JP2001118354A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape cassette capable of reliably preventing a window member from coming off with a simple structure. SOLUTION: In this magnetic tape cassette which has a sticking face 8 at the circumferential part, makes the welded rib 9 of a window member 3 forming the rib 9 on the face 8 abut on a sticking face 4 formed at the circumference of an opening part 2 for the window member of a half 1 and welds the member 3 to the face 4 of the half 1 by ultrasonic vibrations, the rib 9 formed on the face 8 of the member 3 is also provided at the corner part A of the member 3.

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, and more particularly to a magnetic tape cassette characterized by a window frame structure of a magnetic tape cassette having a window member for confirming a winding amount of a magnetic tape. .

[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. .

Referring to FIG. 5, conventionally, for example, DVC
(Digital Video Cassette) The magnetic tape cassette 50 used for the
1 and 52, and upper and lower halves 51 and 52 thereof.
Are combined with each other and fastened by a plurality of screws 54. In the cassette case, a pair of tape reels 53, 53 formed by welding an upper flange and a hub integrally formed with a lower flange are rotatable with the magnetic tape 57 wound thereon. Supported.

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

[0005] Also, the rear end side of the lower half 52 (back side in the figure).
The tape reel lock member 58 having the tape reel locking arm 58a is assembled to the tape reel lock member 58. 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 engaging teeth 53a formed on the outer periphery of the lower flange of each tape reel 53. Prevent 53 accidental rotation. This prevents the magnetic tape 57 from loosening.

A reel biasing leaf spring 63 is attached to the top plate 51a of the upper half 51 for each tape reel 53. Each reel urging leaf spring 63 is supported by the upper half 51 in a cantilever manner.
Energize to two sides. Furthermore, on the front end side of the upper half 51,
In order to obtain dustproofness that can withstand outdoor use, the lower half 5
An outer lid 60, a top lid 61, and an inner lid 62, which cover the front and back surfaces of the magnetic tape 57 stretched between the pair of two tape guides 55, are respectively attached to be openable and closable.

In such a magnetic tape cassette 50,
On the top plate 51a of the upper half 51, one side of the top plate 51a in the longitudinal direction (the right side in the drawing) is used to check the winding amount (remaining amount) of the magnetic tape 57 on the tape reel 53. An opening 65 extending in the lateral direction is formed, and a transparent window member 64 is attached so as to close the opening 65.

As shown in FIG. 6, the substantially hexagonal window member 64 has a plurality of welding ribs 66 on a fixing surface 64a formed on the periphery. On the other hand, the periphery of the opening 65 has a fixing surface 65 a for fixing the window member 64.
The thickness of the fixing surface 65a is formed to be thinner than that of the top plate 51a, and the fixing surface 65a is continuous with the top plate 51a via the inclined surface 67. Further, on the periphery of the opening 65, positioning ribs 68 are provided upright on each side of the opening 65.

In order to attach such a window member 64 to the upper half 51, first, the window member 64 is guided by the positioning rib 68 to cover the opening 65, and the welding rib 6 of the window member 64 is formed.
6 is placed on the fixing surface 65 a on the periphery of the window member opening 65. Next, in a state where the window member 64 is pressed against the fixing surface 65a of the peripheral edge of the window member opening 65, as shown in FIG.
Is welded to the fixing surface 65a.

[0010]

In the above-described conventional magnetic tape cassette 50, when an external force acts on the window member 64, the external force acts intensively on the corner portion A. As a result, the window member 64 may come off from the corner portion A where the concentrated load acts. If the window member 64 is peeled off, dust may enter. Therefore, it is necessary to prevent the peeling off from the viewpoint of dust resistance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic tape cassette which has been made in view of the above situation, and which can reliably prevent a window member from peeling off with a simple structure.

[0012]

In order to solve the above problems, the present inventor conducted various tests by changing the shape of the periphery of the window member and the opening of the half window member opening, and as a result, it was found that the structure was simple. Have found a magnetic tape cassette that can reliably prevent the window member from peeling off. That is, in the magnetic tape cassette of the present invention, a fixing surface is formed on a peripheral portion of the window member having a fixing surface on which the welding rib is formed, and the fixing rib is formed on the peripheral edge of the half window member opening. And a welding rib formed on the fixing surface of the window member is also provided at a corner portion of the window member in a magnetic tape cassette in which the window member is welded to the fixing surface of the half by ultrasonic vibration. ing. In other words, conventionally, welding ribs have not been provided at the corners due to molding reasons and problems such as space, but by newly arranging welding ribs at the corners according to the present invention, the present invention It has been found that the above object can be achieved.

Here, the corner portion refers to a range in which the extension portions of the fixing surfaces that meet each other overlap with each other. Further, as the welding rib provided at this corner portion, the end of the welding rib is defined as the inside of the corner portion. The weld ribs may be formed independently at the corners. The shape of the welding rib is not particularly limited, but a simple hemispherical projection is
Although it depends on its size, since it is welded at points, the welding power is weak. For this reason, preferred shapes of the welding rib include a linear shape, an L-shaped shape, and a curved shape that matches the outer peripheral curve of the corner portion. Naturally, in order to ensure a sufficient welding force, it is necessary to increase the range of the corner portion, in other words, the range in which the welding rib is provided.

