JP2000215636A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent or reduce deviation in a position due to vibration or the like before fixing a window member to an opening for a window. SOLUTION: A window member tapered face 23 formed at a notched part 22 for positioning at the outer edge part of a window member 20 and an opening tapered face 14 for a window formed at a rib 13 for positioning at the inner edge part of an opening 11 for a window are inclined at the inner side and outer side of the opening 11 for a window, that is, opposite sides (both right and left sides in the Fig.) from the cross-sectional view of an upper cassette half 10, and both inclination θ1 and θ2 are set so as to be 90 deg. or less.

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), and more particularly, to a magnetic tape cassette at a predetermined position of a window opening of an upper cassette half.
The present invention relates to a structure for preventing displacement of a window member fixed by welding due to vibration or the like before welding.

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

A tape guide 3 is provided on both sides of the window opening 34 on the front side in FIG.
5 are provided. Each of the tape guides 35 guides the magnetic tape t sent from one tape reel 31 and wound on the other tape reel 31, and passes the magnetic tape t through a predetermined position in the window 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.

The upper cassette half 32 has an outer lid 50 for covering the window opening 34 of the lower cassette half 33,
The inner lid 51 and the upper lid 52 are each attached to be openable and closable.

A lock pin 54 projects from the side plate 53 of the outer lid 50. The lock pin 54 is provided with a lid lock 55 rotatably provided on the lower cassette half 33.
Is locked. Reference numeral 56 denotes a lid spring mounted on the rotation shaft 57 of the outer lid 50.

Each of the tape reels 31 has an upper reel 42 and a lower reel 43 facing each other fixed with a predetermined gap between a flange central portion 44 of the upper reel 42 and a boss 45 of the lower reel 43. Be composed.

That is, in each of the tape reels 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 central portion 44 of the upper reel 42. Also, the lower reel 43
A welding boss 48 protruding at a position radially away from the pivot 47 in the boss portion 45 is provided at a position corresponding to the welding boss 48 in the flange central portion 44 of the upper reel 42. 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 distal end surface (the upper end surface in FIG. 3) of the welding boss 48. This allows
The opposing upper reel 42 and lower reel 43 are fixed.

Referring to FIGS. 3 to 5, a window opening 60 for confirming the remaining amount of the tape or the like is provided at a predetermined position in the upper cassette half 32. In the window opening 60, a window member 61 made of a transparent or translucent material is fixed at a predetermined position by welding. That is, the window member 61 abuts the fixing surface 61 a formed on the outer edge portion with the fixing surface 60 a formed on the inner edge portion of the window opening 60, and projects from the inner edge of the window opening 60. The tips (inside the window opening 60) of the plurality of (seven in FIG. 4) positioning ribs 62
It is engaged with the outer edge and positioned. In this state, the window member 61 is fixed to a predetermined position of the window opening 60 by welding the welding rib 65 formed on the fixing surface 61a.

A window member tapered surface 63 which is continuous with the fixing surface 61a is provided on the outer edge of the window member 61 at which the positioning rib 62 is engaged. 60 is formed at a predetermined angle toward the outside (the right side in FIG. 5).

A positioning rib 62 for the window opening 60 is provided.
A window opening tapered surface 64 that is continuous with the fixing surface 60a is provided at the front end of the upper cassette half 32 in a thickness direction of the upper cassette half 32 in a direction substantially parallel to the window member tapered surface 63.
It is formed to be inclined at a predetermined angle toward the outside.

[0013]

In the conventional magnetic tape cassette 30, the tapered surface 63 of the window member and the tapered surface 64 of the opening for the window are formed substantially parallel in cross section. For this reason, when fixing the window member 61 to the window opening 60, when the window member 61 is positioned at a predetermined position of the window opening 60, the clearance between the respective tapered surfaces becomes relatively large, and the window member 61 is fixed. However, there has been a problem that the position is easily displaced by vibration or the like so that the tapered surface 63 of the window member rides on the tapered surface 64 of the window opening.

