JPH0526275B2 - - Google Patents

Description

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

[Background technology and its problems]

A magnetic disk cassette is known in which a flexible magnetic disk, for example, 3.5 inches in diameter, is housed in a hard case and digital data can be recorded and reproduced in this state. A shutter is attached to this magnetic disk cassette so that it can be opened and closed in order to protect the magnetic disk.
That is, this shutter is opened only when in operation, and the magnetic disk is exposed through an 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 U-shaped cross section. The shutter was formed with an elongated hole of approximately the same shape as the opening of the case, and the shutter 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. Also,
This shutter must be in uniform contact with the outer surface of the case and must 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 were manufactured by drilling, bending, deburring, and other processes on flat stainless steel plates. However, since the stainless steel flat plate is stored in a rolled state, stress may remain and it may deform, making it difficult to perform highly accurate processing in the bending process.

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, which causes dust to get into the case. It was hot. 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, resulting in high costs. Therefore, shutters made of synthetic resin have been considered, but if the core of the mold used for injection molding has flat parts that correspond to the top and bottom plates of the shutter, The top and bottom plates of the shutter were sometimes warped in a concave manner with respect to the outside.
Furthermore, even when the upper and lower plates of the shutter are formed flat, they may warp in a concave shape toward the outside due to aging.

If the top or bottom plate of the shutter is warped in a concave manner with respect to the outside, when the shutter is slid against the case, the hole for inserting the head in the shell or the hole for inserting the head pad in the case may be damaged. In some cases, the end of the hole for inserting the head or the hole for inserting the head pad provided in the shutter could get caught in the end of the hole for the shutter.

[Purpose of the invention]

Therefore, an object of the present invention is to prevent the top and bottom plates of the shutter from being warped in a concave manner with respect to the outside, so that when the shutter is slid relative to the case, the head provided on the shell To provide a disk cassette equipped with a shutter that does not get caught in an insertion hole or a head pad insertion hole.

[Summary of the invention]

The present invention provides a disk cassette comprising a disk, a case containing the disk, and a shutter that is slidably provided in the case and can take an operating position and a non-operating position, the shutter having a U-shaped cross section. The top plate, the bottom plate, the side plate connecting the top plate and the bottom plate, and the opening for inserting the head formed in at least one of the top plate and the bottom plate are removed from the case so as to sandwich the case. This disc cassette is integrally molded of synthetic resin with a mold having a shape corresponding to the shape of the shutter, so that both the upper surface plate and the lower surface plate approach each other toward the unconnected part in the state of the disc cassette.

〔Example〕

An embodiment of the invention will be described below with reference to the drawings. FIGS. 1A and 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 the upper shell and 2 is the 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 heat-welded 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 circumference of the upper shell 1 and the outer circumference of the lower shell 2 are joined by ultrasonic welding, and the magnetic disk 3 is housed in a case in which the upper shell 1 and the lower shell 2 are combined. 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 pin insertion hole 6 is located at a position offset from the insertion hole 5 by a predetermined distance.
is formed. A circular opening 7 is formed in the center of the lower shell 2, and the center plate 4 is placed in this opening 7 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 inserted through the elongated holes 8 and 9.
is exposed.

Recesses 10 and 11 are formed on the outer surfaces of the upper shell 1 and lower shell 2, including the portions where the elongated holes 8 and 9 are formed, and within these recesses 10 and 11 are shutters having a U-shaped cross section as shown in FIG. 12 is slidably attached. 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 inserting the head, the elongated hole 8 for inserting the head pad, and the elongated holes 14 and 15 formed in the shutter 12 coincide, and the magnetic disk 3 is exposed to the outside, and as shown by imaginary lines in FIGS. 1A and 1B, the elongated holes 8 and 9 are closed, and the magnetic disk 3
The shutter 12 slides so that it can be in an unused state covered by 2. This shutter 12 protects the magnetic disk 3 and prevents dust from entering.

