JPH0514389Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a magnetic disk cartridge in which a flat magnetic disk is rotatably housed within a hard case. Demand for this type of magnetic disk cartridge is rapidly increasing as a storage device for computers.

<Prior art> A floppy disk, which has been conventionally used as a storage device for computers, is a disk-shaped magnetic disk that is rotatably housed in a flexible jacket mainly made of vinyl chloride or the like. The jacket had a structure in which a window for inserting the magnetic head and a window for driving the rotation of the magnetic disk were opened. For this reason, the jacket may bend during handling and damage the magnetic disk stored inside, or fingers may touch the internal magnetic disk through openings such as the magnetic head insertion window and the rotation drive window, causing magnetic recording. There was a risk of destroying the material, and great care was required when handling it.

In order to eliminate these drawbacks of floppy disks, a hard case is used instead of a soft jacket, and a flat magnetic disk is rotatably housed within the case, and the magnetic disk is inserted through the opening of the case. A hard type magnetic disk cartridge has been proposed in which the magnetic disk is not exposed to the outside. Figure 1 is a perspective view of a hard type magnetic disk cartridge, Figure 2 is a perspective view of a hard type magnetic disk cartridge.
The figure is an enlarged sectional view of the main part to show its internal structure. In the figure, 1 and 2 are case members that are combined with each other to form a case, and 3 is a disc-shaped magnetic disk that is rotatably housed inside the case members 1 and 2.

Each of the case members 1 and 2 has a half-split shape, and the inner circumferential sides thereof are brought into contact with each other so that the abutment surfaces on the outer circumferences appear approximately in the middle of the thickness of the case to form a case. Both case members 1 and 2 are
It is molded from hard plastic, etc.
Compared to conventional jackets, it has greater mechanical strength, is less susceptible to deformation due to bending, and has a high protective effect on the magnetic disk 3 housed inside.
These case members 1 and 2 have liners 4 and 5 respectively attached to their inner surfaces facing the magnetic disk 3, and are assembled to each other from above and below so that a magnetic disk rotation area 6 is formed. A circular opening 7 is formed in the center of the case member 2, but the face plates of the case members 1 and 2 facing this opening 7 are in a closed state, and wear-resistant members 8, etc. It has a glued structure.

Furthermore, as shown in FIGS. 3 and 4, at positions facing each other in the diametrical direction of the case members 1 and 2,
Magnetic head insertion windows 9 and 10 are formed. When the magnetic head insertion windows 9 and 10 are not in use, they are closed by shutters 11 (see FIG. 1).

The magnetic disk 3 has a stepped hub 12 made of a non-magnetic material such as plastic in the center, and a donut disk-shaped magnetic recording medium 13 is coaxially connected to the outer circumferential side of the hub 12. . A center hole 14 is provided in the center of the hub 12, into which a rotational drive shaft of a recording/reproducing device (not shown) is mounted.
This magnetic disk 3 has a relationship such that the outer peripheral side of the hub 12 is exposed to the outside through the opening 7 of the case member 2, and the magnetic recording medium 13 is located in the rotation area 6 formed between the face plates of the case members 1 and 2. It is rotatably housed between case members 1 and 2.

Furthermore, at the corners of the case members 1 and 2, there are provided accidental erasure prevention mechanisms 15 which, in cooperation with the detection means of the recording/reproducing device, determine whether recording is possible or not on the magnetic disk 3. This type of accidental erasure prevention mechanism 15 is functionally the same as that provided on magnetic tape cassettes for audio or video, but is structurally different. That is, in the case of a magnetic tape cassette, it is generally molded integrally with the case, but in the case of a magnetic disk cartridge, it is not molded integrally with the case 1 and 2, but has a movable plug 16 molded separately from the case members 1 and 2, as shown enlarged in Figures 5 to 7, and this movable plug 1
The insertion portions 19 and 20 are surrounded by ribs 17 and 18 that protrude from the inner surfaces of the case members 1 and 2.
The movable plug 16 is housed in the case member 2 so as to be movable in the direction of the arrow A. The movable plug 16 has a height such that a part of the movable plug 16 is exposed to the outside through an opening 21 formed in a corner of the case member 2.
Whether recording is possible or not is determined by selecting a position by moving the focus.

The ribs 17 of the case member 1 and the ribs 18 of the case member 2 have flat end surfaces and substantially the same height, and are assembled with their end surfaces joined in a planar manner.

