JPH0544944Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a magnetic tape cassette, and more particularly to a magnetic tape cassette having a lid that closes a front opening from which a magnetic tape is pulled out.

(Prior Art) Conventionally, magnetic tape cassettes (hereinafter simply referred to as "cassettes") for video, digital audio, etc.
When the cassette is used, when the cassette is loaded into a magnetic recording and reproducing device, a loading mechanism provided in the device pulls out the magnetic tape from an opening for pulling out the tape provided in the front of the cassette body, and the magnetic recording and reproducing device It is configured to be attached to the rotating head cylinder of the device for recording and reproducing. When the cassette is stored, the opening is closed by a lid (front lid) which is always biased in the closing direction in order to protect the tape and prevent dust from entering the cassette.

However, in the magnetic tape cassettes used in recently developed 8mm video systems, etc., the cassette space is limited in order to achieve miniaturization, so a spring that always biases the lid in the closing direction, Generally, it is also used as a spring that constantly biases the lid lock, which engages with the lid and restricts the opening and closing of the lid, in the locking direction.

Japanese Utility Model Application Publication No. 60-16384, Japanese Utility Model Application Publication No. 61-121582, etc. disclose magnetic tape cassettes having the above-mentioned dual-purpose biasing spring.

In other words, according to the descriptions in these publications, etc.,
A torsion coil spring serving as a spring member for biasing the lid and the lid lock is wound around a rotating support shaft provided on the lid, and has one end latched to the lid and the other end abutted against the lid lock. provided in the structure. Therefore, the lid and the lid lock are biased by the torsional force of the torsion coil spring so as to engage the spring engaging portions of the lid and the lid lock, and the lid is biased in the closing direction and the lid lock is biased in the locking direction. Each is energized.

(Problem to be Solved by the Invention) However, in any configuration of the above-described biasing means for the lid and lid lock, the spring action at both ends of the biasing spring, which is also used, affects the spring pressure at the other end. This has the disadvantage of making it unstable. In particular, the torsional force of the spring end on the side that biases the lid is greatly affected by the amount of twist of the spring end on the side that biases the lid. Therefore, depending on the open/closed state of the lid, the pressing force of the pressing member that comes into contact with the lid lock and releases it is varied.

In particular, magnetic tape cassettes, which are recording and reproducing devices used in high-definition televisions and other devices that have been developed in recent years and can provide higher resolution and higher quality images than the current NTSC system, are more expensive than the 8mm video system mentioned above. Dust-proofing and high precision are required, and the spring pressures of the biasing springs of the lid and lid lock are also strictly regulated by the recording and reproducing apparatus, so it is necessary to stabilize the spring pressures.

That is, for example, since the pressing force of the pressing member that releases the lid lock is set within a predetermined range, when the lid is opened, the spring pressure of the biasing spring of the lid lock exceeds the specified range. If the pressure becomes too strong, there is a problem in that the operation of the pressing member, which is operated against the spring pressure of the biasing spring, is hindered.

Therefore, the purpose of the present invention is to solve the above-mentioned problems, and it is possible to apply a stable biasing force to each spring without affecting each other, and to do so at low cost without increasing the number of component parts. The present invention provides a suitable magnetic tape cassette comprising a lid and a lid lock having a biasing means.

(Means for Solving the Problems) The object of the present invention is to provide a lid that is swingably held in the main body to close the front opening of a cassette body containing a magnetic tape, and a lid that can be closed by opening the lid. In a magnetic tape cassette having a lid lock for regulating the lid and a biasing member for biasing the lid and the lid lock in the direction of closing and regulating, the biasing member is engaged with a support shaft formed inside the lid end piece. One end thereof engages with an engaging portion formed inside the lid end piece in front of the cassette from the support shaft, and biases the lid in a direction to always close it;
The other end comes into contact with the upper end surface of the lid lock to constantly urge the lid lock to the locked position, and a locking portion provided on the side wall of the cassette body engages the support shaft locking portion and the lid lock abutting portion. This is achieved by a magnetic tape cassette characterized in that the biasing member is locked between the lid and the lid so that the biasing force applied by the biasing member to the lid and the biasing force applied to the lid lock are substantially separated. .

(Embodiment) Hereinafter, one embodiment of the magnetic tape cassette based on the present invention will be described.

FIG. 1 is a perspective view of essential parts showing the lid lock portion of a magnetic tape cassette based on the present invention.

In the figure, the magnetic tape cassette 20 has an upper cassette half and a lower cassette half 2 (not shown).
The magnetic tape is drawn out from tape draw-out holes provided at both left and right ends of the front opening of a cassette body consisting of 2, and is stored in a suspended state between the tape draw-out holes.

The lid 24 covering the opening is formed into a substantially U-shape having a front wall 25 covering the front opening and end pieces 26 extending at right angles from both ends of the front wall 25. Support shafts 27 projecting inside the end pieces 26 are rotatably supported in shaft holes (not shown) defined by the overlapped portions of the upper and lower half cases.

