JP2000048528A - Magnetic tape cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rigidity of a cartridge case, particularly the cartridge case formed of a resin material not containing a reinforcing agent such as a glass fiber or the like. SOLUTION: In a magnetic tape cartridge formed of a resin material in which a magnetic tape draw-out opening 26 is formed at the side wall for rotatably accommodating single reel winding the magnetic tape, at least, a pair of projections 30 extending in at least a pair of diagonal line directions are provided on the internal surface of the upper wall 2A and lower wall 3A of the cartridge case or the upper wall 2A and lower wall 3A of the cartridge case are formed to become thick toward the center from the side wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-reel type magnetic tape cartridge used for a computer or the like.

[0002]

2. Description of the Related Art A magnetic tape cartridge (hereinafter, also referred to as a "cartridge") for storing a magnetic tape used as a recording medium used in an external storage device such as a computer has a single reel wound with the magnetic tape. This reel is rotatably housed in a cartridge case, and one end of a magnetic tape is used by being pulled out to a device side from a magnetic tape draw-out opening provided on a side wall of the cartridge case. Are known.

[0003] The magnetic tape cartridge is used by being mounted on a recording / reproducing device (hereinafter referred to as "drive") such as an external storage device. At the time of loading, the cartridge is mounted at a predetermined position of the drive. The positioning is performed with reference to a reference hole provided on the bottom surface of the cartridge case, the outer wall surface of the cartridge case itself, and the like. Further, the cartridge case is provided with a stacking projection and a recess that engage with each other in order to prevent displacement of the cartridges during stacking and storage.

The main body of the cartridge case is generally manufactured by injection molding, but the upper and lower walls of the cartridge case are pushed outward by the urging force of a coil spring in the cartridge case, and the cartridge case is bent (bulged). May occur. When such a warp or warp occurs, the cartridge case and the reel interfere with each other even if the cartridge is loaded in the corresponding drive, and the reel cannot be rotated, cannot be positioned, or has a problem in stacking and storing. There may be problems such as hospitality.

As one method for solving such a problem, a polycarbonate resin containing glass fiber is conventionally used as a raw material resin for forming a cartridge case to improve the rigidity of the cartridge case and to reduce the warpage of the cartridge case. Some prevent bending.

[0006]

However, the glass fiber-containing polycarbonate resin can improve the rigidity of the cartridge case by the glass fiber contained therein, but when the magnetic tape cartridge is loaded or unloaded from the drive, the magnetic tape cartridge is removed from the drive. May wear or shorten the life of the mold during molding. Therefore, from such a viewpoint, it is preferable not to use glass fiber as a reinforcing material.

The present invention has been made in view of the above circumstances, and effectively prevents the cartridge case from bending or bulging due to the urging force of a coil spring or the like even in a cartridge case formed of a resin containing no glass fiber. It is another object of the present invention to provide a magnetic tape cartridge capable of improving rigidity while securing a space between a reel and a cartridge case.

[0008]

According to the magnetic tape cartridge of the present invention, a single reel on which a magnetic tape is wound can be rotated in a resin cartridge case having a magnetic tape draw-out opening formed in a side wall. Wherein the cartridge case is provided with at least a pair of diagonally extending protrusions on the inner surfaces of the upper wall and the lower wall, respectively. .

The "upper wall" means a ceiling surface when the upper case of the cartridge case in which the upper case and the lower case are fastened by screws or the like is up, and the "lower wall" means a bottom surface. "Inner surface" means the surface inside the cartridge case in which the wound magnetic tape is stored.

[0010] The "projection" means a shape in which the projection is elongated, and the height thereof is preferably about 0.1 mm to 0.5 mm, more preferably 0.1 mm to 0.3 mm. If the height of the ridge is lower than this, the rigidity of the cartridge case cannot be expected to be improved, and if it is higher than this, interference with the reel on which the magnetic tape is wound is not preferable. Also, not all parts of the ridge need to be at the same height, but since the runout when the reel rotates is greater at the outer periphery than at the center of the reel, the cartridge case is used to prevent interference with the reel. It is preferable that the thickness becomes thinner toward the side wall. In this case, the ridge may be formed so as to become thinner at a uniform ratio toward the side wall, or may be formed so as to become thinner stepwise. The width of the ridge is not particularly limited, but it is necessary that the ridge has a width that can prevent warpage and bending.