To drive the magnetic disk cartridge having the above structure, the rotary drive shaft of the recording/reproducing device is fitted into the center hole 14 of the hub 12, and the tip of the rotary drive shaft is attached to the inner surface of the case member 1. The rotating shaft is brought into contact with the wear-resistant member 8, and the rotating shaft is driven in this state. This causes the magnetic disk 3 to move to the case member 1.
and is rotationally driven within the lower case 2. Note that at this stage, the shutter 11 (Fig. 1) is open;
A magnetic head is inserted through the insertion windows 9 and 10,
Magnetic recording writing/reading is performed.

As mentioned above, in the hard type magnetic disk cartridge, the case members 1 and 2 are hard and have a very high protection function for the internal magnetic disk 3, and the magnetic head insertion windows 9 and 10 are hard.
The shutter 11, the hub 12, etc. are located in the center opening 7, etc., in which the rotary drive shaft of the recording/reproducing device is mounted, so that the magnetic recording medium 3 is not exposed to the outside. Therefore, the protection function for the magnetic recording medium is higher than in the case of a floppy disk, and handling becomes easier.

Furthermore, since the erroneous erasure prevention mechanism 15 is provided, it is possible to determine whether or not recording is possible on the magnetic disk 3 in cooperation with the detection means of the recording and reproducing apparatus.

<Problem to be solved by the invention> However, in the conventional magnetic disk cartridge, each of the case members 1 and 2 is half-shaped, and the contact surface on the outer periphery appears at approximately the middle part of the case thickness. In addition, the inner surfaces of the movable plug 16 are in contact with each other to form the case, and the movable plug 16 has a height such that a portion of the movable plug 16 is located within the opening 21. Since the end surfaces of the rib 17 and the rib 18 of the case member 2 are flat, when the case members 1 and 2 are combined, the contact surfaces of the ribs 17 and 18 are flat, and the height of the movable plug 16 is reduced. It is assembled in such a positional relationship that it is located approximately in the middle of the two. For this reason, during assembly, the movable plug 16 pops out from the insertion portions 17 and 18 due to the influence of vibrations, etc., resulting in a problem that assembly failures often occur.

Although the above problem does not occur if the height of the movable plug 16 is reduced, it is necessary that the movable plug 16 has a height such that a portion of the movable plug 16 is located within the opening 21 so that it can be operated from the outside. 16
It is impossible to prevent it from popping out by adjusting the height.

Therefore, the object of this invention is to solve the above-mentioned problems and to create a magnetic disk cartridge that prevents the movable plug that constitutes the accidental erasure prevention mechanism from popping out during assembly, thereby eliminating assembly defects. It is to provide.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention provides a magnetic disk cartridge in which a magnetic disk is rotatably housed in a case, and a mechanism for preventing accidental erasure is provided in the corner of the case. The case is composed of a pair of case members,
Each of the case members is half-shaped, and
The case is configured such that the inner surfaces are in contact with each other so that the contact surface on the outer periphery appears at approximately the middle part of the thickness of the case, and the accidental erasure prevention mechanism includes an insertion portion and a movable plug. The insertion portion is surrounded by ribs protruding from the inner surface of each of the case members, is formed by bringing end surfaces of the ribs into contact with each other, and is surrounded by the ribs. the movable plug has an opening on at least one of its inner surfaces; the movable plug is movably inserted into the insertion portion and has a height such that a portion thereof is located within the opening; The end face of the portion parallel to the moving direction of the movable plug partially protrudes with a difference in height, and is formed in a stepped shape that engages with each other between the case members.

<Function> The insertion portion of the accidental erasure prevention mechanism is surrounded by ribs protruding from each inner surface of the case member.
The ribs are formed by bringing the end surfaces of the ribs into contact with each other, and the ribs have end surfaces that partially protrude with height differences, and are formed in a stepped shape that engages with each other between the case members. The abutment surfaces of the ribs of one case member and the ribs of the other case member form a zigzag surface with a height difference, and the side surface of the movable plug is supported by the convex stepped portion. This prevents the movable plug from popping out during assembly.