A side wall 28 on one side of the cassette 20 that pivotally supports the lid 24 is connected to the end piece 2 of the lid 24.
6 is provided with a double wall structure having a partition wall 39, and a lid lock 31 is provided between the partition walls.
A space 32 is formed for storing the.

In the lower half case 22, the upper edge 38 of the side wall 28 has a height necessary for storing the lid lock 31, and a cutout 33 is provided in the lower edge of the outer wall where the space 32 is formed. There is.

The lid lock 31 is capable of holding the lid in the closed position by engaging a locking portion 44 provided on the inside of the end piece 26 of the lid 24 and adjacent to the lid lock 31. an engaging portion 34; and an engagement release portion 35 that separates the engaging portion 34 from the locking portion 44 to release the engaged state.
and further includes the engaging portion 34 and the disengaging portion 35.
It has a structure in which a rotation support shaft 36 is provided at the base.

The rotation support shaft 36 is fitted into a notch 37 provided in the upper edge 38 of the lower half 22 that forms the space 32, and is held by a combination of upper halves (not shown) to hold the lid lock 31 in the cassette. It is made swingable along the side wall 28 of 20.

The lid lock 31 is formed long toward the rear of the cassette so that the upper end surface 41 of the rotation support shaft 36 is along the cassette side wall 28, and the torsion coil spring 3
The engaging portion 34 is rotated by the bending force of the spring applied by the contact of the rear end portion 45 of the locking portion 45 to engage the engaging portion 34 with the locking portion 44 . Further, a presser contact portion 40 is formed in the disengagement portion 35, and when the magnetic tape cassette 20 is loaded into a recording/reproducing apparatus, a presser (not shown) that is inserted from below the cassette comes into contact with the magnetic tape cassette 20. This allows the presser contact portion 40 to move along the notch 33.

The coil spring 30 is wound around the support shaft 27 of the lid 24 so that the tip end 46 is attached to the lid side wall 2.
6 and is engaged with an engaging protrusion 43 provided closer to the front of the cassette than the support shaft 27, and the rear end portion 45 is slightly bent at its tip so that it can be attached to the lid lock 31 as described above. Upper end surface 41
is in contact with. Further, the torsion coil spring 30 is a spring having a U-shaped cross section and is provided on the inner wall of the cassette side wall 28 so that the approximately central portion of the contact portion between the support shaft 27 and the upper end surface 41 corresponds to the position. The cassette is clamped in the vertical direction by a locking portion 42.

Therefore, the tip portion 46 acts on the engagement protrusion 43 to bias the lid 24 in the closing direction, and the rear end portion 45 acts on the upper end surface 43.
The engaging portion 3 of the lid lock 31
4 to engage with the locking portion 44 and the reaction forces for applying the respective reaction forces are supported by the support shaft 27 and the spring locking portion 42. Therefore, the twisting force of the leading end 46 and the bending force of the rear end 45 are not influenced by each other.

That is, when the magnetic tape cassette 20 configured as described above is loaded into a magnetic recording/reproducing apparatus (not shown), a presser (not shown) provided in the magnetic recording/reproducing apparatus presses the torsion coil spring 30. The contact portion 40 provided on the engagement release portion 35 is pushed toward the rear of the cassette as indicated by the arrow X against the urging force due to the bending force of the rear end portion 45 of and oscillate it. When the lid lock 31 is displaced, the engaging portion 34 disengages from the locking portion 44 of the lid 24 and releases the engagement, making the lid 24 openable and closable. After that, the torsion coil spring 30
The lid 24, which is always urged in the closing direction by the torsional force of the tip 46, is opened by a hook rod (not shown) of the magnetic recording/reproducing device.

The torsion coil spring 30 is activated during the opening/closing movement of the lid 24 or when the lid lock 3
During one swing, the lid 24 is always supported at two points by the support shaft 27 and the spring locking portion 42, and the torsional force that biases the lid 24 is exerted by the support shaft 27 and the spring. supported by the locking part 42;
On the other hand, since the bending force that biases the lid lock 31 is also supported by the support shaft 27 and the spring locking portion 42, each biasing force is separated from each other.

Therefore, the biasing force of the lid lock 31 is influenced by the open/closed state of the lid 24.
If the operation of the presser, which is operated against the biasing force, is hindered, there will be no problem. Furthermore, the torsional force that biases the lid 24 and the bending force that biases the lid lock 31 can each be applied with optimum biasing forces by appropriately setting the degree of bending of the torsion coil spring 30.

