JP2000132941A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable maintaining of quality through elimination of hitting mark by providing a projected part to a reel spring to form a gap at the time of extracting only one reel spring from among a plurality of springs, providing a setting guide to a cassette case for regulating the fixed position of the fixing end of the reel spring and providing the reel spring in such a manner that the projected part is not projected from the setting guide. SOLUTION: A reel spring 12 is regulated in one by one with a setting guide 18 of a reel spring setting means 16 and is fixed through engagement of half boss with a boss hole 22 provided at the reel spring setting means 16. The upper half boss fixing the reel spring 12 is broken through fusing from the upper side using an ultrasonic welder and thereby the reel spring 12 is fixed. The bottom surface 19 of the reel spring setting means is recessed rather than the external surface 21 of the setting guide 18. Therefore, even if the magnetic cassette tape is fallen on the floor to give an extensive shock thereto, the projected part 20 of the reel spring 12 made of metal material is in contact with the flange of reel not to generate the hitting mark and the tape cassette is never broken.

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 which winds a magnetic tape and presses a rotatably mounted reel in the axial direction of rotation of the reel.

[0002]

2. Description of the Related Art Conventionally, in audio equipment and video equipment, a magnetic tape cassette is used which is wound around a pair of reels so that a magnetic tape can run in a cassette case for recording and reproduction. These magnetic tape cassettes are provided with a reel spring in a cassette case so that the pair of reels around which the magnetic tape is wound can smoothly move the tape without moving in the rotating axial direction. Is pressed in one direction of the cassette case.

For example, in a VHS type magnetic tape cassette, this reel spring is a metal plate-like spring having arms symmetrically extending from the fixed portion at the center of the reel spring and having appropriately curved and projecting. The portion is fixed at the center of the cartridge and presses a pair of reels simultaneously. In recent years, with the increase in density of magnetic tapes and the miniaturization of magnetic tape cassettes, a reel spring that presses the above-mentioned pair of reels has been replaced, and unlike an 8 mm cassette or DDS cassette, installation space is not so much required and cost is reduced. Also, a pair of inexpensive flat plate-shaped reel springs is used.

FIG. 4 shows a part of a digital video cassette (DVC) having such a reel spring. As shown in FIG. 4, the digital video cassette 30 has an upper half 32 of a cassette case, a pair of reels 34 wound around a magnetic tape and rotatably mounted, and a reel spring 36 simplified to a substantially rectangular flat plate shape. In addition, the lower half which is a part of the cassette case,
It is composed of an outer lid, an upper lid, an inner lid, various springs, and the like that constitute a lid that covers the opening in front of the cassette case. Here, the reel spring 36 simplified to a flat plate shape is made of aluminum or SU as a material.
5 (a) or 5 (a).
As shown in (b), a projection 38 is provided.

The projection 38 is provided by a reel spring 38.
Is supplied to the upper half 32 of the cassette case to improve the supply efficiency. The reel spring 36
As shown in FIG. 6, a plurality of sheets are stacked and fixed on a supply rod 52 erected on the reel spring supply device 50 and supplied one by one to the cassette case by suction means such as a suction pad. By pressing the end of the reel spring 38 in the direction A, as shown in FIG. 6, the end opposite to the pressed side is lifted up in the direction B to form a gap by the action of the projection 38, as shown in FIG. The reel springs 38 are separated one by one, and as a result, the reel springs 38 are easily taken out one by one by a suction means such as a suction pad or the like and supplied to the cassette case. In this way, even if a plurality of reel springs 36 come into close contact with each other due to the flash generated during the manufacture of the reel springs 36 and the residual oil remaining in the cleaning process remaining on the reel springs 36, the reel springs 36 can be supplied one by one. .

The left and right sides of the reel spring 36 supplied to the reel spring installation section 40 are regulated by the installation guide 44 of the reel spring installation section 40, and a boss hole 46 provided on the reel spring 36 is provided in the reel spring installation section 40. The upper half boss 42 is hooked and locked on the
The reel spring 36 is attached by welding using an ultrasonic welder or the like.

