JPH0554193B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording/reproducing disk cassette containing a disk-shaped recording medium.

[Prior art and its problems]

This type of disk cassette includes a disk-shaped recording medium housed between an upper shell and a lower shell,
A head insertion hole is formed in one of the upper and lower shells. Furthermore, a shutter is provided in the cassette housing so as to be openable and closable for blocking the head insertion hole to prevent foreign matter, dust, etc. from entering. This shutter is normally biased by a coil spring or the like to a position where it closes the head insertion hole.

By biasing the shutter with a spring, it is now possible to provide the disc recorder with a mechanism that automatically opens and closes the shutter when a disc cassette is attached to or removed from the disc recorder, making it extremely easy to use for the user. Makes a good disk cassette. However, from the manufacturer's perspective, incorporating minute spring parts into the cassette is
This is not preferable because it increases the number of assembly steps.
Especially when considering automatic assembly, it is not easy for automatic machines to handle springy parts compared to rigid parts, and special devices and delicate methods are required for the means of capturing and inserting (attachment means) of the parts. Requires adjustment.

Therefore, the applicant of the present invention has proposed a magnetic disk cassette using a torsion coil spring shown in FIG. 1 for biasing the shutter. This torsion coil spring 1 is made of, for example, a stainless steel wire wound several times, and both ends of the coil portion 2 are extended linearly in the tangential direction, and one end 3 is bent into an Ω shape to form one of the upper and lower shells. It serves as an engaging part with the support shaft formed in the. Further, the other end portion 4 is bent at a substantially right angle to form a locking portion with a locking portion of the shutter. This spring 1 can be installed in the cassette shell by press-fitting the Ω-shaped bent end 3 into the support shaft of the cassette shell, and the other end 4 is engaged with the locking part of the shutter by the restoring force of the spring. Since it can be stopped, it has the advantage that the work can be done by automatic machines or by hand very easily.

When using a torsion coil spring 1 as shown in Fig. 1, if the bending length of one end 4 of the spring 1 that is locked to the shutter side is short, the spring will easily come off from the shutter, so it is necessary to Requires. If such a minute spring component comes off and enters the disk drive device, it may cause a short circuit in the circuit section or damage to the mechanism section.

In view of this problem, the present invention aims to make the bending length of the end of the spring that biases the shutter sufficiently long within the thickness limit of the cassette case, and to prevent the spring from coming off easily. purpose.

[Means for solving problems]

The disk cassette according to the present invention includes a cassette housing consisting of upper and lower shells 10 and 11 that accommodates a disk-shaped recording medium (flexible magnetic disk 12), and a head insertion hole 15 formed in the cassette housing that opens and closes. A shutter 17 is slidably mounted across the side end surface of the cassette case, and a substantially V-shaped torsion coil spring 20 biases the shutter to a position that closes the head insertion hole. However, one tip end of the torsion coil spring is a bent part (24 or 25) which is bent in parallel to the overlapping direction of the coils as a locking end.

The shutter 17 is provided with one tip (bent portion 24 or 2) of the torsion coil spring 20.
5) is provided, and a fixing portion for fixing the other tip of the torsion coil spring 20 is provided at one end of the side end surface of the housing.

A movement space of the bent portion defined by the inner surface of the shutter 17 and the side end surface (upper end surface 32) of the cassette housing, and that spans the range in which the bent portion of the torsion coil spring 20 moves when the shutter is opened and closed. has.

According to this configuration, the bent length of the locking end of the torsion coil spring 20 can be made sufficiently long within the thickness limit of the cassette casing, so that the spring does not easily come off.

〔Example〕

Hereinafter, the disk cassette of the present invention will be explained along with examples.

Fig. 2 is a plan view of a flexible magnetic disk cassette to which the present invention is applied, Fig. 3 is a partial plan view with the shutter open, and Figs. 4 A and B are a plan view and a side view of the shutter. .