FIG. 2 shows another embodiment of the present invention, in which the upper surface 51 of the spring locking portion 50, which has a substantially U-shaped cross section and is provided on the inner wall of the cassette side wall 28, is inclined toward the bottom of the cassette. It is formed by Thereby, when the torsion coil spring 30 is assembled, after the tip end portion 46 of the torsion coil spring 30 wound around the support shaft 27 is brought into contact with the engagement protrusion 43, the rear end portion 45 is brought into contact with the engagement protrusion 43. Lidlock 3
1, the center portion of the torsion coil spring 30 can be slid onto the upper surface 51 of the spring locking portion 50 to be clamped in the recess 52, improving ease of installation.

In the embodiment described above, the biasing member is constituted by a torsion coil spring, but the present invention is not limited to this, and other biasing members may be used. Furthermore, it goes without saying that the lid, lid lock, etc. can take various shapes. Furthermore, the configuration of the spring locking portion is not limited to that of the embodiment described above, but may take various shapes as long as it locks the biasing member in the vertical direction of the cassette.

(Effects of the invention) The magnetic tape cassette of the invention has a structure in which the front opening of the cassette main body is held in a swingable manner by the main body and is locked to a support shaft formed inside a lid end piece that can be closed. One end of the biasing member engages with an engaging portion formed on the inside of the lid end piece in front of the support shaft to bias the lid in a direction that always closes the lid, and the other end engages with an engaging portion formed inside the lid end piece in front of the support shaft and biases the lid in a direction that always closes the lid. The lid lock is always urged to the locked position by contacting the upper end surface of the lid lock that restricts opening movement, and the locking portion provided on the side wall of the cassette main body engages the support shaft locking portion and the lid lock abutting portion. The biasing member is locked between the lid and the lid, so that the biasing force applied by the biasing member to the lid and the biasing force applied to the lid lock are substantially separated.

Therefore, the lid lock biasing force is not affected by the open/closed state of the lid, and the lid lock release pressurizer, which operates against the biasing force, is not hindered. Also, the lid biasing force and the lid lock biasing force can be optimally set by appropriately setting the biasing member.

Therefore, the lid and lid lock can be constructed so that the respective biasing forces do not influence each other and can apply stable biasing forces appropriately, and also have an inexpensive biasing means without increasing the number of component parts. A suitable magnetic tape cassette could be provided.

(Example) Hereinafter, the effects of the present invention can be further clarified through examples.

When the lid 24 of the magnetic tape cassette of the present invention shown in FIG. The spring pressure acting on was measured. The results are shown in FIG. Note that the lid lock release position a in the figure indicates the minimum position for releasing the lock when the abutting portion 40 moves along the notch 33,
The unlocking position b indicates the maximum movement position of the abutting portion 40 within the specified unlocking range.

Further, as a comparative example, the spring pressure of a conventional magnetic tape cassette was similarly measured, and the results are shown in FIG.

As is clear from FIG. 3, compared to the conventional magnetic tape cassette, in the magnetic tape cassette of the present invention, the stability of the spring pressure acting on the upper end surface 41 is significantly greater when the lid lock 31 is within the specified release range. It was confirmed that this improved. This means that the spring pressure that biases the lid 24 is stable regardless of the operating state of the lid lock 31.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the main parts of a magnetic tape cassette according to one embodiment of the present invention, FIG. 2 is a partially enlarged perspective view showing the main parts according to another embodiment of the invention, and FIG.
The figure is a graph showing the relationship between the spring pressure acting on the lid lock and the moving position of the lid lock. Code in the figure: 20...Magnetic tape cassette, 2
4... Lid, 22... Lower half case, 27...
... Support shaft, 28 ... Cassette side wall, 30 ... Torsion coil spring, 31 ... Lidlock, 32 ... Space, 33 ... Notch, 34 ... Engagement part, 35
... Disengagement portion, 36 ... Rotation shaft, 37 ... Notch, 38 ... Upper edge, 39 ... Partition wall, 40 ...
Presser contact portion, 41... Upper end surface, 42... Spring locking portion, 43... Engagement protrusion, 44... Locking portion, 45
. . . rear end, 46 . . . tip, 50 . . . spring locking portion, 51 .

Claims (1)

[Scope of utility model registration request] A lid that is swingably held by the main body to allow the front opening of a cassette body containing a magnetic tape to be closed; a lid lock that restricts the opening movement of the lid; and a lid and lid lock that are attached in the closing and restricting direction. In the magnetic tape cassette, the biasing member is engaged with a support shaft formed inside the lid end piece, and one end thereof is located inside the lid end piece at a position in front of the support shaft of the cassette. The lid is engaged with an engaging portion formed in the lid to constantly bias the lid in the direction of closing, and the other end is in contact with the upper end surface of the lid to constantly bias the lid to the locked position. A locking portion provided on the side wall of the main body locks the biasing member between the spindle locking portion and the lid lock abutting portion, thereby reducing the biasing force of the biasing member toward the lid and the lid lock. A magnetic tape cassette characterized in that the biasing force of the magnetic tape cassette is configured such that the biasing force of the magnetic tape cassette is substantially divided.