JPS61131277A - Recoding disk - Google Patents

Abstract

PURPOSE:To make larger the junction strength of an annular body for a metallic disk and to eliminate the deformation of recording media by tapering off a cross section shape of a linking groove located at the border between a metallic disk and the annular body, and deepening the depth toward the groove bottom part. CONSTITUTION:A cross section shape of a linking groove 13 located at the border between a metallic disk 7 and an annular body 9 is tapered off and the depth is deepened toward the groove bottom part. In such a way by tapering off the linking groove 13, part of the linking groove 13 can be deepened, the flow of a synthetic resin at the time of molding an outsert into the linking groove 13 is improved, the thick part of a bridge part 11 is formed, almost at the center of the linking groove 13 and therefore, the junction of the annular body 9 to the metallic disk 7 goes to secure and strong.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording disk equipped with a recording medium used in a magnetic disk cartridge or the like.

[Conventional technology]

As shown in the fifth section and FIG. The matching holes 6a and 6b are fitted into supporting means of a drive device (not shown), and a recording/reproducing head (not shown) is brought into contact with the recording medium 4 through the through hole 5b.

As an example of the structure of the hub 3, the inner circumference of an annular metal disk 7 is embedded in the outer circumference of the hub 3 made of synthetic resin. As shown in FIG. 7, a plurality of through holes 8 are formed in the circumferential direction of this metal disk 7, and a shallow connecting groove 10 is formed between each pair of adjacent through holes 8. A resin annular body 9 is provided. This annular body 9 comes into contact with a part of the circumferential side of the through hole 5a of the case 2, and regulates the position of the hub 3.
This restricts the movement of the recording medium 4 in the radial direction. The base end 9a of this annular body 9 is formed in the through hole 8 of the metal disk 7 as shown in FIG. The bridge portion 11 (see FIG. 7) passes through the bridge portion 11 (
(see Figure 8). As mentioned above, forming the proximal end 9a of the annular body 9 in the through hole 8 and providing the bridge portion 11 connecting a pair of adjacent proximal ends 9a are done in accordance with the metal disc 7. Although this is intended to increase the bonding strength of the annular body 9, it is not without its drawbacks.

That is, since the connecting groove 10 of the metal disk 7 is formed by press working, the area around the connecting groove 10 is easily deformed into a wavy shape due to the aperture. Since the flexible recording medium 4 is adhesively fixed to the upper surface of the metal disk 7 as shown in FIG. , the influence inevitably appears on the recording medium 4, and the recording medium 4 also waves in response to the deformation of the metal disk 7. As a result, the contact between the recording medium 4 and the magnetic head (not shown) deteriorates, causing partial wear of the recording medium 4 and deterioration of its magnetic properties.

In addition, since the cross-sectional shape of the connecting groove 10 is rectangular, 1
, when the depth of the connecting groove 10 is increased, the constricted portion 1 of the metal disk 7
2 may be cut by the shearing force, so the depth of the connecting groove 10 cannot be made too deep. Therefore, when forming the bridge portion 11, not only does the synthetic resin flow poorly and there is a problem with moldability, but also the bridge portion 1 is thin.
1, the bonding strength of the annular body 9 to the metal disk 7 is insufficient.

[Problem that the invention seeks to solve]

The present invention eliminates the drawbacks of the prior art, and provides a recording disk in which the annular body has a high bonding strength to the metal disk, has good productivity, and does not cause deformation of the recording medium.

[Means for solving problems]

In order to achieve this object, the present invention has a connecting groove located at the boundary between the metal disk and the annular body that has a tapered cross-sectional shape, and its depth increases toward the bottom of the groove.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. 1st
The figure is a sectional view of a main part of a magnetic disk cartridge according to an embodiment, FIG. 2 is an enlarged sectional view of part A in FIG. 1, and FIGS. 3 and 4 show other embodiments of FIG. 2. FIG.

In FIGS. 1 to 4, numerals 1 to 12 indicate the same parts as the conventional ones.

13 is a connecting groove according to an embodiment of the present invention, and this connecting groove 13
The cross-sectional shape is tapered, and the depth increases toward the groove bottom 14.

The difference between this structure and the conventional one shown in FIG. 8 is that in the one shown in FIG. On the other hand, the connecting groove 13 shown in FIG. 2 of the present invention has a cross-sectional shape of a figure 7 or an inverted triangle, and its depth increases as it approaches the groove bottom 14.

By tapering the connecting groove 13 in this way, a part of the connecting groove 13 can be deepened, and the flow of the synthetic resin during molding of the hair guard inside the connecting groove 13 is improved.
Since the thick portion of the bridge portion 11 is formed approximately in the center of the connecting groove 13, the annular body 9 can be joined to the metal disk 7 reliably and firmly.

Further, by tapering the cross-sectional shape of the connecting groove 13, the length of the constricted portion 12 of the metal disk 7 becomes longer, and the constricted portion 12 does not need to be cut during press working, resulting in improved formability.

The one shown in FIGS. 3 and 4 is connected to the connecting groove 13 shown in FIG.
The difference from the one in Fig. 2 is that in the one in Fig. 2, the cross-sectional shape of the connecting groove 13 is a 7-shaped inverted triangle, but in the one in Fig. The cross-sectional shape of the groove 13 is trapezoidal, and in the case of the one shown in FIG. 4, it is semicircular or U-shaped, and the depth increases as it approaches the groove bottom 14.Other explanations are the same as those of FIG. are the same.

〔Effect of the invention〕

As described above, since the present invention uses a metal disk having a through hole that is not drawn, deformation of the recording medium due to deformation of the metal disk is eliminated, and the positional relationship between the recording medium and the head is always maintained. Constant and stable characteristics can be obtained.

In addition, since the cross-sectional shape of the connecting groove is tapered, a part of the connecting groove can be deepened to increase the bonding strength of the annular body to the metal disk, and the narrow part of the metal disk can be lengthened. It has various advantages over conventional products, such as better moldability and suitability for mass production.

[Brief explanation of drawings]

1 to 4 are for explaining the recording disk of the present invention. FIG. 1 is a partial sectional view of a magnetic disk cartridge using the recording disk, and FIG. 2 is a section A of FIG. 1. FIGS. 3 and 4 are detailed views for explaining other embodiments of FIG. 2, and FIGS. 5 to 8 are for explaining conventional recording disks. 6 and 6 are a bottom view and a partially enlarged cross-sectional view of a magnetic disk cartridge using the recording disk, FIG. 7 is a plan view of a metal disk used in the recording disk, and FIG. 8 is a part of the recording disk. FIG. 3...Hub, 4...Recording medium, 7...Metal disk, 8...Through hole, 9...Annular body, 11...
...Bridge part, 13...Connection groove. Figure 1 Figure 2 Figure 3 Figure 3 Figure 4 Figure 5 Figure 6 7 Haruka 47 Hirogakure

Claims (1)

[Claims] (1) A hub made of synthetic resin with an annular metal disc embedded in its outer periphery, a disc-shaped recording medium whose inner periphery is adhesively fixed onto the metal disc, and along the circumferential direction of the metal disc. A plurality of through holes are provided along the circumferential direction of the metal disk, and connecting grooves are provided between a pair of adjacent through holes, and the metal disk and the annular body are provided with a protruding annular body made of synthetic resin. What is claimed is: 1. A recording disk which is joined to a body by a bridge portion filled in a through hole and a connecting groove, wherein the connecting groove has a tapered cross-sectional shape.