An object of the present invention is to provide a magnetic tape cassette capable of preventing or reducing a displacement due to vibration or the like before fixing a window member to a window opening.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing surface for fixing an inner edge portion of a window member provided in a cassette case accommodating a magnetic tape by bringing an outer edge portion of the window member into contact with the inner edge portion. A magnetic tape cassette having a tapered surface of a window opening formed continuously with the fixing surface and defining an obtuse angle space in a sectional view, and fixing the window member at a predetermined position of the window opening. A window member tapered surface formed continuously with a fixing surface of the window member with the window opening at an outer edge portion thereof and inclined at a predetermined angle of 90 ° or less toward the inside of the window opening in a sectional view. This is achieved by a magnetic tape cassette.

[0016]

In the magnetic tape cassette according to the present invention,
In fixing the window member to the window opening, when positioning the window member at a predetermined position of the window opening, the window member taper surface and the window opening taper surface are respectively inclined to opposite sides in cross section. And the inclination angle is 90 ° or less, the contact between the corner between the fixing surface of the window member and the tapered surface of the window member, and the tapered surface of the window opening,
The state is similar to the line contact.

With this arrangement, when the positional deviation is about to occur, the load of the window member is concentrated on the position, and the corner between the fixing surface of the window member and the tapered surface of the window member is formed in the tapered portion of the window opening. The force that cuts into the surface acts. In addition, since the tapered surface of the window member and the tapered surface of the window opening do not face each other, the portion that comes into contact when the two are going to be displaced is reduced, and the window member is less guided by the window opening tapered surface. Become. Therefore, displacement of the window member due to vibration or the like is prevented or reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged perspective view of a main portion of a window opening and a window member of an upper cassette half of a magnetic tape cassette according to an embodiment of the present invention, and FIG.
It is -A sectional drawing.

Referring to FIG. 1 and FIG. 2, a window opening 11 for checking the remaining amount of the tape or the like is provided at a predetermined position in the upper cassette half 10 of the magnetic tape cassette. The window member 20 made of a transparent or translucent material is fixed to the window opening 11 by welding at a predetermined position with its outer edge abutting on the inner edge of the window opening 11.

That is, the window member 20 is brought into contact with a fixing surface 21 formed substantially horizontally in FIG. 2 on the outer edge portion and a fixing surface 12 formed substantially horizontally in FIG. 2 on the inner edge portion of the window opening 11.
Further, the positioning rib 13 projecting from the inner edge of the window opening 11 is loosely fitted into the positioning notch 22, and the fixing surface 21 of the window member 20 is positioned in a predetermined position.
Is welded. Thereby, the window member 20 is fixed at a predetermined position of the window opening 11.

A plurality of positioning notches 22 are provided at predetermined positions on the outer edge of the window member 20. A window member tapered surface 23 is provided on each of the positioning notches 22 on the side surface on the center side of the window member 20 so as to be continuous with the fixing surface 21 of the outer edge portion of the window member 20 with the window opening 11. 90 ° from the thickness direction of the half 10 (vertical direction in FIG. 2) toward the inside of the cross-section window opening 11 (left side in FIG. 2).
It is formed at a predetermined angle θ1 below. Tilt angle θ
1 is preferably θ1 = 0.5 ° to 5 °.

At the tip of the positioning rib 13 (inside the window opening 11) at the inner edge of the window opening 11, a window opening tapered surface 14 is fixed to the window member 20 at the positioning rib 13. Continuing from the surface 12, the upper cassette half 10 is inclined at a predetermined angle θ2 of 90 ° or less from the thickness direction of the upper cassette half 10 (vertical direction in FIG. 2) toward the outside of the cross-sectional view window opening 11 (right side in FIG. 2). It is formed. Thereby, a space having an obtuse angle is defined in a sectional view.

The tapered surface 23 of the window member and the tapered surface 14 of the window opening are located inside and outside the window opening 11 in a sectional view from the thickness direction of the upper cassette half 10, that is, on the sides opposite to each other in the sectional view (the left and right in FIG. 2). (In both sides) and the inclination angles θ1 and θ2 are both 90 ° or less, so that the window member 20 can be positioned in the window opening 11 before welding. Notch 22
Outer edge (right end in FIG. 2) of fixing surface 21 of window and window opening 1
The contact state between the positioning rib 13 and the fixing surface 12 is as follows.
The state is similar to the line contact.

