JPH0422450Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to magnetic tape cassettes used in VTRs (video tape recorders), etc.
This invention relates to a mounting structure for a front cover that can be opened and closed on the front side of a cassette main body on the VTR insertion side.

[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 assembly, Figure 9 is a cross-sectional view of Figure 6, and Figure 10 corresponds to the notch in the upper left of Figure 6. A partial view of the lower half corner 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 open and close the magnetic tape 5 that is unwound from the reels 6 and 7 and runs on the front surfaces of the tape guide sections 4a and 4b. There is.

This front lid 8 is formed in a U-shape in plan, with side plates 8c and 8d formed 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. Further, a notch 13 is formed in the thin wall 12 in which the recess 11 is formed, and the cutout 13 is opened on the front side of the upper half 2 and the lower half 3 side, and a corner 13a of the cutout 13 is formed.
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 spiral spring 14 that maintains 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
4 is provided with a locking protrusion 15b and a releasing protrusion 15c protruding from the side wall 3b of the lower half 3 by the biasing force of a spring 16 for the 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.

The spring 14 made of the helical spring is
It is formed by bending a spring 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 14 externally fitted onto support shaft 10
b, 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 front portion 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 cover 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 of the spring 14 is attached to the upper half 2.
Since it is in pressure contact with the top inner surface 2c of the upper half 2, the pivot shaft 10 is moved by the elastic force of the spring 14.
It was easy to come off the corner 13a of the notch 13, requiring much effort to reassemble, and the spring 14 was lost, resulting in poor workability.

For this reason, as disclosed in Japanese Utility Model Publication No. 59-3424, an engaging protrusion is provided from the thin wall in which the recess of the upper half is formed to the front part of the upper half, and the pivot shaft is supported by the elastic force of the spring. This eliminates the above-mentioned disadvantage by preventing it from lifting due to force.

[The problem that the idea attempts to solve]

However, since this engaging protrusion engages with the pivot shaft itself, there is a good chance that the sliding contact caused by the rotation of the pivot shaft will scrape each other and generate debris. Since the position of the engagement protrusion coincides with or is close to the space formed when the half and the lower half are assembled for the insertion of the pivot shaft, it is easy for this debris to enter the cassette body from the space. If it enters the cassette body, it may adhere to the magnetic tape and cause dropouts.

The present invention was developed against the background of the above circumstances, and an object thereof is 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 support shaft, the other end slidably pressed against the front inner surface of the upper half, and a curved part that bulges toward the lower half between the one end and the other end. The lower half of the recess is engaged with the rotation support portion of the front lid before the lower half is assembled to the upper half, and the rotation support shaft is moved toward the lower half of the recess. The present invention is characterized in that an engaging protrusion that restricts movement is provided to protrude into the opening on the lower half side of the notch.

[Effect]

Therefore, the spring attached to the rotation support shaft is attached to the lower half side between one end that is locked to the rotation support shaft and the other end that is slidably pressed against the front inner surface of the upper half. Since it is formed of a leaf spring with a bulging curved part, 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. Therefore, 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 is difficult to come off even before the lower half is assembled to the upper half.

In addition, even if the rotation support shaft for some reason tries to lift up from the corner of the notch in the upper half before assembling the lower half to the upper half, the rotation support portion of the front cover will not fit into the engagement protrusion. Since it engages with the rotation support shaft and restricts its movement toward the lower half side, it is possible to prevent the rotation support shaft from lifting up, and when the upper half and lower half are assembled, the rotation support shaft Even when the shaft rotates, the generation of debris due to sliding contact can be minimized, and the generated debris is less likely to enter the cassette body from the empty space.

〔Example〕

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 2 of upper half 2 on which rotation support shaft 20 is supported
Similar to the conventional example shown in FIG.
4 is formed with a notch 26 that opens on the front side and the bottom half side of the upper half 2 (see FIG. 1), and at a corner 26a of the notch 26,
A rotation support shaft 20 is supported.

