JP2000123538A - Tape reel of magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the time required for the ultrasonic welding of a welding boss and to improve the welding stability by increasing the transmission efficiency of the ultrasonic oscillation energy to the welding boss. SOLUTION: The boss part 15 of a lower reel 16 is provided with a side wall 22 which forms the winding surface of a magnetic tape, on the circumference separated in the radial direction from a center part 21 of the boss and further constituted in such a manner that the center part 21 of boss and the side wall 22 are connected by plural ribs 23 arranged along the radial direction of the boss part 15. Each rib 23 is provided along the radial direction of the boss part 15 respectively between the specified positions keeping away base end parts 24 of the welding boss 20 on the side surface 21a of the center part 21 of boss and the inner surface 22a of the side wall 22, and the gap is arranged therein against the welding boss 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape reel of a magnetic tape cassette such as a digital video cassette (DVC), and more particularly to a structure for efficiently performing ultrasonic welding of a boss for welding a tape reel.

[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. 6, a pair of tape reels 31 wound with a magnetic tape t is wound in a lower cassette half 33 paired with an upper cassette half 32 as a magnetic tape cassette 30 conventionally used for DVC, for example. Some are movably supported.

[0006] Tape guides 35 are provided on both sides of an opening 34 on the near side in FIG. 6 of the lower cassette half 33. Each tape guide 35 is sent from one tape reel 31 to the other tape reel 31.
And guides the magnetic tape t to pass through a predetermined position in the opening 34.

On the rear side of the lower cassette half 33, a reel lock member 39 having a tape reel locking arm 38 is provided. Reel lock member 39
Is urged by a compression coil spring 40 to move the tape reel locking arm 38 to each tape reel 3.
The tape reel 31 is engaged with the engaging teeth 41 formed on the outer circumference of the tape reel 1 to prevent the tape reels 31 from being accidentally rotated. This prevents loosening of the magnetic tape t.

[0005] An outer lid 50, a top lid 51, and an inner lid 52 that cover the opening 34 of the lower cassette half 33 are respectively attached to the upper cassette half 32 so as to be freely opened and closed. Side plate 53 of outer lid 50
Is provided with a lock pin 54 protruding therefrom. Lock pin 54
Is locked by a lid lock 55 rotatably provided on the lower cassette half 33. Reference numeral 56 denotes a lid spring mounted on the rotation shaft of the outer lid 50.

Referring to FIGS. 6 and 7, each of the tape reels 31 includes an upper reel 42 and a lower reel 43 facing each other, and a flange portion 44 and a lower reel 4 of the upper reel 42.
The third boss 45 is fixed with a predetermined gap therebetween.

That is, in each tape reel 31, a pivot 47 projecting from the boss 45 of the lower reel 43 is fitted into a pivot hole 46 provided in the flange 44 of the upper reel 42. Further, a welding boss 48 projecting from the boss portion 45 of the lower reel 43 at a position radially away from the pivot 47 is provided at a position corresponding to the welding boss 48 on the flange portion 44 of the upper reel 42. It is inserted into the welding boss hole 49. In this state,
The welding boss 48 is ultrasonically welded by bringing a welding horn (not shown) into contact with substantially the center of the tip surface (the upper end surface in FIG. 6) of the welding boss 48. Thereby, the upper reel 42 and the lower reel 43 facing each other are fixed with a predetermined gap between the flange portion 44 and the boss portion 45.

The boss 45 of the lower reel 43 is
7 are provided radially away from a boss center 57 projecting from the boss 7, and a side wall 58 serving as a winding surface of the magnetic tape t is provided between the boss center 57 and the side wall 58, and a welding boss 48. Between the base end 59 and the side wall 58 of the boss 45
Are connected by a plurality of ribs 60 provided along the radial direction.

[0009]

However, in the conventional magnetic tape cassette 30, when the welding boss 48 is ultrasonically welded, the ultrasonic oscillation energy from the welding horn is reduced.
For example, it is dispersed to other portions of the lower reel 43 via the rib 60 between the base end portion 59 of the welding boss 48 and the side wall 58. For this reason, the transmission efficiency of the ultrasonic oscillation energy from the welding horn to the welding boss 48 is low, so that there is a problem that welding takes time and welding stability is lacking. If the welding stability is lacking, the facing posture of the upper reel 42 and the lower reel 43 may be distorted, which may cause a surface runout when the tape reel 31 rotates.

