JPS60231985A - Magnetic disk cassette - Google Patents

Abstract

PURPOSE:To simplify a manufacturing process by molding a shutter out of synthetic resin. CONSTITUTION:Recessed parts 10 and 11 are formed in external surfaces of an upper shell 1 and a lower shell including parts where ablong holes 8 and 9 are bored. The shutter 12 which is sectioned nearly in a U shape is fitted slidably in the recessed parts 10 and 11. The shutter 12 consists of a top plate 21, a flank plate 23, and a back plate 22 molded in one body. The shutter 12 is formed of thermoplastic synthetic resin, such as polyoxymethylene resin, which has superior elasticity, small frictional resistance, and relatively high strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk cassette having a flexible magnetic disk housed in a hard case, and particularly to a shutter for opening and closing an opening for inserting a head.

[Background technology and its problems]

A magnetic disk drive is known in which a flexible magnetic disk having a diameter of, for example, 3.5 inches is housed in a hard case, and digital data can be recorded and reproduced in this state. This magnetic disk cassette is equipped with a shutter that can be opened and closed to protect the magnetic disk. In other words, this shutter is opened only when the device is in operation, and the magnetic disk is exposed through the elongated head insertion opening provided in the case, and when it is not in operation, the shutter is closed and this opening is closed. By closing the opening in this manner, foreign matter and dust are prevented from entering the case, and the magnetic disk within the case is protected.

Conventionally, this shutter has been made of metal such as stainless steel and has a cross-sectional shape. The shutter was formed with an elongated portion having approximately the same shape as the opening of the case, and was slidably attached to the case. This shutter needs to be attached to the case so that it slides smoothly and does not easily come off the case.

Further, this shutter must be in uniform contact with the outer surface of the case and completely close the opening to prevent dust from entering the cassette. Therefore, the height of the opening of the shutter in the portion that holds the cassette case and the guide protrusion within the shutter must be strictly determined to correspond to the standardized thickness of the cassette case.

Conventional shutters are made by drilling holes in a stainless steel flat plate.
It had been processed through processes such as bending and removing the edges.

However, since the stainless steel flat plate is stored in a rolled state, stress remains and may deform, making it difficult to perform highly accurate bending.

In addition, with conventional shutters, when the shutter is attached to the case or when the shutter slides on the hard case, the hard case may be scraped by the guide protrusions, resulting in the problem of dirt entering the case. was there. Furthermore, since metal materials are used, it is difficult to color the shutter or print manufacturer's information on the shutter. As mentioned above, conventional shutters require a large number of manufacturing steps and require strict dimensional accuracy, which inevitably results in high costs.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a magnetic disk cassette with a shutter that is easy to manufacture and has a low-cost shutter, in order to overcome the above-mentioned drawbacks.

Another object of the present invention is to provide a magnetic disk cassette equipped with a shutter that uniformly adheres to the outer surface of the case to prevent a gap from forming between the case and the shutter.

Still another object of the present invention is to provide a magnetic disc cap that does not scrape the case when the shutter slides on the case and prevents dirt from entering the case.

[Summary of the invention]

The present invention provides a magnetic disc cent that includes a magnetic disk, a case containing the magnetic disk, and a shutter that is slidably provided in the case and that can take an operating position and a non-operating position. , a top plate, a bottom plate, a side plate connecting the top plate and the bottom plate, and an opening for inserting a head formed in at least one of the top plate and the bottom plate are combined so as to sandwich the case with a cross-sectional shape. This is a magnetic disc concentrate characterized by being integrally molded using a resin material. The present invention is a magnetic disfusator that includes a shutter in which both an upper plate and a lower plate of the shutter approach each other toward the uncoupled portion when the shutter is detached from the case. In this way, in order to form a shape in which the top plate and the bottom plate are close to each other in the unconnected part, the present invention controls the cooling conditions of two molds that fit into each other when molding a shutter from synthetic resin. It is something.

