JPH11250608A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent unexpected close contact of plate springs in the cleaning process or transfer process of plate spring for biasing a reel without increase of manufacturing steps. SOLUTION: A through-hole 22 of each reel biasing plate spring 20 is respectively formed to a base end portion 21 of each reel biasing plate spring 20 in such a manner as to give a predetermined step as shown in the cross-sectional view in the periphery (upward projecting step in the drawing). Namely, the through-hole 22 of each reel biasing plate spring 20 is respectively given the predetermined step in the periphery at the same time when the boring process is carried out to generate the projected and recessed areas at the surface of the reel biasing plate spring 20.

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 reel urging leaf spring for urging 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. . Referring to FIG. 5, a pair of tape reels 31 each wound with a magnetic tape (not shown) as a magnetic tape cassette 30 conventionally used, for example, for DVC, is mounted in a lower cassette half 33 paired with an upper cassette half 32. Are rotatably supported.

Tape guides 35 are provided on both sides of an opening 34 on the near side in FIG. 3 of the lower cassette half 33, respectively. Each tape guide 35 is sent from one tape reel 31 to the other tape reel 31.
And guides the magnetic tape through a predetermined position in the opening 34.

On the rear side of the lower cassette half 33, a tape reel lock member 38 having a tape reel locking arm 37 is provided. The tape reel lock member 38 is urged by a compression coil spring 39 to engage the tape reel locking arm 37 with an engagement tooth 40 formed on the outer periphery of each tape reel 31, and Prevent unexpected rotation. 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 46 rotatably provided on the lower cassette half 33.

The upper cassette half 32 is provided with a pair of reel biasing leaf springs 47 for each tape reel 31. Each of the reel biasing leaf springs 47 has a through hole 49 formed in the base end portion 48 and the upper cassette half 32.
The boss is welded in a state of being inserted into the boss (not shown). As a result, each of the reel urging leaf springs 47 is cantilevered by the upper cassette half 32 and urges the corresponding tape reel 31 to a predetermined side.

[0007]

In the conventional magnetic tape cassette described above, since the surface of the biasing leaf spring 47 is flat, the reel biasing leaf spring 47 can be cleaned or transported in a cleaning step or a transporting step. There was a problem that the leaf springs 47 unexpectedly adhered to each other. Therefore, in the cleaning process of the reel urging leaf springs 47, cleaning failure occurs, and in the transporting process by the welding machine, it becomes difficult to perform a feeding operation of transporting the reel urging leaf springs 47 one by one. There was a problem.

According to the present invention, without increasing the number of manufacturing steps,
It is possible to reliably prevent unexpected contact between the leaf springs in the cleaning process or the transporting process of the reel biasing leaf springs, thereby preventing defective cleaning of the reel biasing leaf springs and realizing reliable transport, etc. It is an object of the present invention to provide a magnetic tape cassette capable of achieving the following.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to form a pair of tape reels around which a magnetic tape is wound, rotatably supported in a cassette case composed of upper and lower cassette halves, and formed at a base end. The through-hole is inserted into the boss portion of the upper cassette half, and is welded to the boss portion, thereby being cantilevered by the upper cassette half and biasing each of the tape reels to a predetermined side. In a magnetic tape cassette provided with a reel urging leaf spring, the through hole of the reel urging leaf spring is perforated so as to have a predetermined step in a cross-sectional view around the magnetic tape cassette. Achieved.

[0010]

In the magnetic tape cassette according to the present invention, the reel biasing leaf spring is provided with a through hole formed in the base end portion so as to have a predetermined step in cross section in the boss portion of the upper cassette half. The boss is welded in the inserted state. Thus, the reel biasing leaf spring is cantilevered by the upper cassette half, and biases each of the tape reels to a predetermined side. Since the reel urging springs are perforated so that a step is formed around the through hole, the reel urging springs do not unexpectedly come into close contact with each other during transportation or the like, and proper conveyance and assembly are realized.

[0011]

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view showing a reel biasing leaf spring and an upper cassette half of a magnetic tape cassette according to a first embodiment of the present invention. FIG. 2 is a perspective view of a reel urging leaf spring of the magnetic tape cassette of FIG. 1, and FIG. 2 (a) shows a single state of the reel urging leaf spring.
(B) shows a state where the reel biasing leaf spring is attached to the upper cassette half, respectively. FIG. 3 is a sectional view of a main part of the leaf spring for urging the reel shown in FIG.

In these figures, a magnetic tape cassette 10 comprises a pair of tape reels (not shown) wound with a magnetic tape (not shown) and a lower cassette half (not shown) paired with an upper cassette half 11. , Rotatably supported.

