JPH0514383Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic tape cassette used in VTRs and the like.

[Conventional technology]

Figures 6 and 7 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 showing the magnetic tape cassette. A cross-sectional view of FIG. 6 is shown.

The magnetic tape cassette 1 has a cassette body 4 formed by an upper half 2 and a lower half 3, and houses a pair of winding reels, a supply reel 6 and a take-up reel 7, of a magnetic tape 5 in the cassette body 4. A front cover 8 is provided which can be opened and closed to cover the magnetic tape 5 that is unwound from the supply reel 6 and runs on the front surface of the tape guide portions 4a, 4a of the cassette body 4.

The front lid 8 is formed in a substantially U-shape in plan with side plates 8c, 8c extending on both sides of a front plate 8a and a top plate 8b, and pivot shafts 9, 10 protruding inside the side plates 8c, 8c. is attached to the front side of the side walls 2a, 2a of the upper half 2, and the long pivot shaft 9 has a helical front lid spring that keeps the front lid 8 in the closed state. 11 is locked.

The front lid spring 11 is formed by bending a wire rod having spring properties, and has a coil portion 11a fitted onto the rotation support shaft 9, and a fixed end 11b protruding from the support shaft 9. It is attached to the locking pin 12 and the free end 11c is loosely fitted into the guide groove 13 formed on the inner surface of the upper half 2.

The front lid 8 that locks the front lid spring 11
The rotation support shaft 9 is locked in the mounting recess 14 formed in one side wall 2c, and the rotation support shaft 10 is locked in the mounting recess 14 formed in one side wall 2c.
It is attached to the upper half 2 by being pivotally supported in the shaft hole of c, and the cassette body 4 is assembled by screwing both halves 2 and 3 with screws 15.
After this, the front lid 8 is normally biased in the closing direction by the torsion force of the front lid spring 11.

[The problem that the idea attempts to solve]

However, in the above-described front lid spring 11, in order to give the coil portion 11a a torsion force, the coil portion 11a is inserted into the rotation support shaft 9;
2 for locking the fixed end 11b to the locking pin 12
Installation work was required during the process, and installation was troublesome.

The present invention was developed against this background, and provides a magnetic tape cassette that improves the ease of attaching the front cover spring to the pivot shaft and also improves the ease of assembling the front cover and the upper half. It is intended to.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention has a front cover that is always attached in the closed direction to cover the magnetic tape that is fed out from the winding reel housed in the set body consisting of an upper half and a lower half to the front of the cassette body. In the magnetic tape cassette provided with a front lid spring that biases the magnetic tape, the front lid spring has a curved portion that bulges toward the lower half between a fixed end and a free end, and a press-fitting engagement portion that continues to the fixed end. A recess is formed in the rotation support shaft of the front cover, into which the press-fitting engagement portion of the front cover spring is fitted and locked, and a spring lock is formed in the vicinity of the rotation support shaft. It is characterized in that shafts are arranged in parallel, and the fixed end of the front lid spring is locked to the spring locking shaft.

〔Example〕

Hereinafter, each embodiment of the present invention will be described based on the drawings.

It should be noted that the same components as those of the above-mentioned conventional example are given the same reference numerals and detailed explanations will be omitted.

1 to 3 show a first embodiment of the present invention, in which a front lid spring 2 biases the front lid 8 in the closing direction.
0 is formed by bending a leaf spring material cut to a required length, and between the substantially circular fixed end 20a and the opposite free end 20b, there is a bulge toward the lower half 3 side. A curved portion 20c is formed, and the fixed end 20a
A pressing engagement portion 20d that bulges out on the opposite side of the curved portion 20c is formed near the front lid spring 20, and the fixed end 20a of the front lid spring 20 is inserted through the front lid spring 20.
It is attached to the front lid 8 by a spring locking shaft 21 arranged in parallel near the pivot shaft 22 of the front lid 8.

The spring locking shaft 21 branches from the base of a rotation support shaft 22 that is locked in a mounting recess 14 formed in one side plate 2c of the upper half 2.
A small diameter shaft installed in parallel near the spring locking shaft 2
1 has a fixed end 20 of the front lid spring 20.
Tapered chamfered part 2 that smoothly guides insertion of a.
1a is formed, and a retaining recess 22a for holding the spring 20 without wobbling is provided around the shaft portion of the pivot shaft 22 against which the press-fitting engagement portion 20d of the front lid spring 20 comes into contact. .

The front lid spring 20 has a curved portion 20c.
facing the lower half 3 side, the fixed end 20a is inserted through the chamfered portion 21a at the tip of the spring locking shaft 21 to hold the locking shaft 21, and the press-fitting engagement portion 2
0d is fitted and locked into the retaining recess 22a of the rotation support shaft 22, and the free end 20b, which is guided by the guide groove 23 of the upper half 2, comes into contact with the locking protrusion 24 and is supported in pressure contact with the upper half 2. .

A front lid locking member 25 is provided at a corner of the lower half 3 facing the mounting portion of the front lid spring 20 to lock the front lid 8 in a closed state when not in use.

