JPH11238346A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape cassette which is reduced in costs and is excellent in assembling by making a lid lock spring inexpensive and making it in a form with high versatility. SOLUTION: A straight wire spring 11 is used as a lid lock spring for energizing a lid lock 82 into a shut state of the lid. This wire spring 11 is fitted on a lower half 61 by forming a straight groove 87a on the top end of a part 87 of the side-wall of the lower half 61, and press-fitting one end of the wire spring 11 in this groove 87a. And, the free end is fitted with the lid lock 82 from the side of the upper half 75 to energize it into a closed state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cassette suitable for application to a video tape cassette and the like.
In particular, the present invention relates to a lid lock spring for urging a lid lock for covering a front end opening of a cassette case so as to be openable and closable to a closed state of the lid, and a magnetic tape cassette having an improved incorporation thereof.

[0002]

2. Description of the Related Art There are various types of conventional magnetic tape cassettes. For example, there is a relatively small magnetic tape cassette as shown in FIG. In the magnetic tape cassette 6, a pair of reel hubs 62 and 63 are rotatably arranged in a lower half 61 which is a half of a cassette case, and a magnetic tape (not shown) is wound around the reel hubs 62 and 63. ing. Each reel hub 62, 6
3 (peripheral edge of the lower flange), the teeth 7
0, 71 are formed. The magnetic tape is supplied to the tape guides 6 at the front of the cassette (the left side in FIG. 11) and at the left and right sides.
5 and 66, and passes through the opening 67 on the front side of the lower half 61.

An upper half 75 as the other half forming a cassette case together with the lower half 61 includes:
A lid 69 that covers the magnetic tape passing through the opening 67 in front of the cassette case is attached to be openable and closable. The lid 69 includes three members: an outer lid 76, an upper lid 77, and an inner lid 78.

A side plate 79 of the outer lid 76 includes:
A lock pin 80 protrudes. And lower half 6
A lid lock 82 that locks the lock pin 80 and locks the lid 69 in the closed state of the opening 67 is rotatably attached to one of the side plates 81.
A leaf spring 83 is provided as a lid lock spring for urging the lid lock 82 to the closed state of the lid 69.

In the drawings, reference numeral 85 denotes a reel hub 6.
Reference numeral 86 denotes a lid spring mounted on the rotation shaft of the outer lid 76. In addition, in FIG. 11, members other than the main part are not denoted by reference numerals, and description thereof is omitted. FIG. 12 is an enlarged view taken along the line AA in FIG. 11. As is apparent from FIG. 12, the lid lock 82 has support pins 82a projecting from both ends at the upper end thereof. The support pin 82a is rotatably supported by smoothly fitting into a concave groove formed at the upper end of the lower half 61. That is, the rotation of the lid lock 82 is performed in a vertical plane. And lid lock 82
The free end of the lock pin 80 of the outer lid 76
Is formed.

Also, as shown in FIG. 12, the leaf spring 83 has a linear portion 83 which presses a lid lock 82.
b, and a curved portion 83a that engages with the lower half 61, and is formed by bending a thin steel plate or the like.
The curved portion 83a of the leaf spring 83 has a lower half 61
Rib 88 projecting from the bottom wall or side wall of the
Is elastically deformed and inserted between the part of the side wall 87 facing the side wall. Since the leaf spring 83 can assume such an engaged state, temporary fixing until the upper half 75 is put on the lower half 61 is performed.

When the magnetic tape cassette 6 having the above structure is loaded into a video deck (not shown), the lid lock 82 is released by a leaf spring 83 by a release mechanism in the video deck, as shown by an arrow R in FIG. It is turned against the urging force. As a result, the concave portion 82b of the lid lock 82 is disengaged from the lock pin 80, and the locked state of the lid 69 including the outer lid 76 is released. Then, the lid 69 is opened by a mechanism in the video deck, and information is read from the pulled-out magnetic tape or information is recorded on the magnetic tape.

[0008]

However, in the conventional magnetic tape cassette 6, a special leaf spring 83 bent into a shape corresponding to the mounting portion as described above is used as the lid lock spring. The leaf spring 83 is expensive in itself, has no versatility to be used for other parts, and causes an increase in cost.

In order to mount the leaf spring 83,
The ribs 88 must be formed in the lower half 61 as described above. If such a rib 88 is formed in the lower half 61, deformation due to resin shrinkage is likely to occur near the rib 88 when the lower half 61 is formed. Therefore, it is difficult to maintain good molding accuracy of the mounting portion of the leaf spring 83. On the other hand, since the leaf spring 83 is a very small elastic member, it is relatively difficult to improve the accuracy of punching, bending and the like.

