JPH11149746A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape cassette in which a mechanism or the like used to temporarily hold a reel spring is not required separately and in which the reel spring can be fixed and bonded surely to a cassette half. SOLUTION: In a magnetic tape cassette, a pair of magnetic tape reels on which a magnetic tape is wound are housed inside a cassette case which is composed of an upper cassette half and of a lower cassette half. A base end 23b is cantilever-held at the inside of the upper cassette half by a fusing operation, and a long-shape reel spring 21 which presses the magnetic tape reels to the lower part of the cassette is provided. In the magnetic tape cassette, a temporary holding means 7 which temporarily holds the reel spring 21 by force-fitting the base end 23b of the reel spring 21 is installed at the inside of the upper cassette half.

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 having a reel spring for pressing a magnetic tape reel below the cassette.

[0002]

2. Description of the Related Art Conventionally, in audio equipment, video equipment and the like, a magnetic tape cassette configured to perform recording and reproduction while holding a magnetic tape wound around a pair of magnetic tape reels in a cassette case so as to be able to run is used. It is heavily used.

[0003] Among these magnetic tape cassettes, a DVC cassette (digital video cassette) used for video equipment and the like includes a pair of magnetic tapes wound around a lower cassette half integrally formed of a synthetic resin such as an ABS resin. Is held rotatably. The magnetic tape reel is configured to be pressed downward by the cassette by means of a longitudinal reel spring mounted on the upper cassette half in a cantilever manner.

FIG. 6 is a plan view showing the inner surface of the upper cassette half of the DVC cassette, and FIG. 7 is a perspective view of a reel spring. As shown in FIG.
Has a pair of reel springs 21 for pressing a pair of magnetic tape reels below the cassette. As shown in FIG. 7, the reel spring 21 is made of a long metal plate and presses the magnetic tape reel downward in the cassette.
3a and a base end 23b fixed to the inner surface of the upper cassette half 20. A through hole 25 is provided in the base end 23b.

Next, a method of fixing the reel spring 21 to the upper cassette half 20 will be described. As shown in FIG. 8, first, the through hole 25 of the reel spring 21 is inserted into a boss 29 provided on the upper cassette half 20. Then, a pair of positioning ribs 27 provided on the upper cassette half 20 position both sides of the base end 23b. While maintaining this state, the top of the boss 29 is melted by ultrasonic vibration, and the arm 23a is fixed so as to project inward (downward) of the cassette to finally reach the state shown in FIG.

[0006]

Usually, the diameter of the through hole 25 is slightly larger than the diameter of the boss 29 so that the boss 29 can be easily inserted into the through hole 25 of the reel spring 21. As a result, when the top of the boss 29 is melted by ultrasonic vibration and the reel spring 21 is fixed to the upper cassette half 20, the reel spring 2
Since the center of gravity of 1 is located on the right side in FIG. 8, the reel spring 21 may have floated by the distance t as shown in FIG. Here, it is conceivable to prevent the reel spring 21 from floating by temporarily holding the reel spring 21 with a machine or the like. However, a separate machine for temporarily holding the reel spring 21 or the like is required, so that there is a problem in cost. is there. Accordingly, an object of the present invention is to provide a magnetic tape cassette that can securely fix a reel spring to a cassette half without requiring a separate machine for temporarily holding a reel spring.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to accommodate a pair of magnetic tape reels for winding a magnetic tape in a cassette case composed of upper and lower cassette halves, and to weld the inner surface of the upper cassette half by welding. In a magnetic tape cassette whose base end is cantilevered and has a longitudinal reel spring that presses the magnetic tape reel below the cassette, the reel spring is temporarily held by press-fitting the base end of the reel spring. The problem is solved by a magnetic tape cassette wherein the temporary holding means is provided on the inner surface of the upper cassette half.

According to the present invention, provisional holding means is provided on the inner surface of the upper cassette half, and the reel spring is temporarily held by press-fitting the base end of the reel spring into the temporary holding means. Even when the reel spring is welded to the upper cassette half, the reel spring is maintained in an appropriate state. Therefore, the reel spring can be securely fixed to the cassette half without the necessity of a separate machine for temporarily holding the reel spring.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a plan view showing the inner surface of the upper cassette half according to one embodiment of the present invention. FIG. 1 shows the inner surface of the upper cassette half before the reel spring is fixed. The shape of the reel spring is
Since it is the same as the reel spring shown in FIG. 7, its description is omitted. As shown in FIG.
A pair of ribs 3 for positioning both sides of the base end of the reel spring and a welding boss 5 for fixing the reel spring
And a rib 7 which is a temporary holding means located at the rear end of the base end of the reel spring.

Next, a method of fixing the reel spring 21 to the inner surface of the upper cassette half 1 will be described with reference to FIGS. In this embodiment, as shown in FIG. 2, the distance from the rear end of the base end 23b of the reel spring 21 to the edge of the through hole 25 on the arm portion 23a side is W _1.
From the rib 7 to the arm 23a of the welding boss 5
When the distance to the circumference of the side as W _2, is set as W ₁ = W _2.

