JPH056614Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention is a front cover that biases the front cover attached to the front part of the cassette body of a magnetic tape cassette used in a video tape recorder (VTR), etc. Regarding the spring mounting structure.

[Prior Art] Conventional magnetic tape cassettes used in home VCRs have a front cover that can be opened and closed to cover the magnetic tape that is fed out from the cassette body to the front of the cassette. It is always biased in the closing direction by.

4 and 5 show this type of magnetic tape cassette. FIG. 4 is a partially cutaway rear view of the magnetic tape cassette seen from the lower half side, and FIG. 5 is a cross-sectional view taken from the side shown in FIG. Show the diagram.

The magnetic tape cassette 1 has a supply reel 6 for winding a magnetic tape 5 and a take-up reel 7 housed in a cassette body 4 formed by an upper half 2 and a lower half 3. 4
At the front part of the
A front cover 8 for covering the magnetic tape 5 running on the front surface of the tape guide parts 4a, 4a is attached so as to be openable and closable.

The front lid 8 has side plates 8c, 8c extending on both sides of the front plate 8a and the top plate 8b, and pivot shafts 9, 10 protruding from the inside of the side plates 8c. A front lid spring 11 is mounted on one rotation support shaft 9 to bias the front lid 8 in the closing direction.

The front lid spring 11 is formed by bending a wire spring material, and a coil-shaped fixing part 11a is fitted onto the pivot shaft 9, and a locking end 11b is attached to the pivot shaft 9.
The free end 11c is locked to a locking pin 12 protruding from the
It is attached by loosely fitting into the guide groove 13 formed on the inner surface of the upper half 2.

Then, the front lid 8 with the front lid spring 11 attached
is temporarily fixed to the upper half 2 by supporting the rotation support shaft 9 in a mounting recess 14 formed in one side wall of the upper half 2, and supporting the rotation support shaft 10 in a shaft hole in the other side wall, After the two halves 2 and 3 are screwed together with screws 15 to form the cassette body 4, the front lid 8 is normally biased in the closing direction by the torsion force of the front lid spring 11.

In addition, at the corner of the lower half 3 corresponding to the front lid spring 11, a front lid locking member 16 connects the support shafts 16a, 16a on both sides of the upper part to the ribs 3a of the lower half 3,
3a, and is rotatably suspended from one support shaft 1.
Spring 17 for front lid locking member attached to 6a
The front lid is held closed by the biasing force of the front lid.

[Problem that the invention attempts to solve]

However, since the above-mentioned leading edge spring has a unique shape, it is a relatively expensive outsourced product, making it difficult to reduce costs, and it is also troublesome to install.

The present invention was developed against the background of the above circumstances, and an object of the present invention is to provide a magnetic tape cassette in which a front cover spring is easily formed at a low cost, and the front cover spring is easily installed.

[Means for solving problems]

In order to achieve the above object, the present invention has a front cover spring that biases the front cover in the closing direction, which is attached to the pivot shaft of the front cover that opens and closes the front part of the cassette body in which the tape reel is housed. In the front cover spring mounting structure of a magnetic tape cassette with a fixed part locked,
The front cover spring is formed of a plate spring, and a locking end is bent at the end of the fixed part, and an axial slit opening at the tip is formed in the rotation support shaft, and the slit is The fixing portion of the front cover spring is inserted through the tip of the rotation support shaft, and the locking end protruding from the side of the slit is locked to the outer peripheral surface of the rotation support shaft.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

Incidentally, the same components as those in the conventional example are given the same reference numerals and detailed explanations will be omitted.

The front cover 8 attached to the front part of the upper half 2 is attached to one pivot shaft 20 supported by the mounting recess 14.
A slit 20a opening at the tip of the support shaft 20 is provided in the axial direction, and a front cover spring 21 is attached to the slit 20a.

The slit 20a is connected to the front cover spring 2.
The opening width is wider than the thickness of 1, and the front lid spring 21
It has a depth that allows it to be inserted to a predetermined position.

On the other hand, the front lid spring 21 is formed by bending a leaf spring material cut to a required length, and has a linear fixed part 21a that is latched to the rotation support shaft 20 at one end.
is formed to have approximately the same length as the diameter of the rotation support shaft 20,
A loop-shaped spring portion 21c and a holding portion 21d of the rotation support shaft 20 are formed between the fixed portion 21a and the locking portion 21b at the other end, and the locking portion 21b is provided at the end of the fixed portion 21a. The end 21e is bent.

Then, the front cover spring 21 is attached to the rotation support shaft 2.
The fixing part 21a is inserted into the slit 20 from the tip side of the support shaft 20 while holding the holding part 21d around the outer periphery of the support shaft 20.
After insertion, the front cover spring 21 is rotated to the position shown by the imaginary line in FIG. The end locking part 21b is attached to the top plate 8 of the front lid 8.
b, the spring portion 21c is bent to provide a spring force, and this spring force is used to elastically lock the fixed portion 21a to the slit 20a of the pivot shaft 20.