Furthermore, a lug 16 for preventing accidental erasure is provided at one corner of the lower shell 2.
If you break it up and remove it, it cannot be erased. A pair of positioning holes 17 and 18 are provided at the two corners of the lower shell 2 for positioning the magnetic disk cassette when it is attached to the disk recorder body. One of the positioning holes 17 is an elongated hole, so that even if there is some error in the position of the hole, it can be tolerated. The other two corner parts where these positioning holes 17 and 18 are not provided serve as reference planes, and 4
The magnetic disk cassette is supported at the reference position at each corner. In this state, the magnetic disk 3 is rotated by the motor, and digital 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 2
1. The side plate 23 and the bottom plate 22 are integrally molded. The shutter 12 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 has a U-shaped cross section.
As shown in FIG. C and FIG. 3, the upper plate 21 and the lower plate 22 become closer toward the opening ends of the front and side surfaces.

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, on the side plate 23, a spring locking protrusion 28 protruding inwardly is provided.
is formed.

The opening of the shutter 12 is widened, and the case is inserted through the opening. In this installed state, the inner surfaces of the upper surface plate 21 and the lower surface plate 22 touch the surfaces of the upper shell 1 and the lower shell 2, respectively. The shutter 12 holds the case so that it comes into close contact with the case. A spring is interposed between the inside of the side plate 23 of the shutter 12, the case, and the end surface. The shutter 12 slides through the recesses 10 and 11 of the upper shell 1 and lower shell 2, and the elongated holes 8 and 9
is opened and closed. Due to the tension of the spring interposed between the shutter 12 and the cassette case, when the magnetic disk cassette is not in use, the top plate 21 and bottom plate 22 of the shutter 12 close the elongated holes 8 and 9, and the magnetic disk 3 closes the shutter 12.
kept covered with.

The top plate 21 and bottom plate 22 of the shutter 12 are
As mentioned above, since the two become closer toward the periphery of the opening end, the inner surfaces of the upper surface plate 21 and the lower surface plate 22 are in contact with the bottom surfaces of the recesses 10 and 11 of the upper shell 1 and the lower shell 2. Adheres evenly.

FIG. 4 is an enlarged view of a portion of the magnetic disk cassette shown in FIG. Shutter 1
The protrusion 27 of No. 2 is slidably inserted into the guide groove 13, and the protrusion 26 is similarly inserted into the guide groove 1, although not shown.
3 is slidably inserted. One end 32 of the spring 31 is located in a recess 33 formed in the cassette shell.
is inserted and locked. The other end 34 of the spring 31 is locked to a spring locking projection 28 of the shutter 12.

FIG. 4 shows the shutter 12 biased by the spring 31 to a non-use position. When the magnetic disk cassette is attached to the disk recorder main body during use, the shutter 12 is automatically moved against the spring force of the spring 31 by the actuating section of the disk recorder main body as the magnetic disk cassette slides during the installation. 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 shutter 12 is formed by injection molding, for example. Injection molding is performed by injecting synthetic resin through a gate into a space formed by a mold consisting of a core and a cavity.

As shown in FIGS. 5 to 7, the mold for this purpose includes a core 41 for forming the entire shape of the shutter 12, a slide core for forming the cavities 42 and 43, and the protrusion 26 of the shutter 12. 44 and a slide core 45 for forming the projections 27 and 28 of the shutter 12.

In order to form a protrusion 26 inside the shutter 12, a notch 2 corresponding to the position of the slide core 44 is formed.
4, and in order to form the projections 27 and 28 inside the shutter 12, a notch 25 corresponding to the position of the slide core 45 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, both of the two protrusions 27 and 28 can be formed by one slide core 45. In addition, in order to form the elongated holes 14 and 15 of the shutter 12, the elongated holes 14 and 15 are formed in the cavities 42 and 43.
Convex portions 48 and 49 having shapes corresponding to 15 and 15 are formed, and concave portions 52 and 53 having shapes corresponding to these are formed in the core 41.

Slide cores 44 and 45 are inserted into the cavity 42, and the cavities 42 and 43 are fitted into the core 41. In the mold thus configured, a gate 57 is formed by the grooves 57A and 57B of the cavities 42 and 43. Also, cavity 42,4
3 concave portions 46, 47 and core 41 convex portions 50, 5
1 and the grooves 55 and 56 of the core 41 form a gap. This gap corresponds to the outer diameter of the shutter 12. Furthermore, the slide core 44 and the core 4
1 and the projection 26 of the shutter 12.
A gap having a shape corresponding to the projections 27 and 28 of the shutter 12 is formed by the step portions 59 and 60 of the slide core 45 and the core 41. Molten synthetic resin is injected from the gate 57 of this mold, and flows into the void within the mold. This synthetic resin is then cooled within the mold and solidified into a shape corresponding to the voids within the mold.

The recesses 46, 47 of the cavities 42, 43, the protrusions 50, 51 of the core 41, the grooves 55 of the core 41,
The cavity in the mold formed by 56 corresponds to the outer shape of shutter 12. Therefore, the shutter 12 having a U-shaped cross section as shown in FIGS. 2 and 3, with both the top plate 21 and the bottom plate 22 coming closer toward each other toward the opening end, is formed by this gap. In addition, as shown in Fig. 6, the cavity 4
Convex portions 48 and 49 of 2 and 43 and concave portion 5 of core 41
2 and 53 create a portion within the mold into which the synthetic resin does not flow. Elongated holes 14 and 15 of the shutter 12 are formed corresponding to this portion. Furthermore, the gap formed by the slide core 45 and the stepped portion 58 of the core 41 corresponds to the projection 26 of the shutter 12, as shown in FIG. Therefore, the protrusion 26 is formed by this gap. Furthermore, the gaps formed by the slide core 45 and the stepped portions 59, 60 of the core 41 correspond to the protrusions 27, 28 of the shutter 12, as shown in FIG. Therefore, projections 27 and 28 are formed by these gaps. By inserting the slide cores 44 and 45, a portion is created in the mold into which the synthetic resin does not flow. Notches 24 and 25 are formed in the shutter 12 by this portion.

〔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 is not scraped by the shutter when the shutter is attached to the case or when the shutter slides on the case, and the dust generated by this is removed from inside the case. There is no possibility of intrusion. In addition, the core of the mold used for injection molding of the shutter is curved in a convex manner toward the outside in parts corresponding to the top and bottom plates of the shutter. The face plate has a shape that is curved convexly toward the outside, or even if a strain force that causes it to become concave to some extent is applied, it remains flat, and conversely, it does not curve concavely. Furthermore, even if the material warps in the direction of becoming concave due to aging, the probability of it becoming concave is considerably low. Therefore, when the shutter slides on the case, it is possible to prevent the shutter from getting caught in the head insertion hole or head pad insertion hole provided in the shell of the case. In addition, the peripheral edges of the top and bottom plates of the shutter are curved inward so that they approach each other toward the unconnected part, so that the shutter can completely insert the head insertion port and pad insertion port of the case. Can be occluded.

[Brief explanation of the drawing]

FIG. 1 is a top view and a bottom view of an embodiment of the invention, FIG. 2 is a front view, bottom view, and side view of a shutter in an embodiment of the invention, and FIG. 3 is a top view and a bottom view of a shutter in an embodiment of the invention. A sectional view of the shutter, FIG. 4 is a partially enlarged view of the shutter in an embodiment of the present invention, and FIGS. 5, 6, and 7 are examples of a mold for molding the shutter in an embodiment of the present invention. FIG. 1...Upper shell, 2...Lower shell, 3...
Magnetic disk, 12...Shutter, 13...Guide groove, 21...Top plate, 22...Bottom plate, 23
...Side plate, 24, 25...Notch, 26, 27...
...Protrusion, 28...Protrusion for spring locking, 31
... Spring, 41 ... Core, 42, 43 ...
Cavity, 44, 45...Slide core.

Claims (1)

[Claims] 1. A disk, a case including the disk,
A shutter is slidably attached to the case to open and close an opening for inserting the head provided in the case. and a lower plate, a side plate connecting the upper plate and the lower plate, and an opening for inserting a head formed in at least one of the upper plate and the lower plate. By injection molding from a synthetic resin material using a mold consisting of a core whose portions corresponding to the upper surface plate and the lower surface plate are curved in a convex shape toward the outside, and a cavity arranged on the outer periphery of the core. A disk cassette, characterized in that it is integrally formed and has a shape in which the unconnected portion sides of the upper surface plate and the lower surface plate of the shutter are close to each other.