JP2000173227A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape cassette which allows the easy placement of a window member in an exact position on a flat plate of an upper cassette half at the time of mounting the window member to this flat plate. SOLUTION: This magnetic tape cassette is formed with an opening at the flat plate 25 on the upper cassette half 11 and is mounted with the window member 64 which is a separate body so as to close the opening. The inside surface of the peripheral wall 26 of the upper cassette half 11 is provided with a positioning rib 27 extending to a height above the half the peripheral wall height from the base part of the peripheral wall. The positioning rib 27 executes the positioning of the window member 64 by coming into contact with part of the peripheral edge of the window member when the window member 64 is placed on the flat plate 25.

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 having a characteristic on a peripheral wall of an upper cassette half.

[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. 4 is an exploded perspective view of a DVC which is an example of a magnetic tape cassette. Magnetic tape cassette 50
Is provided with an upper cassette half 51 and a lower cassette half 52 each having a flat plate and a peripheral wall. The upper and lower cassette halves 51 and 52 are combined and fastened by a plurality of screws 54. In the lower cassette half 52, a pair of tape reels 53 each formed by welding an upper flange and a lower flange are rotatably supported with a magnetic tape 57 wound thereon.

A tape guide 55 is provided on both sides of an opening 56 on the front end side (front side in the figure) of the lower cassette half 52.
Is provided. Each tape guide 55 guides the magnetic tape 57 sent out from one tape reel 53 and wound on the other tape reel, and passes the magnetic tape at a predetermined position in the opening 56.

[0005] A tape reel lock member 58 having a tape reel locking arm 58a is mounted on the rear end side (the rear side in the figure) of the lower cassette half 52. The tape reel lock member 58 is urged by the compression coil spring 59 so that the tape reel locking arm 58a is engaged with the engagement teeth 5 formed on the outer periphery of the lower flange of each tape reel 53.
3a to prevent unexpected rotation of each tape reel 53. This prevents the magnetic tape 57 from loosening.

On the front end side of the upper cassette half 51, the front and back surfaces of a magnetic tape 75 stretched between a pair of tape guides 55 of the lower cassette half 52 are provided in order to obtain dustproofness that can withstand outdoor use. Cover, outer lid 6
0, the upper lid 61 and the inner lid 62 are respectively attached to be freely opened and closed. A reel biasing leaf spring 63 is attached to the flat plate of the upper cassette half 51 for each tape reel 53. Each reel urging leaf spring 63 is cantilevered by the upper cassette half 51 and urges the corresponding tape reel 53 toward the lower cassette half 52.

On the flat plate of the upper cassette half 51,
An opening extending in the transverse direction of the flat plate is formed on one side in the longitudinal direction of the flat plate (right side in the figure) so that the winding amount of the magnetic tape 57 on the tape reel 53 can be checked. , A transparent window member 64 is attached. Usually, the window member 64 is welded to the flat plate of the upper cassette half 51.

In FIG. 5, the window member 64 is connected to the upper cassette half 5.
A state in which a window member 64 is placed on a lithographic plate so as to close an opening provided in the flat plate when welding to one flat plate is shown. As shown in the figure, this operation is usually performed manually. The flat plate 65 of the upper cassette half 51 is formed such that a peripheral portion of an opening (hereinafter, referred to as a “window support surface”) 65a of the flat plate inner surface (upper surface in the drawing) is recessed from other portions of the flat plate inner surface. . When the window member 64 is placed on the flat plate 65, the window support surface 65a supports the periphery of the window member 64. Here, the side surface 65b connecting the inner surface of the flat plate and the window support surface 65a is formed as a tapered surface as an introduction surface for guiding the window member 64 to the window support surface 65a.

FIG. 6 is a sectional view taken along the line YY when the window member 64 is placed on the flat plate 65 in FIG. As shown in FIG. 6, a concave portion 66a for attaching a label is provided on the outer surface of the peripheral wall (rear end wall) 66 of the upper cassette half 51. A window member 6 is provided on the inner surface of the base of the peripheral wall 66.
4 are arranged close to each other. The window member 64 is a portion (hereinafter, referred to as a “supported surface”) 64 a of the outer surface of the window member (the lower surface in the drawing) supported by the window support surface 65 a of the flat plate 65.
Are formed in a plane that is more concave than the other portion of the outer surface of the window member. Further, when the window member 64 is placed on the flat plate 65, the supported surface 64a contacts the window support surface 65a of the flat plate.
A welding rib 64b having a triangular cross section protrudes.