The upper cassette half 11 is provided with a pair of leaf urging leaf springs 20 for each tape reel. Each of the reel biasing leaf springs 20 has a through hole 22 formed in the base end 21 and an upper cassette half 11.
The boss portion 12 is welded using ultrasonic vibration or the like in a state of being inserted into the boss portion 12. As a result, each of the biasing leaf springs 20 is cantilevered by the upper cassette half 11 and biases the corresponding tape reel to a predetermined side.

As shown in FIG. 3, each of the through-holes 22 of each reel urging leaf spring 20 is
The base portion 21 is formed by drilling a predetermined step (in FIG. 3, a step having an upward convexity) in the base end portion 21. That is, the through holes 22 of the respective reel biasing leaf springs 20 are respectively
A predetermined step is formed at the same time as the perforation, so that the surface of each of the biasing leaf springs 20 becomes uneven. In order to form a step at the same time as drilling, for example, by providing a ring-shaped pressing means for forming a step around the drilling blade, the pressing means can press the periphery of the through hole 22 during the drilling operation.

The operation of the embodiment will be described. When the magnetic tape cassette 10 is mounted on the upper cassette half 11, each of the biasing leaf springs 20 is attached to the base end 2.
The boss portion 12 of the upper cassette half 11 is inserted into a through hole 22 formed by punching the first cassette half 1 so as to have a predetermined step in cross section, and the positioning rib 13 provided on the upper cassette half 11 It is positioned in a predetermined posture with respect to the upper cassette half 11. In this state, the top of the boss 12 is melted using ultrasonic vibration or the like. As a result, each of the reel biasing leaf springs 20 is fixed to the upper cassette half 11 in a predetermined posture.

When the boss portion 12 of the upper cassette half 11 is welded, the step of the through hole 22 of each of the biasing leaf springs 20 is compressed to generate a required elasticity. Etc. can be prevented.

As shown in FIG. 4, the step formed in the through hole 22 of each of the biasing leaf springs 20 has a downwardly convex shape which is opposite to the upwardly convex shape shown in FIG. It is also possible (second embodiment). The shape of the step and the number of steps are not limited to those shown in the drawings, and various steps can be applied.

As described above, according to each of the above-described embodiments, the through-hole 22 is formed at the base end portion 21 of each of the leaf springs 20 for biasing the reel so that a step that is upwardly convex in a sectional view is formed in the periphery. Since it is formed by perforation, it is possible to form a predetermined step in the through hole 22 in cross section, that is, to make the surface of each of the biasing leaf springs 20 uneven without increasing the number of manufacturing steps and manufacturing cost. .

For example, if a process for simply providing irregularities on the surface of each of the urging leaf springs 20 is added to the manufacturing process of the reel urging leaf springs 20, the number of manufacturing steps and the manufacturing cost increase. Therefore, in each of the above-described embodiments, a predetermined step is formed in the through-hole 22 at the same time as the perforation of the through-hole 22 of each of the reel biasing leaf springs 20, so that the number of manufacturing steps and the manufacturing cost are not increased. The surface of the biasing leaf spring 20 is made uneven.

This makes it possible to reliably prevent unexpected contact between the leaf springs 20 in the cleaning step and the transport step of the reel biasing leaf springs 20. For example, a large number of the reel biasing leaf springs 20 are skewered. Even in the case of cleaning or transporting in a state, a required gap can be created between the respective biasing leaf springs 20. Therefore, it is possible to reliably prevent defective cleaning in the cleaning process of the reel biasing leaf spring 20 and to realize a reliable feeding operation in the transporting process by a welding automatic machine (not shown).

[0021]

As described above, according to the present invention, a through-hole is formed at the base end of the leaf spring for biasing the reel so as to form a predetermined step in its periphery in a sectional view. The surface of the reel biasing leaf spring can be made uneven without increasing the number of manufacturing steps. This makes it possible to reliably prevent unexpected close contact between the leaf springs in the cleaning step or the transporting step of the reel biasing leaf springs, thereby preventing defective cleaning of the reel biasing leaf springs and realizing reliable transport. Etc. can be achieved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a reel biasing leaf spring and an upper cassette half of a magnetic tape cassette according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a leaf spring for urging the reel of the magnetic tape cassette of FIG. 1;

FIG. 3 is a sectional view of a main part of the reel urging leaf spring of FIG. 2;

FIG. 4 is a cross-sectional view of a main part showing a leaf biasing leaf spring of a magnetic tape cassette according to a second embodiment of the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Magnetic tape cassette 11 Upper cassette half 12 Boss part 13 Positioning rib 20 Reel biasing leaf spring 21 Base end part 22 Through hole

Claims (1)

[Claims] 1. 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, and a through hole formed in a base end portion is provided in a boss portion of the upper cassette half. A magnetic tape having a reel biasing leaf spring that is cantilevered by the upper cassette half by being welded to the boss portion in a state where the tape reel is biased toward a predetermined side. In the cassette, the through-hole of the leaf spring for urging the reel is perforated so as to have a predetermined step in a cross-sectional view at the periphery thereof.