〔Example〕

An embodiment of the invention will be described below with reference to the drawings. FIG. 1A and FIG. 1B are a top view and a bottom view of the entire magnetic disk cassette in one embodiment of the present invention. In FIGS. 1A and 1B, 1 is an upper shell and 2 is a lower shell. The upper shell 1 and the lower shell 2 are, for example, ABS resin molded products containing an antistatic agent. A liner made of a nonwoven fabric such as rayon is thermally or ultrasonically welded to the inner surface of each of the upper shell 1 and the lower shell 2 to prevent dropout and wear of the magnetic disk and generation of static electricity.

The outer periphery of the upper shell 1 and the outer periphery of the lower shell 2 are joined by ultrasonic welding, and the upper shell 1 and the lower shell 2
The magnetic disk 3 is housed in a case formed by combining the two. The magnetic disk 3 is a flexible magnetic disk that is based on a disc-shaped polymer film and has a magnetic layer uniformly formed on its lower surface. A circular opening is formed in the center of the magnetic disk 3, and a ring-shaped center plate 4 is fixed to this opening. A substantially square motor shaft insertion hole 5 is formed in the center of the center plate 4, and a rectangular position regulating bottle insertion hole 6 is formed at a position offset from the insertion hole 5 by a predetermined distance. A circular open lower portion is formed in the center of the lower shell 2, and the center plate 4 is placed in this open lower portion with some play. Elongated holes 8 and 9 are formed in the upper shell 1 and the lower shell 2, and the magnetic disk 3 is exposed through the elongated holes 8 and 9.

Upper shell 1 including the part where elongated holes 8 and 9 are formed
Recesses 10 and 111 are formed on the outer surface of the lower shell 2, and a shutter 12 having a U-shaped cross section as shown in FIG. 2 is slidably mounted within the recesses 10 and 11. A guide groove 13 is provided along the side edge of the outer surface of the lower shell 2, and a protrusion projecting inward of the shutter 12 is guided within the guide groove 13. As shown by solid lines in FIGS. 1A and 1B, the elongated hole 9 for head insertion, the elongated hole 8 for head pad insertion, and the elongated size 14.15 formed in the shutter 12 match, and the magnetic disk 3 is exposed to the outside, and an unused state where the elongated holes 8 and 9 are closed and the magnetic disk 3 is covered by the shutter 12, as shown by the imaginary lines in FIGS. 1A and 1B. The shutter 12 slides so that the This shutter 1
2 protects the magnetic disk 3 and prevents dust from entering.

Further, a lug 16 for preventing accidental erasing is provided at a part of one corner of the lower shell 2, and if the lug 16 is broken off and removed, the data cannot be erased. This lower shell 2
A pair of positioning holes 17 and 18 are provided in some of the two corners for positioning the magnetic disk device when installing it in the disk recorder main body. One of the positioning holes 17 is elongated so that even if there is some error in the position of the hole, it can be tolerated. Parts of the other two corners where the positioning holes 17 and 18 are not provided serve as reference surfaces, and the magnetic disk cassette is supported at the reference position at part of the four corners. In this state, the magnetic disk 3 is rotated by the motor, and digital signals or analog signals are recorded or reproduced.

FIG. 2 is a front view, a bottom view, and a side view of the shutter 12. The shutter 12 has a top plate 21 and a side plate 23.
The lower plate 22 is integrally molded. Shutter 1
2 is made of a thermoplastic synthetic resin with excellent elasticity, low frictional resistance, and relatively high strength, such as polyoxymethylene resin. The shutter 12 has a U-shaped cross section, and when removed from the case, the shutter 12 is shown in FIG.
As shown in FIG. 3, the upper surface plate 21 and the lower surface plate 22 facing the opening ends of the front and side surfaces are arranged close to each other.

Elongated holes 14 and 15 are formed in the upper surface plate 21 and the lower surface plate 22. For example, two rectangular notches 24 and 25 are formed in the bottom plate 22, and guide protrusions 26 and 27 are formed along the inner periphery of the notches 24 and 25 so as to face the side plate 23. has been done. Further, the side plate 23 is formed with a spring locking protrusion 28 that protrudes inward. Further, a small portion of the outer surface corners of the peripheral edges 29 and 30 on the opening end side (both on the open end side) are cut off at the peripheral edge of the shutter 12.