The "diagonal direction" means a direction connecting two non-adjacent corners in each of the upper case and the lower case. Therefore, "a pair of diagonal directions" means two orthogonal directions connecting two non-adjacent corners. “At least” means that, in addition to a pair of ridges extending in a diagonal direction, ridges may be further provided in a diagonal direction, for example, two ridges may be provided in one direction. In addition to the diagonal ridges, radial ridges may be provided. However, it is preferable that the ridge passes through the center of the case in consideration of injection molding.

The ridges may be provided only inside substantially annular ribs provided on the upper wall and the lower wall, which surround the outer periphery of the wound magnetic tape. "A substantially annular rib provided on the upper wall and the lower wall, which surrounds the outer periphery of the wound magnetic tape," means that the magnetic tape is wound on the inner surfaces of the upper case and the lower case. To reinforce the cartridge case surrounding the outer periphery of the reel, the `` inside only '' means that a ridge is provided only on the side where the wound magnetic tape is housed, and the case is removed from the substantially annular rib. This means that no ridge is provided up to the side wall.

Further, the magnetic tape cartridge of the present invention comprises
In a magnetic tape cartridge in which a single reel on which a magnetic tape is wound is rotatably housed in a resin cartridge case having a magnetic tape drawer opening formed in a side wall, the upper wall of the cartridge case and The lower wall is formed so as to become thicker from the side wall toward the center. "The wall is formed so as to become thicker from the side wall toward the center" means that the upper wall and the lower wall are formed so that the wall thickness is gradually increased from the side wall toward the center. It may be formed gently so as to become thicker at a uniform ratio from the side wall toward the center, or may be formed so as to gradually increase in thickness.

[0014]

According to the magnetic tape cartridge of the present invention, at least a pair of diagonally extending ridges are provided on the inner surfaces of the upper wall and the lower wall of the cartridge case. Even without using a reinforcing agent, it is possible to effectively prevent the cartridge case from bending or expanding due to the urging force of the coil spring in the cartridge case.

In injection molding, the gate for injection molding is generally provided substantially at the center of the molded product in order to equalize the injection pressure of the resin with respect to the molded product. It is possible to flow evenly in the rectangular cartridge case, and even pressure can be applied even with a low resin pressure, so that the dimensional accuracy of the case can be improved.

Further, between the substantially annular rib surrounding the outer periphery of the wound magnetic tape and the side wall of the case, other components such as a memory element (Memory In Cartridge) may be installed. When the ridge is provided only inside the rib, the ridge and other parts do not interfere with each other, and the cartridge case can be effectively prevented from warping or bending.

Further, the axial deflection of the reel when the reel rotates is larger at the outer periphery than at the center of the reel, so that the margin between the reel and the cartridge case is more on the side wall than the center of the cartridge case. There is a possibility that the outer periphery of the reel will come into contact with the ridge because it is smaller at the near side. However, if the ridge is provided so as to become thinner toward the side wall of the cartridge case, such interference between the reel and the case may occur. Can be prevented.

In the case where the upper wall and the lower wall of the cartridge case are formed so as to become thicker from the side wall toward the center, a reinforcing agent such as glass fiber is not required at the time of injection molding. Thus, it is possible to effectively prevent the cartridge case from warping or bending.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing the configuration of a magnetic tape cartridge according to an embodiment of the present invention. As shown in FIG. 1, a magnetic tape cartridge 1 according to an embodiment of the present invention is a single reel formed by joining a lower reel 5 and an upper reel 6 by ultrasonic welding or the like and having a magnetic tape 20 wound thereon. 4 is rotatably housed in a cartridge case 7 in which the upper case 2 and the lower case 3 are fastened by screws or the like.

