JPH0333983Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applicable to devices such as floppy disk devices that record or reproduce information signals on a rotating disc-shaped recording medium (hereinafter referred to as a disk). Concerning the disks used.

Conventional structure and its problems In conventional floppy disk devices, the magnetic disk rotates by engaging with a spindle on the device side, and signals are recorded on or reproduced from the magnetic disk by a magnetic head on the device side. be done. At this time, if the center of rotation of the magnetic disk is not always constant, the relative position between the magnetic head and the magnetic disk will shift, causing problems such as the inability of the magnetic head to accurately scan the recording track during reproduction. In order to solve this problem, magnetic disks as shown in FIGS. 1 to 3 have been devised.

In FIG. 1, a magnetic disk 1 consists of a magnetic sheet 2 and a resin-molded center core 3, and the center core 3 has an engagement hole 4, a nib hole 5, and a pressing piece 6 formed between them. . A cross-sectional view taken along the line A-A' in FIG. 1 is shown in FIG. 2. The magnetic sheet 2 is stuck on a sheet receiver 7 formed in an annular shape around the outer periphery of the center core 3. Also,
A magnetic member 8 (for example, an iron plate) is attached to the lower surface of the center core 3. A spindle 9 is provided on the device side to rotate the magnetic disk 1. When inserted into the engagement hole 4 of the center core 3, the magnetic member 8 is attracted to a magnet 10 provided integrally with the spindle 9. be done. Therefore,
The magnetic disk 1 rotates integrally with the spindle 9. FIG. 3 shows the spindle 9 inserted into the engagement hole 4. The engagement hole 4 is connected to the wall A, 4a, the wall B, 4
b, walls C, 4c, walls D, 4d, walls E, 4e, and the pressing piece 6, and the spindle 9
It is configured to be slightly smaller in the vertical direction of the figure. The center core 3 is made of flexible resin, and the pressing piece 6 has elasticity. Therefore, when the spindle 9 is inserted into the engagement hole 4, the pressing piece 6 is bent in the direction of arrow B from the position shown by the dashed line in the figure. This also means that the pressing piece 6
presses the spindle 9 in the direction of arrow C, and the spindle 9 comes into contact with the walls B, 4b and walls C, 4c, and the relative positions of the spindle 9 and the center core 3 are determined. That is, as long as the spindle 9, walls B, 4b, walls C, and 4c are not worn out or deformed, in the same device, no matter how many times you replace the magnetic disk or reinstall it, the rotation center of the spindle 9 and The relative position of the magnetic disk 1 is
Always the same.

According to this method, the relative positions of the magnetic disk 1 and the spindle 9 are determined more reliably as the pressing force of the pressing piece 6 becomes stronger. Also, magnetic disk 1
Due to the high speed rotation of the magnetic disk 1, depending on the position of the center of gravity of the magnetic disk 1, the wall B of the magnetic disk 1,
4b, walls C, and 4c may be subjected to a force that tends to separate them from the spindle 9, and the pressing force of the pressing piece 6 is further required. However, since the pressing piece 6 is formed by resin molding, if the pressing force is increased by increasing the thickness of the pressing piece 6 or increasing the amount of deflection when the spindle 9 is inserted, the pressing piece 6 will be Deterioration due to wear and plastic deformation becomes significant, and the pressing force decreases significantly, shortening the life of the magnetic disk and impairing its reliability. Furthermore, wall B,
In order to accurately position the center core 3 with respect to the spindle 9 using the walls C and 4c, the material of the center core 3 should be as hard as possible, such as polycarbonate resin.
In order to provide the pressing piece 6 with appropriate elasticity, the material of the center core 3 must be flexible. Therefore, the wall B that abuts the spindle 9,
4b, walls C, and 4c are deformed by the pressing force, and the positioning accuracy of the center core with respect to the spindle 9 is low.