As described above, conventionally, the processing accuracy of the leaf spring 83 is not easily stabilized, and the molding accuracy of the mounting portion is also unstable, so that the leaf spring 83 is securely locked at the time of mounting. Without shifting from the specified mounting position,
Depending on the case, there is a possibility that a situation of jumping out of the lower half 61 due to its own elasticity may occur, and the assembling property is extremely poor. In particular, when an automatic assembling device or the like is used, the leaf spring 83 has a problem that automatic assembly becomes difficult.

Therefore, an object of the present invention is to solve the above-mentioned problems, and to reduce the cost by making the lid lock spring inexpensive and have a versatile form, and to provide a magnetic tape cassette with good assemblability. To provide.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cassette case comprising a pair of upper and lower halves having a pair of reels rotatably mounted by winding a magnetic tape and providing an opening at a front end of the cassette case. A lid for opening and closing the magnetic tape passing through the opening is attached,
In a magnetic tape cassette including a lid lock for locking the lid in a closed state of the opening and a lid lock spring for urging the lid lock to a closed state of the lid, the lid lock spring is attached to the lower half. This is achieved by a magnetic tape cassette comprising a cantilever spring whose one end is locked, the free end of which engages with the lid lock from the upper half side and urges it to the closed state.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where a magnetic tape cassette according to the present invention is applied to a video tape cassette will be described below in detail with reference to the accompanying drawings. However, since the magnetic tape cassette 1 has the same configuration as the above-described conventional magnetic tape cassette 6 except for the parts described below, the same reference numerals are given to the same parts as those in the related art, and the description thereof will be omitted. Omitted as appropriate.

FIG. 1 is an exploded perspective view of a magnetic tape cassette according to a first embodiment of the present invention, and FIG.
FIG. 3 is an enlarged perspective view of a main part of the magnetic tape cassette shown in FIG. In the magnetic tape cassette 1 according to the first embodiment, the wire spring 11 is used as a lid lock spring for urging the lid lock 82 to close the lid 69.

The wire spring 11 is a linear wire spring obtained by simply cutting a wire made of stainless steel or the like into a predetermined length. The wire spring 11
As the material, a material having a circular cross section, which can be easily obtained commercially, is preferable from the viewpoint of cost, but the cross sectional shape is not limited to a circle. The wire spring 11 is attached to the lower half 61 as a cantilever spring having one end locked. Specifically, as shown in FIGS. 2 and 3, a linear groove 87 is formed at the upper end of a part 87 of the side wall of the lower half 61.
is formed, and one end of the wire spring 11 is press-fitted into the groove 87a to be attached to the lower half 61.

The free end of the wire spring 11 is engaged with the lid lock 82 from the upper half 75 side (upper side) to urge the wire spring 11 to the closed state. Specifically, as shown in FIGS. 2 and 3, a swelling portion 82 d is formed at the upper end of the lid lock 82 toward the rear of the cassette, and the free end of the wire spring 11 is placed on the swelling portion 82 d. Are engaged. Accordingly, the lid lock 82 urged downward by the wire spring 11 on the bulging portion 82d is rotated clockwise in FIG. 2 around the support pin 82a, and urged to close the lid 69. . The bulging portion 82d has a small groove 82f.
Are formed, and the free end of the wire spring 11 is
And is configured not to be shifted laterally.

As is apparent from the above configuration, in the magnetic tape cassette 1, an extremely simple wire spring 11 is used as a lid lock spring, and the wire spring 11 is compared with a conventional special leaf spring. It can be formed at considerably low cost, and cost can be reduced. Moreover,
The wire spring 11 having a simple shape can easily stabilize the processing accuracy.

The magnetic tape cassette 1 according to the first embodiment has a leaf spring 83 as in the conventional magnetic tape cassette 6.
Since the rib 88 for temporarily fixing the lower half 61 is not required, the shrinkage of the resin when the lower half 61 is formed can be reduced to prevent deformation. As a result, the spring can be mounted accurately and the assembling property is good, and the inconvenience such as the lid lock 82 and the wire spring 11 jumping out of the lower half 61 when the temporarily assembled product is being conveyed on the assembly line. Is reliably avoided. Further, when the wire spring 11 is incorporated into the lower half 61 as a component, the wire spring 11 can be mounted from above the lid lock 82. Therefore, for example, in performing automatic assembly by an automatic assembling apparatus or the like, workability is extremely improved, which contributes to improvement in production efficiency.

