JPS6316050Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a disk cassette for recording and reproducing various analog and digital signals, etc., and is particularly composed of an upper and a lower half, and has a head insertion hole in at least one of the upper and lower halves. a cassette housing, a disk-shaped recording medium such as a magnetic disk made of a magnetic sheet rotatably housed within the cassette housing; The present invention relates to a recording/reproducing disk cassette equipped with a shutter for opening and closing a head insertion hole.

According to the above recording/playback disk cassette,
When the head insertion hole is not in use, the head insertion hole can be closed with a shutter, so that foreign matter and dust can enter the cassette through the head insertion hole and adhere to the recording/playback surface of the disk-shaped recording medium. This is effective because it can prevent damage to recording and reproduction.

Conventionally, when the shutter is moved to a position where the head insertion hole is opened, an engagement hole provided in the shutter is click-engaged with a chevron-shaped protrusion provided on the half to lock the shutter. Further, by moving the shutter from the open position to the closed position, the engagement hole is clicked off from the chevron-shaped protrusion to release the lock, and even in the closed position, another engagement hole and the chevron-shaped protrusion are engaged. It was configured to lock in the same way. When in use, after the shutter is moved to the open position and locked, the cassette is inserted into the recording/playback device, and after the cassette is removed from the recording/playback device, the shutter is moved to the closed position and locked. That's what I was doing.

However, in such a conventional structure, while the shutter is frequently reciprocated, the chevron-shaped protrusion provided on the half is gradually scraped off by the edge of the engagement hole of the shutter. Eventually, there was a flaw that made it impossible to lock the shutter.

The present invention aims to provide a shutter that can correct the above-mentioned defects, has a highly reliable locking structure that can reliably lock the shutter even after long-term use, and is easy to operate by allowing the shutter to be moved easily from the open position to the closed position with a single touch, and is particularly easy to assemble.

Embodiments of a recording/reproducing disk cassette to which the present invention is applied will be described below with reference to the drawings.

First, in FIGS. 1 and 2, the cassette housing 1 is constructed as a thin, substantially square-shaped housing as shown in FIG. The cassette housing 1 is composed of an upper half 2 and a lower half 3 as shown in FIG. Alternatively, the four corners are fixed and joined together by an appropriate fixing method such as welding dowel tightening or screw fixing. Note that the upper and lower halves 2 and 3 are molded from a synthetic resin having appropriate elasticity, such as ABS resin. A disk-shaped recording medium (hereinafter simply referred to as disk) 4, such as a magnetic disk made of a magnetic sheet, is rotatably housed within the cassette housing 1. As shown in FIG. 1, the disk 4 is fitted into a circular hole 6 provided in the center of the lower half 3 by a disk 5 made of a magnetic material that is integrally fixed to the center thereof. It is rotatably stored. Also upper half 2 and lower half 3
A pad insertion hole 7 and a head insertion hole 8 are provided in each of the pads. These insertion holes 7 and 8 are formed by long holes extending in the radial direction of the disk 4, and are arranged to face each other from above and below. The recording/reproducing surface 4a of the disk 4 has a head insertion hole 8.
It is placed facing downwards to face the

Next, as shown in FIG. 2, a shutter 11 is movably attached to the cassette housing 1. As shown in FIG. 1, this shutter 11 is made of stainless steel, aluminum, synthetic resin, etc. and is molded into a substantially U-shape. is a pair of window holes 12 that are aligned with both the insertion holes 7 and 8,
13 are provided. On the other hand, rectangular recesses 14 are formed in the upper and lower surfaces of the upper and lower halves 2 and 3 on the side of one end 1a, respectively. And shutter 11
is capable of linearly reciprocating along one end edge 1a of the cassette casing 1 with its upper and lower pieces 11a and 11b fitted in both the upper and lower recesses 14 so as to straddle the cassette casing 1 vertically. installed.