FIG. 7 shows another upper cassette half 151 conventionally used. The flat plate 165 of the upper cassette half 151 has a window support surface 165a similarly to the flat plate 65 of the above-described upper cassette half 51, and a side surface 165b connecting the flat plate inner surface and the window support surface 165a is formed as a tapered surface. . Then, the flat plate 1 is provided on the inner side of the base of the peripheral wall 166.
Positioning rib 16 having a side surface perpendicular to the inner surface
7 are provided. Such upper cassette half 15
In (1), by forming the side surfaces of the positioning ribs 167 with high precision, the window member 64 can be accurately positioned on the flat plate 165 without impairing the mountability.

[0011]

In order to weld the window member 64 to the flat plate 65 of the upper cassette half 51 shown in FIG. 6, the window member 64 is manually placed on the flat plate 65 and the window member 64 is removed from the window member. When releasing the hand, the window member 64 may adhere to the hand due to static electricity or the like as shown by a two-dot chain line in FIG. When the window member 64 is released from the hand in the air, the window member 64 may not be placed at an accurate position on the flat plate 65. For example, as shown by a solid line in FIG. Sometimes got on the inner surface of the flat plate.
As described above, the operation of placing the window member 64 at an accurate position on the flat plate 65 is extremely complicated, and improvement has been demanded.

The upper cassette half 15 shown in FIG.
Similarly, when the window member 64 is to be placed on the first flat plate 165, when the hand is to be released from the window member 64, FIG.
As shown by the two-dot chain line, the window member 64 sometimes adheres to the hand and rises from the flat plate 165 in some cases. When the window member 164 is released from the hand in the air, for example, the supported surface 64a of the window member may ride on the upper surface of the positioning rib 167 as shown by a solid line in FIG.

The present invention has been made based on the above background, and an object thereof is to easily attach a window member to an accurate position on a flat plate when mounting the window member on the flat plate of the upper cassette half. An object of the present invention is to provide a magnetic tape cassette that can be mounted.

[0014]

An object of the present invention is to provide an upper cassette half and a lower cassette half, each having a flat plate provided with a peripheral wall and an opening, and having a separate window member for closing the opening. In a magnetic tape cassette configured to rotatably support a tape reel wound with a magnetic tape in a cassette case formed by combining the above, the inner surface of the peripheral wall is at least half the height of the peripheral wall from the base of the peripheral wall. And a positioning rib is provided to abut on a part of the periphery of the window member.

If the positioning rib does not reach half of the height of the peripheral wall, the window member adheres to the hand when the hand is released from the window member and is easily lifted up. When released, the window member may not be placed at an accurate position on the flat plate.

According to the magnetic tape cassette configured as described above, when attaching the window member to the flat plate of the upper cassette half, the window member can be easily placed at an accurate position on the flat plate.

In the case where a window member is attached to the upper cassette half of the magnetic tape cassette having the above structure,
When placing the window member on the flat plate and releasing the hand from the window member, a finger or the like in contact with the window member is pulled on the window member by pulling the hand toward the peripheral wall provided with the positioning rib. It is preferable to slide with. This prevents the window member from rising from the flat plate. A plurality of positioning ribs may be provided on the peripheral wall of the upper cassette half, but even one positioning rib can sufficiently function.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. 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 shows a state in which a window member is placed on a flat plate of an upper cassette half in the embodiment of the present invention so as to close an opening formed in the flat plate when the window member is welded to the flat plate. Show. The flat plate 25 of the upper cassette half 11 has a window support surface 25a formed at the periphery of the opening. When the window member 64 is placed on the flat plate 25, the window support surface 25a To support. Here, most of the side surface 25b connecting the inner surface of the flat plate and the window support surface 25a is formed as a tapered surface as an introduction surface, but the portion of the side surface 25b extending in the short direction of the upper cassette half 11 is formed. A part is formed as a curved convex surface 25c that is perpendicular to the inner surface of the flat plate and sandwiches the window member and positions the window member at an accurate position.

A positioning rib 27 is provided on the inner surface of the peripheral wall (rear end wall) 26 of the upper cassette half 11 so as to extend from the base of the peripheral wall to at least half the height of the peripheral wall. The shape of the positioning rib 27 is not particularly limited, and a triangular shape, another polygonal shape, a semicircular shape, or the like can be employed.