The lower reel 5 is formed by integrally molding a cylindrical reel hub 23 around which the magnetic tape 20 is wound around an outer periphery, and a flange portion 24 projecting radially from the lower end outer periphery of the reel hub 23 using a synthetic resin. . Reel hub 23
A reel plate 8 for attaching a magnetic rotary driving means for rotating the reel 4 is mounted on the bottom outer surface of the reel hub 23.
A stopping gear 23A that is engaged with a stopping gear 9A formed on the brake member 9 to restrain rotation when not in use is engraved. An opening 23B is formed in the reel hub 23, through which a drive release spindle provided in a recording / reproducing device such as an external storage device using the magnetic tape cartridge 1 is inserted to move the brake member 9 upward. . Here, the brake member 9 includes a reel hub 23.
The above-mentioned stopping gear 9A is formed on the side opposite to the above, and a fitting groove 9B in which the brake guide projection formed on the upper case 2 is fitted is formed on the opposite side.
When the cartridge is not used, the brake member 9 is urged downward by a coil spring 10 in the drawing, and
3, the braking gears 9 </ b> A, 23 </ b> A between the brake member 9 and the reel hub 23 are engaged with each other, and
Rotation is prevented. On the other hand, when the cartridge is used, the drive release spindle of the magnetic tape device presses the brake member 9 to move the brake member 9 upward in the drawing against the urging force of the coil spring 10, whereby the braking gears 9 </ b> A, The engagement of 23A is released, and the reel 4 becomes rotatable.

An opening 26 for drawing out the magnetic tape 20 is formed in one side wall of the cartridge case 7. A slide door 27 movable in the direction of arrow A is attached to the opening 26 in parallel with the side wall of the cartridge case 7. The slide door 27 is urged by a spring (not shown) in a direction to close the opening 26.

When the magnetic tape cartridge 1 is not used, the magnetic tape 20 is completely wound around the reel 4, and the tape pull-out member 21 (using the magnetic tape cartridge 1) attached to the end of the magnetic tape 20 is used. Means for the recording / reproducing apparatus to introduce the magnetic tape 20 into the tape running path in the apparatus) is locked in a concave portion 28 formed near the opening 26.

When the magnetic tape cartridge 1 is set in the corresponding drive, the stopping gears 9A, 23A between the brake member 9 and the reel hub 23 are set as described above.
Is released so that the reel 4 is rotatable, and the magnetic rotary drive unit is joined to the reel plate 8 to rotate the reel 4. At the same time, the slide door 27 is opened, the tape pull-out member 21 is pulled into a predetermined position on the tape running path, and data can be read from and written to the magnetic tape 20.

Next, the ridges provided on the magnetic tape cartridge 1 will be described.

FIG. 2 is a structural view of the inside of a cartridge case showing an embodiment of the present invention, and FIG. 3 is a sectional view of the cartridge case taken along line XX or YY shown in FIG. 4 is a configuration diagram showing a modification of the above embodiment,
FIG. 5 is a cross-sectional view of the cartridge case taken along the line ZZ shown in FIG. 4, FIG. 6 is a configuration diagram showing still another modified example of the above embodiment, and FIG. 7 is another embodiment of the present invention. FIG. 4 is a configuration diagram showing the inside of a cartridge case.

On the inner surfaces of the upper wall 2A and the lower wall 3A of the upper case 2 and the lower case 3, ridges 30 extending diagonally are provided. In this case, the protruding ridges 30 extending in the diagonal direction can be provided all the way to the corners of the upper case 2 and the lower case 3 as shown in FIG.

On the other hand, between the side walls 2B and 3B and the substantially annular rib 31 surrounding the outer periphery of the reel 4 on which the magnetic tape 20 is wound, other components such as a memory element may be provided. In such a case, the ridge 30 can be provided only inside the substantially annular rib 31 as shown in FIG.

