JPH01191384A - Disk cartridge - Google Patents

Abstract

PURPOSE:To prevent the damage of a torsion coil spring and to improve the opening closing durability of a shutter by causing the winding number of the torsion coil spring, which energizes the shutter in a blocking direction, in a central winding part to be >=1-<2. CONSTITUTION:A torsion coil spring 6 is equipped to energize a shutter 5 in the blocking direction and the winding number of the torsion coil spring 6 in a central winding part 7 is made to be >=1-<2. As a result, the central winding part 7 goes to be thin and a danger to be contacted with the inner surface of a case 1 is almost erased. Then, the adhesion of respective wire rods can be decreased in the central winding part 7. Thus, the damage of the torsion coil spring can be prevented and the opening closing durability can be improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to disk cartridges such as magnetic disk cartridges, optical disk cartridges, and magneto-optical disk cartridges, and particularly relates to a shutter that can open and close an opening for head access. The present invention relates to a disk cartridge including a spring that biases the shutter in a closing direction.

[Conventional technology]

The shutter of the nuclide disk cartridge has one end engaged with the case and the other end engaged with the shutter, and is constantly biased in the closing direction by nine springs. When the disk cartridge is inserted into the device, the shutter is closed against the springs. When the shutter moves to the open position and the disk cartridge is ejected or ejected from the apparatus, the shutter returns to the closed position by the force of the spring.

As mentioned above, torsion coil springs are commonly used as springs that bias the shutter in the closing direction.
Ends of two arm portions extending from the central winding portion of the torsion coil spring having a number of turns of 2 to 5 are engaged with the case and the shutter, respectively. The reason why such a torsion coil spring is used is that it is easier to assemble than a tension coil spring and is suitable for thinned disk cartridges.

[Problem to be solved by the invention]

The torsion coil spring is repeatedly expanded and compressed between its two arm portions as the shutter opens and closes. On this occasion,
The center winding part of the torsion coil spring is provided to equalize the stress distribution in the approximately V-shaped turn part between the two arm parts, but in the conventional configuration, as mentioned above, the number of windings of the center winding part is Since it is set to be 2 to 5, the following inconveniences occurred.

In other words, due to the side surface of the central winding coming into contact with the inner surface of the case and the close contact of the wire rods at the central winding, stress is concentrated on a part of the torsion coil spring, resulting in fatigue damage due to repeated opening and closing of the shirt flap. There was a problem in that this occurred much earlier than the set value.

Therefore, the technical problem to be solved by the present invention is to solve the problems of the above-mentioned prior art, and its purpose is to:
To provide a disk cartridge which prevents damage to a torsion coil spring and has excellent durability in opening and closing a shutter.

[Means for solving problems]

In order to achieve the above object, the present invention includes an opening for head access provided in a case rotatably housing a disk, a shutter that can open and close the opening, and a torsion coil spring that biases the shutter in the closing direction. In the nine-disc cartridge, the torsion coil spring has a central winding portion having a number of turns of 1 or more and less than 2.

[Effect]

If the number of turns of the center winding part of the torsion coil spring is less than 2, there is almost no possibility that the center winding part will become thin and come into contact with the inner surface of the case. This makes it possible to reduce as much as possible the close contact between the wire rods at the parts. Therefore, excessive stress is not concentrated on a local part of the torsion coil spring, the arm part of the torsion coil spring operates smoothly and without difficulty, and the spring does not break within the number of shutter openings and closings required for the disk cartridge.

〔Example〕

The present invention will be described below with reference to nine embodiments shown in FIGS. 1 to 5.

Although this embodiment shows the application of the present invention to a hunting disc cartridge, the present invention is not limited thereto.

In FIG. 5, reference numeral 1 denotes a synthetic resin case in which a magnetic disk 2 is rotatably housed. An opening 3 for head access and a center hub hole 4 are formed in the upper and lower surfaces of the case 1, respectively.

Reference numeral 5 denotes a shutter made of synthetic resin or metal, which is attached so as to be slidable along one side of the case 1. In the closed position shown in FIG. 5, the shutter 5 covers the opening 3 and the center hub hole 4, and when the disk cartridge is inserted into the disk drive device (not shown) with the left side leading in the figure, the shutter 5 covers the opening 3 and the center hub hole 4. , the shutter 5 slides toward the right in the figure with respect to the case 1, exposing the opening 3 and the center hub hole 4.

Reference numeral 6 denotes a torsion coil spring, which is made of a metal spring wire such as a stainless steel wire for springs, and as shown in FIGS. 8 and a second arm part 9, and the first arm part 8 and the second arm part 9 each have a bent part 8a for locking at the tip.

9a is provided. The number of turns of the central winding portion 70 is set to be 1 or more and less than 2, and in this embodiment, the number of turns of the central winding portion 70 is set to 1 or more and less than 2. The opening angle α between the second arm portions 8.9 is set to 116°±5°.

The torsion coil spring 6 is inserted through an elongated opening (not shown) in the side surface of the case 1, and in the assembled state, as shown in FIG. Two protrusions 10.
11 in the engagement recess 12, and the second
A bent portion 9a of the arm portion 9 is engaged with an engaging portion 13 of the case 1. As a result, the shutter 5 is urged in the closing direction by the torsion coil spring 6, and the shutter 5 is maintained in the closed position shown in FIG. 5 when the disk cartridge is not in use.

In the above configuration, the central winding portion 7 of the torsion coil spring 6
Since the number of turns 0 is a little more than one turn, the thickness of the center winding part 7 is extremely thin, and it can be sufficiently separated from the inner surface of the case 1 as shown in FIG.
Even if it is tilted, there is no risk of it coming into contact with the inner surface of case 1.

Furthermore, the first part of the torsion coil spring 6. Second arm part 8
. is sufficiently achieved, and the area where the wire rods of the center winding portion 70 are in close contact with each other is made as small as possible, so that the contact resistance force between the wire rods can be substantially ignored.

Therefore, when the shutter 5 is moved from the closed position to the open position, the torsion coil spring 6 reduces the open angle between the second arm parts 8 and 9 by 1° using the bent part 9a of the second arm part 9 as a fulcrum. However, the central winding part 7 does not come into contact with the inner surface of the case 1, and the number of parts where the wire rods come into close contact with each other in the central winding part 7 is very small.
The torsion coil spring 6 is compressed smoothly without causing local stress concentration. Furthermore, when the shutter 5 moves from the open position to the closed position, the torsion coil spring 6 similarly unfolds smoothly and effortlessly. As a result, the torsion coil spring 6
The lifespan of the shutter has been significantly extended compared to previous models, and the durability of the shutter opening and closing is more than guaranteed.

In the above embodiments, the shutter is shown as one that slides, but the present invention is also applicable to those in which the shutter rotates, and can be applied to optical disk cartridges and magneto-optical disk cartridges in addition to magnetic disk cartridges. Needless to say, it is also applicable.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent damage to the torsion coil spring for closing the shutter, and to provide a disk cartridge with excellent durability in opening and closing the shutter.

[Brief explanation of the drawing]

The drawings all relate to embodiments of the present invention; Fig. 1 is an enlarged partially cutaway plan view of the manufacturing part showing the relationship between the central winding part of the torsion coil spring and the inner surface of the case, and Fig. 2 shows the locking of the torsion coil spring. FIG. 3 is a plan view of the torsion coil spring, FIG. 4 is a side view of the torsion coil spring, and FIG. 5 is a plan view of the entire disk cartridge. 1... Case, 2... Magnetic disk,
3...Opening, 4...Center hub hole,
5...Shutter, 6...Torsion coil spring, 7...Central winding part, 8...First
Arm part, 8a...Bending part, 9...
・Second arm part, 9a...Bending part, 10・
...Protrusion, 11...Protrusion, 12...
...Engagement recess, 13...Engagement portion. Figure 1 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] In the disk cartridge, the disk cartridge includes an opening for head access provided in a case rotatably housing a disk, a shutter that can open and close the opening, and a torsion coil spring that biases the shutter in a closing direction. A disk cartridge characterized in that the number of windings of the central winding portion is 1 or more and less than 2.