JP4053135B2 - Magnetic tape cartridge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic tape cartridge in which a single reel on which a magnetic tape is wound is rotatably accommodated in a flat cartridge case formed by superposing an upper half and a lower half, and in particular, the cartridge case. The present invention relates to a magnetic tape cartridge provided with a notch for preventing erroneous insertion into an external device at one corner of the outer surface of the tape.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a magnetic tape cartridge that is mainly used as a recording medium that functions as a backup for computer memory has a single reel on which a magnetic tape is wound as shown in FIG. Some of them are rotatably accommodated in a flat cartridge case 1 having a substantially square planar shape.
[0003]
When the magnetic tape cartridge having such a configuration is inserted in the lower left direction in FIG. 1 with respect to the external recording / reproducing apparatus, the engagement of the reel exposed from the circular opening formed in the central portion of the lower half 3 The rotation drive unit on the device side engages with the teeth, and the magnetic tape is pulled out from the cartridge case 1 by the tape pulling mechanism on the device side and pulled into a predetermined position on the tape running path, and data is written to the magnetic tape. / Reading is possible.
[0004]
Inside the upper and lower halves 2 and 3 of the cartridge case 1, arc-shaped ribs 6 (FIG. 2) surrounding the reel concentrically are formed.
[0005]
[Problems to be solved by the invention]
By the way, the side wall of the upper half 2 or the lower half 3 has a portion where the end of the arc-shaped rib 6 intersects in the tangential direction and a thick portion is formed on the side wall in the vicinity of this intersection.
[0006]
On the other hand, this type of magnetic tape cartridge may be required to be provided with a notch 4 at one corner of the outer surface of the upper half 2 in order to prevent erroneous insertion into an external recording / reproducing apparatus. In this case, the notch 4 has a substantially triangular shape at one corner on the leading side in the insertion direction of the magnetic tape cartridge of the upper half 2 from the upper surface of the upper half 2 to a substantially middle position in the height direction of the side wall. It is formed in a form cut into a planar shape.
[0007]
However, when the notch 4 is formed so as to include the vicinity of the intersection of the side wall of the upper half 2 with the end of the arc-shaped rib, the vicinity of the intersection of the side wall (part indicated by P in FIG. 1) In this case, since the upper half of the side wall in the height direction is a recess due to the presence of the notch 4, only the lower half of the side wall in the height direction is thicker than the other parts.
[0008]
Therefore, at the time of molding, the cooling rate of the thick part becomes slower than the surrounding part, and due to the difference in shrinkage rate in the cooling process, the portion indicated by the symbol P of the side wall is deformed and “sink” or “fall down” occurs. Or inconvenience that a step is formed at the abutting portion with the lower half.
[0009]
In view of the above circumstances, an object of the present invention is to provide a magnetic tape cartridge that effectively avoids the above-described disadvantages.
[0010]
[Means for Solving the Problems]
In the present invention, a magnetic tape is wound in a flat cartridge case comprising a lower half having a square planar shape and an upper half having a planar shape similar to the lower half and superimposed on the upper portion of the lower half. The end of an arc-shaped rib that concentrically surrounds this reel intersects the side wall of the upper half or the lower half, and a thick wall portion is formed on the side wall near the intersection. In the formed magnetic tape cartridge,
At one corner of the outer surface of either the upper half or the lower half, there is a notch for preventing erroneous insertion into an external device from the top surface of the upper half or the height of the side wall from the bottom surface of the lower half. Reduced so that the thickness of the side wall is substantially constant on the back side of the side wall in the vicinity of the intersection point in a manner in which the one corner is cut into a substantially triangular planar shape up to a midway direction. A meat part is formed.
[0011]
【The invention's effect】
According to the present invention, on the back side of the side wall of the part where the notch for preventing erroneous insertion into the external device and the rib intersects, a thinned portion that makes the thickness of the side wall of this part substantially constant is formed. Therefore, there is almost no difference in the cooling rate in the vicinity of the intersection at the time of molding. Therefore, there is no possibility that a disadvantage such as “sink” or “falling” occurs at this portion, and a step is generated at the abutting portion with the other half.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
