JPH0525101Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a video tape recorder (hereinafter referred to as
The present invention relates to magnetic tape cassettes used in VTRs, etc., and particularly to a mounting structure for a front cover that is openable and closable on the front surface of the cassette body on which the VTR is inserted.

[Conventional technology]

Figures 6 to 10 show conventional magnetic tape cassettes used in household VTRs, with Figure 6 being a partially cutaway rear view of the magnetic tape cassette seen from the lower half side, and Figure 7 being the top. A perspective view showing the front part of the side wall of the half, Figure 8 is a perspective view of the main parts after both halves are assembled, Figure 9 is a cross-sectional view of Figure 6, and Figure 10 is the notch on the upper left of Figure 6. A partial view of the lower half corner corresponding to is shown.

The magnetic tape cassette 1 has a cassette body 4 formed by an upper half 2 and a lower half 3, and a supply reel 6 for winding a magnetic tape 5 inside the cassette body 4.
A pair of winding reels including a winding reel 7 and a winding reel 7 are housed. A front cover 8 is attached to the front part of the cassette main body 4, which is the side where the VTR is inserted, to cover the magnetic tape 5, which is unwound from the reels 6 and 7 and runs on the front surfaces of the tape guide parts 4a and 4b, in an openable and closable manner. ing.

The front lid 8 is formed in a U-shape in plan with side plates 8c and 8d extending on both sides of a front plate 8a and a top plate 8b.
Rotation support portions 8e and 8f extend from the side plates 8c and 8d, and a short shaft-shaped rotation support shaft 9 is provided inside the rotation support portion 8e, and a rotation support shaft 9 in the shape of a short shaft is provided inside the rotation support portion 8f. , and long axis-shaped rotation support shafts 10 are provided, respectively.

Side wall 2 of upper half 2 on which rotation support shaft 10 is supported
In the front part of b, as shown in FIG.
A recess 11 is formed in which f is placed. In addition, a notch 13 is formed in the thin wall 12 in which the recess 11 is formed, and the cutout 13 is opened at the front side of the upper half 2 and the lower half 3 side.
A rotation support shaft 10 is supported on. A recess similar to the recess 11 is also formed in the front part of the side wall 2a of the upper half 2 on which the rotation support shaft 9 is supported, and the rotation support part 8e is disposed in the recess.

A helical spring 14 that keeps the front cover 8 in a normally closed state is engaged with the rotation support shaft 10 .

At the corner of the lower half 3 corresponding to the spring 14, a front lid locking member 15 is rotatably suspended by supporting shafts 15a, 15a on both sides of the upper part thereof, suspended from the ribs 3a, 3a of the lower half 3. The front lid locking member 1
5 is provided with a locking protrusion 15b and a releasing protrusion 15c protruding outward from the side wall 3b of the lower half 3 by the urging force of a spring 16 for a front cover locking member attached to one of the support shafts 15a. The locking protrusion 15b engages with the front lid 8 to hold the front lid 8 in a closed state.

Spring 14 made of the helical spring
is formed by bending a spring-like wire rod, and has one end 14a that is locked to a locking pin 17 protruding from the rotation support shaft 10, and is formed in a continuous manner with the one end 14a. Coil portion 1 externally fitted on rotation support shaft 10
4b, and a bent portion 14c that extends linearly from the coil portion 14b and presses against the top inner surface 2c of the upper half 2.
and the other end 14d that extends linearly from the bent portion 14c and is slidably pressed against a guide groove 18 formed on the inner surface of the upper half 2.

Corner 1 of the notch 13 of the upper half 2
3a supports the pivot shaft 10 of the front lid 8, and the bent portion 14c of the spring 14 attached to the pivot shaft 10 is attached to the top inner surface 2c of the upper half 2, and the other end 14d is attached to the guide groove 18. Press them together and attach the front lid 8.
After assembling the lower half 3 to the upper half 2, screw the lower half 3 to the upper half 2 with screws 19, and the upper half 2 and lower half 3 completely support the pivot shaft 10, and the cassette main body 4 is mounted. Form.

However, when assembling the front cover 8 to the upper half 2, the bent portion 14c and the other end 14d of the spring 14
Since only the front cover 8 and the upper half 2 are in pressure contact with the inner surface of the upper half 2, the connection state between the front cover 8 and the upper half 2 is unstable due to the elastic force of the spring 14, and the rotation support shaft 10 on the side where the spring 14 is attached is placed above the notch 13. Since the half 2 easily comes off toward the front side, reassembling the front cover 8 is time-consuming, and the work efficiency is poor as the spring may be lost.