The upper half 2 is located on the lower half 3 side of the recess 24.
Before assembling the lower half 3, an engaging protrusion 27 that engages with the rotation support portion 8f of the front wall 8 to restrict the movement of the rotation support shaft 20 toward the lower half 3 is attached to the notch 26.
It protrudes into the opening on 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 is attached to the pivot 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, in this state, for some reason, the rotation support shaft 2
0 tries to rise from the corner 26a of the notch 26 of the upper half 2, the rotation support part 8 of the front cover 8
f engages with the engagement protrusion 27 and restricts the movement of the rotation support shaft 20 toward the lower half 3 side, so the rotation support shaft 2
0 can be prevented from lifting up, and the front cover 8 can be placed in the upper half 2.
can be stably assembled.

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 assembled.

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., it becomes difficult to enter the cassette main body 4.

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 for locking the front lid 8 in the closed state, and a support shaft 29a on both sides of the upper part of the front lid locking member 29 is provided.
29a is suspended from the ribs 3a, 3a of the lower half 3 so as to be rotatable. The front lid locking member 29
The pressed portion 29b for rotation pressed by the curved portion 21c of the spring 21 and the side wall 3 of the lower half 3
A locking protrusion 29c and a releasing protrusion 29d are provided that protrude outward from b. The front lid locking member 29 has a pressed portion 29b that is connected to the spring 2.
By being pressed by the curved portion 21c of 1, the side wall 3b of the lower half 3 is
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 the closed state. When the working claw pushes the release protrusion 29d, the above-mentioned engaged state is released.

Note that, before assembling the lower half 3 to the upper half 2, the thin wall 25 engages with the rotation support shaft 20 to restrict the movement of the rotation support shaft 20 toward the front side of the upper half 2. By providing the engaging protrusion 30 protruding from the front side of the upper half 2, 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 loaded into the VTR, the rotation support shaft 20 with the spring 21 engaged 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. The thin wall modified by the recess is provided with a notch that opens the front side of the upper half and the lower half side, and the rotation support of 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. The plate spring 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 lower half of the recess, and the lower half is attached to the upper half of the recess. An engaging protrusion that engages with the rotation support portion of the front cover to restrict movement of the rotation support shaft toward the lower half side is provided to protrude into the lower half side opening of the notch before assembly. Therefore, 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 if a helical spring is used. Compared to this, the pivot shaft hardly lifts up from the corner of the notch of the upper half, and 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 somehow tries to lift up from the corner of the notch in the upper half, the rotation support part of the front lid will engage with the engagement protrusion. Since the movement of the rotation support shaft toward the lower half side is restricted, lifting of the rotation support shaft can be prevented.

Furthermore, when the upper and lower halves are assembled, even if the pivot shaft rotates, the generation of debris due to sliding contact can be minimized, and drop-outs that occur when debris adheres to the magnetic tape can be minimized. The cause of this can be eliminated.

[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 main body 4, and a front lid 8 is attached to the front of the side wall 2b of the upper half 2 so as to be openable and closable. A recess 24 in which the rotation support portion 8f is disposed is formed, and a notch 26 is formed in the thin wall 25 in which the recess 24 is formed, opening the front side of the upper half 2 and the side of the lower half 3. , the notch 2
A rotation support shaft 20 provided on the rotation support portion 8f of the front lid 8 is supported on the corner 26a of the front lid 8, and a spring 21 attached to the rotation support shaft 20 causes the front lid 8 to be normally held in the closing direction. In the loaded magnetic tape cassette, the spring 21 has one end 21a locked to the pivot shaft 20, the other end 21b slidably pressed against the front inner surface of the upper half 2, and the one end 21a
1a and the other end 21b, and has a curved portion 21c bulging toward the lower half 3 side of the recessed portion 24 before assembling the lower half 3 to the upper half 2. An engaging protrusion 27 that engages with the rotation support portion 8f of the front lid 8 and restricts movement of the rotation support shaft 20 toward the lower half 3 side is projected into the lower half 3 side opening of the notch portion 26. A magnetic tape cassette characterized by: