JPH0424546Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic tape cassette such as a video cassette tape.

[Conventional technology]

As shown in FIGS. 3 and 4, for example,
A magnetic tape cassette 1 used in a VTR (video) device has an upper half 2 and a lower half 3 forming a cassette body 4, and a supply reel 6 and a take-up reel 7 of a magnetic tape 5 are housed in the cassette body 4. At the same time, in order to protect the magnetic tape 5 fed out to the front of the cassette main body 4, a front cover 8 covering the magnetic tape 5 is provided on the front of the cassette main body 4 so as to be openable and closable, and the front cover 8 can be closed when not in use. A front lid locking member 9 is provided inside the cassette body 4, and the front lid locking member 9 is always closed by a helical spring 10 that is fitted onto the support shaft of the front lid locking member 9. The front lid 8 is held in a closed state by being biased in this direction.

The front lid locking member 9 includes support shafts 9a, 9a rotatably supported by the lower half 3, and one support shaft 9a.
A pin 9b that extends from the top and attaches the spiral spring 10, and an engaging protrusion 9c that locks the front cover 8.
and a release protrusion 9d that is pushed by a working claw of the VTR device to release the engagement between the engagement protrusion 9c and the front cover 8.
and is biased by a helical spring 10 to project the engaging protrusion 9c and the releasing protrusion 9d to the outside from the cassette body 4, and lock the front cover 8 with the engaging protrusion 9c. ing.

However, the helical spring 10
As shown in the figure, a coil portion 10a is fitted onto the pin 9b, a bent piece 10b extends from one end of the coil portion 10a and comes into pressure contact with the front cover locking member 9, and a piece 10b of the coil portion 10a is bent. Extending from the other end,
Since it consists of the other piece 10c that presses against the rib 11 of the lower half 3, the shape is complicated and manufacturing is troublesome.
Furthermore, during assembly, the helical spring 10 was attached to the front lid locking member 9, and then the front lid locking member 9 was assembled to the lower half 3, which required time and effort.

On the other hand, the front lid locking member is always biased in the closing direction,
The spring that holds the front cover in the closed state is a roughly U-shaped wire spring bent at an acute angle, and both ends of this wire spring are directed toward the lower half from the tip of the support that is erected in the lower half. Japanese Utility Model Publication No. 14958/1983 discloses a spring inserted into a spring insertion hole, with the bent portion held between the tip of the support and the upper half.

[The problem that the idea aims to solve]

However, with this wire spring, both ends of the wire spring bent at an acute angle are inserted into the spring insertion hole and held between the tip of the strut at the bend and the upper half, so although the assembly work is improved, The shape of the spring is complicated, making it troublesome to manufacture, and since the bent portion is held between the tip of the support and the upper half, the elastic force of the bent portion cannot be used effectively.

Therefore, the present invention makes it easy to manufacture a spiral spring that always biases the front lid locking member in the closing direction to hold the front lid in the closed state, and effectively utilizes the elastic force of the bent part. The object of the present invention is to provide a magnetic tape cassette that can be easily assembled.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a front cover that covers the magnetic tape so that it can be opened and closed on the front surface of a cassette body consisting of an upper half and a lower half, and a front cover locking member that locks the front cover in a closed state. In the magnetic tape cassette, the magnetic tape cassette is rotatably provided with a helical spring that always biases the front lid locking member in the closing direction to hold the front lid in a closed state. The spring has a symmetrical linear part projecting in a V-shape from the coil part, and a boss part with a smaller diameter than the pillar is provided at the tip of the pillar installed in the lower half, and the coil part of the spring is attached to the boss part. When fitted, the helical spring is prevented from coming out by the stepped portion formed at the tip of the support and the tip of the boss portion of the upper half into which the tip of the boss portion is fitted. The tip of one straight part,
While engaging and press-contacting the groove of a locking protrusion formed on the front lid locking member at approximately the same height as the boss portion, the tip of the other straight portion of the helical spring is connected to the rib of the lower half. It is characterized by pressure contact.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

A front lid 24 is provided on the front surface of the cassette body 23, which is constructed by combining an upper half 21 and a lower half 22, so as to be openable and closable, and the front lid 24 is locked to the lower half 22 in a closed state. A front lid locking member 25 is provided. The front lid locking member 25 has an engaging projection 15a that locks the front lid 24 and a releasing projection 15b that project from the cassette body 23 to the outside. It stands out.

A column 26 is provided upright on the inner surface of the lower half 22, and a boss portion 26a having a diameter smaller than that of the column 26 projects from the tip of the column 26. The front lid locking member 25 has an engaging projection 25c formed at approximately the same height as the boss portion 26a of the support column 26.

A helical spring 27 is attached to the boss portion 26a of the support column 26. This helical spring 27 has a coil portion 27a and a coil portion 27a.
Symmetrical linear portions 27b, 27 projecting in a V-shape from
It is formed by c.