According to the magnetic tape cassette of the present invention, the welding rib at the corner of the window member is welded to the fixing surface formed on the peripheral edge of the half window member opening. Therefore, since the window member is fixed also at the corner portion, abnormal deformation due to concentrated load or the like at the corner portion of the window member is prevented, and peeling of the window member is prevented.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a magnetic tape cassette according to the present invention will be described in detail with reference to the accompanying drawings. FIG.
FIG. 2 is a perspective view showing an upper half and a window member near a window member opening of a magnetic tape cassette according to an embodiment of the present invention. FIG. 2 is an enlarged plan view showing a corner portion of the window member. FIGS. 3 and 4 are plan views showing another embodiment of the window member.

In this magnetic tape cassette, the upper half 1
A fixing surface 4 for fixing the window member 3 is formed on the periphery of the window member opening 2 formed in the above. This fixing surface 4
Is a portion to which the window member 3 is fixed.
It is formed thinner than that of the top plate 5 of the upper half 1.
The fixing surface 4 is connected to one surface (back surface) 5 a of the top plate 5 via the slope 6. On the periphery of the opening 2, positioning ribs 7 are provided upright on each side of the opening 2.

On the other hand, the window member 3 has discontinuous welding ribs 9 over the entire periphery of the fixing surface 8 formed at the peripheral edge. In the window member 3 shown in FIG. The end of the welding rib 9a formed closest to the corner portion A of the fixing surface 8 forming the side extends to the inside of the corner portion A as shown in an enlarged manner in FIG. In addition, corner part A
Is the range in which the extended portions of the respective fixing surfaces 8 and 8 that meet each other overlap (the range between the imaginary line and the outer peripheral curve R).
Say.

In the magnetic tape cassette constructed as described above, the window member 3 is guided by the positioning rib 7 to cover the opening 2, and the welding ribs 9 and 9a of the window member 3 are fixed to the fixing surface 4 on the peripheral edge of the opening 2. To be placed. Next, the welding ribs 9 and 9a are welded to the fixing surface 4 by ultrasonic vibration or the like while the window member 3 is pressed against the fixing surface 4 on the peripheral edge of the opening 2. Therefore, the window member 3 and the fixing surface 4 are firmly fixed by the welding rib 9a also at the corner portion A, so that the corner portion A does not peel off from the corner portion A where a concentrated load acts.

FIGS. 3 and 4 show another embodiment of the window member in the magnetic tape cassette according to the present invention. In the window member 3 shown in FIG. The end portion of the welding rib 9b formed closest to the corner portion A is extended to the inside of the corner portion A in the fixing surface 8 constituting the above.

On the other hand, in the window member 3 shown in FIG. 4, the welding rib 9c is formed independently at the corner portion A. Rib 9
The shape of c is a straight line (approximately 45 ° with respect to the imaginary line S) shown in FIG. 4 (a), and approximately L shown in FIG. 4 (b).
Various shapes such as a letter shape and an arc shape matching the outer peripheral curve R shown in FIG. 4C can be adopted.

In the above embodiment, only the peripheral portion of the window member opening 2 and the window member 3 in the upper half 1 are shown, but the other parts and the lower half are the same as those in the prior art, and are shown and described. Is omitted.

The present invention is not limited to the above-described embodiment, but can be appropriately changed and improved. For example, the application target of the present invention is not limited to a digital video cassette, but can be applied to various magnetic tape cassettes having a window member. Further, in the above embodiment, in the hexagonal window member 3, the fixing surface 8 on which the welding rib 9 a is provided and the fixing surface 8 on which the welding rib 9 b is provided meet at the corner portion A. Although the present invention is applied, the present invention may be applied to a corner portion where other fixing surfaces 8 meet.

[0023]

As described above, in the magnetic tape cassette of the present invention, the welding rib of the window member having the fixing surface on the peripheral edge and the welding rib formed on the fixing surface is used as the corner portion of the window member. Is also provided. Therefore, the welding rib is welded to the fixing surface formed on the periphery of the half window member opening, and the window member is also fixed at the corner portion. Deformation is prevented, and peeling of the window member is prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an upper half and a window member in the vicinity of an opening for a window member of a magnetic tape cassette according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view showing a corner portion of a window member of the magnetic tape cassette shown in FIG.

FIG. 3 is a perspective view showing another embodiment of the window member according to the present invention.

FIG. 4 is a perspective view showing still another embodiment of the window member according to the present invention.

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

FIG. 6 is an enlarged perspective view showing a main part of the magnetic tape cassette shown in FIG. 5;

FIG. 7 is a cross-sectional view showing a state where the window member of the magnetic tape cassette shown in FIG. 6 is installed in the window member opening;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper half 2 Window member opening 3 Window member 4 Fixing surface 5 Top plate 5a Surface (back surface) 6 Slope 7 Positioning rib 8 Fixing surface 9, 9a, 9b, 9c Welding rib A Corner

Claims (1)

[Claims] 1. A welding member having a fixing surface on a peripheral edge thereof and having a welding rib formed on the fixing surface, wherein the welding rib of the window member is brought into contact with a fixing surface formed on a peripheral edge of a half window member opening; A magnetic tape cassette for welding the window member to the fixing surface of the half by ultrasonic vibration, wherein a welding rib formed on the fixing surface of the window member is also provided at a corner of the window member. Magnetic tape cassette.