The operation of this embodiment will be described. Window member 20
When fixing the window member 20 to the window opening 11 by welding, when positioning the window member 20 at a predetermined position of the window opening 11, the positioning notch 22 of the window member 20 is used for positioning the window opening 11. The rib 13 is fitted. At this time, the window member taper surface 23 and the window opening taper surface 14 are each inclined to the side opposite to the cross-sectional view, and the inclination angles θ1 and θ2 are both 90 ° or less.
The contact state between the outer edge (right end in FIG. 2) of the fixing surface 21 of the positioning notch 22 of the window member 20 and the fixing surface 12 of the positioning rib 13 of the window opening 11 is close to line contact. State.

Thus, the window member 20 is moved to the window opening 11.
When the position of the window member 20 is shifted, the load of the window member 20 concentrates on the corresponding portion of the window opening tapered surface 14 and the window member 2
The angle between the fixing surface 21 of the zero and the tapered surface 23 of the window member is
Since a force acts so as to bite into the window opening tapered surface 14, misalignment is prevented or reduced. In addition, since the window member tapered surface 23 and the window opening tapered surface 14 do not face each other, the window member 20 is not
The number of contact portions that are guided in contact with the window opening tapered surface 14 is small, and it is possible to prevent or reduce the window member 20 from being guided by the window opening tapered surface 14. Therefore, displacement of the window member 20 due to vibration or the like is prevented or reduced,
Good positioning of the window member 20 is ensured.

As described above, according to the above-described embodiment, the tapered surface 23 of the window member and the tapered surface 14 of the window opening are formed inside and outside the window opening 11 in a sectional view from the thickness direction of the upper cassette half 10, that is, respectively. The cross section is inclined to the opposite side, and the inclination angles θ1 and θ2 are both 90.
° or less. Therefore, the window member 20 is connected to the window opening 1.
1, the window member 20 is fixed to the window opening 11.
When positioning at a predetermined position, the window member 2
The displacement of 0 can be prevented or reduced. Thereby, good positioning of the window member 20 can be ensured.

In the above-described embodiment, the positioning ribs 13 project from the inner edge of the window opening 11 and the positioning notches 22 are provided on the outer edge of the window member 20. Although the magnetic tape cassette having the window member tapered surface 23 on the side surface on the center side of the window member 20 and the window opening tapered surface 14 at the tip of each positioning rib 13 has been described, the present invention is not limited to such a configuration. Absent.

That is, the positioning notch 22 may not be provided at the outer edge of the window member 20. Also, the positioning notch 22 is not provided at the outer edge of the window member 20, and the positioning rib 13 is not protruded at the inner edge of the window opening 11. It is formed over the entire periphery of the inner edge of the portion 11, and the window member tapered surface 2
3 may be formed over the entire outer periphery of the window member 20.

[0029]

As described above, according to the present invention, a predetermined angle of 90 ° or less toward the inside of the window opening in a cross-sectional view is continuous to the surface of the outer edge of the window member fixed to the window opening. The tapered surface of the window member inclined at an angle of? Therefore, it is possible to prevent or reduce the displacement due to vibration or the like before fixing the window member to the window opening. Thereby, good positioning of the window member can be ensured.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view of a main portion of a window opening and a window member of an upper cassette half of a magnetic tape cassette according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an exploded perspective view of a conventional magnetic tape cassette.

4 is a schematic perspective view showing a window opening and a window member of an upper cassette half of the magnetic tape cassette of FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 4;

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Upper cassette half (cassette case) 11 Window opening 12 Fixing surface formed on inner edge of window opening 13 Positioning rib 14 Window opening tapered surface 20 Window member 21 Formed on outer edge of window member Fixed surface 22 positioning notch 23 window member tapered surface 25 welding rib

Claims (1)

[Claims] 1. A fixing surface formed by contacting an outer edge of a window member with an inner edge of a window opening provided in a cassette case accommodating a magnetic tape and fixing the window member, and a fixing surface formed continuously with the fixing surface. A magnetic tape cassette having a window opening tapering surface defining an obtuse angle space in a cross-sectional view, and fixing the window member at a predetermined position of the window opening; It is formed continuously to the fixing surface with the opening, and faces 90
A magnetic tape cassette comprising a window member tapered surface inclined at a predetermined angle of not more than °.