JPH0210631Y2 - - Google Patents

Description

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

[Conventional technology]

Figures 4 to 6 show conventional magnetic tape cassettes used in household VCRs, with Figure 4 being a partially cutaway rear view of the magnetic tape cassette seen from the lower half side, and Figure 5 being a rear view of the magnetic tape cassette seen from the lower half side. 4 is a cross-sectional view of FIG. 4, and FIG. 6 is a partial view of the corner of the lower half corresponding to the notch in FIG. 4. formed,
A pair of winding reels 6, a supply reel 6a and a take-up reel 6b, for winding the magnetic tape 5 are housed within the cassette body 4. Both reels 6 are located at the front of the cassette main body 4, which is the VTR insertion side.
A front cover 7 is attached so as to be able to open and close the magnetic tape 5 that is fed out from the magnetic tape 5a and 6b and runs on the front surface of the tape guide portions 4a and 4b of the cassette main body 4.

The front lid 7 is formed into a U-shape in plan with side plates 7c and 7d extending on both sides of a front plate 7a and a top plate 7b. Inside the side plate 7c, there is a long axis-shaped rotation support shaft 8.
However, on the inside of the side plate 7d, there is a short shaft-like rotation support shaft 9.
The front cover 7 is attached to the cassette body 4 by supporting the pivot shafts 8 and 9 in shaft holes bored in the front side of the side walls 2a and 2b of the upper half 2, respectively. The front cover spring 1 is attached to the rotation support shaft 8.
0, the helical spring is locked.

Front lid spring 10 made of the helical spring
At the corner of the lower half 3 corresponding to
is rotatably suspended by supporting shafts 11a, 11b on both upper sides thereof being suspended from ribs 3b, 3c of the lower half 3. The front lid locking member 11 is rotated by the biasing force of the helical front lid locking spring 12 attached to the support shaft 11a.
The locking protrusion 11c and the release protrusion 1 formed in
1d protrudes outward from the side wall 3a of the lower half 3, and a locking protrusion 11c engages with the front lid 7 to hold the front lid 7 in a closed state.

Front lid spring 10 made of the helical spring
is formed by one end 10a hooked on the rotation support shaft 8, an arm portion 10b on the other end side, and a coil portion 10c formed between the one end 10a and the arm portion 10b,
The arm portion 10b has a bent portion 10d that comes into contact with the inner surface of the upper half 2. This front lid spring 10
The coil portion 10c is externally fitted onto the rotation support shaft 8, and one end 10a is hooked from the outside onto a locking protrusion 8a protruding from the support shaft 8, thereby forming an arm portion 10b on the inner surface of the upper half 2. The front cover 7 is temporarily fixed to the upper half 2 by loosely fitting it into the guide groove 13. The front cover 7 in this temporarily fixed state
Connect upper half 2 with screw 14 and lower half 3 with screw 14.
The magnetic tape cassette 1 is constructed by screwing them together.

[The problem that the idea aims to solve]

However, the front cover spring 10 made of a helical spring has one end 10b of the coil portion 10c hooked on the locking protrusion 8a of the rotation support shaft 8 as described above, and the arm portion 10b having a bent portion 10d at the other end. It was disadvantageous in terms of cost because it had a unique shape and required processing technology.

Further, since the connection between the front cover 7 and the upper half 2 via the front cover spring 10 is unstable, the front cover 7 cannot be opened and closed smoothly.

Further, the front lid 7 is provided on the upper half 2, and the front lid locking member 11 is provided on the lower half 3, but when the upper half 2 is assembled to the lower half 3, the front lid spring 10 and the front lid locking member 11 are provided on the lower half 3. Even though the stop spring 12 is located close to the stopper spring 12, both are required.

Therefore, the present invention has been developed to create a magnetic tape cassette in which the front cover spring is easy to manufacture and costs can be reduced, the connection between the front cover and the upper half is stabilized, and the front cover spring can also be used as a front cover locking spring. is intended to provide.