The disk cassette shown in FIGS. 2 and 3 consists of an upper shell 10 and a lower shell 11, between which a magnetic disk 12 is rotatably housed. The magnetic disk 12 has a metal center core 1
3, and this center core 13 serves as the lower shell 11.
It is chucked to the spindle of a disk drive device through a central hole 14 formed in the disk drive device. Further, a rectangular head insertion hole 15 is formed in the lower shell 11 along the radial direction of the disk, while a presser pad insertion hole 15 is formed in the corresponding position in the upper shell 10.
6 is formed.

In order to close the head insertion hole 15 and pad insertion hole 16, the shutter 17 shown in FIGS. 4A and 4B is inserted into the recess 18 formed in the upper shell 10 and the lower shell 11, respectively, so as to straddle the cassette case. It is installed so that it can freely move back and forth. Window holes 19 are formed on both sides of the shutter 17 to match the insertion holes 15 and 16, and when the shutter 17 is in the open position as shown in FIG. 16, and the head and presser pad can be inserted. Also shutter 1
7 is in the closed position as shown in FIG. 2, the pad insertion hole 16 and the head insertion hole 15 are closed by the shutter 17. A torsion coil spring 20 is compressed between the shutter 17 and the cassette housing so that the shutter 17 is always in the closed position shown in FIG. 2 when the disk cassette is not in use.
As a result, the shutter 17 is urged in the direction of arrow a in FIG.

5A and 5B show a top view and a side view of the torsion coil spring 20. FIGS. This torsion coil spring 20 is made by winding a stainless steel wire several times, and both ends of a coil portion 21 are connected to arm portions 22 and 23 extending linearly. Each arm 22,
The ends of 23 form approximately 90° bent portions 24 and 25. The bending directions of the respective bending portions 24 and 25 are opposite to each other, and face the height direction of the coil portion 21. Each arm portion 22 of this torsion coil spring 20,
The lengths b and c of 23 are equal, and each bent portion 2
The lengths d and e of 4 and 25 are also equal. Therefore, the torsion coil spring 20 has a point-symmetric structure, and either of the bent portions 24 and 25 may be a fixed end to the shutter 17 or the disk housing.

That is, since the torsion coil spring 20 has no directionality in attachment, assembly work by an automatic machine or by hand becomes extremely easy. Further, since the spring 20 has a simple shape and is easy to manufacture, and there is no Ω-shaped bent portion as shown in FIG. 1, the springs do not become entangled with each other, and assembly efficiency can be improved. Furthermore, since the bent portions 24 and 25 of the spring 20 are oriented in the height direction of the coil portion 21, the spring 20 is oriented in the thickness direction of the disk cassette.
0 height can be made lower and is therefore suitable for thinner cassette structures.

Next, a structure for attaching the torsion coil spring 20 to the cassette housing and the shutter 17 will be explained.
FIG. 6 is a top side view of the main part of the disk cassette showing the mounting structure of the torsion coil spring 20, and FIG. 7 is a plan view of the main part. Also, Figures 8 and 9 are respectively 7
A partial cross section taken along the - line and - line in the figure is shown.

A bent portion 24 (or 25) at one end of the torsion coil spring 20 shown in FIG. 5 is inserted and locked into a recess 27 formed in the cassette shell. In addition, the bent portion 25 (or 24) at the other end is connected to the shutter 17.
It is latched to a hook portion 28 formed by cutting and raising the upper surface of the holder. As shown in FIG.
It is surrounded by 0a and 11a and an overhang portion 29 formed in the upper shell 10. Therefore, the spring 20 inserted into the recess 27 will not fall out in the vertical and horizontal directions in FIG. Further, in the insertion direction, the spring 20 is fixed by its own return force.

On the other hand, the bent portion 25 (or 24) of the spring 20
is the hook part 28 of the shutter 17 as shown in FIG.
In the state in which the shutter is hung, the upper and right directions in FIG.
1 to prevent it from coming off.

Note that, as shown in the conventional example in FIG. 12, which corresponds to FIG. L cannot be made longer, and if the spring 20 twists as shown by the dashed line as the shutter 17 opens and closes, the inner surface of the lower shell 11 and the tip of the spring 20 will come into sliding contact, causing the shavings 1
1b occurs. When this shavings 11b adheres to the surface of the disk 12, dropout of the recording/reproducing signal occurs.