For this reason, as disclosed in Japanese Utility Model Application Publication No. 59-138083, an L-shaped support wall is provided inside the recess of the upper half to protrude from the inner surface of the top of the upper half to hold the front cover in the closed state. The coil part of the spring to be rotated is fitted onto the rotation support shaft, and both ends of this spring are locked to the front cover and the upper half, respectively, and the rotation support shaft is pressed against the ridge edge of the support wall to rotate the spring. The support shaft prevents the upper half from coming off toward the front side by the elastic force of the spring, thereby solving the above-mentioned problem.

[The problem that the idea aims to solve]

However, since the above-mentioned support wall is constantly pressed into contact with the rotational support shaft itself, there is a good chance that the sliding contact caused by the rotation of the rotational support shaft will scrape each other and generate debris. When the upper and lower halves are assembled, the sliding contact between the pivot shaft and the support wall is located inside the cassette body, so debris can adhere to the magnetic tape and cause dropouts. Sometimes.

The present invention was developed against the background of the above circumstances, and aims to provide a magnetic tape cassette that improves the workability of assembling it to the upper half of the front cover and prevents drop-outs as much as possible.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes an upper half and a lower half that form a cassette body, and a side plate of a front lid that is attached to the front of the side wall of the upper half so as to be openable and closable. A recess is formed in which the rotation support part extending from the top is formed, and a notch is formed in the thin wall in which the recess is formed, and the front side of the upper half and the lower half are opened, and the notch is A magnetic tape cassette in which a rotation support shaft provided on the rotation support portion of the front cover is supported at a corner of the front cover, and the front cover is always biased in the closing direction by a spring attached to the rotation support portion, The spring has one end locked to the rotation shaft, the other end slidably pressed against the inner surface of the front part of the upper half, and a curved part bulging toward the lower half between the one end and the other end. A leaf spring is formed on the front side of the recess, and engages with the pivot shaft before assembling the lower half to the upper half to prevent the pivot shaft from moving toward the front side of the upper half. The device is characterized in that a restricting engagement protrusion is provided to protrude from the thin wall toward the lower half side.

[Effect]

Therefore, the spring attached to the rotation support shaft is expanded toward the lower half between one end that is locked to the rotation support shaft and the other end that is slidably pressed against the inner surface of the front part of the upper half. Since it is formed of a leaf spring with a curved part that extends, when the front cover is assembled to the upper half, the elastic force of the spring is applied almost equally to the pivot shaft and the front inner surface of the upper half. Compared to the case where a helical spring is used, the pivot shaft hardly lifts up from the corner of the notch of the upper half, and it is difficult to come off even before the lower half is assembled to the upper half.

In addition, even if the rotation support shaft somehow tries to move toward the front side of the upper half before assembling the lower half to the upper half, the rotation support shaft will engage with the engagement protrusion and the rotation will be interrupted. Since the movement of the upper half of the dynamic support shaft toward the front side is restricted, it is possible to prevent the front cover from falling off before assembling the lower half to the upper half. Even when the rotation shaft rotates, the generation of debris due to sliding contact can be minimized, making it difficult for the generated debris to enter the cassette body, eliminating the cause of dropouts caused by debris adhering to the magnetic tape. be able to.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

The spring 21 for the front cover, which is locked to the long axis-shaped rotation support shaft 20 of the front cover 8, is formed of an elastic plate spring such as a spring steel plate or a stainless steel plate. one end 21a that is inserted into and locked in a slit 20a formed on the distal end side of the upper half 2; 21
A curved portion 21c that bulges toward the lower half 3 side between
It has And this spring 21
is one end 21a that holds approximately half the circumference of the rotation support shaft 20.
is inserted into the slit 20a and locked to the rotation support shaft 20, and the other end 21b is slidably pressed against the guide groove 22 and attached. At this time, the tip of the other end 21b may be brought into contact with the stopper protrusion 23.

Side wall b of the upper half 2 on which the rotation support shaft 20 is supported
In the front part thereof, as in the conventional example shown in FIG.
A notch 26 that opens on the front side of the upper half 2 and the side of the lower half 3 is formed in the thin wall 25 in which the thin wall 25 is formed (see FIG. 1).
A rotation support shaft 20 is supported.