This helical spring 27 has a coil portion 27a fitted onto the boss portion 26a, and a stepped portion 26b formed at the tip of the support column 26 and the boss portion 26a.
The helical spring 27 is prevented from coming out by the tip 28a of the boss portion 28 of the upper half 21, which the tip of the spring 27 is fitted with.
The tip of the straight part 27b of the spiral spring 27 is
Groove 25 of the locking protrusion 25c of the front lid locking member 25
d and press the tip of the straight portion 27c to the rib 29 of the lower half 22 to urge the front lid locking member 25 to lock the front lid 24 in the closed state. There is.

In this way, by forming the helical spring 27 with the coil portion 27a and the symmetrical linear portions 27b and 27c protruding from the coil portion 27a in a V-shape, the shape of the helical spring 27 can be changed. It is simple and easy to manufacture, and after assembling the front cover locking member 25 to the lower half 22, the coil part 27a of the spiral spring 27 is attached to the boss part 26a of the support column 26. The one linear part 27b is engaged and pressed into contact with the groove 25d of the locking protrusion 25c of the front lid locking member 25, and the other straight part 27c is pressed into contact with the rib 29 of the lower half 22. Since the boss portion 28 of the upper half 21 that is assembled into the upper half 21 prevents the helical spring 27 from coming off, the elastic force of the bent portion can be effectively used, and the front lid locking member 25 and the helical spring 27 can be easily assembled, and costs can be reduced.

[Effect of idea]

As described above, in the present invention, the helical spring that always biases the front lid locking member in the closing direction and holds the front lid in the closed state has a symmetrical spring that projects from the coil part in a V-shape. A step portion is formed at the tip of the support, which has a straight portion and has a boss portion smaller in diameter than the support at the tip of the support that is erected in the lower half, and a coil portion of a spring is externally fitted to the boss. and the tip of the boss portion of the upper half into which the tip of the boss portion fits, and prevent the spiral spring from coming out, and the tip of one straight portion of the spiral spring is connected to the front lid locking member. At the same time, the tip of the other straight part of the helical spring is pressed into engagement with the groove of the locking protrusion formed at approximately the same height as the boss part, and
Since it is pressed against the rib of the lower half, the coil part and the symmetrical straight part protruding from the coil part in a V-shape form a spiral spring, so that the shape of the spiral spring can be simply changed. As a result, manufacturing is easier, and the assembly work is as follows: After assembling the front cover locking member to the lower half, fit the coil part of the helical spring onto the boss part of the column, and then attach the straight part to one of the straight parts. are engaged and pressure-contacted to the locking protrusion of the front lid locking member, and the other straight part is pressed to the ribs of the lower half, and the helical spring is prevented from coming off with the boss part of the upper half that is assembled to the lower half. Therefore, the elastic force of the bent portion can be effectively utilized, and the front lid locking member and the spiral spring can be easily assembled, resulting in cost reduction.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention. Figure 1 is a partial cross-sectional plan view of the main part with the upper half removed, and Figure 2 is a cross-sectional view of the main part of Figure 1. 3 is a partial cross-sectional plan view of a conventional video cassette tape, FIG. 4 is a cross-sectional view taken from FIG. 3, and FIG. 5 is a perspective view of a spring for a front lid locking member. 21...upper half, 22...lower half, 23...
...Cassette body, 24...Front lid, 25...Front cover locking member, 25c...Latching protrusion, 25d...Groove, 2
6... Support column, 26a... Boss part, 26b... Step part, 27... Helical spring, 27a... Coil part, 27b, 27c... Straight part, 28... Boss part, 29... Rib .

Claims (1)

[Scope of utility model registration request] A front cover 2 that covers the magnetic tape 5 is provided on the front of the cassette main body 23 consisting of an upper half 21 and a lower half 22.
4 is provided so that it can be opened and closed, and a front lid locking member 25 that locks the front lid 24 in the closed state is rotatably provided, and the front lid locking member 25 is normally biased in the closing direction to lock the front lid 24 in the closed state. Lid 2
In the magnetic tape cassette 1, the spiral spring 27 has symmetrical linear parts 27b and 27c projecting in a V-shape from the coil part 27a. A boss part 26a having a smaller diameter than the support pillar 26 is provided at the tip of the support pillar 26 erected on the lower half 22.
The coil portion 27a of the spring 27 is externally fitted onto the upper half 21, and the step portion 26b formed at the tip of the support column 26 and the tip of the boss portion 26a fit together.
The helical spring 27 is prevented from coming out by the tip 29a of the boss portion 28, and the tip of the straight portion 27b of the helical spring 27 is attached to the front lid locking member 25 at approximately the same height as the boss portion 26a. A locking protrusion 25c formed in
The magnetic tape cassette is characterized in that the straight portion 27c of the helical spring 27 is pressed into contact with the rib 29 of the lower half 22.