The opening of the shutter 12 is widened and the case is inserted through the opening, and in this installed state, the inner surfaces of the upper surface plate 2I and the lower surface plate 22 are in contact with the surfaces of the upper shell 1 and the lower shell 2, respectively. The shutter 12 clamps the case so that it comes into close contact with the case. Side plate 2 of shutter 12
A spring is interposed between the inside of 3 and the end surface of the case.

The shank 12 slides in the recesses 10 and 11 of the upper shell 1 and lower shell 2, and the elongated holes 8 and 9 are opened and closed. Due to the tension of the spring interposed between the shutter 12 and the cassette case, when the magnetic diffuser is not in use, the top plate 21 and bottom plate 22 of the shutter 12 are
closes the elongated holes 8 and 9, and the magnetic disk 3 is kept covered by the shutter 12.

Top plate 21 of shutter 12. As described above, the lower plate 22 is designed so that the closer they are toward the periphery of the opening end, the inner surfaces of the upper plate 2I and the lower plate 22 are as follows.
It is uniformly and closely attached to the bottom surfaces of the recesses 10 and 11 of the upper shell I and the lower shell 2.

FIG. 4 is an enlarged view of a portion of the magnetic dispersion shown in FIG. 1. FIG. The protrusion 27 of the shunter 12 is slidably inserted into the guide groove 13, and the protrusion 26 is similarly slidably inserted into the guide groove 13, although not shown.

One end 32 of the spring 31 is inserted into a recess 33 formed in the case recess tunnel and locked therein. Spring 31
The other end 34 is locked to a spring locking protrusion 28 of the shutter 12.

In FIG. 4, the shutter 12 is moved by the spring 31.
Indicates a state where it is biased to a position where it is not in use. During use, when the magnetic disc focus is attached to the disc recorder body, shutter 1 is automatically activated by the actuating part of the disc recorder body as it slides when attached.
2 is moved against the spring force of spring 31. Then, an operating state is reached in which the elongated holes 14 and 15 of the shutter 12 and the elongated holes 8 and 9 of the upper shell 1 and the lower shell 2 respectively coincide with each other.

The upper surface plate 21 and the lower surface plate 22 of the shutter 12 may warp due to aging or the like.

If the upper surface plate 21 and the lower surface plate 22 warp outward, when the shutter 12 is attached to the case, the upper surface plate 2I and the lower surface plate 2
2 is not evenly brought into close contact with the recesses 10 and 11, and the peripheral edge of the shutter 12 rises from the recesses 10 and 11. If the peripheral edge rises from the recesses 10 and 11 in this way, when installing this magnetic disk cassette into the disc recorder body, the raised peripheral edge comes into contact with the restriction part of the insertion slot of the disk recorder body. Otherwise, it may not be possible to install the product smoothly. However, in this embodiment, the corners of the outer surface of the peripheral edge 29, 30 on the opening end side of the shutter 12 are cut off, so that the restriction part 35. Even if the edge portion 36 and the peripheral portion 29° 30 come into contact, smooth attachment can be achieved.

The shutter 12 is manufactured by injection molding, for example. Injection molding is performed by injecting synthetic resin through a gate into a space formed by two molds, a core and a cavity.

As shown in FIGS. 6 to 11, a mold for this purpose is used to form a core 42 and a cavity 44 to form the overall shape of the shutter 12, and a length 14.15 of the shutter 12. A slide core 55 for forming the slide cores 51 and 52 and the protrusion 26 of the shutter 12
and a slide core 56 for forming the projections 27 and 28 of the shutter 12.