On the front side of the recess 24, before assembling the lower half 3 to the upper half 2, there is a groove that engages with the rotation support shaft 20 to move the rotation support shaft 20 toward the front side of the upper half 2. An engaging protrusion 27 for regulating the movement is provided to protrude from the thin wall 25 toward the lower half 3 side. Then, the rotation support part 8f of the front cover 8 is attached to the recess 24 of the upper half 2, and the rotation support shaft 20 inside the rotation support part 8f is supported by the corner 26a of the notch 26. Assemble 8 to upper half 2.

When the front cover 8 and the upper half 2 are assembled, the spring 21 mounted on the rotation support shaft 20
one end 21a that is locked to the rotation support shaft 20 and the other end 2 that is slidably pressed against the front inner surface of the upper half 2.
1b, the curved portion 21 bulges toward the lower half 3 side.
Since it is formed with a leaf spring having c, spring 2
Since the elastic force of No. 1 is applied almost equally to the pivot shaft 20 and the front inner surface of the upper half 2, the pivot shaft 20 hardly lifts up from the corner 26a of the notch 26 of the upper half 2, and the upper half Even before lower half 3 is screwed onto 2, it is difficult to remove.

Moreover, even if the rotation support shaft 20 tries to move to the front side of the upper half for some reason in this state,
The rotation support shaft 20 engages with the engagement protrusion 27 and restricts the movement of the rotation support shaft 20 toward the front side of the upper half 2. The lid 8 can be prevented from falling off, and the front lid 8 can be stably assembled to the upper half 2.

The rotation support shaft 20 is rotatably inserted and held in a rectangular space 28 formed by screwing the lower half 3 onto the upper half 2 to which the front lid 8 is attached.

Therefore, even if the rotation support shaft 20 rotates when the upper half 2 and the lower half 3 are assembled, the generation of debris due to sliding contact can be suppressed as much as possible, and the generated debris can be removed from the empty space. 28 etc. becomes difficult to enter into the cassette main body 4, and the cause of dropouts caused by debris adhering to the magnetic tape 5 can be eliminated.

At the corner of the lower half 3 corresponding to the attachment part of the spring 21, there is a front lid locking member 29 that locks the front lid 8 in the closed state.
29a is suspended from the ribs 3a, 3a of the lower half 3 so as to be rotatable. This front lid locking member 2
Reference numeral 9 is provided with a pressed portion 29b for rotation that is pressed by the curved portion 21c of the spring 21, and a locking projection 29c and a releasing projection 29d that project outward from the side wall 3b of the lower half 3. and,
When the pressed portion 29b of the front lid locking member 29 is pressed by the curved portion 21c of the spring 21,
The side wall 3 of the lower half 3 is supported around the support shafts 29a, 29a.
The locking protrusion 29c and the releasing protrusion 29d project outward from the side wall 3b, and the locking protrusion 29c engages with the front cover 8 to hold the front cover 8 in a closed state. When the operating claw of the VTR pushes the release protrusion 29d, the engaged state is released.

In addition, before assembling the lower half 3 to the upper half 2, the lower half 3 side of the recess 24 engages with the rotation support part 8f of the front lid 8, and the rotation support shaft 20 is attached to the lower half 3 side. The protrusion 30 that restricts movement is inserted into the notch 26.
By protruding into the opening on the lower half 3 side, it is possible to further prevent the front lid 8 from falling off before the lower half 3 is assembled to the upper half 2.

The present embodiment is constructed as described above, and when the magnetic tape cassette 1 is installed in a VTR, the rotation support shaft 20 with the spring 21 locked is moved to the second position in conjunction with the opening of the front cover 8. The spring 21 is rotated clockwise in the figure, the spring 21 is wound around the rotation support shaft 20, the curved portion 21c is slightly retreated toward the upper half 2, and the other end 21b is inserted into the guide groove on the front inner surface of the upper half 2. 22 and retreat to the rotation support shaft 20 side.

Further, when the magnetic tape cassette 1 is taken out from the VTR, the rotation support shaft 20 is rotated counterclockwise in FIG. 2 due to the restoring force of the spring 21.
The other end 21b of the spring 21 moves forward in the opposite direction to the pivot shaft 20, the front lid 8 returns to the closed position, and the front lid locking member 29 locks the curved portion 21 of the spring 21.
c, the locking protrusion 29c engages with the front lid 8, and the front lid 8 is held in the closed state.