First, prior to the description of the embodiment of the present invention, a configuration which is a premise of the present invention will be described with reference to FIGS. 2 and 3A and 3B.
[0014]
FIG. 2 is a rear view of the corner of the upper half 2 provided with a notch 4 for preventing erroneous insertion into an external device. FIGS. 3A and 3B are respectively A- It is sectional drawing along the A line and the BB line.
[0015]
The ends of the arc-shaped ribs 6 erected at the corners of the upper half 2 surrounding the reel (not shown) of the magnetic tape intersect the side wall 5 in a tangential direction. As shown, a notch 4 for preventing erroneous insertion into an external device extends from the upper surface of the upper half 2 to a midway position in the height direction of the side wall 5 (in FIG. The lower half of the height direction is formed so as to include the vicinity of the intersection of the rib 6 and the side wall 5 in a form in which one corner of the upper half 2 is cut into a substantially triangular planar shape.
[0016]
Accordingly, as shown in FIG. 3B, the upper portion 7 of the notch 4 in the side wall 5 is a thick portion, and the above-described disadvantage occurs due to the presence of the thick portion.
[0017]
On the other hand, in the embodiment of the present invention, as shown in FIG. 4 corresponding to FIG. 2 and FIG. 5 which is a sectional view taken along line BB of FIG. 4 corresponding to FIG. A thinned portion 9 is formed on the back side of the upper portion 7 of the notch 4 in the side wall 5 so that the thickness of the side wall 5 at this portion is substantially constant.
[0018]
In order to maintain the dustproof property, as shown in FIGS. 3B and 5, the abutting edge 5 a against the side wall 8 of the lower half 3 of the side wall 5 of the upper half 2 is provided on the side wall 8 of the lower half 3. A stamping joint is formed with the abutting edge 8a. The same applies to the abutting edge 6a of the rib 6 of the upper half 2 with respect to the rib of the lower half 3 (not shown).
[0019]
In the present embodiment, since the thinned portion 9 is formed on the back side of the portion 7 adjacent to the notch 4 in the height direction of the side wall 5, the difference in the cooling rate in the vicinity of the intersection at the time of molding is almost eliminated. Can be eliminated. Therefore, there is no possibility that a disadvantage such as “sinking” or “falling” occurs in this part and a step is generated in the abutting portion with the lower half 3.
[0020]
In the present embodiment, the notch 4 for preventing erroneous insertion into an external device is formed in the upper half 2. However, the notch 4 has a side wall height from the bottom surface of the lower half 3. The same applies to the case of forming up to an intermediate position in the direction.
[Brief description of the drawings]
FIG. 1 is a perspective view of a magnetic tape cartridge in which the present invention is implemented. FIG. 2 is a rear view of the main part of an upper half of a cartridge case which is a premise for carrying out the present invention. 4 is a cross-sectional view taken along line A and BB. FIG. 4 is a rear view of the main part of the upper half of the cartridge case embodying the present invention. FIG. 5 is a cross-sectional view taken along line BB in FIG. Explanation of]
DESCRIPTION OF SYMBOLS 1 Magnetic tape cartridge 2 Upper half 3 Lower half 4 Notch 5 Side wall 6 Rib 9 Thinning part

Claims (1)

A single unit in which a magnetic tape is wound in a flat cartridge case comprising a lower half having a square planar shape and an upper half having a planar shape similar to the lower half and superimposed on the upper portion of the lower half The end of an arc-shaped rib that concentrically surrounds the reel intersects with the side wall of the upper half or the lower half, and a thick part is formed on the side wall near the intersection. In the magnetic tape cartridge
A notch for preventing erroneous insertion into an external device at one corner of the outer surface of either the upper half or the lower half having the rib is a side wall from the upper surface of the upper half or from the bottom surface of the lower half Up to a midway position in the height direction, including the vicinity of the intersection in a manner in which the one corner is cut into a substantially triangular planar shape, and on the back side of the side wall in the vicinity of the intersection , the height direction of the side wall A magnetic tape cartridge is characterized in that a thinned portion for making the thickness of the side wall substantially constant is formed in a range where the notch is not formed.

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