JP2000076819A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape cassette in which a reel spring can be easily and securely fixed to the upper cassette half. SOLUTION: A magnetic tape cassette has a reel energizing flat spring 10 which has an arm part 11 and a base end part 12. A boss 19 formed on the inside surface 52a of an upper cassette half is fitted to the base end part 12 of the reel spring 10 and, further, the base end part 12 is held by position restricting ribs 17. At that time, a mating part 14 provided on the base end part 12 is mated with a mating part 18 formed in the inside surface 52a to restrict the position of the reel spring 10.

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 particularly, the present invention relates to a magnetic tape cassette having a feature in an assembly structure of a leaf urging leaf spring for urging each tape reel to a predetermined side.

[0002]

2. Description of the Related Art In general, in audio equipment and video equipment, a magnetic tape cassette for recording and reproducing data by holding a magnetic tape wound around a pair of tape reels movably in a cassette case is often used. . FIG. 7 is an exploded perspective view of the magnetic tape cassette. The magnetic tape cassette 50 includes an upper cassette half 52 and a lower cassette half 53. In the lower cassette half 53, a pair of tape reels 51 around which a magnetic tape 65 is wound are rotatably supported.

[0003] 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.

A tape reel lock member 66 having a tape reel locking arm 67 is attached to the lower cassette half 53 on the far side in the drawing. 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.

On the other hand, the upper cassette half 52 has an outer lid 6 covering the opening 54 of the lower cassette half 53.
1. The upper lid 62 and the inner lid 63 are each attached to be openable and closable.

The upper cassette half 52 is provided with a reel biasing leaf spring (hereinafter, referred to as a reel spring) 70 for each tape reel 51. The reel spring 70 has an arm portion 71 formed by bending a band-shaped metal plate and a base end portion 72, and a through hole 73 formed in the base end portion 72 is formed in a boss portion of the upper cassette half 52 (described later). The boss portion is welded in a state where the boss portion is inserted. As a result, each of the reel springs 70 is cantilevered by the upper cassette half 52, and the arm portion 71 connects the corresponding tape reel 51 to the lower cassette half 5.
Energize to the 3 side.

FIG. 8 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, the boss portion 59 to be inserted into the through hole 73 of each reel spring 70, and the base end portion 7 of each reel spring 70
2 and a position regulating rib 57 for sandwiching the arm portion 71 and regulating the displacement of the reel spring in the planar direction.

FIG. 9 is an enlarged perspective view of the vicinity of the reel spring 70 in FIG. The solid line in FIG. 9 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 fixing is in contact with the inner side surface 52a, and the base end portion 72 rises from the inner side surface 52a. By melting the top of the boss portion 59 by ultrasonic vibration, the base end portion 72 is moved to the inner side surface 52.
7A, the arm portion 71 rises from the inner side surface 52a as shown by the two-dot chain line in FIG. 7, and the reel spring 70 is fixed in such a state.

[0009]

In the above-described step of fixing the reel spring 70 to the inner surface 52a of the upper cassette half, a part of the base end 72 and a part of the arm 71 are positioned between the position regulating ribs 57. And the reel spring 70 before fixation in a state where the boss portion 59 is inserted into the through hole 73.
Is transported to a position where the boss 59 can be welded. Due to the vibration at the time of the conveyance and the vibration at the time of performing the welding, the reel spring 70 may be displaced from between the position regulating ribs 57 and rotate around the boss portion 59, and the position of the reel spring 70 may be shifted. In order to solve such a problem, it is conceivable to raise the position regulating rib 57 or the like.

In recent years, magnetic tape cassettes have been reduced in size one after another, but with such miniaturization, the space inside the cassette case has become extremely narrow. Therefore, for example, when the position regulating rib 57 is raised, the tape reel 51 (see FIG. 7) slightly moves in the cassette case, and the position regulating rib 57 comes into contact with the tape reel 51 to damage the tape reel. Put on. In particular, when the magnetic tape cassette is dropped, the tape reel 51 is easily damaged by the position regulating rib 57. When the position regulating rib 57 is raised, the reel spring 70 is difficult to fit between the pair of position regulating ribs 57, and the efficiency of the assembling operation is reduced.

