JPH11317044A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape cassette furnished with the structure capable of easily fitting a reel spring between a pair of ribs and surely preventing the reel spring from positionally deviating after the fitting. SOLUTION: In this magnetic tape cassette, a pair of ribs 1 having guide surfaces on each of the confronted inner walls 1a for guiding and positioning the reel spring 50 before the fixing are provided on the inside surface 22 of an upper cassette half. Then, a control member 2 having no guide surface, positioned to the side of the free end of the reel spring 50 than the position of a pair of ribs 1, is provided on the inside surface 22.

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 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. 8 shows a magnetic tape cassette used for DVC, for example. The magnetic tape cassette 30 includes an upper cassette half 32
And the lower cassette half 33, and the lower cassette half 3
A pair of tape reels 31 around which a magnetic tape (not shown) is wound are rotatably supported in 3.

[0003] Tape guides 35 are provided on both sides of an opening 34 in the lower cassette half 33 on the near side in FIG.
Is provided. Each of the tape guides 35 guides the magnetic tape sent out from one tape reel 31 and wound on the other tape reel 31, and passes the magnetic tape through a predetermined position in the opening 34.

A tape reel lock member 38 having a tape reel locking arm 37 is provided on the rear side of the lower cassette half 33. The tape reel lock member 38 is urged by a compression coil spring 39 to cause the tape reel locking arm 37 to engage with an engagement tooth 40 formed on the outer periphery of each tape reel 31.
The unexpected rotation of each tape reel 31 is prevented. This prevents loosening of the magnetic tape.

On the other hand, the upper cassette half 32 has an outer lid 4 that covers the opening 34 of the lower cassette half 33.
1. The upper lid 42 and the inner lid 43 are attached to be openable and closable, respectively. Outer lid 41
A lock pin 45 protrudes from the side plate 44. The lock pin is locked by a lid lock 45 rotatably provided on the lower cassette half 33.

The upper cassette half 32 has a pair of plate springs for biasing the reels (hereinafter referred to as reel springs) 70.
It is provided for each tape reel 31. Each reel spring 70
The bosses are welded in a state where the through holes 73 formed in the base end 72 are fitted into bosses (not shown) of the upper cassette half 32, respectively. Thus, each of the reel springs 70 is cantilevered by the upper cassette half 32 and urges the corresponding tape reel 31 to a predetermined side.

FIG. 5 is a plan view showing the inner side surface 22 of the upper cassette half 21 of the small (S) size DVC magnetic tape cassette 20. The reel spring 70 for pressing a reel in the lower cassette half (not shown) is provided in a large (L) size DVC in addition to the one extending parallel to the short direction of the upper cassette half 21 as shown in FIG. Some extend from a corner in the upper cassette half 21 toward a position corresponding to the center of each reel in the lower cassette half (not shown) in the upper cassette half.

FIG. 6 is an enlarged view of the vicinity of the reel spring 70 in FIG. FIG. 6 shows a state in which the reel spring 70 has not yet been fixed to the inner surface 22 of the upper cassette half. The reel spring 70 is formed of a band-shaped metal plate. The arm portion 71 for pressing a reel in the lower cassette half (not shown) by bending the metal plate, and a base end portion 72 fixed to the inner side surface 22 of the upper cassette half. Are formed. A through hole 73 is formed in the base end 72.

On the other hand, on the inner side surface 22, a boss 23 to be inserted into the through hole 73 and a pair of ribs 24 for regulating the displacement of the reel spring 70 due to the rotation of the reel spring 70 about the boss 23. Is provided.

In order to fix the reel spring 70 to the inner surface 22 of the upper cassette half, first, the tip of the boss 23 is inserted into the through hole 73 while holding the tip 70a of the reel spring 70, and the rear end 70b is The inner surface 22 is brought into contact. Next, by lowering the distal end portion 70a of the reel spring toward the inner side surface 22, the arm portion 71 is sequentially fitted between the pair of ribs 24 from the rear end side. The state where the fitting of the arm portion 71 at this time is completed is shown by a solid line in FIG.

Finally, the top 23a of the boss is melted by heating or ultrasonic vibration, so that the base end 7a is melted.
2 is fixed to the inner surface 22, and accordingly, the arm portion 71 bent toward the base end portion 72 rises from the inner surface 22. FIG. 7 shows the state at this time.