FIG. 4 is an enlarged perspective view of a main part of a magnetic tape cassette according to a second embodiment of the present invention. In the second embodiment, other components (not shown) are configured in the same manner as the magnetic tape cassette 1 of the first embodiment described above, and the description thereof will be omitted. The wire spring 21 according to the second embodiment includes a coil part 21 having a fixed end on one turn.
a part 87 of the side wall of the lower half 61
The coil portion 21a is externally fitted to a cylindrical mounting pin 87c formed integrally with the coil portion 21a. Note that the coil portion 21a and the mounting pin 87c need not be circular.

In the second embodiment, the mounting pins 87c
Assuming that the diameter of the wire spring 21 is d ₁ and the inner diameter of the coil portion 21a of the wire spring 21 before insertion is d ₂ , it is preferable that d ₂ <d ₁ is satisfied. That is, the coil portion 21a of the wire spring 21 is expanded when fitted to the mounting pin 87c, and is firmly fitted to the mounting pin 87c due to the reaction force due to the diameter expansion.

FIGS. 5 and 6 are an enlarged perspective view and an enlarged sectional view of a main part of a magnetic tape cassette according to a third embodiment of the present invention. The wire spring 21 is incorporated into the lower half 61 by a different structure. The wire spring 21 according to the third embodiment is configured such that the coil portion 21a is loosely fitted to a prismatic mounting pin 84a integrally formed at the tip of a cylindrical boss 84 protruding from the bottom wall of the lower half 61, The intermediate portion at the free end of the wire spring 21 is engaged with a guide groove 87 b formed at the upper end of a part 87 of the side wall, and is attached to the lower half 61. Note that the mounting pin 84a has a height sufficient to allow the wire spring 21 to assume such an engaged state and to temporarily fix the upper half 75 to the lower half 61.

By covering the upper half 75 on the lower half 61, the guide groove 72a of the support wall 72 projecting from the inner wall surface of the upper half 75 is bridged by the cylindrical boss 84 and a part 87 of the side wall. The wire spring 21 is engaged with the intermediate portion of the wire spring 21 from above, and the positioning of the wire spring 21 is performed. Therefore, similarly to the above-described embodiment, the free end of the wire spring 21 is engaged with the lid lock 82 from the upper half 75 side (upper side) to urge the wire spring 21 to the closed state.

That is, in the magnetic tape cassette according to the third embodiment, the inner diameter of the coil portion 21a of the wire spring 21 is set to be larger than the outer diameter of the mounting pin 84a and is loosely fitted. The groove width of the guide groove 87 b for preventing the wire spring 21 from touching the side is set to be sufficiently wider than the wire diameter of the wire spring 21. Therefore, compared to the case where the wire spring 21 is press-fitted and fixed to a predetermined portion of the lower half 65, the wire spring 21
Can be easily incorporated.

Further, the guide groove 72a on the upper half 75 side
Is set to be narrower than the groove width of the guide groove 87b, and the wire spring 2 is located at a position closer to the fixed end than the guide groove 87b.
Since the side contact of the wire spring 1 is regulated and firmly held in the vertical direction, the wire spring 21 after assembly can be accurately positioned, and a stable spring force can be applied.

FIG. 7 is an enlarged sectional view of a main part of a magnetic tape cassette according to a fourth embodiment of the present invention. The wire spring 21 is attached to the lower half 61 by a structure different from the above-described structure in which the wire spring 21 is incorporated. Incorporated. The wire spring 21 in the fourth embodiment is similar to the third embodiment,
A prismatic mounting pin 8 in which a coil portion 21a is integrally formed at a tip of a cylindrical boss 84 protruding from a bottom wall of the lower half 61.
4a, the free end intermediate portion of the wire spring 21 is engaged with a guide groove 87b formed at the upper end of a part 87 of the side wall, and is attached to the lower half 61.

Then, by covering the upper half 75 with the lower half 61, the tip of the support wall 73 protruding from the inner wall surface of the upper half 75 is made to face the tip of the cylindrical boss 84. At the tip of the support wall 73, the mounting pin 84a
The receiving hole 73a for receiving the wire spring 21 is recessed.
Of the support wall 73 and the cylindrical boss 84
And it is clamped and fixed. FIG. 8 is a front view showing a wire spring 31 which is a modification of the wire spring 21. As shown in the drawing, the coil portion 31a of the wire spring 31 has a large number of turns, for example, five turns. With such a large number of windings, the attachment of the wire spring 31 becomes more firm.