[0007]

However, the projection 38 on the fixed reel spring 36 is restricted below the outer peripheral portion of the flange 35 as shown in FIG. Because it has to be located in
There has been a problem that the protrusion 36 of the reel spring 36 attached to the magnetic tape cassette easily causes damage to the flange 35 which is a resin molded product. That is, as shown in FIG. 7, the reel spring 36 presses the flange 35 of the reel 34 in one direction to enable stable winding of the magnetic tape. However, if the magnetic tape cassette is dropped and subjected to an impact, the projection 38 of the reel spring 36 made of a metal material may come into contact with the flange 35 in the cassette to form a sharp dent. there were. In such a case, the dent of the flange 35 can be visually recognized through the window 48 of the cassette case 30, which is not preferable in appearance. Also, the resin shavings of the flange 35 shaved by the dents may adhere to the surface of the magnetic tape or the like, causing noise during reproduction and deteriorating the performance of the magnetic tape. In the worst case, the protrusion 3
8 could hit the flange 35 and damage the flange 35.

It is conceivable to provide the projection 38 of the reel spring 36 near the boss hole 46 so that the projection 38 does not come into contact with the flange 35. However, in a miniaturized magnetic tape cassette such as a digital video cassette, As shown in FIG. 7, the outer periphery of the flange 35 is
There is no position where the projection 38 does not contact the flange 35 when the magnetic tape cassette is dropped and subjected to an impact. Therefore, the reel spring 3
Even if the projection 38 of No. 6 is provided in the vicinity of the boss hole 46, the dent cannot be eliminated. In addition, the protrusion 38 is formed by the flange 35
It has also been considered that the height of the protrusion 38 is reduced so as not to come into contact with the protrusion. However, when the projection height is reduced, the reel spring supply device often supplies the reel spring installation unit 40 with the plurality of reel springs 36 in close contact with each other, and the efficiency of the supply operation is extremely deteriorated. Further, when the boss hole 46 of the reel spring 36 is hooked on the upper half boss 42 and locked, the height of the ridge (mountain) of the installation guide 44 for regulating the reel spring 36 and positioning it at a predetermined position may be increased. It is conceivable that increasing the height of the ridge of the installation guide 44 is difficult in view of the limited narrow space inside the upper half 32, and the height of the ridge of the installation guide 44 cannot be increased.

In view of the above, the present invention solves the above-mentioned problems, and when assembling a magnetic tape cassette such as a digital video cassette, a plurality of reel springs are securely supplied one by one without being supplied to a cassette case in a state of being in close contact. ,on the other hand,
It is an object of the present invention to provide a magnetic tape cassette that does not produce dents on the reel flange even when the magnetic tape cassette is dropped and a strong impact is applied, thereby maintaining excellent quality in appearance and performance of the magnetic tape. And

[0010]

Accordingly, in order to achieve the above object, the present invention provides a cassette case, a pair of reels rotatably mounted by winding a magnetic tape in the cassette case, A fixing portion attached to a case to form a fixed end, an arm portion for pressing the reel in the direction of its rotation axis, and a bent portion between the fixing portion and the arm portion; The reel cassette has a projection that forms a gap when one of the plurality of reel springs stacked on the fixing portion is taken out. The case has a reel spring installation part for attaching the reel spring provided with an installation guide that regulates a fixing position of a fixed end of the reel spring, and the reel spring includes:
An object of the present invention is to provide a magnetic tape cassette attached to the reel spring installation portion so that the projection does not project from the installation guide.

Here, the bottom surface of the reel spring installation portion is
Preferably, it is recessed from the cassette case surface outside the reel spring installation portion. Further, it is preferable that the reel spring is attached such that the projection faces the bottom surface of the reel spring installation portion, and the bottom surface of the reel spring installation portion preferably has a concave portion that receives the projection of the reel spring.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a magnetic tape cassette of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 shows a characteristic portion of a digital video cassette (DVC) which is an embodiment of the magnetic tape cassette of the present invention, that is, a reel spring is attached to a predetermined position of an upper half of a cassette case of the digital video cassette. It is a top view showing the state where it fell. The digital video cassette 10, like the conventional digital video cassette 30,
In addition to the reel spring 12 and the upper half 14, a pair of reels which are rotatably mounted by winding a magnetic tape, a lower half which is a part of a cassette case, and an outer which constitutes a lid which covers an opening in front of the cassette case. It consists of a lid, an upper lid, an inner lid and various springs. Various kinds of springs of the digital video cassette 10 except for a pair of reels, a lower half, an outer lid, an upper lid, an inner lid, and a reel spring 12 are substantially the same as those of the conventional digital video cassette 30. The reel spring 12 and the reel spring installation portion 16 of the upper half 14 to which the reel spring 12 is attached will be described in detail.