In order to form the protrusion 26 inside the shutter 12, a notch 24 corresponding to the position of the slide core 55 is created, and to form the protrusion 27 and the protrusion 28 inside the shutter 12, a notch 24 corresponding to the position of the slide core 56 is created. A notch 25 is created. Here, the protrusion 27 is formed in contact with the peripheral edge of the notch 25, and a protrusion 28 protrudes from the side plate 23 into an internal space corresponding to the position of the notch 25. Therefore, by - number of slide cores 56, two protrusions 27
．． 28 can be formed.

FIGS. 6A and 6B are a front view and a side view of a mold for molding the shutter 12 described above.

7 is a sectional view taken along line AA' in FIG. 6, FIG. 8 is a sectional view taken along line BB' in FIG. 6, and FIG. 9 is a sectional view taken along line CC' in FIG. The core 42 inserted into the cavity 44 is
Top plate 21 of the shutter 12. Bottom plate 22. Side plate 2
A convex portion 4 having the same shape as the internal space formed by 3.
1. A gate 58 is provided at the top of the cavity 44 to inject molten synthetic resin into the mold.

As shown in FIG. 9, a recess 45 into which the end of the slide core 55, 56 is inserted is provided on the distal end surface of the convex portion 41 of the core 42.
, 46 are provided. The recess 45 has a depth equal to the width of the protrusion 41, as shown in FIG. 7, and the recess 46 has a depth up to the position where the protrusion 28 is formed, as shown in FIG. Steps 47, 48 are formed on the bottom surface of each of these recesses 4,5,46. The shapes of the step portions 47 and 48 correspond to the projections 26 and 27, respectively.

Slide core insertion holes 49.50 having shapes corresponding to the elongated holes 14 and 15 of the shutter 12 are formed on the front and back sides of the cavity 44, and slide cores 51 and 52 are slid through these insertion holes 49.50. Ru. As shown in FIGS. 7 and 8, slide core insertion openings 53 and 54 are formed in the front of the cavity 44, into which rod-shaped slide cores 55 and 56 are inserted, respectively. This sly
The position of the cores 55 and 56 is the notch 24 of the shutter 12
．． It becomes 25. As shown in FIG. 8, the slide core 56
A stepped portion 57 having a shape corresponding to the protrusion 28 of the shutter 12 is formed at the tip of the convex portion 41 of the core 42 that comes into contact with the tip of the shutter 12 .

A molten resin such as polyoxymethylene is injected into the inside of the mold from the gate 58, and the slide core 51,
This resin flows into the gap between the core 42 and the cavity 44 into which the cores 52, 55, and 56 are inserted. The resin is then cooled and solidified within the mold. In this case, the surface temperature of the mold is set so that the surface temperature of the cavity 44 is lower than the surface temperature of the core 42. Therefore, this solidification starts from the resin around the cavity 44.

After the liquid resin is cooled and solidified in the mold, the first
As shown in Figure 0, slide cores 51°52 and 55,5
．． 6 is laterally slid by a predetermined distance, and the mold consisting of the core 42 and cavity 44 is separated as shown in FIG. The shutter 12 having the shape shown in FIG. 2 described above is taken out from this mold. That is, by pouring liquid resin into the gap between the cavity 44 and the core 42, the top plate 21. Bottom plate 22. A side plate 23 is formed.

As shown in FIG. 6, the slide cores 51 and 52 are inserted into the cavity 44, and the resin does not flow into these parts, and the elongated holes 14 and 15 are formed there. The slide cores 55 and 56 are inserted into the core 44, and the resin does not flow into these parts, so that the notches 24 and 25 are formed there. The concave portion 45 at the tip of the convex portion of the core 42 has a stepped portion 47.
A gap is formed between the core 42 and the slide core 55 by this stepped portion 47, and the resin flows into this gap to form the protrusion 26.

As shown in FIGS. 7, 8, and 9, a step 48 is formed in the step 46 at the tip of the convex portion 41 of the core 42, and this step 48 allows the core 42 and slide core 5 A gap is formed between the two contacts, and the resin flows into this gap to form the protrusion 27. At the same time, since a stepped portion 57 is formed at the tip of the convex portion 41, the resin flows into this stepped portion 57, and the protrusion 28 is formed.

