JPH0452856Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a disk cartridge most suitable for use with a micro floppy disk made of a magnetic sheet having a diameter of 3.5 inches, for example.

[Summary of the idea]

This idea involves forming a horizontal annular flange integrally by press working on the upper part of the outer periphery of a horizontal metal center disk having a central hole and an eccentric hole, through a vertical cylindrical part, and A sheet-shaped recording medium is fixed horizontally to the flange of the center disk, and a ring is integrally outsert-molded with synthetic resin on the outer periphery of the cylindrical part on the bottom surface of the flange of the center disk, and this center disk and the sheet-shaped recording medium are attached vertically. In a disk cartridge that is rotatably housed in a cartridge consisting of a half, when the ring is outsert molded, a small protrusion of synthetic resin that is inevitably formed at the injection gate position of the molten resin protrudes from the bottom surface of the ring. By preventing this from happening, stability is improved when the center disc is magnetically chucked onto the turntable of a disc player.

[Conventional technology]

Regarding a disk cartridge using a micro floppy disk, the applicant of this invention has previously filed an earlier application, for example, Utility Model Application No. 177345/1983.

In this prior application, a horizontal annular flange is integrally formed by press working through a vertical cylindrical part on the upper part of the outer periphery of a horizontal central disk made of metal such as stainless steel, which has a central hole and an eccentric hole. Then, a sheet-like recording medium is fixed horizontally to the flange, and a ring is integrally outsert-molded from synthetic resin such as ABS resin to the outer periphery of the cylindrical part on the lower surface of the flange of the center disk. This is a disk cartridge in which a plate and a sheet-like recording medium are rotatably housed in a cartridge consisting of upper and lower halves.

[Problem that the invention attempts to solve]

By the way, as shown in FIGS. 7 and 8, as in the previous application, a ring 4 is integrally outsert-molded with synthetic resin on the outer periphery of the cylindrical portion 3 on the lower surface of the flange 2 of the metal central disk 1. In order to
As shown in the figure, molding must be carried out by using molds 5 and 6 that are divided into upper and lower parts, and injecting molten resin 8 between the upper and lower molds 5 and 6 from an injection gate 7 provided in the lower mold 6. No. This is because the metal flange 2 is arranged on the upper surface of the ring 4, so the injection gate 7 cannot be provided in the upper mold 5. Furthermore, it is difficult to provide the injection gate 7 on the outer peripheral surface of the ring 4 in the lower mold 6 due to the mold structure.

However, when the ring 4 is outsert molded using the mold structure in which the injection gate 7 is provided in the lower mold 6, as shown in FIGS. 7 and 8, after the molding, the mold 5, When the ring 6 is separated vertically, the small protrusion 9 of the synthetic resin cut off at the injection gate 7 remains on the lower surface 4a of the ring 4, which is the position of the injection gate. If the small protrusion 9 remains on the lower surface 4a of the ring 4 as described above, the stability when magnetically chucking the center disk 1 on the turntable of a disc player becomes extremely poor, and the flange 2 The central disk 1 is glued to the top surface and is rotated by a turntable.
A large surface runout occurs in the sheet-shaped recording medium 10 that is rotationally driven through the recording medium 10, which has a significant adverse effect on recording and reproduction accuracy.

Therefore, conventionally, after the ring 4 was outsert-molded, it was necessary to perform a finishing process such as scraping off the small protrusions 9 remaining on the lower surface 4a of the ring 4 one by one, which required a large number of processing steps.

This invention was devised to solve these problems, and when the ring is outsert molded, a small protrusion of synthetic resin that is inevitably formed at the injection gate position of the molten resin is removed from the ring. This is to prevent it from protruding from the bottom surface of the.

[Means for solving problems]

In this invention, the lower surface of the ring, which is integrally outsert-molded with synthetic resin on the lower surface of the metal center disk and the outer periphery of the cylindrical portion, is formed flush with the lower surface of the center disk, and the ring One or more recesses are provided on the lower surface of the ring, and the injection gate position for the molten resin when outsert molding the ring is selected within the recess.

[Effect]

According to this invention, the small protrusion of the synthetic resin that is necessarily formed at the injection gate position after outsert molding of the ring remains in the recess provided on the bottom surface of the ring, so that the small protrusion does not protrude from the bottom surface of the ring. There is no.

〔Example〕

An embodiment in which this invention is applied to a disk cartridge using a micro floppy disk will be described below with reference to FIGS. 1 to 6.

First, the structure of the disk cartridge will be explained with reference to FIGS. 1 to 3.

The micro floppy disk 15 has a central disk 16 made of a flat disk of metal such as stainless steel.
and a magnetic sheet 17 with a diameter of 3.5 inches, which is a sheet-like recording medium.