Also, when the front lid 8 is temporarily attached to the upper half,
The locking part 21b of the front cover spring 21, which is loosely fitted into the guide groove 22 of the upper half 2, comes into contact with the stopper protrusion 23, and the reaction force causes the fixing part 21a to move into the slit 20.
The front lid spring 21 is in pressure contact with the front lid 8, so that it is supported more reliably without wobbling even when the front lid 8 is opened and closed.

A front lid locking member 24 for locking the front lid is provided at a corner of the lower half 3 corresponding to the mounting portion of the front lid spring 21.
However, the support shafts 24a, 24a on both sides of the upper part are connected to the lower half 3.
It is rotatably suspended from the ribs 3a, 3a of
The front lid locking member 24 has a protrusion 2 that is pressed against the middle part of the spring portion 21c of the front lid spring 21.
4b, and a locking protrusion and a release protrusion (not shown) projecting outward from the side wall of the lower half 3, and the front lid 8 is engaged with the locking protrusion to maintain the closed state.

When the magnetic tape cassette 1 configured as described above is mounted on a VTR, the working claw of the VTR pushes the release protrusion and the front cover locking member 24 is moved by the pressing force of the spring portion 21c of the front cover spring 21. When the engagement state is released and the front lid 8 is opened, the rotation support shaft 20 that locks the front lid suffling 21 rotates clockwise in FIG. The spring 21 is wound around the support shaft 20, and the intermediate loop shape of the spring portion 21c retreats upward.

Furthermore, when the magnetic tape cassette 1 is removed from the VTR and the open state of the front cover 8 is released, the spring portion 21c of the front cover spring 21 expands downward.
Due to the restoring force, the rotation support shaft 20 is rotated counterclockwise in FIG. The front lid 8 is held closed by pressing the protruding piece 24b.

As described above, according to this embodiment, the front cover spring 21 can be formed easily and inexpensively by simply bending a leaf spring material cut to a required length, and the magnetic tape cassette 1 can be provided at a low cost.

Further, this front lid spring 21 is attached to a fixed portion 21
a into the slit 20a from the tip of the rotation support shaft 20, and by simply locking the locking end 21e protruding from the side of the slit 20a to the outer circumferential surface 20b of the rotation support shaft 20, it is easy to prevent it from falling off. When the front cover 8 is temporarily attached to the upper half 2, the fixing part 21
Since the spring force of the front cover spring 21 itself acts on the front cover spring 21 so that the front cover spring 21 is resiliently locked, the attachment can be made more secure.

Further, since the front lid spring 21 of this embodiment also serves as a press for the front lid locking member 24, there is no need to use a spring for the front lid locking member as in the conventional case, and by reducing the number of parts, Furthermore, it is possible to reduce costs and improve assembly workability.

It should be noted that the shape of the pivot shaft, slit, or front cover spring is not limited to the above-mentioned embodiment, but can be appropriately determined depending on the type and shape of the magnetic tape cassette.

Further, as the spring for the front lid locking member, another spring may be used as in the conventional example.

[Effect of idea]

As explained above, the front cover spring mounting structure of the magnetic tape cassette of the present invention is such that the front cover spring is formed of a plate spring, and the locking end is bent at the end of the fixed part to support rotation. The fixed part of the front cover spring is inserted through the slit formed in the shaft from the tip of the pivot shaft, and the locking end protruding from the side of the slit is locked to the outer circumferential surface of the pivot shaft. It can be easily formed by simply cutting the leaf spring material to the required length and bending it, without using expensive helical wire spring material, which reduces in-process costs and reduces costs. I can figure it out.

In addition, by simply inserting the fixed part of the front cover spring into the slit of the rotation support shaft and locking the locking end on the outer circumferential surface of the rotation support shaft, it can be installed securely without falling off, and the front cover spring is linked when opening and closing. The locked state can be reliably maintained even when expanding and contracting.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention,
Figure 1 is a perspective view of the main parts of the front lid and the front lid spring.
FIG. 2 is a cross-sectional rear view of the main part of the upper half with the front lid attached, seen from the inner side, FIG. 3 is a cross-sectional view of FIG. 2, and FIGS. 4 and 5 show a conventional example. FIG. 4 is a partially cutaway rear view of the magnetic tape cassette seen from the lower half side, and FIG. 5 is a cross-sectional view taken from the side shown in FIG. 4. 1... Magnetic tape cassette, 2... Upper half,
3...Lower half, 4...Cassette body, 8...Front cover, 8c...Side plate, 20...Rotation shaft, 20a...
...slit, 20b...outer peripheral surface, 21...front lid spring, 21a...fixing part, 21e...locking end.

Claims (1)

[Scope of utility model registration request] A front cover of a magnetic tape cassette, in which a fixed part of a front cover spring that biases the front cover in the closing direction is locked to a pivot shaft of the front cover that opens and closes the front part of a cassette body that houses a tape reel. In the spring mounting structure, the front lid spring is formed of a leaf spring, and a locking end is bent at the end of the fixed part, and an axial slit opening at the tip is formed on the rotation support shaft. The fixing part of the front cover spring is inserted into the slit from the tip of the rotation support shaft, and the locking end protruding from the side of the slit is locked to the outer peripheral surface of the rotation support shaft. Front cover spring mounting structure for magnetic tape cassettes.