FIG. 2 is a sectional view taken along the line YY when the window member 64 is placed on the flat plate 25 in FIG. As shown in FIG. 2, a concave portion 26a for attaching a label is provided on the outer surface of the peripheral wall (rear end wall) 26 of the upper cassette half 11. On the inner surface side of the base of the peripheral wall 26, a part of the peripheral edge of the window member 64 is in contact with the side surface of the positioning rib 27, and the window member 64 is arranged at an accurate position on the flat plate 25. The side surface of the positioning rib 27 is formed in a plane perpendicular to the inner surface of the flat plate. Here, the difference H between the height of the peripheral wall 26 and the height of the positioning rib 27 is set to 0.5 mm.

When releasing the hand from the window member 64 arranged at the correct position, the hand is pulled toward the peripheral wall 26 on which the positioning rib 27 is provided in the direction of arrow A in the figure, whereby the window member 6 is released.
It is preferable to slide a finger or the like in contact with 4 on the window member 64. By doing so, the edge of the peripheral edge of the window member 64 can be kept in contact with the positioning rib 27, and the edge of the edge can be prevented from floating from the flat plate 25.

As shown by the two-dot chain line in FIG. 3, even when the window member 64 arranged at an accurate position is raised in the air, the supported surface 64a of the window member 64 There is no chance of running on the upper surface 27a.
Here, since the edge of the peripheral edge of the raised window member 64 is in contact with the side surface of the positioning rib 27, the hand is pulled toward the peripheral wall 26 on which the positioning rib 27 is provided in the direction of arrow B in the figure, and By sliding a finger or the like in contact with the window member 64 on the window member 64, the window member 64 can be released from the hand. The window member 64 released from the hand is positioned on the positioning rib 2.
Guided by the side of 7, it is repositioned at the exact position on the plate 25, shown in solid lines in FIG.

According to the magnetic tape cassette having the above structure, the window member 64 is attached to the flat plate 25 of the upper cassette half 11.
In welding, the window member 64 can be easily placed at an accurate position on the flat plate 25. Also, as compared with the upper cassette half of the conventional magnetic tape cassette, the only difference is that one narrow positioning rib 27 is provided on the peripheral wall, so that the molding die structure does not become complicated. Further, molding failure such as sink marks does not occur on the outer surface of the peripheral wall.

It should be noted that the magnetic tape cassette of the present invention is not limited to the above-described embodiment, and appropriate modifications and improvements can be made. For example, in the above-described embodiment, the positioning rib 27 is provided on the rear end wall 26 of the upper cassette half 11, but the positioning rib may be provided on the side wall of the upper cassette half depending on the shape of the window member and the opening. Good. In the above-described embodiment, the window member 64 is manually placed on the flat plate 25 of the upper cassette half 11, but this operation may be automated.

[0026]

As described in detail above, in the magnetic tape cassette of the present invention, the inner peripheral surface of the upper cassette half extends from the base of the peripheral wall to a height of at least half the height of the peripheral wall, and the peripheral edge of the window member. Since the positioning rib is provided so as to contact a part of the upper cassette half, the window member can be easily placed at an accurate position on the flat plate when the window member is mounted on the flat plate of the upper cassette half.

[Brief description of the drawings]

FIG. 1 is a diagram showing an upper cassette half in an embodiment of the present invention.

FIG. 2 is a sectional view taken along line YY in FIG.

FIG. 3 is a diagram showing the operation of the embodiment shown in FIG. 2;

FIG. 4 is an exploded perspective view showing a conventional magnetic tape cassette.

FIG. 5 is a diagram showing an upper cassette half of a conventional magnetic tape cassette.

FIG. 6 is a sectional view taken along line YY in FIG. 5;

FIG. 7 is a view showing another conventional upper cassette half.

FIG. 8 is a view showing the operation of a conventional upper cassette half.

FIG. 9 is a view showing the operation of a conventional upper cassette half.

[Explanation of symbols]

 11 Upper cassette half 25 Flat plate 26 Peripheral wall 27 Positioning rib 64 Window member

Claims (1)

[Claims] A magnetic tape is provided in a cassette case comprising a combination of an upper cassette half and a lower cassette half having a flat plate provided with a peripheral wall and an opening and having a separate window member closing the opening. A magnetic tape cassette configured to rotatably support a wound tape reel, the inner surface of the peripheral wall extending from a base of the peripheral wall to a height of half or more of a height of the peripheral wall, and a peripheral edge of the window member being one end of the peripheral edge of the window member. A magnetic tape cassette provided with a positioning rib for abutting on a portion.