If a space for movement of the bent portion 25 is provided as shown in FIG. 9, the length of the bent portion 25 of the spring 20 can be made sufficiently long to prevent it from coming off easily, and the sliding contact with the inner surface of the shell 11 can be made. can be avoided.

In order to facilitate the installation work of the spring 20, a stepped portion 31 lower than the upper side surface 30 of the shell is formed in the upper shell 10 near the entrance of the recess 27, as shown in FIGS. 6 and 7. ing. This step 3
1 is connected to an overhang portion 29 forming a spring locking recess 27. In addition, the corresponding part of the lower shell 11 has a stepped portion 3 that protrudes from the upper side of the shell.
3 is formed.

Figures 10 and 11 show a torsion coil spring 20.
FIG. 2 is a top side view and a perspective view of a main part for explaining the installation work. As shown in these figures, the arm portion 22 of the spring 20 is pressed against the side wall of the protruding step portion 33 of the lower shell 11, and the bent portion 24 is pressed against the upper surface of the lowered step portion 31 of the upper shell. Part 3
The spring 20 can be inserted into the recess 27 by sliding the spring 20 in the direction of the arrow E while being guided by the springs 1 and 33. Note that since the lower step portion 31 is provided, the insertion angle θ (FIG. 11) of the spring 20 may be small. Therefore, spring 2
The insertion work line of 0 is straight. Therefore, the installation work is very simple, and it is also easy to install using an automatic machine.

〔Effect of the invention〕

As described above, the present invention uses a V-shaped torsion coil spring 20 as a spring for urging the shutter 17 to close, one end of which is fixed to the cassette case side, and the other end is formed into a bent portion 25 to engage the shutter 17. In the range in which the tip of the folded portion 25 moves as the shutter 17 is closed, the fold defined by the inner surface of the shutter 17 and the side end surface (upper end surface 32) of the cassette case is retained. Since the bending part is a moving space, the bending part 25 of the spring 20 is
can be made sufficiently long within the thickness limit of the cassette housing so that the spring 20 does not easily come off and fall.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the conventional shape of a torsion coil spring for urging the shutter of a magnetic disk cassette. 2 to 11 show embodiments of the magnetic disk cassette according to the present invention, FIG. 2 is a plan view, FIG. 3 is a partial plan view with the shutter open, and FIGS. 4A and 4B are views of the shutter. A plan view and a side view, FIGS. 5A and 5B are a plan view and a side view of the torsion coil spring 20, FIG. 6 is a top side view of the main part of the disk cassette showing the mounting structure of the torsion coil spring, and FIG. 7 is a plan view of the main part. Figures 8 and 9 are partial cross-sectional views taken along lines - and - in Figure 7, respectively, and Figures 10 and 11 are top side views and perspective views of essential parts for explaining the installation work of the torsion coil spring. It is a diagram. FIG. 12 is a partial sectional view similar to FIG. 9 showing the prior art. In addition, in the symbols used in the drawings, 10... upper shell, 11... lower shell, 12... magnetic disk, 15... head insertion hole, 17... shutter, 20... torsion coil spring, 21... coil part, 22, 23... Arm part, 24, 25... Bent part, 27... Recessed part, 28... Hook part, 32...
...This is the upper side.

Claims (1)

[Scope of Claims] 1. A cassette casing consisting of upper and lower shells for storing a disc-shaped recording medium, and a head insertion hole formed in the cassette casing that straddles the side end surface of the cassette casing in order to open and close the head insertion hole. It has a shutter that is slidably attached, and a bent portion that is approximately V-shaped and has one tip bent in parallel to the overlapping direction of the coils, which urges the shutter to a position that closes the head insertion hole. a torsion coil spring; a locking part provided on the shutter and locking the one tip of the torsion coil spring; provided at one end of the side end surface of the cassette casing;
It is defined by a fixing part that fixes the other tip of the torsion coil spring, an inner surface of the shutter, and the side end surface of the cassette housing, and the bent part of the torsion coil spring moves when the shutter is opened and closed. A disk cassette with a movable space for a bending part over a wide range.