The front cover locking member 25 is supported by support shafts 25 on both sides of the upper portion.
The front cover locking member 25 is rotatably suspended from the ribs 3a, 3a of the lower half 3, and is integrally provided with a protrusion 25b which is pushed by the curved portion 20c of the front cover spring 20, and a locking projection and a releasing projection which protrude outward from the side wall of the lower half 3 to lock and release the front cover 8.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, a spring locking shaft 21 arranged in parallel near the rotation support shaft 22 is attached to the upper half 2 in the same way as the rotation support shaft 22.
The front lid spring 20 is formed in the same manner as in the first embodiment, and the pivot shaft 22 has a retaining recess 22a that fits and locks the press-fitting engagement portion 20d. However, each of the spring locking shafts 21 is formed with a tapered chamfered portion 27a for guiding the attachment of the fixed end 20a, and the front lid spring 20 is attached to the spring locking shaft 21 in the same manner as in the first embodiment. It is locked.

FIG. 5 shows a third embodiment of the present invention. The spring locking shaft 21 of this embodiment has a slit 30 on the front plate 8a side of the rotation support shaft 22 formed with a semicircular cross section. The front lid spring 20, which is a shaft with a different diameter and approximately four-and-a-half shapes in cross section and is disposed in parallel with the support shaft 22, is secured to the spring locking shaft 21. The lower half 3 is connected between the engaging portion 20d and the free end 20b.
A curved portion 20c that bulges out to the side is formed.

The front lid spring 20 has a fixed end 20a.
into the slit 30 and lock the spring locking shaft 21.
At the same time, the free end 20 is guided by the guide groove 23, and the press-fitting engagement part 20d is pressed against and wrapped around the retaining recess 22a of the rotation support shaft 22.
b is pressed against and supported by the upper half 2 in contact with the locking protrusion 24.

The spring locking shaft 21 of this embodiment may be provided branched from the rotation support shaft 22 as in the first embodiment, or may be provided on the side plate 8 of the front lid 8 as in the second embodiment.
It may be installed directly on c.

Also in this embodiment, as in both of the above embodiments, a chamfered portion is provided at the tip of the spring locking shaft 21 to facilitate insertion of the front lid spring.

As described above, according to each of the embodiments described above, the front lid spring 20 has its fixed end 20a connected to the pivot shaft 2.
Since it is locked to a dedicated spring locking shaft 21 that is arranged in parallel with the spring locking shaft 2, assembly can be performed reliably and with one touch, and work efficiency can be improved.

[Effect of idea]

As described above, in the magnetic tape cassette according to the present invention, the front cover spring has a curved portion that bulges toward the lower half between the fixed end and the free end, and a press-fit engagement portion that continues to the fixed end. A recess formed of a leaf spring is formed on the rotation support shaft of the front cover, into which the press-fitting engagement portion of the front cover spring is fitted and locked, and a spring locking shaft is provided near the rotation support shaft. are installed in parallel,
Since the fixed end of the front cover spring is locked to the spring locking shaft, the front cover spring can be reliably assembled to the rotation support shaft with one touch, improving work efficiency and achieving stable quality at low cost. magnetic tape cassettes.

Further, since the press-fitting engagement portion of the front cover spring is fitted and locked in the recess of the rotation support shaft, it is possible to prevent the front cover spring from falling off from the rotation support shaft.

In addition, since the front lid spring is a leaf spring and has a curved part that bulges toward the lower half, the pressing force on the free end is stronger, and the connection between the front lid and the upper half is strengthened. The ease of assembly with the upper half is improved, and the front cover can be opened and closed reliably.

[Brief explanation of drawings]

Figures 1 to 3 show the first embodiment of the present invention. Figure 1 is a perspective view of the front lid spring and main parts of the front lid, and Figure 2 is a main part of the upper half viewed from the inside. Fig. 3 is a sectional bottom view of Fig. 2;
FIG. 4 is a perspective view of the front lid spring and main parts of the front lid of the second embodiment, and FIG. 5 is a sectional view of the main parts of the third embodiment.
6 and 7 show a conventional example, in which FIG. 6 is a partially cutaway rear view of the magnetic tape cassette seen from the lower half side, and FIG. 7 is a sectional view taken along the line taken in FIG. 6. 1... Magnetic tape cassette, 2... Upper half,
3...Lower half, 4...Cassette body, 5...Magnetic tape, 8...Front cover, 8c...Side plate, 14...
Mounting recess, 20...Front lid spring, 20a...
Fixed end, 20b...free end, 20c...curved part,
20d...Pressure engagement portion, 21...Spring locking shaft, 21a...Chamfered portion, 22...Rotation support shaft, 2
2a... Retention recess.

Claims (1)

[Scope of utility model registration request] A front lid spring 20 that always biases a front lid 8 in the closing direction that covers the magnetic tape 5 that is fed out to the front of the cassette body 4 from a winding reel housed in the cassette body 4 consisting of an upper half 2 and a lower half 3. In the magnetic tape cassette, the front lid spring 20 has a curved portion 20c that bulges toward the lower half 3 between the fixed end 20a and the free end 20b;
The rotation support shaft 22 of the front lid 8 is formed of a plate spring having a press-fitting engagement portion 20d following the fixed end 20a.
, the press-fitting engagement portion 20d of the front lid spring 20
Forms a recess 22a in which is fitted and locked,
A spring locking shaft 21 is provided near the rotation support shaft 22.
A magnetic tape cassette characterized in that the front cover spring 20 has a fixed end 20a fixed to the spring locking shaft 21.