First, as shown in FIG.
1 through holes 25 of the upper cassette half 1
Insert Then, the base end 23 is formed by the pair of ribs 3.
At the same time as the positioning of both sides of b, the rear end of the base end 23b is positioned by the rib 7. Here, when inserting the reel spring 21 to the welding boss 5, since the distance W ₁ between the distance W ₂ is set to the same length, and FIG 3
As shown by the arrow A, the base end 23b of the reel spring 21
Are pressed into the welding boss 5 and the rib 7, and the reel spring 21 is temporarily held. Therefore, the proper state of the reel spring can be maintained without using the reel spring temporary holding machine or the like. Then, while maintaining this state, the top of the boss 29 is melted by ultrasonic vibration, and the arm 23a is fixed so as to project inward of the cassette.

By setting the positional relationship between the rib 3 and the boss 5 appropriately without providing the rib 7, the base end 23b of the reel spring 21 is pressed into the rib 3 and the boss 5. The reel spring 21 may be temporarily held. Further, not only is the pair of ribs 3 used for positioning as in the conventional case, but also the mutual positional relationship of the ribs 3 is appropriately set, so that the base end 23b of the reel spring 21 is positioned with respect to the ribs 3. The reel spring 21 may be temporarily held by press-fitting.

Next, a second embodiment of the present invention will be described.
As shown in FIG. 4, in the second embodiment, a groove 11 located at the rear end of the base end 31 of the reel spring 30 is provided on the inner surface of the upper cassette half. In the case of the second embodiment, the groove 11 forms temporary holding means. And the groove 11
Corresponding to the rear end 32 of the base end 31 of the reel spring 30.
The base end 3 is formed by bending so that it can be pressed into the groove 11.
1 and at right angles. Also in the case of the second embodiment,
The appropriate state of the reel spring can be maintained from the groove 11 without using a reel spring temporary holding machine or the like, so that welding can be reliably performed.

Next, a third embodiment of the present invention will be described.
As shown in FIG. 5, in the third embodiment, the upper cassette half is provided with a projecting recess 13 located at the rear end 42 of the base end 41 of the reel spring 40. The projecting recess 1
3 is provided so as to protrude from the inner surface of the upper cassette half. In the case of the third embodiment, the protruding concave portion 13 forms temporary holding means. The rear end 42 of the base end 41 of the reel spring 40 corresponding to the projecting recess 13 is
3 is formed by bending so that it can be press-fitted. Here, the bent angle of the rear end 42 and the arm portion 43 of the reel spring 40 is appropriately adjusted, unlike the first and second embodiments, because of the fact that the projecting recess 13 is provided so as to project. Also in the case of the third embodiment, the proper state of the reel spring can be maintained from the projecting concave portion 12 without using a reel spring temporary holding machine or the like, so that welding can be reliably performed.

The magnetic tape cassette of the present invention can be appropriately modified and improved without being limited to the above-described embodiment. For example, the magnetic tape cassette is not limited to DVC, but can be applied to various types of cassettes.

[0016]

As described above, according to the present invention, the temporary holding means for temporarily holding the reel spring by press-fitting the base end of the reel spring is provided on the inner surface of the upper cassette half. Even when the reel spring is welded to the cassette half, the reel spring is maintained in an appropriate state. Therefore, the reel spring can be securely fixed to the cassette half without the necessity of a separate machine for temporarily holding the reel spring.

[Brief description of the drawings]

FIG. 1 is a plan view showing an inner surface of an upper cassette half according to an embodiment of the present invention.

FIG. 2 shows a method of fixing a reel spring to an upper cassette half.

FIG. 3 shows a method of fixing a reel spring to an upper cassette half.

FIG. 4 shows a method of fixing a reel spring to an upper cassette half according to a second embodiment of the present invention.

FIG. 5 shows a method of fixing a reel spring to an upper cassette half according to a third embodiment of the present invention.

FIG. 6 is a plan view showing an inner surface of a conventional upper cassette half.

FIG. 7 is a perspective view of a reel spring.

FIG. 8 shows a conventional method of fixing a reel spring to an upper cassette half.

FIG. 9 shows a conventional method of fixing a reel spring to an upper cassette half.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper cassette half 3 Rib 5 Welding boss 7 Rib 11 Groove 13 Projecting recess 20 Upper cassette half 21 Reel spring 23a Arm part 23b Base end 25 Through hole 29 Boss 30 Reel spring 31 Base end 32 Rear end 40 Reel spring 41 Base end 43 Arm

Claims (1)

[Claims] 1. A pair of magnetic tape reels for winding a magnetic tape are accommodated in a cassette case composed of upper and lower cassette halves, and the base end thereof is cantilevered by welding to the inner surface of the upper cassette half. In a magnetic tape cassette provided with a longitudinal reel spring that presses a tape reel below a cassette, temporary holding means for temporarily holding the reel spring by press-fitting a base end of the reel spring is provided on an inner surface of the upper cassette half. A magnetic tape cassette, which is provided.