An object of the present invention is to improve the efficiency of transmitting ultrasonic oscillation energy to a welding boss, thereby shortening the time required for ultrasonic welding of the welding boss and improving welding stability. It is an object of the present invention to provide a magnetic tape cassette tape reel.

[0011]

The above object of the present invention is achieved by the following constitution. An upper reel having a flange portion, a lower reel disposed opposite to the upper reel and having a boss portion on a surface facing the upper reel, a pivot hole provided in a flange portion of the upper reel, The welding boss provided on the flange portion of the upper reel and the pivot boss provided on the flange portion of the upper reel are inserted into the boss portion of the boss portion and the welding boss projecting at a position radially away from the pivot in the boss portion of the lower reel. In the tape reel of the magnetic tape cassette in which the upper reel and the lower reel are fixed with a predetermined positional relationship by inserting the welding boss by ultrasonic welding in this state, the boss portion of the lower reel is A side wall, which is a winding surface of the magnetic tape, is provided around the boss centrally provided with the pivot in a radial direction, and the boss center and the side wall are fixed along the radial direction of the boss. In is configured by connecting,
The rib is provided so as to avoid the base of the welding boss. An upper reel having a flange portion, a lower reel disposed opposite to the upper reel and having a boss portion on a surface facing the upper reel, a pivot hole provided in a flange portion of the upper reel, The welding boss provided on the flange portion of the upper reel and the pivot boss provided on the flange portion of the upper reel are inserted into the boss portion of the boss portion and the welding boss projecting at a position radially away from the pivot in the boss portion of the lower reel. In the tape reel of the magnetic tape cassette in which the upper reel and the lower reel are fixed with a predetermined positional relationship by inserting the welding boss by ultrasonic welding in this state, the boss portion of the lower reel is A side wall, which is a winding surface of the magnetic tape, is provided around the boss centrally provided with the pivot in a radial direction, and the boss center and the side wall are fixed along the radial direction of the boss. In is configured by connecting,
Further, the rib is achieved by a tape reel of a magnetic tape cassette, wherein a part of the rib is provided with a gap with respect to a base of the welding boss.

[0012]

In the tape reel of the magnetic tape cassette according to the present invention, a pivot projecting from the boss of the lower reel is inserted into a pivot hole provided in the flange of the upper reel. Further, a welding boss protruding from the boss portion of the lower reel at a position radially away from the pivot is fitted and inserted into a welding boss hole provided on the flange portion of the upper reel. In this state, the welding boss is ultrasonically welded. At this time, the rib is provided so as to avoid the base of the welding boss, or a part of the rib is provided with a gap with respect to the base of the welding boss, so that the oscillation energy of the ultrasonic wave is increased. Is efficiently transmitted to the welding boss without being transmitted from the welding boss to the other, and the welding boss is ultrasonically welded in a short time. As a result, the upper reel and the lower reel are fixed in a predetermined positional relationship.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a lower cassette half of a magnetic tape cassette to which a tape reel according to a first embodiment of the present invention is applied, FIG. 2 is a perspective view of the lower reel of the tape reel, and FIG. FIG. 4 is a partially enlarged plan view of a lower reel 2.

In FIG. 1, a magnetic tape cassette 10
Shows a pair of tape reels 12 wound around a magnetic tape t (see FIG. 6) (a tape reel on the right side in the figure is not shown).
It is rotatably supported by a lower cassette half 11 that forms a pair with an upper cassette half (not shown). The lower cassette half 11 is integrally formed of a synthetic resin such as an ABS resin.

Referring to FIGS. 1 to 3, each tape reel 12 has an upper reel 14 having a flange portion 13.
And a lower reel 16 which is disposed to face the upper reel 14 and has a boss 15 on a surface facing the upper reel 14. The upper reel 14 and the lower reel 16 are fixed with a predetermined gap between the lower surface of the flange 13 of the upper reel 14 and the upper surface of the boss 15 of the lower reel 16. The upper reel 14 is integrally formed of, for example, a transparent synthetic resin,
The lower reel 16 is integrally formed of, for example, an opaque synthetic resin.