The present invention has been made based on the above background, and an object of the present invention is to securely and easily fix a reel spring to an upper cassette half without damaging other parts. An object of the present invention is to provide a magnetic tape cassette.

[0012]

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 for biasing each of the tape reels toward the lower cassette half, the respective contact surfaces of the reel biasing leaf spring and the upper cassette half are fitted to each other. The magnetic tape cassette is further provided with a fitting portion for preventing a displacement of the reel urging leaf spring. .

Here, the shape of the fitting portion is not particularly limited. To provide, for example, a concave portion or a convex portion on the reel spring,
The base end or the arm may be embossed or the like. According to the magnetic tape cassette having such a configuration, by fitting the fitting portion of the reel spring and the fitting portion of the upper cassette half, the reel spring is positioned, and the reel spring is securely and securely attached to the upper cassette half. It can be easily fixed.

[0014]

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 is a perspective view of a structure for mounting a reel spring according to a first embodiment of the present invention. As shown in the drawing, the reel spring 10 has an arm portion 11 and a base end portion 12. However, as compared with the conventional product shown in FIG.
Account for a larger proportion. A through hole 13 into which the boss 19 is inserted is formed on the left side of the base end 12 in the figure (on the side where the arm 11 is not connected). On the right side (the side to which the arm portion 11 is connected) of the base end portion 12 in the drawing, a convex portion 1 formed by embossing and protruding toward the inner side surface 52a of the upper cassette half.
4 are formed.

The projections 14 are provided so that even if the reel spring 10 is arranged so as to overlap with other reel springs in a supply device (not shown) of the reel spring 10, the reel springs can be easily separated from each other. , Provided. In the present embodiment, the convex portion 14 corresponds to a fitting portion in the present invention.

On the other hand, on the inner side surface 52a of the upper cassette half, a boss portion 19 having a leading end formed on an introduction surface (here, a hemispherical shape) so as to be easily fitted into the through hole 13 of the reel spring 10, Are provided. Further, a concave portion 18 into which the convex portion 14 can be fitted is provided at a position corresponding to the convex portion 14 of the reel spring 10.

The inner surface 52a has a reel spring 10
First, the arm portion 11 of the reel spring 10 is fixed.
While holding the boss 19 in the through hole 13 of the base end 12.
And the base end 12 is fitted between the pair of position regulating ribs 17. Then, the convex portion 14 of the reel spring 10 fits into the concave portion 18 of the inner side surface 52a.

At this time, as shown in FIG. 2, the reel spring 10 has the base end 12 in contact with the inner side surface 52a and the arm 1
1 is raised from the inner surface 52a. In this state, the reel spring 10 is transported to a position where the boss 19 can be welded. FIG. 3 shows a state in which the boss 19 is welded to fix the reel spring 10 to the inner side surface 52a.

In the magnetic tape cassette constructed as described above, the reel spring 10 before fixing is fixed to the projection 14 provided on the base end 12 and the inner surface 52a of the upper cassette half.
The position displacement is regulated twice by fitting with the concave portion 18 provided on the base member 12 and holding the base end portion 12 by the position regulating rib 17. Therefore, the reel spring 10 is not displaced by the vibrations at the time of transportation and welding, and the reel spring 10 can be securely and easily fixed to the upper cassette half without raising the position regulating rib 17.

Further, since the base end 12 of the reel spring 10 is long and heavy, the boss 19 is inserted into the through hole 13 and the base end 12 is clamped by the position regulating rib 17 before being fixed. The base end 12 comes into contact with the inner side surface 52a, and the arm portion 11 rises from the inner side surface 52a. Conventional (see Fig. 9)
Makes the base end 72 contact the inner side surface 52a at the time of welding,
The arm portion 11 is raised from the inner side surface 52a, but at this time, the reel spring 10 may rotate around the boss portion 59. However, according to the present embodiment, since such a problem does not occur, the reel spring 10 can be securely fixed to a proper position.