Purpose of the invention The present invention was devised in view of the above-mentioned difficulties, and provides a disk that has a simple configuration, can obtain reliable positioning, has little deterioration, is highly reliable, and is inexpensive. The purpose is to

Structure of the invention The present invention provides an engagement hole in the center core provided at the center into which a spindle provided on the device side is inserted, and the spindle inserted into the engagement hole is inserted into the side surface of the engagement hole. A disk equipped with a pressing member that comes into elastic pressure contact, the pressing member being supported at both ends by a member constituting an engagement hole, and a metal wire or metal whose center portion is disposed within the engagement hole. By using a single piece, deterioration of the pressing member is significantly reduced, and the positioning of the disk can be performed reliably over a long period of time.

DESCRIPTION OF EMBODIMENTS A disk cassette containing magnetic disks, which is an embodiment of the present invention, will be described.

FIG. 4 is a perspective view showing the external appearance of the disk cassette. A magnetic disk 12 is rotatably housed inside a housing made up of a thin upper half 10 and a lower half 11. A center core 13 is provided at the center of the magnetic disk 12. The upper half 10 is provided with openings 14 and 15. These openings 14 and 15 are constructed so as not to obstruct the insertion of a head for recording information on a magnetic sheet or for reproducing recorded information and a spindle for rotating a magnetic disk (both not shown). It's summery.

FIG. 5 shows the magnetic disk 12. As shown in FIG. The magnetic sheet 16 is pasted onto an annular sheet receiver 17 formed on the resin-molded center core 13 in a conventional manner. The center core 13 includes an engaging hole 18, a nip hole 19, and a pressing piece 20. The pressing piece 20 is not made of resin molded from the same material as the center core 13 as in the prior art, but is made of a metal spring wire supported at both ends by the center core 13. The pressing piece 20 made of the metal spring wire can have a rectangular, square, circular, oval or other arbitrary shape in cross section, but as shown in FIG.
It consists of a simple piece of metal that has a linear shape or a strip shape that is long in the long side direction. Therefore, no matter how many times the magnetic disk 12 is used, the pressing piece 20 does not deteriorate, and it is possible to always apply a substantially constant pressing force. Furthermore, since the metal spring wire can be embedded during center core molding, the center core 13 can be easily manufactured.

Furthermore, since the material of the center core 13 does not need to be flexible as in the past, it is possible to use polycarbonate resin or the like which is hard and has high molding precision. Therefore, the positioning accuracy of the magnetic disk 12 is high.

FIG. 6 is a diagram with the spindle 21 inserted.
As with the conventional example, the spindle 21
In order to insert the spindle 21 into the engagement hole 18, which is configured to have a diameter slightly smaller than the diameter of The walls A, 18a and the walls B, 18b come into contact with the spindle 21, and the center core is reliably positioned with respect to the spindle 21. In this embodiment, the elastic member is made of a metal spring wire, but it goes without saying that it is also effective to use a metal plate spring material.

Effects of the invention As described above, according to the invention, the elastic member that elastically presses the spindle inserted into the engagement hole,
The disc is constituted by a metal wire or a metal piece whose both ends are supported by the members constituting the engagement hole and whose central portion is arranged in the engagement hole, so that the disk engages with the spindle and rotates. A highly reliable disk that can be positioned with respect to a spindle with high accuracy over a long period of time can be provided at a low cost, and its practical effects are great.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conventional magnetic disk, Fig. 2 is a sectional view of the main part of the magnetic disk, Fig. 3 is a plan view of the main part showing the state of engagement of the magnetic disk with the spindle, and Fig. 4 is a plan view of the main part of the magnetic disk. An external perspective view of a disk cassette containing a magnetic disk, which is an embodiment of the present invention, FIG. 5 is a plan view of the magnetic disk, which is an embodiment of the present invention, and FIG. FIG. 3 is a plan view of main parts showing an engaged state. 12... Magnetic disk, 13... Center core, 18... Engagement hole, 20... Pressing piece, 21...
spindle.

Claims (1)

[Scope of utility model registration request] An engagement hole into which a spindle provided on the apparatus side is inserted is provided in a center core provided in the center, and the spindle inserted into the engagement hole is elastically pressed against a side surface of the engagement hole. A disc-shaped recording medium characterized in that the pressing member is constituted by a metal wire or a metal piece whose both ends are supported by the member constituting the engagement hole and whose center portion is disposed within the engagement hole.