphery, thereby forming the lower portion of the guide roller 10. The contact area with the end face is smaller than before.

As shown by the hatched line in FIG. 9, the tape guide receiving surface of the boss 15 on the lower half 2 has a contact area with the guide roller 10 on the boss 14 on the upper half 1 (see FIG. 3). ) (Approximately 7 mm ^{2 in} actual area). Therefore, the amount of abnormal noise generated during rotation of the guide roller 10 is very small, and there is almost no problem.

Further, as shown in FIGS. 9 and 10, the tape guide receiving surface of the boss 15 on the lower half 2 side is provided as a measure against a protrusion 16 generated by press-fitting the guide pin 13 into the mounting hole 12. At the place where the protrusion 16 occurs (four places around the square mounting hole 12 in this example),
A second recess 19 is formed which is dug deeper than the first recess 18.

Therefore, even if the projection 16 is formed around the mounting hole 12 by press-fitting of the guide pin 13, this projection 16
Since the lower end surface of the guide roller 10 does not come into contact with the guide roller 10, no abnormal noise is generated when the guide roller 10 rotates.

FIG. 11 shows another structural example, that is, in this example, a mounting hole 12 is formed in a pentagonal shape, and a portion around the pentagonal mounting hole 12 is entirely dug down to form a second concave portion. 19 is formed. In the example of FIG. 11, exactly the same effects as in the examples of FIGS. 9 and 10 described above can be obtained.

The inventor of the present invention actually manufactured a prototype of the tape cassette according to the present invention and compared it with a conventional tape cassette in order to confirm the effect of reducing abnormal noise when the guide roller 10 was rotated. The test results shown in FIG. In this test, a sample tape cassette was set on a cassette deck (with a top plate removed) in a quiet measuring room, and the tape was run.
At a distance of m, the magnitude of abnormal noise caused by the rotation of the guide roller is discriminated.

[0033]

[Table 1]

As can be seen from the test results, in the tape cassette according to the present invention, there is no X-level tape at a distance of 1 m from the cassette deck, so that there is almost no problem of abnormal noise in actual use.

Although the embodiment of the present invention has been described above, the present invention is not limited to the so-called beta type video tape cassette shown here, but can be widely applied to various tape cassettes having guide rollers. Of course there is.

[0036]

As apparent from the above description, the present invention relates to a tape cassette having a structure in which a guide pin for supporting a guide roller for guiding a tape is attached to the cassette half by press-fitting. The surface forms a first concave portion for reducing a contact area with an end surface of the guide roller, and a second concave portion for preventing a protrusion generated by press-fitting of a guide pin from contacting the end surface of the guide roller. Is formed, when the guide roller rotates during tape running, generation of abnormal noise due to contact between the guide roller and the cassette half is effectively suppressed, and a high quality tape cassette can be provided. Further, the present invention can be easily implemented because the conventional guide pin press-fitting technique can be used as it is.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a tape cassette, wherein A is a plan view of the upper half as viewed from the inner surface side, and B is a plan view of a lower half.

FIG. 2 is a vertical sectional view of a guide roller mounting portion of the tape cassette.

FIG. 3 is a two-sided view (longitudinal sectional view and plan view) of a mounting hole portion on the upper half side.

FIG. 4 is a two-sided view (a plan view and a longitudinal cross-sectional view) of a lower half-side mounting hole showing a conventional example.

FIG. 5 is a longitudinal sectional view of a portion where a guide pin is inserted and supported in a mounting hole on the upper half side.

FIG. 6 is a plan view showing a state in which a guide pin is pressed into a mounting hole on the lower half side.

FIG. 7 is a longitudinal sectional view of the same.

FIG. 8 is a longitudinal sectional view of a contact portion between a guide roller and a lower half.

FIG. 9 is a two-sided view (a plan view and a longitudinal sectional view) of a lower half-side mounting hole showing an embodiment of the present invention.

FIG. 10 is a vertical sectional view of a contact portion between the guide roller and the lower half.

FIG. 11 is a two-sided view (a plan view and a longitudinal cross-sectional view) of a lower half-side mounting hole showing another embodiment of the present invention.

[Explanation of symbols]

1 ‥‥ upper half, 2 ‥‥ lower half, 3 ‥‥ tape, 10
{Guide rollers, 11, 12} Mounting holes, 13
{Guide pin, 16} convex, 18} first concave, 1
9 Second recess

Claims (2)

[Claims] 1. A tape cassette having a structure in which a guide pin for supporting a guide roller for guiding a tape is attached to a cassette half by press-fitting, wherein a guide roller receiving surface of the cassette half has a contact area with an end surface of the guide roller. And a second concave portion for preventing a projection generated by press-fitting of the guide pin from contacting the end face of the guide roller. And a tape cassette. 2. The tape cassette according to claim 1, wherein the hole into which the guide pin is press-fitted has a polygonal shape.