Next, FIGS. 3A and 3B show the opening and closing states of both insertion holes 7 and 8 by the shutter 11. When the shutter 11 is moved to the open position on one side as shown in FIG. 3A, both windows are opened and closed. The holes 12 and 13 are superimposed on both the insertion holes 7 and 8, and these insertion holes 7 and
8 is released. Furthermore, when the shutter 11 is moved to the closed position on the other side as shown in FIG. 3B, the window holes 12 and 13 are laterally shifted from above the insertion holes 7 and 8.
Both insertion holes 7, 8 are closed by upper and lower pieces 11a, 11b.

At this time, as shown in FIGS. 3A and 3B, the shutter 11 is equipped with a compression coil spring 1.
6 from the open position to the closed position (direction of arrow a)
It has been energized to move to. When the shutter 11 is moved to the open position (in the direction of arrow b), the compression coil spring 16 is compressed. The shutter 11 is locked in the open position by a lock structure to be described later, but when the lock is released, the shutter 11 is automatically moved to the closed position by the repulsive force of the compression coil spring 16, and returns to the closed state. It is configured to be held in

Further, this recording/reproducing disk cassette is installed in a recording/reproducing apparatus by locking it with the shutter 11 moved to the open position as shown in FIG. 3A, for example. Note that it is also possible to open the shutter 11 by using the operation of inserting a cassette into the recording/reproducing apparatus. Then, the disk 4 is magnetically attracted by the disk 5 and positioned on a disk drive rotary table provided in the recording/reproducing apparatus. Then, a recording/reproducing head consisting of a magnetic head or the like is inserted into the cassette casing 1 through the head insertion hole 8 and is brought into contact with the recording/reproducing surface 4a of the disk 4, while being inserted into the cassette casing 1 through the pad insertion hole 7. The top side of the disk 4 is held down by the pad. In this state, the disk 4 is rotated and the recording/reproducing head scans the disk 4 in the radial direction, thereby performing a desired recording/reproducing operation.

Next, a method of assembling the shutter 11 and the compression coil spring 16 will be explained with reference to FIGS. 4 to 8B.

First, as shown in FIGS. 4 and 5, a groove 17 is formed along one end edge 1a of the cassette housing 1, and the core rod 1 is inserted along the inside of the groove 17.
8 is installed. Both ends 18a of the core rod 18 are embedded and fixed in the cassette housing 1, and this is done when the upper and lower halves 2 and 3 are fitted from above and below. The compression coil spring 16 is inserted into the outer periphery of the core rod 18 and installed in the groove 17. At this time, the length of the compression coil spring 16 is configured to be approximately equal to or slightly shorter than the length of the groove portion 17. On the other hand, as shown in FIG.
An engaging piece 19 is fixed to the inside of a vertical piece 11c located at the middle of the folded portions of the upper and lower pieces 11a and 11b. This engaging piece 19 is the vertical piece 11
It stands upright at right angles to c, and has a substantially U-shaped engagement groove 20 formed at its tip. Further, a jig insertion hole 21 is provided in a portion of the lower piece 11b of the shutter 11 at a position near the engagement piece 19. A pair of projections 22 are formed on the inside of the lower piece 11b at a distance from each other. In addition, as shown in FIG.
A pair of guide grooves 23 parallel to one end edge 1a are formed in the recessed portion 14 on the lower surface side.

Next, the shutter 11 is fitted into the cassette housing 1 as shown in FIGS. 7A and 8A in the closed position shown in FIG. 3B, and its pair of protrusions 22 are respectively engaged with the pair of guide grooves 23. Ru. When the shutter 11 is fitted, the engagement pieces 19 are engaged with the upper and lower sides of a portion of the core rod 18 at right angles through the engagement grooves 20. However, when fitting the shutter 11, as shown in FIGS. 7A and 8A, a jig plate 26 having a substantially U-shaped engagement groove 25 at the tip is inserted into the jig insertion hole 21 of the shutter 11. Insert and engage a portion of the compression coil spring 16. Then, in the engaged state, the jig plate 26 is moved a little in the direction of arrow b in FIG. 7A to compress the compression coil spring 16 in the direction of arrow b. Then, one end 16a of the compression coil spring 16 is slightly separated from the engagement piece 19 of the shutter 11 in the direction of arrow b. Therefore, with the one end 16a of the compression coil spring 16 slightly separated from the engaging piece 19 in the direction of arrow b, the shutter 11 is inserted into the cassette case 1 as shown in FIGS. 7A and 8A, as described above. Fit the engagement piece 19 into the engagement groove 20.
to engage a part of the core rod 18 at right angles.
Then, as shown in FIG. 8B, when the jig plate 26 is pulled out of the jig plate insertion hole 21, the compressed state of the compression coil spring 16 is released.
One end 16a thereof is extended in the direction of arrow a as shown in FIG. 7B, and one end 16a is pressed against the side surface of the engagement piece 19 from the direction of arrow a. With the above steps, the assembly of the compression coil spring 16 and the shutter 11 is completed, and the compression coil spring 16 urges the shutter 11 to move toward the closed position in the direction of arrow a, as shown in FIG. 3B.