The center disk 16 has a substantially square center hole 18 and a substantially rectangular eccentric hole 19 formed in the center and near the outer periphery of the center disk 16 by press working. A horizontal annular flange 2 is attached to the upper part of the outer periphery via a vertical cylindrical part 20.
1 is integrally formed by press working.
The magnetic sheet 17 has an annular shape,
An adhesive 22 is applied to the upper surface of the flange 21 on the inner circumference of the flange 21.
It is glued by.

Also, the center hole 18 is located on the upper surface 16a of the center disk 16.
The outer periphery of the cylindrical portion 2 and the lower surface 21a of the flange 21
Two cylindrical rings 24 and 25 of a small diameter and a large diameter are integrally outsert molded on the outer circumference of the 0 from synthetic resin such as ABS resin.

And this micro floppy disk 1
5 is rotatably housed in a cartridge 29 consisting of upper and lower halves 27 and 28, and the center disk 16 is loosely fitted into a turntable insertion hole 30 provided in the lower half 28. And upper half 27
A small-diameter ring 24 is inserted into a cylindrical small-diameter positioning rib 31 integrally molded on the lower surface of the center disc 1 in the turntable insertion hole 30.
6 has been positioned. Note that the upper and lower halves 27 and 28 are provided with a pair of upper and lower head insertion holes 32 that are opened and closed by a shutter (not shown). A adhesive sheet 33 is attached.

When this disk cartridge 29 is attached to the disk player, the micro floppy disk 15 is magnetically chucked horizontally onto the turntable 35 by the center disk 16, as shown in FIG. The center pin 36 of the turntable 35 is inserted into the center hole 18 and the eccentric hole 19.
and drive pin 37 are inserted, respectively. Also,
When the shutter is opened, a pair of upper and lower recording/reproducing heads 38 are inserted into both head insertion holes 32 and brought into contact with the upper and lower recording surfaces of the magnetic sheet 17. In this attached state, while the magnetic sheet 17 is rotated horizontally within the cartridge 29 by the turntable 35 via the center disk 16, both recording and reproducing heads 38 are moved in the radial direction of the magnetic sheet 17. Thus, the upper and lower recording surfaces of the magnetic sheet 17 are selectively recorded and reproduced.

Next, the coupling structure between the large diameter ring 25 and the center disk 16 will be explained with reference to FIGS. 2 to 5.

First, as shown in FIGS. 2 and 3, coupling portions 40 with the ring 25 are provided at, for example, four locations in the circumferential direction of the flange 21. As shown in FIGS. 4 and 5, these coupling parts 40 include a projecting piece 41 that projects downward from the lower surface 21a of the flange 21 and is substantially parallel to the lower surface 21a;
A pair of through holes 4 arranged to sandwich the protrusion 41
It is composed of 2. The protruding piece 41 is usually formed by a pressing method called half-blanking process, and the protruding piece 41 and both through-holes 42 can be formed very easily at the same time when the center disk 16 is press-formed. be done. The projecting piece 41 has a shape that is long in the circumferential direction of the flange 21 and short in the radial direction of the flange 21.
Both side edges 41b along the longitudinal direction are bent into a substantially V-shape and are integrally connected to the flange 21, and both through holes 42 are arranged on both sides of the projecting piece 41 in the longitudinal direction.

Then, as shown in FIGS. 4 and 5, a part 25a of the ring 25, which is integrally outsert-molded with synthetic resin on the lower surface 21a of the flange 21, is passed through both through holes 42 to the upper surface 41a side of the protruding piece 41. The protruding piece 41 is sandwiched and passed around to the opposite side from the ring 25.

According to such a coupling structure, the ring 25 is mechanically attached to the flange 21 by the part 25a of the ring 25 passing through the through-holes 42 and going around to the opposite side of the protruding piece 41 from the ring 25. The center disk 16 and the ring 2
The bonding strength with 5 becomes significantly higher.

In addition, as shown in FIGS. 2 and 3, the center hole 1
For example, 4 in the circumferential direction of the outer peripheral portion 18a of 8
A connecting portion 43 between the small-diameter ring 24 and the central disk 16 is provided at this location. These joints 43
has the same structure as the coupling part 40 but is vertically symmetrical, and the center disk 1 is formed by half punching.
6 upwardly from the upper surface 16a thereof.
It has a protruding piece 44 that protrudes substantially parallel to the protruding piece 44, and a pair of through holes 45 arranged on both sides of the protruding piece 44 in the longitudinal direction. Then, a part 24a of the ring 24, which is integrally outsert-molded with synthetic resin on the upper surface 16a of the center disk 16, is passed through both through-holes 45, and the lower surface side of the protruding piece 44 is held in between. 24, turn it around to the opposite side, and insert the ring 2.
4 is mechanically coupled to a central disk 16.