FIG. 9 is an enlarged perspective view of a main part of a magnetic tape cassette according to a fifth embodiment of the present invention. Also in the fifth embodiment, the other components (not shown) are configured in the same manner as the magnetic tape cassette of each of the above-described embodiments, and thus description thereof will be omitted. As shown in FIG.
In the fifth embodiment, the leaf spring 15 is employed as a lid lock spring that biases the lid lock 82 to the closed state of the lid 69 (see FIG. 1).

The leaf spring 15 is, as shown in FIG.
It is formed linearly over its entire length and is not bent at all. That is, for example, it can be obtained only by punching a material such as a stainless steel plate. Leaf spring 1
For example, a circular mounting hole 15a is formed on the fixed end side of the mounting hole 5a. Done. This fitting is performed, for example, by fitting. A tapered surface 87e is formed at the tip of the mounting pin 87d, and serves as an insertion guide when the leaf spring 15 is fitted to the mounting hole 15a.

The free end of the leaf spring 15 is engaged with the bulging portion 82d of the lid lock 82 from the side of the upper half 75 (see FIG. 1) forming the half of the cassette case.
The lid lock 82 is biased to a closed state. Therefore, the leaf spring 15 has an extremely simple shape, like the wire spring 11 in the first embodiment described above, so that the manufacturing cost is low and it contributes to the cost reduction of the magnetic tape cassette.
In addition, if this leaf spring 15 is used, the wire spring 11
The above-mentioned effect achieved by using
Good assemblability and inconveniences such as the lid lock 82 and the wire spring 11 protruding from the lower half 61 in the temporarily assembled state are reliably avoided.

[0030]

As described above, in the magnetic tape cassette of the present invention, an extremely simple wire spring or a linear leaf spring is used as the lid lock spring for urging the lid lock to the closed state of the lid. Therefore, cost can be reduced. In addition, simple shape wire springs and straight leaf springs are easy to stabilize the processing accuracy, and the springs can be mounted accurately and the assemblability is good. Inconveniences, such as a spring jumping out during transportation on the upper side, are reliably avoided.

Furthermore, when the lid lock spring is incorporated as a component into the lower half, the lid lock spring can be mounted from above the lid lock. For example, when performing automatic assembly by an automatic assembling device or the like, workability is improved, and production efficiency is improved. Can be improved. Therefore, cost reduction is achieved by making the lid lock spring inexpensive and having a versatile form,
In addition, a magnetic tape cassette having good assemblability can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a magnetic tape cassette according to a first embodiment of the present invention.

FIG. 2 is an enlarged view showing a view taken in the direction of arrows BB in FIG. 1;

FIG. 3 is an enlarged perspective view of a main part of the magnetic tape cassette shown in FIG.

FIG. 4 is an enlarged perspective view of a main part of a magnetic tape cassette according to a second embodiment of the present invention.

FIG. 5 is an enlarged perspective view of a main part of a magnetic tape cassette according to a third embodiment of the present invention.

FIG. 6 is an enlarged sectional view of a main part of the magnetic tape cassette shown in FIG. 5;

FIG. 7 is an enlarged sectional view of a main part of a magnetic tape cassette according to a fourth embodiment of the present invention.

FIG. 8 is a front view showing a modified example of the wire spring shown in FIG.

FIG. 9 is an enlarged perspective view of a main part of a magnetic tape cassette according to a fifth embodiment of the present invention.

10 is a top view and a front view of the leaf spring shown in FIG.

FIG. 11 is an exploded perspective view of a conventional magnetic tape cassette.

FIG. 12 is an enlarged view of AA in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic tape cassette 11 Wire spring (lid lock spring) 61 Lower half 69 Lid 75 Upper half 76 Outer lid 82 Lid lock 87a Groove

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hidetoshi Yamamoto 2-12-1, Ogimachi, Odawara-shi, Kanagawa Prefecture Fuji Photo Film Co., Ltd.

Claims (1)

[Claims] 1. A cassette case comprising a pair of upper and lower halves having a pair of reels wound around a magnetic tape so as to be rotatable and having an opening at the front end and opening and closing the magnetic tape passing through the opening. A magnetic tape cassette having a lid for freely covering the lid, a lid lock for locking the lid in a closed state of the opening, and a lid lock spring for urging the lid lock to a closed state of the lid. The lid lock spring comprises a cantilever spring having one end locked to the lower half, and a free end thereof is engaged with the lid lock from the upper half side to bias the lid lock in a closed state. Magnetic tape cassette.