FIG. 2A is a side view of the reel spring 12, and FIG. 2B is a plan view of the reel spring 12. The reel spring 12 is a flat plate-shaped leaf spring for pressing the reel in the direction of its axis of rotation. The reel spring 12 presses the reel in the direction of its axis of rotation with a fixing portion 12a attached to the upper half 10 to form a fixed end. And a bent portion 12c between the fixed portion and the arm portion. Also,
Both ends of the reel spring 12 are chamfered in a triangular or arc shape as shown in FIG. The reel spring mounting portion 16 to which the reel spring 12 is attached is a pair of ridges having a certain length and arranged in parallel at certain intervals corresponding to the width of the reel spring 12.
8, a bottom surface 19 between the installation guides 18 which are in surface contact with the reel spring 12, and an upper half boss 17 which hooks and locks the reel spring 12. An installation guide 18 composed of a pair of ridges regulates a fixed position so that the mounted reel spring 12 does not shift left and right.

The position and the bending angle of the bent portion 12c of the reel spring 12 are designed in a degree of freedom which can be determined according to the urging force required for the reel spring 12, and are not particularly limited. Also, the material of the reel spring 12 is not particularly limited.
4 are mentioned. The fixing portion 12a has a boss hole 22 and is hooked and locked on an upper half boss 17 provided on a reel spring installation portion 16 of the upper half 14. Since the reel spring 12 is fixed to the upper half boss 17 together with the installation guide 18 that regulates the left and right movement of the reel spring 12, when the reel spring 12 is supplied to the reel spring installation section 16 and conveyed to the next welding step, During the transfer, the reel spring 12 does not deviate from a predetermined position, and after the transfer, the upper half boss 17 and the reel spring 12 are welded using an ultrasonic welder or the like. Also, the fixing part 1
2a has a protrusion 20 near the boss hole 22. The protrusions 20 are provided so that the conventional reel springs 38 are taken out one by one from the stacked reel springs 12 and supplied to the upper half 14 similarly to the method shown in FIG. This projection 20 is provided on the fixed portion 12a, unlike the position where the projection 38 of the conventional reel spring 36 is provided, but is overlapped similarly to the projection 38 of the conventional reel spring 36 shown in FIG. When the end of the reel spring 12 is pushed down, the end opposite to the pushed side is lifted up to form a gap and to be separated one by one.

Although the height of the projection 20 on the reel spring 12 is not limited, as described below, a dent is formed on the flange 35 of the reel, and in some cases,
The projections 20 of the reel spring 12 attached to the upper half 14 do not exceed the height of the ridge (mountain) of the installation guide for regulating the reel spring 12 so as not to damage the flange 35 of FIG. Height. However, if the height of the projections 20 is made lower than necessary, the reel springs 20 are supplied one by one when the reel springs are supplied by the reel spring supply device, and in some cases, the reel springs 12 are supplied in an overlapping state. Therefore, the protrusion 2
The height of 0 cannot be reduced unnecessarily.

The reel springs 12 are regulated one by one by an installation guide 18 of the reel spring installation section 16, and a boss hole 22 provided on the reel spring 12 is provided with an upper half boss provided on the reel spring installation section 16. It is hooked on 17 and locked. After that, the upper half boss 17 to which the reel spring 12 is fixed is melted and crushed from above using an ultrasonic welder or the like, and the reel spring 12 is fixed. Fixed part 1
The vicinity of the boss hole 2a is fixed from above by the crushed upper half boss 17 to form a fixed end.