Next, the shape of the lower surface 25b of the large diameter ring 25 will be explained with reference to FIGS. 3, 4, and 5.

The lower surface 25b of this ring 25 is formed flush with the lower surface 16b of the center disk 16. and,
Approximately trapezoidal recesses 47 are provided at, for example, two locations in the circumferential direction on the lower surface 25b of this ring 25, and the injection gate position 48 of the molten resin when outsert molding this ring 25 is located at these recesses 4.
Selected within 7. As a result, small protrusions 49 of synthetic resin that are inevitably formed at these injection gate positions 48 after outsert molding are formed in these recesses 47.
The small protrusion 49 will remain inside the ring 2.
5 does not protrude below the lower surface 25b.

Therefore, the lower surface 25b of the ring 25 and the center disk 1
6 can be made flush with the lower surface 16b of the turntable 35 with high precision, and when the center disk 16 is magnetically chucked on the turntable 35, as shown in FIG. Bottom surface 1 of ring 25
6b, 25b as the upper surface 35a of the turntable 35
The stability of the center disk 16 on the turntable 35 can be significantly improved.

In addition, when outsert molding the ring 25 having the above shape, as shown in FIG. An injection gate 53 is opened at the top of the convex portion 52 of the shape. Then, with the center disc 16 positioned between the two molds 50 and 51 in advance, the molten resin 54 is injected between the two molds 50 and 51 from the injection gate 53 to form the flange 21 of the center disc 16. A ring 25 is integrally outsert molded on the lower surface 21a.

Therefore, a concave portion 47 is formed in the lower surface 25b of the ring 25 by the convex portion 52 of the lower mold 51, and when the molds 50 and 51 are vertically separated after molding the ring 25, the injection gate 53 portion The small protrusion 49 of the synthetic resin that has been cut off remains at the injection gate position 48 within the recess 47.

Although the embodiments of this invention have been described above, this invention is not limited to the embodiments, and various effective changes can be made based on the technical idea of this invention.

Furthermore, this invention is not limited to disk cartridges using micro-floppy disks, but can be applied to various disk cartridges that use sheet-like recording media to record and reproduce data in various ways.

[Effect of idea]

As mentioned above, the disk cartridge of this invention is designed to remove the small protrusion of synthetic resin that is always formed at the injection gate position after outsert molding of the ring, by leaving it in the recess provided on the underside of the ring. Since the ring does not protrude from the lower surface of the ring, the lower surface of the ring and the lower surface of the center disk can be flush with each other with high precision. Therefore, the stability when magnetically chucking the center disk on the turntable of a disk player can be significantly improved, the surface wobbling of the sheet-shaped recording medium can be eliminated, and the accuracy of recording and reproduction can be significantly improved. can be improved.

Moreover, the small protrusions remaining in the recessed portion of the ring can be left as they are, and there is no need to carry out finishing work such as cutting off these small protrusions one by one.

[Brief explanation of the drawing]

Figures 1 to 6 show an embodiment of this invention, in which Figure 1 is a cross-sectional view of the entire disk cartridge, Figure 2 is a plan view of the center disk, and Figure 3 is a center view of the disk cartridge. A bottom view of the disk, FIG. 4 is a partially enlarged sectional view taken in the direction of the − arrow in FIG. 3, and FIG. 5 is a − in FIG. 4.
A sectional view taken in the direction of arrows, and FIG. 6 is a sectional view illustrating outsert molding of the ring. FIG. 7 is a sectional view of the main part of the earlier application example, FIG. 8 is a sectional view taken in the - arrow direction of FIG. 7, and FIG. 9 is a sectional view illustrating outsert molding of the ring of the earlier application example. . In addition, in the symbols used in the drawings, 16...
Center disk, 16b... lower surface of center disk, 17...
Magnetic sheet, 18...center hole, 19...eccentric hole,
20... Cylindrical part, 21... Flange, 21a...
Lower surface of flange, 25... Ring, 25b... Lower surface of ring, 27... Upper half, 28... Lower half, 29... Cartridge, 47... Recess, 48
...the injection gate position.

Claims (1)

[Claims for Utility Model Registration] A horizontal annular flange is formed integrally with the upper part of the outer periphery of a horizontal metal central disk having a center hole and an eccentric hole through a vertical cylindrical part by press working. A sheet-shaped recording medium is fixed horizontally to the flange, and a ring is integrally outsert-molded with synthetic resin on the outer periphery of the cylindrical part on the lower surface of the flange of the center disk, and the center disk and the sheet-shaped recording medium are In a disk cartridge in which a recording medium is rotatably stored in a cartridge consisting of an upper and lower half, the lower surface of the ring is formed flush with the lower surface of the center disk, and one or more 1. A disk cartridge comprising: a recessed portion, and an injection gate for molten resin when outsert-molding the ring is located within the recessed portion.