As mentioned above, the surface temperature of the mold is controlled so that the surface temperature of the cavity 440 is lower than the surface temperature of the core 42, so that the resin near the surface of the cavity 44 is lower than the surface temperature of the core 42. Therefore, the volume reduction in the vicinity of the core 42 occurs later than the volume reduction in the vicinity of the cavity 44. This strain is released after being removed from the mold, and as a result, the volume reduction in the vicinity of the core 42 occurs later than the volume reduction in the vicinity of the cavity 44.
is curved inward so that the open end becomes narrower, as shown in FIGS. 2C and 3.

This invention, as in the above-mentioned embodiment, has a slide core 5.
It can be applied not only to shutters in which the slide cores 5 and 56 are inserted from the front and therefore the notches 24 and 25 are formed, but also to shutters in which the slide cores are inserted from both sides and the notches 24 and 25 are not formed. . FIGS. 12 to 17 show a mold for integrally molding the shutter without creating the notches 24 and 25. However, the same reference numerals as those relating to the shutter 12 are used for each part of the shutter except for the notches 24 and 25.

The mold includes slide cores 69 and 70 that form the core 61 and the cavity 63 and the length 14.15 of the shutter, respectively.
and slide cores 73 and 74 for forming the projections 26, 27 and 28 of the shack. 12A and 12B are a front view and a side view of the mold, 13 is a sectional view taken along the line D-D' in FIG. 12, and FIG. 14 is a sectional view taken along the line EE' in FIG. 12. Line sectional view, Figure 15 is F-F in Figure 12
FIG. Cavity 63 and this cavity 6
The core 61 having a convex portion 62 that is fitted into the core 61 forms a shutter shape as a whole.

At the tip of the protrusion 62 of the core 61, there is a protrusion 26 of the shutter.
Step portions 65° and 66 of a shape corresponding to 27 and 27 are formed. Further, a protrusion 64 is formed at the tip of the convex portion 62, and a groove 74 having a width approximately equal to the thickness of the protrusion 28 of the shutter is formed in this protrusion 64.

The core 61 is inserted into the cavity 63. Cavity 6
3 has four slide core insertion openings formed therein.

Slide cores 69 and 70 are inserted into the slide core insertion openings, respectively. Slide core 69. The shapes of the end faces of and 70 correspond to the long holes 14 and 15 of the shutter. Slide core 73.74 from slide core insertion slot
are inserted respectively. One slide core 74 has a protrusion 76 formed at its tip.

As in the example of the mold described above, liquid resin is injected from the gate 75. The resin thus injected flows into the void within the mold and is solidified. Slide core 69.70
is slid a predetermined distance as shown in FIG. 16, the slide cores 73 and 74 are similarly slid as shown in FIG. Separated. In this way, the shutter is formed.

In other words, the gate 7 is located in the gap between the core 61 and the cavity 63.
The resin from 5 flows into the top plate 21 of the shutter. Bottom plate 22. A side plate 23 is formed. slide core 69
, 70 are inserted into this gap, the resin does not flow into this part and a long size 14.15 is formed. core 6
A gap is formed by the stepped portions 65 and 66 at the contact surface between the end face of the first convex portion 62 and the slide core 73, 74, and resin flows into this gap to form protrusions 26, 27, respectively.

The resin flows into the gap formed by the groove 72 formed in the protrusion 71 of the convex portion 62 and the protrusion 76 formed in the slide core 74, and the protrusion 28 is formed.

Core 61 and cavity 63 when the synthetic resin is solidified
By controlling the surface temperature in the same manner as described above, the peripheral edges of the upper and lower plates 21 and 22 of the shutter are curved inward when the shutter is removed from the case gill of the disk cassette.

〔Effect of the invention〕

According to this invention, since the shutter is molded from synthetic resin, the manufacturing process can be simplified and manufacturing costs can be reduced.