Next, the reel spring installation portion 1 of the upper half 12
6 will be described. As described above, the reel spring installation section 16 includes the installation guide 18 which is a pair of ridges provided on the bottom surface of the upper half 12, the bottom surface 19 between the installation guide 18 which is a pair of ridges in surface contact with the reel spring 12, and the reel. And an upper half boss 17 which hooks and locks the spring 12. FIG. 2C is a cross-sectional view taken along the line AA ′ shown in FIG. 1 and shows a state in which the reel spring 12 is attached to the reel spring installation section 16, and a characteristic part of the present invention will be described. FIG. The height of the ridge (mountain) of the installation guide 18 is the same as the height of the ridge of the installation guide 44 of the conventional digital video cassette 30, but the bottom surface 19 of the reel spring installation portion 16 is shown in FIG. As described above, it is recessed from the outer surface 21 of the installation guide 18. This is because, as described above, in order to reliably supply the reel springs 12 one by one, the height of the projections 20 cannot be made smaller than necessary, and the space in the upper half 32 cannot be reduced. Therefore, since the height of the ridge of the installation guide 18 cannot be increased, the bottom surface 19 is recessed so that the projection 20 does not protrude the height of the ridge of the installation guide. As a result, even when the magnetic tape cassette is dropped and a strong impact is applied, the projection 20 of the metal reel spring 12 does not contact the flange 35 of the reel to form a sharp dent and is not damaged. Nor.

The following example can be given as an example of such a combination of the reel spring 12 and the reel spring installation section 16. As a digital video cassette tape,
Using an L type cassette of DVC-P, a reel spring 12
The length is 36mm, width 5mm, thickness 0.2mm,
The height of the projection 20 is 0.15 mm. The height of the projections 20 of 0.15 mm is a sufficient height that can be reliably supplied one by one from the reel spring supply device 50. On the other hand, the bottom surface 19 of the reel spring installation portion 16 is
Is recessed by 0.2 mm as compared with the outer surface 21 of. Since the height of the projection 20 is 0.15 mm and the plate thickness of the reel spring 12 is 0.2 mm, the height from the bottom surface 19 to which it is attached to the top of the projection 20 is 0.35 mm. The ridge height of the installation guide 18 is 0.3
mm, the height from the bottom surface 19 to the top of the ridge of the installation guide 18 is 0.5 mm. Therefore, the height of the protrusion 20 of the reel spring 12 is 0.15 mm lower than the ridge of the installation guide 18, and even when the magnetic tape cassette is dropped and a strong impact is applied, the protrusion 20 is There is no sharp dent in contact with the flange 35 and no breakage. When the bottom surface is not concave as in the conventional magnetic tape cassette 30, the height from the bottom surface to the top of the ridge of the installation guide 44 is 0.3 m.
m, while the height from the bottom surface to the apex of the projection 38 is 0.35 mm, so that the apex of the projection 38 is 0.05 mm higher than the apex of the ridge, and as a result, the projection 38 of the metal reel spring 36. Can contact the reel flange and cause sharp dents, possibly damaging it.

As described above, since the reel spring 12 is provided on the surface of the reel spring 12 with the projection 20 for forming a gap when one of the plurality of reel springs 12 is taken out, While the reel springs 12 can be separated one by one and supplied one by one, the bottom surface 19 of the reel spring installation portion 16 is recessed, so that the projection 20 of the mounted reel spring 12 is It does not exceed the height of the ridge of the installation guide 18, does not touch the flange of the reel, does not produce a sharp dent,
There is no damage.

As described above, the digital video cassette having the reel spring 12 has been described as an embodiment of the present invention. In addition, a digital video cassette using a combination of a reel spring and a reel spring installation portion having the following aspects is also described. Examples are given. Note that the digital video cassette described below is substantially the same as the digital video cassette 10, and the same portions are distinguished by adding the same numeral '. Upper half 1 of digital video cassette 10 '
FIGS. 3A and 3B show the reel spring 12 'installed on the 4'. FIG. 3A is a side view of the reel spring 12 ′, and FIG. 3B is a plan view of the reel spring 12 ′. FIG. 3C shows a cross section of the reel spring installation portion where the reel spring 12 'is installed (a cross section at the same position as the cross section of the AA' portion of the digital video cassette 10 shown in FIG. 1).