The upper reel 14 is provided with a pivot hole 17 and a welding boss hole 18. The pivot hole 17 is provided substantially through the center of the flange portion 13 of the upper reel 14. The welding boss hole 18 is provided in the flange portion 1 of the upper reel 14.
3, the same number as the welding bosses 20 is provided so as to penetrate the position corresponding to the welding bosses 20 described later.

The lower reel 16 has a pivot 19 and a welding boss 20 projecting from the upper surface of the boss 15 respectively. That is, the boss portion 15 is provided around the radially distant from the boss center portion 21 on the side wall 2 serving as the winding surface of the magnetic tape t.
2, the boss center portion 21 and the side wall 22 are connected by a plurality of (six in FIG. 3) ribs 23 along the radial direction of the boss portion 15. The pivot 19 protrudes substantially at the center of the upper surface of the boss center 21. In addition, welding boss 20
Is projected from the upper surface of a base end portion 24 provided at the outer edge of the boss center portion 21. That is, a plurality (three in FIG. 3) of the base end portions 24 are provided on the outer edge portion of the boss center portion 21 radially away from the pivot 19 at predetermined intervals in the circumferential direction of the boss center portion 21. The welding boss 20 is
A total of three projections are provided, one each at substantially the center of the upper surface of each base end portion 24. Each of the ribs 23 extends along the radial direction of the boss 15 between a predetermined position on the side surface 21 a of the boss center portion 21 avoiding the base end portion 24 of the welding boss 20 and the inner surface 22 a of the side wall 22. It is provided and has a gap with respect to the base of the welding boss 20.

In each tape reel 12,
A pivot 19 projecting from the boss 15 of the lower reel 16 is fitted into a pivot hole 17 provided in the flange 13 of the upper reel 14. Also, the boss 15 of the lower reel 16
The welding boss 20 projecting from the upper reel 14 is inserted into a welding boss hole 18 provided in the flange portion 13 of the upper reel 14.
In this state, a welding horn (not shown) is brought into contact with a substantial center of the tip end surface (the upper end surface in FIG. 2) of each welding boss 20, so that each welding boss 20 is ultrasonically welded. As a result, the upper reel 14 and the lower reel 16 are fixed in a predetermined positional relationship.

The operation of the present embodiment will be described. When each welding boss 20 is ultrasonically welded, when each welding horn is brought into contact with the distal end surface of each welding boss 20, the ultrasonic oscillation energy is transmitted from each welding horn to the distal end surface of each welding boss 20. It is transmitted to almost the center. At this time, the base end 2 of each welding boss 20
Since the ribs 23 are not provided between the inner wall 22a and the inner surface 22a of the side wall 22, the ultrasonic oscillation energy is not diffused to other portions of the boss portion 15 and the welding bosses 20 Is efficiently transmitted to the user. The welding bosses 20 are each ultrasonically welded in a short time by the transmitted oscillation energy of the ultrasonic waves. That is, in the conventional tape reel 31 shown in FIGS. 6 and 7,
Ultrasonic welding of the welding boss 48 took 0.4 seconds, but in the tape reel 12 of this embodiment, it could be reduced to 0.2 seconds.

FIG. 4 is a perspective view of a lower reel of a tape reel according to a second embodiment of the present invention, and FIG. 5 is a partially enlarged plan view of the lower reel of FIG.

In this embodiment, in addition to the plurality of (six in FIG. 5) ribs 23 provided between the boss center portion 21 of the boss portion 15 and the inner surface 22a of the side wall 22, the welding boss 20 is provided.
A plurality of (three in FIG. 5) ribs 25 (hereinafter referred to as notch ribs 25) each having a notch 26 of a required shape for avoiding the base portion 24 and the side wall 2 of the welding boss 20 are formed.
2 between the inner surface 22a and the second inner surface 22a. The notch 26 of the notch rib 25 is formed at a predetermined interval A in the radial direction from the base end 24 of the welding boss 20 and over a predetermined size B in the vertical direction in FIG. Other configurations and operations are the same as those in the first embodiment. In the second embodiment, the shape of the notch 26 is rectangular in a side view, but the shape of the notch 26 in a side view may be a triangle, a trapezoid, an ellipse, or the like.