[Means for solving problems]

This invention was made in view of the above objectives,
The upper half and lower half form the cassette body,
The magnetic tape that is unwound from the winding reel housed in the cassette main body to the front of the cassette main body is covered in an openable and closable manner by a front cover that is pivotally supported on the upper half, and before it is locked to the rotation shaft of the front cover. In the magnetic tape cassette, the front lid is always biased in the closing direction by a lid spring, and the front lid locking member is rotatably suspended on the lower half by a support shaft, and the front lid spring is a plate spring. One end of the front lid spring is locked to the pivot shaft, the other end is slidably pressed against the upper half, and a lower half is connected between one end and the other end of the front lid spring. The front lid locking member has a curved portion that bulges to the side, and the front lid locking member is formed with a locking projection and a releasing projection that project outward from the side wall of the lower half, and a pressed portion, and the front lid locking member is formed with a pressed portion. The front cover locking member is characterized in that the front cover locking member is always biased in a direction in which the locking protrusion locks the front cover by pressing the curved portion of the front cover against the pressed portion.

The material of the leaf spring used for the front lid spring is not particularly limited as long as it is an elastic member, but is preferably an elastic metal plate such as a normal spring steel plate or a stainless steel plate.

[Effect]

Therefore, the front lid spring made of a plate spring always biases the front lid in the closing direction, and the front lid locking member also moves in the direction of locking the front lid at the curved portion of the front lid spring. Always energized.

〔Example〕

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

An elongated pivot shaft 18 for locking the front cap spring 20 is in contact with the inner surface of the side plate 7c of the front lid 7, and the pivot shaft 18 has an axial slit 18a at its tip. It is formed. Front lid spring 20
is a plate spring made of elastic metal such as a spring steel plate or a stainless steel plate.
one end 20a inserted into the slit 18a of No. 8;
The other end 20b is slidably pressed against the upper half 2
and the lower half 3 between one end 20a and the other end 20b.
It has a curved portion 20c that bulges out to the side. The front cover spring 20 is attached by inserting one end 20a that holds approximately half the circumference of the rotation support shaft 18 into the slit 18a and locking it, and the other end 20b being slidably pressed into contact with the upper half 2. . At this time, the other end 20b
may be guided by guide grooves 23 formed on the inner surface of the upper half 2 on both left and right sides thereof, and may also have its distal end surface abut against the stopper protrusion 25 .

Incidentally, the front lid spring 20 is as follows. For example, the hardness is more than Bitkers hardness Hv400, preferably Hv500
With the above, SUS301H has elasticity and is rich in steel properties.
Stainless steel such as SUS301EH (extra hard), or ribbon steel with a width of 2.0 to 5.0 mm and a thickness
A steel plate of approximately 0.08 to 0.12 mm is used.

At the corner of the lower half 3 corresponding to the attachment part of the front lid spring 20, there is a front lid locking member 21 that locks the front lid 7 in the closed state.
21b is suspended from the ribs 3b, 3c of the lower half 3 so as to be rotatable. This front lid locking member 2
1 includes a locking protrusion 21c and a release protrusion 21d protruding from the side wall 3a of the lower half 3;
A pressed portion 21e, for example a protrusion, is formed to which the curved portion 20c of the front lid spring 20 is pressed.

Then, the pressed portion 21e is pressed against the front lid spring 2.
The front lid locking member 21 pressed by the curved portion 20c of 0 is biased toward the side wall 3a of the lower half 3 using the support shafts 21a and 21b as fulcrums, and the locking protrusion 21
c and an unlocking protrusion 21d protrude outward from the side wall 3a, and the locking protrusion 21c engages with the front cover 7 to hold the front cover 7 in a closed state, and the operating claw of the VTR is connected to the release protrusion. When 21d is pushed, the above-mentioned engaged state is released.

The present embodiment is constructed as described above, and in conjunction with the operation of loading the magnetic tape cassette 1 into a VTR and opening the front cover 7, the rotation support shaft 18, which locks the front cover spring 20, rotates. The rotation support shaft 18
The front cover spring 20 is wound up, the curved part 20c moves back slightly toward the upper half 2, and the other end 20b slides on the inner surface of the upper half 2, and the rotation support shaft 1
Retreat to the 8th side.

When the magnetic tape cassette 1 is removed from the VTR, the restoring force of the front cover spring 20 causes
The pivot shaft 18 rotates in the opposite direction to the opening direction, the other end 20b of the front lid spring 20 moves forward to the side opposite to the pivot shaft 18, and the front lid 7 returns to the closed position. The front lid locking member 21 is pushed by the curved portion 21c of the front lid spring 20, the locking protrusion 21c engages with the front lid 7, and the front lid 7 is held in the closed state.