After completing the above assembly, the shutter 11 is
The protrusions 22 are guided by the guide grooves 23 to linearly reciprocate along the one end edge 1a of the cassette housing 1 between the closed position and the open position. By the way, the projection 22 formed on the lower piece 11b of the shutter 11 may be a drawn projection shown in FIGS. 8A and 8B, or a cut and raised projection shown in FIG. 8C. In any case, if an appropriate radius or tapered portion 22a is formed at the contact portion of the guide groove 23 with the edge 23a, the protrusion 22 will guide the shutter 11 when it reciprocates (slides). Edge 2 of groove 23
It is difficult to cause damage that would cause 3a to be gradually scraped off and become jagged. In addition, the reciprocating movement (sliding movement) of the shutter 11 can always be performed smoothly.

Next, a lock structure for locking the shutter 11 in the open position described above will be explained.

First, Figures 9A to 10C show the first part of the lock structure.
This is an example of the shutter 1.
An engaging portion 29 formed by a square hole is provided at the corner portion of the lower piece 11b and the vertical piece 11c at the end opposite to the window holes 12 and 13 side of the window hole 1. Next, a lock pawl 30 with which the engaging portion 29 is engaged is integrally formed on the lower surface side of the edge portion of the lower half 3 of the cassette housing 1. At this time, the lock pawl 30 is arranged near the corner 3a on the shutter open position side shown in FIG. 3A. There is a predetermined length l1 and width between the corner 3a of the lower half 3 and the corner 2a of the upper half 2 opposite thereto, as shown in FIG. _9A .
A slit 31 of _l2 is formed. Therefore, the corners 2a and 3a of the upper and lower halves 2 and 3 are thinner than other parts, and are indicated by the arrow c in FIG. 10A.
It is configured to be able to bend against elasticity in the and d directions. As shown in FIG. 10A, the locking pawl 30 is formed into a vertical surface such that its locking surface 30a can engage with the engaging portion 29 at right angles, and the end surface opposite to the locking surface 30a is formed into an inclined surface 30.
It is formed in b.

According to the first embodiment of the lock structure constructed as described above, the shutter 11, which is in the closed position shown in FIG. 10A, is first moved in the direction of arrow a, and then moved to the open position shown in FIG. 10B. When this happens, the end of the lower piece 11b of the shutter 11 comes into contact with the lock pawl 30, and the guiding action of the slope 30b causes
While the lock pawl 30 is bent in the direction of arrow c in FIG. 10A against its elasticity, the engaging portion 2 is bent as shown in FIG. 10B.
9. The locking surface 30a of the locking pawl 30 and the edge 29a of the engaging portion 29 are engaged at right angles, and the shutter 11 is automatically locked in the open position.

Next, as shown in FIG. 10C, pinch the corners 2a, 3a of the upper and lower halves 2, 3 from above and below with your fingertips, press the corners 2a, 3a in the directions of arrows c and d,
The corners 2a and 3a are bent in a direction toward each other against their elasticity. At the same time, the lock pawl 30 bends, and the lock pawl 30 engages the engaging portion 29.
come off from As a result, the shutter 11 is unlocked at the open position, and the shutter 11 is automatically moved to the closed position by being pushed in the direction of arrow a by the compressive repulsive force of the compression coil spring 16 mentioned above.