[Effect of idea]

As explained above, the magnetic tape cassette of the present invention is provided with a rotary support section extending from the side plate of the front cover, which is attached to the front of the cassette body so as to be openable and closable, on the front side wall of the upper half of the cassette body. A thin wall formed by the recess is provided with a notch that opens the front side of the upper half and the lower half side, and a rotation support for the front cover is provided at the corner of the notch. One end of the spring is fixed to the rotation support shaft, and the other end is fixed to the upper half. It is formed of a leaf spring that is slidably pressed against the inner surface of the front part and has a curved part that bulges toward the lower half between one end and the other end, and the lower half is attached to the upper half on the front side of the recessed part. An engaging protrusion that engages with the pivot shaft and restricts the movement of the upper half of the pivot shaft toward the front side before assembly is provided so as to protrude from the thin wall toward the lower half. , When the front cover is assembled to the upper half, the elastic force of the spring is applied almost equally to the pivot shaft and the front inner surface of the upper half, so when using a spring made of a helical spring. Compared to this, the pivot shaft hardly lifts up from the corner of the notch in the upper half, and the front cover is held in a state where it is difficult to come off even before the lower half is assembled to the upper half.

Moreover, in this holding state, even if the rotation support shaft tries to move toward the front side of the upper half for some reason, the rotation support shaft will engage with the engagement protrusion and the upper half of the rotation support shaft will move. This prevents the front cover from falling off.Furthermore, even if the pivot shaft rotates when the upper and lower halves are assembled, debris from sliding contact will be prevented. This makes it possible to suppress the generation of magnetic tape as much as possible, prevent the generated debris from entering the cassette body, and eliminate the cause of dropouts caused by debris adhering to the magnetic tape.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, in which Figure 1 is a perspective view of the main parts of the upper half, Figure 2 is a cross-sectional view of Figure 3, and Figure 3 is a cross-sectional view of the upper half. Fig. 4 is a cross-sectional side view of the main part as seen from the inner side, Fig. 5 is a perspective view of the main part after both halves are assembled, and Figs. 6 to 10 are conventional Give an example,
Figure 6 is a partially cutaway rear view of the magnetic tape cassette seen from the lower half side, Figure 7 is a perspective view showing the front side wall of the upper half, and Figure 8 is a perspective view of the main parts after both halves are assembled. FIG. 9 is a cross-sectional view taken from FIG. 6, and FIG. 10 is a plan view of the lower half corner corresponding to the upper left notch in FIG. 6. 1... Magnetic tape cassette, 2... Upper half,
2b...Side wall, 3...Lower half, 4...Cassette body, 5...Magnetic tape, 6...Supply reel, 7
...Take-up reel, 8...Front cover, 8d...Side plate,
8f...Rotation support part, 20...Rotation support shaft, 21...
...Spring, 21a...One end, 21b...Other end, 21c...Curved portion, 24...Concave portion, 25...
Thin wall, 26...notch, 26a...corner, 2
7... Engaging protrusion, 29... Front lid locking member, 29c
...Lock protrusion, 29d...Release protrusion.

Claims (1)

[Scope of utility model registration request] The upper half 2 and the lower half 3 form a cassette body 4, and a recess 24 is formed in the front of the side wall 2b of the upper half 2, in which a rotation support portion 8f is disposed. The rotation support portion 8f is extended from a side plate 8d of a front cover 8 that is attached to the front of the cassette body 4 so as to be able to open and close. A cutout portion 26 that opens to the front side of the upper half 2 and the lower half 3 side is formed in a thin wall 25 in which the recess 24 is formed.
In the magnetic tape cassette, a pivot shaft 20 provided on the pivot support portion 8f of the front cover 8 is supported on the corner 26a of the recess 24. The front cover 8 is constantly biased in a closing direction by a spring 21 attached to the pivot shaft 20. The spring 21 is formed of a leaf spring having one end 21a engaged with the pivot shaft 20 and the other end 21b slidably pressed against the inner surface of the front part of the upper half 2, and having a curved portion 21c between the one end 21a and the other end 21b that bulges out towards the lower half 3.
Before the upper half 2 and the lower half 3 are assembled, the front side of the
a projection 27 for restricting the forward movement of the upper half 2 projects from said thin wall 25 towards the lower half 3.