As described above, in this embodiment, the front cover spring 20
Since it is formed from a leaf spring, it can be easily formed by simply cutting the leaf spring material to the required length and bending it, instead of using an expensive helical spring for the front cover spring as in the past. be. Also,
The elastic force of the curved portion 20c can reduce the play of the front lid 7 in the closed state. And the front lid 7
can be opened and closed more reliably and stably over a long period of time than before. Furthermore, when the deck is attached, with conventional cassettes that use a helical spring for the front lid spring, the connection between the front lid and the upper half via the helical spring is unstable, making it difficult for the cassette's front lid to open. However, with the present invention, such troubles do not occur.

Furthermore, since the front cover spring 20 is used to bias the front cover locking member 21, the front cover locking spring 12 shown in the conventional example is not necessary, and the number of parts can be reduced. Furthermore, significant cost reductions can be achieved.

[Effect of idea]

As explained above, in the magnetic tape cassette of the present invention, the front cover spring, which is locked to the pivot shaft of the front cover of the cassette body, is bulged toward the lower half side between one end and the other end using a leaf spring. forming a curved portion,
one end of the front lid spring is locked to the rotation support shaft, and the other end is slidably pressed against the upper half;
and a curved portion that bulges toward the lower half between one end and the other end of the front lid spring, and the front lid locking member has a locking protrusion and a release protrusion that protrudes from the side wall of the lower half. a projection and a pressed portion are formed, and the curved portion of the front lid spring is pressed against the pressed portion to constantly bias the front lid locking member in a direction in which the locking projection locks the front lid. Therefore, the front lid spring that also serves as the front lid locking spring can be easily formed by simply cutting the leaf spring material to the required length and bending it, thereby reducing the product cost. Moreover, since the front cover spring is used to bias the front cover locking member, the conventionally used front cover locking spring is no longer necessary, and the number of parts can be reduced, resulting in a further significant cost reduction.

In addition, the elastic force of the curved part of the front lid spring reduces play in the front lid in the closed state, stabilizes the connection between the front lid and the upper half, and allows the front lid to open and close smoothly. Since the front cover spring is curved as described above, the opening and closing operations of the front cover of the cassette can be performed reliably and stably for a long period of time.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention; FIG. 1 is a sectional view taken from FIG. 2; FIG. Fig. 3 is a cross-sectional side view of the essential parts, Figs. 4 to 6 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 4 is a cross-sectional view, and FIG. 6 is a plan view of the lower half corner corresponding to the notch in FIG. 4. 1... Magnetic tape cassette, 2... Upper half,
3... Lower half, 4... Cassette body, 5... Magnetic tape, 6... Winding reel, 7... Front cover, 1
2, 22...Front lid locking member, 18...Rotation shaft,
18a...Slit of rotation support shaft 18, 20...Front cover spring, 20a...One end, 20b...Other end, 20c...Curved portion, 21...Front cover locking member,
21a, 21b...Spin shaft, 21c...Lock protrusion, 21d...Release protrusion, 21e...Pressed portion, 23...Guide groove, 25...Stopper 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 the magnetic tape 5, which is unwound from the winding reel 6 housed in the cassette main body 4 to the front of the cassette main body 4, is placed before being pivotally supported by the upper half 2. The front lid 7 is covered in an openable and closable manner by a front lid spring 20 that is locked to a pivot shaft 18 of the front lid 7, and the front lid 7 is always biased in the closing direction.
Front lid locking member 2 rotatably suspended at 21b
1, the front lid spring 20 is a plate spring, and one end 20a of the front lid spring 20 is locked to the rotation support shaft 18, and the other end 20b is connected to the upper half 2. The front lid spring 2 is slidably pressed against the front lid spring 2.
0 between one end 20a and the other end 20b of the lower half 3
The front lid locking member 21 includes a locking protrusion 21c and a release protrusion 21 that protrude outward from the side wall 3a of the lower half 3.
d and a pressed portion 21e are formed, and the curved portion 20c of the front lid spring 20 is pressed against the pressed portion 21e.
A magnetic tape cassette characterized in that a front lid locking member 21 is always biased in a direction in which the locking protrusion 21c locks the front lid 7 by being pressed against the front lid 7.