JPH0319097Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a disk cassette in which flexible disks are rotatably housed.

Such a disk is called a floppy disk, and is used as a storage medium in various devices. When recording or playing back on such a disk, the disk contained in the cassette is inserted into the disk compartment. The disk is then automatically drawn into the support, and positioned at the center of the drive shaft inserted into the cassette by the positioning hole in the center core attached to the center of the magnetic disk. A drive pin provided on the drive shaft engages with the disk, and torque from the drive shaft is transmitted to the disk via this drive pin. However, if a hole is simply provided in the center core, deformation and wear will occur around the hole due to the shock generated between the center core and the drive shaft during startup and the crimping during driving, and the center of the drive shaft will not always be the center of the drive shaft. The center of the magnetic disk no longer coincides with the center of the magnetic disk, and if recording and reproduction are performed in such a state, a track shift will occur.

The present invention was developed in view of these problems, and includes a disk cassette in which a flexible disk is rotatably housed, and a center core attached to a substantially central portion of the disk;
It is provided approximately in the center of this center core, and
a substantially rectangular spindle hole that is engaged with a center spindle disposed on a drive shaft that drives the disk; a drive hole that engages with a drive pin disposed on the drive shaft, and a cylindrical portion with a substantially square cross section provided around the spindle hole, and engages with the center spindle. The present invention relates to a disk cassette in which deformation and wear of the mating spindle hole are prevented by the cylindrical portion.

The present invention will be explained below with reference to illustrated embodiments.
As shown in FIG. 1, this disk cassette includes a circular flexible magnetic disk 1 and a pair of upper and lower halves 2 and 3 for storing the disk 1.
The cassette 4 is made up of a cassette 4 joined together. The magnetic disk 1 is made of a circular flexible polymer film, and has a magnetic layer formed on at least its lower surface. A circular opening 6 is formed approximately in the center of the magnetic disk 1, and a dish-shaped center core 5 is mounted in this opening 6.

The upper and lower halves 2 and 3 constituting the cassette 4 are molded from synthetic resin into a substantially square shape, and ribs 7 are formed on the peripheral edges thereof. By joining the halves 2 and 3 with the tips of these ribs 7 in contact with each other,
A hard case 4 is formed which has a space in which the disk 1 is housed and rotated. lower half 3
An elongated hole 8 for inserting the head is formed in the upper half 2, and an opening 9 for inserting the pad is formed in the upper half 2 corresponding to this elongated hole 8. Further, a circular opening 10 for inserting a spindle is formed in the lower half 3.

Further, liner sheets 11 and 12 are interposed between the upper half 2 and the magnetic disk 1 and between the lower half 3 and the magnetic disk 1, respectively. These sheets 11 and 12 are made of, for example, non-woven fabric and allow the disk 1 to rotate smoothly within the cassette 4. Note that a circular opening 13 for inserting a spindle and a long hole 14 for inserting a head are formed in the lower liner sheet 12, respectively.

As shown in FIGS. 2 and 3, the center core 5 has a flat disk shape, and has a flange 15 integrally connected to its outer periphery. The magnetic disk 1 is bonded to this flange 15, and the center core 5 is attached to the magnetic disk 1 by this. A rectangular cylindrical spindle hole 16 is integrally connected to the center of the center core 5, and as shown in FIG.
8 is inserted.

Furthermore, a drive hole 20 is provided in the center core 5 at a position offset from the center where the spindle hole 16 is located, and a drive pin 21 provided in the drive shaft 17 as shown in FIG. It is now being inserted.

Thus, the torque of the drive shaft 17 is transmitted to the magnetic disk 1 by the revolution of the drive pin 21, which is arranged offset from the center of the drive shaft 17. As a result, the magnetic disk is moved to the drive shaft 1 within the cassette 4.
It becomes possible to rotate with 7.

By the way, since the spindle hole 16 is formed in a cylindrical shape, both strength and rigidity are greater than when a square hole is simply provided at the center of the center core 5. Therefore, the spindle hole 16 that engages with the center spindle 18 will not be deformed or worn out. Therefore, the center of the drive shaft 17 and the center of the magnetic disk 1 can always be correctly aligned, and track deviation can be prevented. Moreover, the root portion 19 of the spindle hole 16 of the center core 5 is formed into a curved surface having a predetermined curvature, so that wear and impact are reduced compared to the case where the root portion 19 is a sharp right-angled edge. Note that instead of providing the root portion 19 with a curvature, the lower end of the inner peripheral surface of the cylindrical spindle hole 16 may be chamfered.

By the way, the reason why the spindle hole 16 is configured to have a rectangular shape as described above is to improve dimensional accuracy by making the contact between the spindle hole 16 and the center spindle 18 in the form of contact between a V-shaped notch and a cylinder. It is based on the same idea as the means often used for precision measurement of cylindrical parts.

In this way, the head (not shown) inserted into the cassette 4 through the long hole 8 shown in FIG. 1 accurately traces the track on the disk 1 to perform recording or reproduction.

As mentioned above, the present invention provides a cylindrical fitting part in the center core attached to the magnetic disk,
This fitting portion is used to position the center of the magnetic disk. Therefore, wear and deformation of the fitting portion are reduced, the center of the magnetic disk can be accurately positioned, and track deviation can be effectively prevented.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a disk cassette according to an embodiment of the present invention, Fig. 2 is a perspective view of a center core used in this device, and Fig. 3 is a schematic view of this magnetic disk device installed in a player. FIG. In the symbols used in the drawings, 1...magnetic disk, 5...center core, 16...spindle hole, 17...drive shaft, 18...center spindle, 20...drive hole, 21...drive pin.

Claims (1)

[Scope of Claim for Utility Model Registration] A disk cassette in which a flexible disk is rotatably housed, a center core attached to a substantially central portion of the disk, and a center core provided substantially in the center of the center core and driving the disk a substantially rectangular spindle hole that engages with a center spindle disposed on the drive shaft; and a substantially rectangular spindle hole that occupies a position offset from the approximate center of the center core where the spindle hole occupies, and transmits torque to the disk. In order to do this, the spindle has a drive hole that engages with a drive pin disposed on the drive shaft, and a cylindrical portion with a substantially square cross section provided around the spindle hole, and the spindle that engages with the center spindle. A disk cassette in which deformation of the hole and occurrence of wear are prevented by the cylindrical portion.