The reel spring 12 'has substantially the same shape as the reel spring 12, and differs only in the position where the projection 20' is provided. That is, as shown in FIG. 3A, the protrusion 20 ′ is different from the reel spring 12 on a surface facing the bottom surface of the reel spring installation portion 16 ′ (in the reel spring 12 ′ shown in FIG. 3A). Are provided on the lower surface side). However, even when the projection 20 ′ is provided on the surface facing the bottom surface of the reel spring installation portion 16 ′, when supplied from the reel spring supply device 50, similarly to the conventional reel spring 36, the reel spring 12 ′ is provided. Can be supplied one by one, and can be supplied one by one.

On the other hand, the bottom surface of the reel spring installation portion 16 '
There is a concave portion 24 for receiving the convex portion of the projection 20 'corresponding to the position of the projection 20'. The reel spring 12 'can be stably mounted on the bottom surface 19' and the projection 20 'is mounted so as to face the bottom surface of the reel spring mounting portion 16'. 'Does not exceed the ridge height. As a result, there is no contact with the flange 35 of the reel 34,
It does not produce sharp dents and does not break.

Although the magnetic tape cassette of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various improvements and modifications may be made without departing from the spirit of the present invention. Of course.

[0025]

As described above in detail, according to the present invention, since the projection forming the gap is provided on the surface of the reel spring, the reel spring is supplied to the cassette case when the reel spring is supplied to the cassette case. While the springs can be separated one by one and supplied one by one reliably, the projection of the attached reel spring is provided so as not to protrude the height of the ridge of the installation guide of the reel spring installation part, so that the magnetic Even if the tape cassette is dropped and subjected to an impact, the projections do not contact the flange and cause sharp dents, do not break, and as a result, the appearance and the performance of the magnetic tape A magnetic tape cassette that maintains excellent quality can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of an embodiment of a magnetic tape cassette of the present invention.

FIG. 2A is a side view of a reel spring used in an embodiment of the magnetic tape cassette of the present invention, and FIG.
Is a plan view of the same. FIG. 2C is a cross-sectional view taken along the line AA ′ shown in FIG. 1 in one embodiment of the magnetic tape cassette of the present invention.

FIG. 3A is a side view of a reel spring used in another embodiment of the magnetic tape cassette of the present invention,
(B) is a plan view thereof. (C) is a sectional view of a reel spring installation portion in another embodiment of the magnetic tape cassette of the present invention.

FIG. 4 is a perspective view showing a main part of an example of a conventional magnetic tape cassette.

FIG. 5A is a cross-sectional view showing an example of a reel spring used in a conventional magnetic tape cassette, and FIG.
Is a plan view of the same.

FIG. 6 is a schematic diagram of a reel spring supply device that supplies a reel spring to a magnetic tape cassette.

FIG. 7 is a diagram illustrating a state where a reel spring is mounted on a conventional magnetic tape cassette.

[Explanation of symbols]

 10, 30 Digital video cassette 12, 12 ', 36 Reel spring 12a Fixed part 12b Arm part 12c Bent part 14, 14', 32 Upper half 16, 16 ', 40 Reel spring installation part 17, 42 Upper half boss 18, 18' , 44 Installation guide 19, 19 'Bottom surface 20, 20' Projecting portion 21 Outer surface 22, 46 Boss hole 24 Recess 34 Reel 35 Flange 48 Window 50 Reel spring supply device 52 Supply rod

Claims (3)

[Claims] 1. A cassette case, a pair of reels rotatably attached by winding a magnetic tape in the cassette case, a fixed portion attached to the cassette case to form a fixed end, and the reel An arm for pressing in the direction of the rotation axis, and a plate-shaped reel spring provided with a bent portion between the fixed portion and the arm, and provided for each of the pair of reels; Has a protruding portion that forms a gap when one of the plurality of reel springs is taken out from the plurality of reel springs, and the cassette case has an installation guide that regulates a fixing position of a fixed end of the reel spring. A reel spring mounting portion for mounting the reel spring, the reel spring being mounted on the reel spring mounting portion so that the protrusion does not protrude from the installation guide. Magnetic tape cassette to be kicked. 2. The magnetic tape cassette according to claim 1, wherein a bottom surface of the reel spring installation portion is recessed from a cassette case surface outside the reel spring installation portion. 3. The reel spring is mounted such that the projection faces the bottom surface of the reel spring installation portion, and the bottom surface of the reel spring installation portion has a concave portion for receiving the projection of the reel spring. The magnetic tape cassette according to claim 1.