In addition, since the shutter is molded from synthetic resin in this way, the case will not be scraped by the shutter when it is attached to the case or when the shutter slides on the case, and the dust generated by this will be removed from the case. There is no intrusion inside. In addition, the peripheral edges of the upper and lower plates of the shutter are curved inward so that they approach each other toward the unconnected part, so the head insertion port and band insertion port of the case can be completely covered with the shutter. Can be occluded. Furthermore, since the corner of the peripheral edge of the open end example is cut off at the peripheral edge of the shutter, the magnetic disk cap can be smoothly attached to the disk recorder main body. Therefore, according to the present invention, it is possible to realize, at low cost, a magnetic disk drive having excellent operability and equipped with a shutter that can sufficiently protect the magnetic disk inside the case.

[Brief explanation of drawings]

Fig. 1 is a top view and a bottom view of an embodiment of the present invention, Fig. 2 is a top view and a bottom view of an embodiment of the present invention;
The figure is a front view of a shutter in one embodiment of this invention.
A bottom view and a side view, FIG. 3 is a sectional view of a shutter in an embodiment of the invention, FIG. 4 is a partially enlarged view of a shutter in an embodiment of the invention, and FIG. 5 is an embodiment of the invention. 6 is a front view and a side view of an example of a mold for molding a shutter according to an embodiment of the present invention, and FIGS. 10 and 11 are cross-sectional views of an example of a mold for forming a shutter in an embodiment of the present invention, and FIG. 12 is a cross-sectional view of this example. Front view and side view of another example of a mold for forming a shutter in one embodiment of the invention, No. 13
14 and 15 are cross-sectional views of other examples of a mold for molding a shutter according to an embodiment of the present invention, and FIGS. FIG. 7 is a cross-sectional view used to explain another example of a mold for molding a shutter. upper shell, 2: lower shell, 3: magnetic disc, 12: shutter, 13 guide groove, 2 upper plate, 2
2: Bottom plate, 23: Side plate, 24° 25: Notch, 26,
27: Projection, 28 Spring locking projection, 31 Spring, 42.61: Core, 44, 63: Cavity, 51', 52° 55.56, 69.70, 73, 74
Nislide core. Agent Masatomo Sugiura Figure 1 Figure 2 Figure 3 Figure 6 A Figure 1 Figure 10 Figure 8 Figure 11 Figure 12 A Figure 13 Figure 16 Figure 15 Figure 18

Claims (4)

[Claims] (1) In a magnetic disk cassette comprising a magnetic disk, a case containing the magnetic disk, and a shutter that is slidably provided in the case and can take an operating position and a non-operating position, the above-mentioned The shutter has a U-shaped cross section and includes a head formed on at least one of the top plate, the bottom plate, a side plate connecting the top plate and the bottom plate, and the top plate and the bottom plate so as to sandwich the case. 1. A magnetic disc insert characterized in that an insertion opening is integrally molded using a synthetic resin material. (2) A magnetic disk cassette comprising a magnetic disk, a case containing the magnetic disk, and a shutter slidably provided in the case and capable of taking an operating position and a non-operating position. The shutter has a U-shaped cross section and a head formed on at least one of the top plate, the bottom plate, the side plate connecting the top plate and the bottom plate, and the top plate and the bottom plate so as to sandwich the case. The insertion opening is integrally molded using a synthetic resin material, and when the case is removed from the case, both the top plate and the bottom plate are shaped so that they approach each other toward the unconnected portion. A magnetic disk cassette characterized by one thing. (3) In the magnetic diffuser according to claim 1 or 2, on one of the upper plate or the lower plate of the shutter,
A magnetic disk cassette characterized in that a protrusion is provided to be inserted into a groove provided in the case. (4) The magnetic disfucus centrifuge according to claim 2, wherein a first mold is inserted into an internal space formed by the top plate, the bottom plate, and the side plate of the shutter; The shutter is formed by a second mold that is fitted into the first mold, and by differentiating the cooling conditions of the first mold and the second mold, the top plate and A magnetic disk cassette, wherein both of the lower plates are shaped so that they approach each other toward the non-coupled portion.