Next, Figures 11 to 12B show the second lock structure.
This shows an example, and in this case, the tip of a pin-shaped lock release protrusion 33 integrally molded inside the upper half 2 is provided on the lower half 3 at a position near the lock pawl 30. It is provided by being inserted into the through hole 34 that is provided. In this case, when the shutter 11 is unlocked, if the corners 2a and 3a of the upper and lower halves 2 and 3 are pressed in the directions of arrows C and d as shown in FIG. Push up the lower piece 11b near the joining part 29 from the direction of arrow d,
The engaging portion 29 is configured to be removed from the lock pawl 30.

Next, FIGS. 13 to 14B show a modification of the second embodiment, in which the lock release protrusion 33 is formed into a prismatic shape, and a lower half is formed at a position opposite to the tip of the protrusion 33. Notch 35 in part of 3
The lock release protrusion 33 operates to disengage the engaging portion 29 from the lock pawl 30 by pushing up the lower piece 11b of the shutter 11, just as in the second embodiment.

Next, FIGS. 15A and 15B show a third embodiment of the lock structure, in which a protrusion 37 projecting at right angles to the upper half 2 side is integrally provided at the tip of the lock pawl 30. On the other hand, a lock pawl regulating projection 38 is integrally molded and provided inside the upper half 2 at a lateral side position of the projection 37 in the direction of arrow b in FIG. 15A.

However, according to the third embodiment, if the shutter 11 is forcibly moved in the direction of arrow a toward the closed position while the shutter 11 is locked in the open position shown in FIG. 15A, To,
It is possible to effectively prevent the lock pawl 30 from being forcibly bent.

That is, when the shutter 11 is forcibly moved in the direction of arrow a in the locked state of FIG. 15A, the end edge 29a of the engaging portion 29
pushes the lock surface 30a of the lock pawl 30 in the direction of arrow a. As a result, the lock pawl 30 receives a moment in the direction of the arrow M with its root side as the fulcrum X, and the lock pawl 30 tends to be bent in the direction of the arrow M against elasticity. However, at this time, the protrusion 37 at the tip of the lock pawl 30 is removed from the lock pawl regulating protrusion 3.
8, the lock pawl 30 is prevented from deflecting in the direction of arrow M. Therefore, even if the shutter 11 is forcibly moved in the direction of arrow a, the lock pawl 30
It is reliably prevented that the shutter 11 is forcibly bent in the direction of arrow M and the lock of the shutter 11 is forcibly released.

As described above, according to the third embodiment, it is possible to reliably prevent the shutter 11 from being forcibly moved from the open position to the closed position due to the above-mentioned unreasonable force, and also to prevent the shutter 11 from being forcibly moved from the open position to the closed position due to the unreasonable force. As the lock pawl 30 was bent in the direction of arrow M, the locking surface 30a of the lock pawl 30 was accidentally scraped off and damaged by the edge of the edge 29a of the engaging portion 29 of the shutter 11. Therefore, it is possible to reliably prevent the subsequent locking of the shutter 11 by the locking pawl 30 from becoming uncertain. Therefore, it is structurally very robust.

According to this third embodiment, as shown in FIG. 15B, the corners 2a of the upper and lower halves 2, 3 are
When the shutter 11 is unlocked by pressing 3a from the directions of arrows c and d, the protrusion 37 at the tip of the lock pawl 30 is only moved approximately parallel to the lock regulating protrusion 38, and the lock is not released. Claw 3
0 is not subject to any restrictions. Therefore, the first and second
The unlocking operation is exactly the same as in the embodiment.

Further, in the first to third embodiments of the lock structure described above, the lock release operation when the shutter 11 is in the open position is performed by locking the corners of the upper and lower halves 2 and 3.
We have explained how to pinch and press a and 3a from above and below with your fingertips.
It is also possible to mechanically press the corners 2a, 3a from above and below.