[0012]

Since the operation of fitting the reel spring 70 (here, the arm portion 71) between the pair of ribs 24 is complicated, it has been desired to improve the workability. Therefore, it is conceivable to form each inner wall of the pair of ribs 24 with a tapered surface. This means that each of the inner walls is formed on an inclined surface so as to reduce the thickness at the upper end side without changing the thickness at the lower end side of each rib.
This is an attempt to make it easier to fit between the pair of ribs 24.

However, when the inner walls of the pair of ribs 24 are formed as tapered surfaces, vibrations generated when the upper cassette half 21 is conveyed in the assembly process of the magnetic tape cassette and vibrations generated when the bosses 23 are welded are generated. The reel spring 70 may be displaced from between the pair of ribs 24 and rotate around the boss 23, and the position of the reel spring 70 may be shifted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a reel spring can be easily fitted between a pair of ribs. It is an object of the present invention to provide a magnetic tape cassette having a structure capable of reliably preventing the magnetic tape cassette.

[0015]

The object of the present invention is to provide a magnetic tape cassette comprising upper and lower cassette halves, each having a biasing leaf spring for biasing a pair of tape reels wound with a magnetic tape. On the inner side surface of the upper cassette half, a boss that is inserted into a through hole provided at the base end of the leaf spring for biasing the reel to project and fix the base end by welding is provided. The rib of
A pair of ribs are provided to project the reel urging leaf spring to a welding fixed position, and a portion of the pair of ribs is provided so as to sandwich the boss. , It is an introduction surface to position it,
A magnetic tape cassette, wherein a regulating member is provided on a free end side of the reel urging leaf spring relative to the pair of ribs so as to prevent the positioned reel urging leaf spring from shifting. Achieved by

Here, as the regulating member, for example, a pair of ribs having no introduction surface protruding from the inner side surface of the upper cassette half so as to position the reel spring similarly to the pair of ribs are used. can do. Further, the regulating member may be provided adjacent to the rib having the introduction surface,
It may be provided at a position away from the rib or may be provided integrally. As the introduction surface, a concave or convex curved surface or the like can be employed in addition to the tapered surface.

According to the magnetic tape cassette having such a configuration, a pair of ribs for guiding and positioning the reel spring are provided on the inner surface of the upper cassette half, and the reel spring is shifted from between the pair of ribs. Since the regulating member is provided to prevent the reel spring from being fitted, the work of fitting the reel spring between the pair of ribs becomes easy, and after the fitting, the displacement of the reel spring due to vibration or the like is reliably prevented.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, about the member already demonstrated, the description is simplified or abbreviate | omitted by attaching | subjecting the same code | symbol in a figure, or a corresponding code | symbol.

As shown in FIG. 1, a metal plate is bent at a bent portion 55 so that an arm portion 51 and a base end portion 52 are formed.
In the reel spring 50 formed as described above, a convex surface 54 is further formed on the arm portion 51 by embossing. By providing the convex surface 54, even if the reel springs 50 are arranged in an overlapping manner in, for example, a supply device (not shown) for the reel springs 50, the reel springs 50 can be easily separated from each other, and assemblability can be improved. .

On the inner side surface 22 of the upper cassette half, a tapered boss 3 to be fitted into a through hole 53 of a reel spring and a pair of ribs 1 capable of fitting an arm portion 51 of the reel spring are provided. I have. Further, similarly to the rib 1, a pair of protrusions 4 for fitting the reel spring 50 are provided. Here, the height of the protrusion 4 is set lower than the height of the rib 1.

Each inner wall 1a of the pair of ribs 1 is formed as a tapered surface as an introduction surface. A pair of regulating ribs 2 as regulating members are provided on the inner side surface 22 at positions adjacent to one end (the right side in the drawing) of each rib 1. Here, the regulating rib 2 is provided integrally with the rib 1. The inner wall 2a of each regulating rib 2 is formed as a vertical surface extending in a direction perpendicular to the inner surface 22.

In order to fix the reel spring 50 to the inner surface 22, first, the tip of the boss 3 is inserted into the insertion hole 53 while holding the leading end 50 a of the reel spring, and the rear end 50 b is connected to the inner surface. 22. At this time, the rear end 50b is fitted between the pair of protrusions 4. In such a state, the hand is released from the distal end portion 50a of the reel spring.

Then, as shown in FIG.
Falls toward the inner side surface 22, and the arm portion 51 slides down on the inner walls 1a of the pair of ribs which are tapered surfaces. Then, as shown in FIG. 3, the arm portion 51 is fitted between the pair of ribs 1. In this state, the arm 51
The portion on the base end portion 52 side that is not fitted to the pair of ribs 1 is positioned between the pair of protrusions 4. Finally, the base end 52 is fixed to the inner surface 22 by melting the vicinity of the top 3a of the boss 3 by ultrasonic vibration, and the fixing of the reel spring 50 is completed.