FIG. 4 shows a second embodiment of the present invention. This embodiment is different from the first embodiment in the shape of the fitting portion, but the other parts are the same as those in the first embodiment. As shown in FIG. 4, the reel spring 20 extends from a position adjacent to the through hole 23 formed in the base end portion 22 to a portion near a connection portion with the arm portion 21 and projects toward the inner side surface 52 a of the upper cassette half. Ridge 24 is provided. The ridge 24 can be formed by embossing or the like. A concave groove 28 is formed on the inner side surface 52a of the upper cassette half so that the convex line 24 of the reel spring 20 can be fitted therein.

FIG. 5 is a sectional view taken along line XX in FIG. As shown in the figure, the convex ridge 24 has a substantially hollow triangular cross section, while the concave groove 28 has two inclined surfaces and has a shape such that the convex ridge 24 can be fitted without any gap. .

In the magnetic tape cassette constructed as described above, the reel springs 20 are fitted by fitting the ridges 24 provided on the base end portion 22 and the concave grooves 28 provided on the inner side surface 52a of the upper cassette half. Is firmly prevented from being displaced. In such an assembly structure of the reel spring 20,
The height of the position regulating rib 17 can be reduced, and
It is also possible to remove the position regulating rib 17.

In the above-described embodiment, the projections 14 and the projections 24 are formed by embossing and are hollow. Instead, solid projections or projections are provided at the base end. Alternatively, the convex portion or the ridge may have a function as a weight. Further, the concave and convex portions may be reversed, that is, a convex portion or a convex line may be provided on the inner surface of the upper cassette half, and a concave portion or a concave groove may be provided on the reel spring.

FIG. 6 shows a third embodiment of the present invention. As shown in the figure, the reel spring 30 includes a pair of locking pieces 34 formed on the base end 32 by bending both sides in the longitudinal direction of the base end 32. A pair of locking grooves 38 capable of locking the locking pieces 34 of the reel spring 30 are formed on the inner side surface 52a of the upper cassette half. In the present embodiment, the first embodiment and the second embodiment
The position regulating rib 17 provided in the embodiment is not provided.

In the magnetic tape cassette thus constructed, a pair of locking pieces 34 provided on the base end 32 are provided.
Is locked in the locking groove 38 provided in the inner side surface 52a of the upper cassette half, whereby the displacement of the reel spring 30 is firmly prevented. For example, the locking pieces 34 have elasticity, the interval between the tips of the pair of locking pieces 34 is made wider than the interval between the pair of locking grooves 38, and the tips of the opposing locking pieces 34 are pushed inward. It may be assembled in the concave groove 38 in a state.
In this case, the displacement of the reel spring 30 is more firmly prevented.

[0028]

According to the magnetic tape cassette of the present invention, a fitting portion is provided on each of the contact surfaces of the reel spring and the upper cassette half to fit each other to prevent the reel spring from being displaced. Therefore, by fitting the fitting portions, the reel spring is positioned, and the reel spring can be securely and easily fixed to the upper cassette half. Further, since it is not necessary to raise the position restricting ribs to prevent the displacement of the reel spring, other parts such as the tape reel are not damaged by the position restricting ribs.

[Brief description of the drawings]

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

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

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

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

FIG. 5 is a sectional view taken along line XX in FIG. 4;

FIG. 6 is a diagram showing a third embodiment of the present invention.

FIG. 7 is an exploded perspective view showing a conventional magnetic tape cassette.

8 is a diagram showing an inner side surface of the upper cassette half in FIG. 7;

FIG. 9 is a perspective view showing an assembly structure of a reel spring in FIG. 8;

[Explanation of symbols]

 10, 20, 30 Reel spring (leaf biasing leaf spring) 11, 21, 31 Arm part 12, 22, 32 Base end part 13, 23, 33 Through hole 14 Convex part (fitting part) 17 Position regulating rib 18 Concave portion (fitting portion) 19 Boss portion 24 Convex ridge (fitting portion) 28 Concave groove (fitting portion) 34 Locking piece (fitting portion) 38 Locking groove (fitting portion)

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. A magnetic tape cassette provided with a biasing reel biasing leaf spring, wherein the reel biasing leaf spring and the upper cassette half are engaged with each other at respective contact surfaces, and the displacement of the reel biasing leaf spring is shifted. A magnetic tape cassette provided with a fitting portion for preventing the magnetic tape cassette.