As described above, the present invention is provided in a part of one of the upper and lower halves by pressing the parts of the upper and lower halves in a direction toward each other against elasticity. The shutter is unlocked at the open position by removing the locking pawl from the engagement part provided on the shutter, and after the lock is released, the shutter is automatically moved to the closed position by a compression coil spring. As the shutter is configured to be able to do this, it is possible to prevent the lock pawl from being gradually scraped off by the edges of the engagement hole during reciprocating movement of the shutter, and to ensure that the shutter remains secure even after long-term use. It is possible to provide a highly reliable lock structure that can be locked to Furthermore, by simply pressing a portion of the upper and lower halves from both sides, the shutter can be easily moved from the open position to the closed position with a single touch, providing very good operability.

The greatest feature of this invention, however, is that a compression coil spring is used as the spring that urges the shutter to move from the open position to the closed position, and a core rod is inserted into the compression coil spring to guide it. The structure is such that the engaging piece provided on the inside is engaged with the compression coil spring, and with this structure, the compression coil spring and the shutter can be assembled very easily, making mass production possible. It has the advantage of significantly improving performance.

[Brief explanation of the drawing]

The drawings show an embodiment of a recording/reproducing disk cassette to which the present invention is applied, in which Fig. 1 is an exploded perspective view of the entire cassette, Fig. 2 is a perspective view of the cassette in an assembled state, and Fig. 3A. 3B is a top view of the main part to explain how the head insertion hole of the cassette case is opened and closed by the shutter, FIG. 4 is a bottom view of the main part to explain how the compression coil spring is installed, and FIG. Fig. 4 is a view taken along the - line arrow, Fig. 6 is a cutaway perspective view showing the engagement piece portion of the shutter, Figs. The figure is 7A
FIG. 8B is an enlarged cross-sectional view taken along line A-A in the figure; FIG. 8B is an enlarged cross-sectional view taken along line B-B in FIG. 7B;
FIG. 8C is a sectional view similar to FIG. 8A illustrating a modified example of the protrusion of the shutter that is engaged with the shutter guide groove of the cassette case, and FIGS. Perspective views of main parts explaining the first embodiment of the structure, Figures 10A to 1
FIG. 0C is an enlarged sectional view of the main parts to explain the locking and unlocking operations of the shutter according to the first embodiment, FIG. 11 is an exploded perspective view of the main parts to explain the second embodiment of the same, FIGS. 12A, and FIG. 12B is an enlarged sectional view of the main parts to explain the unlocking operation of the shutter according to the second embodiment, and FIG. 13 is an exploded perspective view of the main parts to explain a modification of the second embodiment.
14A and 14B are enlarged cross-sectional views of essential parts for explaining the unlocking operation of the shutter according to the modified example, and FIGS. 15A and 15B are the same as the third embodiment of the same.
FIG. 2 is an enlarged cross-sectional view of main parts for explaining an example. In addition, in the symbols used in the drawings, 1...Cassette housing, 2...Upper half, 3...Lower half,
4... Disc-shaped recording medium, 8... Head insertion hole, 11... Shutter, 16... Compression coil spring, 17... Groove, 18... Core rod, 19...
...Engaging piece, 21...Jig insertion hole, 26...Jig plate, 29...Engaging portion, 30...Lock claw, 31...
...Slit.

Claims (1)

[Scope of utility model registration request] A recording/reproducing disk cassette comprising a cassette housing composed of upper and lower halves, with a head insertion hole formed in at least one of the upper and lower halves, a disk-shaped recording medium rotatably housed in the cassette housing, and a shutter movably attached to the cassette housing for opening and closing the head insertion hole, comprising: a compression coil spring for biasing the shutter from a position for opening the head insertion hole to a position for closing the head insertion hole;
a core rod which is inserted into said compression coil spring to guide said compression coil spring; and an engagement piece which is provided inside said shutter and engages with a part of said compression coil spring, wherein when parts of said upper and lower halves are pressed in directions approaching each other against the elasticity, said lock claw is disengaged from said engagement part to release the lock of said shutter in said open position, and said shutter is moved to said closed position by said compression coil spring.