In the magnetic tape cassette constructed as described above, since the inner walls 1a of the pair of ribs 1 are formed as tapered surfaces, the rear end 50b of the reel spring is connected to the inner surface 2a.
The reel spring 50 is released from the boss 3 against the pair of ribs 1 by releasing the reel spring 50 while being in contact with the boss 3.
, The reel spring 50 is guided by the tapered inner wall 1a and securely fitted between the pair of ribs 1. Therefore, the work of fitting the reel spring 50 between the pair of ribs 1 is facilitated, and the workability is improved.

Also, the reel spring 5 extends from between the pair of ribs 1.
Since the regulating rib 2 for preventing the displacement of the reel spring 50 is provided, after the reel spring 50 is fitted between the pair of ribs 1, the displacement of the reel spring 50 due to vibration or the like during conveyance is reliably prevented. Is done.

Further, the rear end 50b of the reel spring is
2 is provided, a pair of protrusions 4 are provided to fit the rear end 50b, so that when the reel spring 50 is released, the reel spring pushes the boss 3 against the pair of ribs 1. It is prevented from being shifted in the rotation direction about the center. Further, when the arm 51 is fitted between the pair of ribs 1, the portion on the base end 52 side of the arm 51 is fitted to the pair of protrusions 4, so that the displacement of the reel spring 50 is further reduced. It is surely prevented.

Next, FIG. 4 shows a modified example of the rib 1 and the regulating rib 2 in the embodiment described above. The rib 11 shown in the figure also has an inner wall 11a formed into a tapered surface.
The regulating rib 12 is provided integrally with the rib 11, and the inner wall 12 a of the regulating rib 12 is
It is formed on a vertical surface smoothly connected to a.

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 pair of ribs 1 fits the arm portion 51 of the reel spring. However, the pair of ribs 1 may fit the base end portion 52 of the reel spring. The inner wall 1 of the pair of ribs
Although a is formed on the tapered surface over the entire surface, for example, only the upper end side of the inner wall 1a may be formed on the tapered surface.
Further, by shifting the position of the bent portion 55 of the reel spring 50 in the above-described embodiment toward the distal end portion 50a of the reel spring 50, the amount of floating of the base end portion 53 from the inner side surface 22 is reduced, and 50 is prevented from coming off the boss 3.

[0029]

As described above, in the magnetic tape cassette of the present invention, the inner surface of the upper cassette half
A pair of ribs for guiding and positioning the reel spring are provided, and a regulating member for preventing the reel spring from shifting from between the pair of ribs is provided, so that the reel spring is fitted between the pair of ribs. The fitting operation becomes easy, and after the fitting, the displacement of the reel spring due to vibration or the like is reliably prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an embodiment of the present invention.

FIG. 2 is a diagram showing the operation of the embodiment of the present invention.

FIG. 3 is a diagram showing the operation of the embodiment of the present invention.

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

FIG. 5 is a plan view showing an upper cassette half of a magnetic tape cassette.

FIG. 6 is a diagram showing a conventional reel spring mounting structure.

FIG. 7 is a diagram showing a conventional reel spring mounting structure.

FIG. 8 is an exploded perspective view showing the magnetic tape cassette.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1, 11 rib 2, 12 regulating rib (regulating member) 3 boss 4 protrusion 20 magnetic tape cassette 21 upper cassette half 22 inner surface of upper cassette half 50 reel spring (reel biasing leaf spring) 51 arm 52 base end Part 53 insertion hole 54 convex surface 55 bent part

Claims (1)

[Claims] 1. A magnetic tape cassette comprising upper and lower cassette halves each having a biasing leaf spring for urging a pair of tape reels around which a magnetic tape is wound, wherein an inner surface of the upper cassette half has A boss that fits into a through-hole provided at the base end of the reel biasing leaf spring and that welds and fixes the base end is protruded, and the reel is configured so that a pair of ribs sandwich the boss. The pair of ribs are projected substantially parallel to the longitudinal direction of the biasing leaf spring, and a part of the pair of ribs guides the reel biasing leaf spring to a welding fixed position, and an introduction surface for positioning the same. The regulating member is provided on the free end side of the reel urging leaf spring with respect to the pair of ribs so as to prevent the positioned reel urging leaf spring from shifting. And magnetism Pukasetto.