The cross section of the ridge 30 when cut along the line XX or the line YY shown in FIG.
A (or lower wall 3A) is thicker than ridge 3
The height t of 0 is about 0.1 to 0.5 mm. In addition, the protrusions 30 may have the same height in all portions of the upper wall 2A and the lower wall 3A. However, since the run-out when the reel 4 rotates is larger at the outer peripheral portion of the reel 4, the allowance of the space between the reel 4 and the upper wall 2A and the lower wall 3A of the cartridge case 7 is limited by the upper wall 2A and the lower wall 3A. Side walls 2B, 3 than center
Since the side closer to B becomes smaller, the reel 4 and the ridge 30 may interfere with each other. Therefore, in such a case, ridge 3
It is preferable that the height t of 0 is smaller as it is closer to the side wall 2B as shown in FIG. At this time, the height t of the ridge 30 may be reduced at a uniform rate, or may be reduced stepwise.

Further, as shown in FIG. 2 and FIG.
May be only a pair of ridges 30 extending in a diagonal direction, or two pairs of ridges 30 may be provided in the same direction. Further, as shown in FIG. 6, it is also possible to provide the protrusions 32, 33 passing through the center of the cartridge case 7 in a radial shape other than the diagonal direction. In this case, the ridge may be provided in a square shape, for example, having four ridges parallel to the substantially square side wall 2B so as not to pass through the center of the cartridge case 7. In order to make the flow of the resin uniform, it is preferable to form a radial ridge passing through the center of the cartridge case 7. As shown in FIG. 6, when two or more pairs of the ridges 30 are provided, the rigidity of the cartridge case 7 can be improved even when the width of the ridges 30 is narrower than when only one pair of the ridges 30 is provided. .

Further, as shown in FIG. 7, the upper wall 2A and the lower wall 3A of the upper case 2 and the lower case 3 respectively approach the central portion from the side walls 2B, 3B side without providing a ridge. Accordingly, it is also possible to increase the wall thickness to improve the rigidity. If the thickness of the wall around which the substantially annular rib 31 is erected is small, the surface of the case where the substantially annular rib 31 is erected will be shrunk after molding and cooling. It is preferable that the wall thickness tb around the raised portion of the substantially annular rib 31 is larger than the wall thickness tw of the side walls 2B, 3B. In order to reduce the bending of the cartridge case 7 and to improve the strength against impact, the side walls 2B, 3B
It is preferable that the corner 33 formed by the upper wall 2A and the lower wall 3A be rounded.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of a magnetic tape cartridge according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of the inside of a cartridge case showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view of the cartridge case taken along line XX or YY shown in FIG.

FIG. 4 is a configuration diagram showing a modification of the above embodiment.

5 is a cross-sectional view of the cartridge case when cut along the line ZZ shown in FIG.

FIG. 6 is a configuration diagram showing still another modification of the above embodiment.

FIG. 7 is a configuration diagram showing the inside of a cartridge case showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic tape cartridge 2 Upper case 2A Upper wall 3 Lower case 3A Lower wall 7 Cartridge case 26 Opening 30 Protrusion 31 Annular rib

Claims (3)

[Claims] 1. A magnetic tape cartridge comprising a resin cartridge case having a side wall formed with an opening for drawing out a magnetic tape and rotatably housing a single reel on which a magnetic tape is wound. A magnetic tape cartridge, wherein the case is provided with at least a pair of diagonally extending projections on respective inner surfaces of the upper wall and the lower wall. 2. The magnetic tape cartridge according to claim 1, wherein the ridge is thinner toward a side wall of the cartridge case. 3. A magnetic tape cartridge in which a single reel on which a magnetic tape is wound is rotatably housed in a resin cartridge case having a magnetic tape draw-out opening formed in a side wall. A magnetic tape cartridge, wherein an upper wall and a lower wall of a case are formed to be thicker from the side wall toward the center.