<Example> Fig. 8 is a partially enlarged view of the inner surface of the case member in the magnetic disk cartridge according to the present invention, and Fig. 9 is a cross-sectional view of the case members mutually in a cross-sectional state taken along line A ₃ - A ₃ in Fig. 8. FIG. 10 is a sectional view taken along line A ₃ -A ₃ in FIG. 8 in an assembled state.
In the figures, the same reference numerals as in FIGS. 1 to 7 indicate the same components. The difference from the conventional case is that the ribs 17 and 18 of the case members 1 and 2 partially protrude with a difference in height and are formed in a stepped shape that engages with each other. In this embodiment, a stepped portion 171 is provided in a portion of the rib 17 of the case member 1 that is parallel to the moving direction A of the movable plug 16.
The rib ₁₈ of the case member 2 has a convex step 181 that engages with the step 171, and a step lower than this step 181. Step portion 182 that meshes with 172
are provided, and the ribs 17 and 18 are connected to these step portions 1.
71, 172, 181, and 182 are interlocked with each other.

With such a structure, the contact surface between the rib 17 of the case member 1 and the rib 18 of the case member 2 is
As shown in FIG. 10, the movable plug 16 has a zigzag surface with height differences, and the side surface of the movable plug 16 is supported by a convex step 172 formed on the rib 17 on the case member 1 side. This prevents the movable plug 16 from popping out during assembly.

Furthermore, in this embodiment, the rib 17 of the case member 1
Projections 173 and 174 are formed on both sides of the movable plug 16 to reduce the gap between the movable plug 16 and the movable plug 16. With such a structure, the movable plug 16 can be prevented from popping out even more effectively.

<Effects of the invention> As described above, the present invention is such that each of the two case members is half-shaped, and the inner surface is formed so that the abutment surface on the outer periphery appears approximately in the middle of the case thickness. They are brought into contact with each other to form a case,
In this type of magnetic disk cartridge in which the movable plug of the accidental erasure prevention mechanism easily pops out from the insertion section, the rib surrounding the insertion section has a partial height difference in the end surface of the portion parallel to the moving direction of the movable plug. Since the magnetic disk cartridge is formed in a stepped shape that protrudes and engages with each other between the case members, it is possible to prevent the movable plug from popping out during assembly, thereby providing a magnetic disk cartridge that can eliminate assembly defects.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of the magnetic disk cartridge, Fig. 2 is an enlarged sectional view of the main part to show its internal structure, Figs. 3 and 4 are plan views of the inner surface of the case member, and Fig. 5 Figure 6 is an enlarged view of the erroneous erasure mechanism of a conventional magnetic disk cartridge, and Figure 5 is
A ₁ - _{A 1} cross-sectional view, Figure 7 is Figure 5 A _2
8 is an enlarged view of the erroneous erasing mechanism portion of the magnetic disk cartridge according to the present invention, and FIG. 9 is a cross-sectional view of the case members taken along line A ₃ -A ₃ in FIG. 8. FIG. 10 is a sectional view taken along line A ₃ -A ₃ in FIG. 8 in an assembled state. 1, 2...Case member, 3...Magnetic disk,
15... Erroneous erasure prevention mechanism, 17, 18... Rib.

Claims (1)

[Claims for Utility Model Registration] (1) A magnetic disk cartridge that rotatably stores a magnetic disk in a case and has a mechanism to prevent accidental erasure at a corner of the case, the case comprising a pair of The case is composed of a case member, and each of the case members is half-shaped, and the case is configured such that the inner surfaces thereof are brought into contact with each other so that the contact surface of the outer periphery appears at approximately the middle part of the thickness of the case. The accidental erasure prevention mechanism includes an insertion section and a movable plug, and the insertion section is surrounded by ribs protruding from the inner surface of each of the case members, and the insertion section is surrounded by ribs protruding from the inner surface of each of the case members. The movable plug is movably inserted into the insertion portion, and has an opening on at least one of the inner surfaces surrounded by the ribs, and the movable plug is movably inserted into the insertion portion, and has an opening on at least one of the inner surfaces surrounded by the ribs. The rib has a height such that the end surface of the portion parallel to the moving direction of the movable plug partially protrudes with a difference in height, and the rib has a height that is located in the opening. What is claimed is: 1. A magnetic disk cartridge characterized by being formed into stepped shapes that engage with each other. (2) The utility model registration claim 1 is characterized in that the rib has a protrusion that partially protrudes toward the inner surface of the insertion portion to reduce the gap between the rib and the movable plug. Magnetic disk cartridge as described.