As described above, according to the above embodiments, the boss center 21 and the side wall 22 of the boss 15 of the lower reel 16 are provided.
Each of the ribs 23 is arranged with a gap with respect to the base of the welding boss 20, avoiding the vicinity of the welding boss 20. That is, in the first embodiment, each rib 23 is arranged so as to avoid the base end 24 of the welding boss 20, and in the second embodiment, the rib 23 is located between the base end 24 of the welding boss 20 and the inner surface 22 a of the side wall 22. A notch 26 of a required shape for avoiding the welding boss 20 was formed in the rib 25 provided therebetween. Therefore, the transmission efficiency of the ultrasonic oscillation energy from the welding horn to the welding boss 20 can be increased. As a result, the time required for ultrasonic welding of the welding boss 20 can be significantly reduced, welding stability can be improved, and the facing posture of the upper reel 14 and the lower reel 16 can be properly maintained. It is possible to reliably prevent surface runout and the like when the tape reel 12 rotates.

[0023]

As described above, according to the present invention, the rib connecting the boss center portion and the side wall of the boss portion of the lower reel is provided so as to avoid the base portion of the welding boss, or a part thereof is provided. Since the gap is provided with respect to the base of the welding boss, the transmission efficiency of the ultrasonic oscillation energy to the welding boss can be increased. Therefore, the time required for ultrasonic welding of the welding boss can be reduced, and the welding stability can be improved. As a result, it is possible to reliably prevent surface runout and the like during rotation of the tape reel.

[Brief description of the drawings]

FIG. 1 is a plan view showing a lower cassette half of a magnetic tape cassette to which a tape reel according to a first embodiment of the present invention is applied.

FIG. 2 is a perspective view of a lower reel of the tape reel.

FIG. 3 is a partially enlarged plan view of a lower reel of FIG. 2;

FIG. 4 is a perspective view of a lower reel of a tape reel according to a second embodiment of the present invention.

FIG. 5 is a partially enlarged plan view of a lower reel of FIG. 4;

FIG. 6 is an exploded perspective view of a conventional magnetic tape cassette.

7 is a partially enlarged plan view of a lower reel of the tape reel of the magnetic tape cassette of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Magnetic tape cassette 11 Lower cassette half 12 Tape reel 13 Flange part 14 Upper reel 15 Boss part 16 Lower reel 17 Pivot hole 18 Welding boss hole 19 Pivot 20 Welding boss 21 Boss center part 22 Side wall 23 Rib 24 Base end 25 Notch rib 26 Notch t Magnetic tape

Claims (2)

[Claims] 1. A pivot hole provided in a flange portion of an upper reel, comprising: an upper reel having a flange portion; and a lower reel disposed to face the upper reel and having a boss portion on a surface facing the upper reel. In addition, a pivot boss protruding from the boss portion of the lower reel is fitted and provided, and a welding boss protruding at a position radially away from the pivot in the boss portion of the lower reel is provided on the flange portion of the upper reel. In the tape reel of the magnetic tape cassette in which the upper reel and the lower reel are fixed in a predetermined positional relationship by inserting the welding boss by ultrasonic welding in this state, the lower reel The boss portion is provided with a side wall serving as a winding surface of the magnetic tape around the radial direction away from the center portion of the boss on which the pivot protrudes. A tape reel for a magnetic tape cassette, wherein the reel is connected by ribs extending in a shooting direction, and the ribs are provided so as to avoid a base of a welding boss. 2. A pivot hole provided in a flange portion of the upper reel, comprising: an upper reel having a flange portion; and a lower reel having a boss portion on a surface facing the upper reel and facing the upper reel. In addition, a pivot boss protruding from the boss portion of the lower reel is fitted and provided, and a welding boss protruding at a position radially away from the pivot in the boss portion of the lower reel is provided on the flange portion of the upper reel. In the tape reel of the magnetic tape cassette in which the upper reel and the lower reel are fixed in a predetermined positional relationship by inserting the welding boss by ultrasonic welding in this state, the lower reel The boss portion is provided with a side wall serving as a winding surface of the magnetic tape around the radial direction away from the center portion of the boss on which the pivot protrudes. The tape of the magnetic tape cassette, wherein the tape is constituted by being connected by ribs along the shooting direction, and a part of the ribs is provided with a gap with respect to the base of the welding boss. reel.