JP3027104B2 - Tape cassette - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette adapted to a video cassette.

[0002]

2. Description of the Related Art Generally, a tape cassette accommodates a pair of reels 5 each having a magnetic tape wound around an upper half 1 and a lower half 3 as shown in FIG.
And the front half 7 is attached to the front of the lower half 3 to open and close the front cover 7 to take out the magnetic tape. As shown in FIG. 2, the conventional tape cassette is provided with a storage section 9 for storing a lock plate 8 for regulating the front lid 7, and the storage section 9 holds the lock plate 8 on the lower half 3. For the purpose, a retaining rib 11 of the lock plate shaft 10 is provided upright. In addition, even if external forces acting on the tape cassette, such as transport, drop test, and high temperature environment, the lock plate 8 allows the lock plate 8 to hold the front lid 7.
Must be held so as to satisfy the opening / closing function.

However, under the current situation where a low production cost is required, the design concept is a lightweight cassette half that can be molded with a small amount of resin. In changing to this lightweight cassette half, most parts can be designed to be thinner with a reduced thickness, but there are also places where the function cannot be simply changed to a thinner design, such as the lock plate shaft holding ribs. . In this case, a product having a thick portion (conventional thickness) in place of a thin portion has an uneven thickness portion, which deteriorates the molding balance, and causes insufficient filling of the product, poor mold release, or poor appearance. Sink failure occurs. Therefore, in a shape in which a thin portion and a thick portion are mixed, molding cannot be performed under the conventional molding conditions, and fine adjustment of the molding conditions is required, and workability is reduced due to a cycle reduction in molding.

On the other hand, if the lock plate bearing is simply made thinner like other parts, the strength is expected to be insufficient, and cracks and cracks of essential parts due to transportation and drop tests are generated, and deformation in a high temperature environment or the like is caused. May be caused. Furthermore, in order to solve the conventional drawbacks, Japanese Utility Model Application Laid-Open No.
No. 0079 has been proposed, but in this case, the conventional disadvantage can be solved, but the pins of the slide mold provided for measures against sink marks are liable to be damaged due to overfilling and improper handling during molding, There was a drawback that mold management became difficult and work efficiency was reduced.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate these disadvantages of the prior art, and to provide a cassette half in which the problem of sink marks on the appearance due to an imbalance in wall thickness caused by weight reduction of all the halves has been solved. That is. Further, a further object of the present invention is to reduce the thickness of the holding ribs in order to eliminate the imbalance in the thickness of all the halves, maintain the strength at the time of the thickness, and in a situation such as transportation and dropping. Another object of the present invention is to provide a cassette half capable of sufficiently satisfying the function as a lock plate.

[0006]

According to the present invention, there is provided a cassette half containing a pair of tape reels around which a magnetic tape is wound, wherein the cassette half has an openable and closable front cover, and regulates the closing direction of the front cover. The present invention provides a tape cassette provided with a lock plate having a cross-shaped rib whose holding rib for holding the lock plate shaft is designed to have a thin wall thickness substantially equal to the thickness of a side wall or a reel area.

[0007]

The thickness of the ribs for the lock plate is made as thin as the thickness of the side wall or the reel area, thereby eliminating uneven thickness in the product and eliminating the problem of sink marks on the appearance. In addition to making the lock plate ribs thinner, by integrally forming auxiliary ribs to assist the strength of the lock plate ribs, the function as the lock plate bearing ribs is fully satisfied against various external influences. To provide a cassette half.

[0008]

FIG. 3 (a) is an enlarged plan view of a lock plate accommodating portion 29 in which a lock plate bearing rib 30 of the present invention is erected, and FIG. 3 (b) is an internal view thereof taken along a line AA. FIG. FIGS. 4A and 4B show a conventional example. FIGS. 3 and 4 show a state in which the lock plate is not attached for easy viewing. The lock plate rib 30 of the present invention is made half the wall thickness and thinner than the conventional one, so that it can be easily understood when compared with the lock plate rib 40 shown in FIGS. Even so, in order to maintain the strength, the ribs 32 and 33 crossing the direction of the conventional rib portion 31 are integrally formed into a cross shape.

As shown in FIG. 3B, the lock plate ribs 30 of the present invention are erected vertically from the bottom wall 12 of the lower half 3 and are integrally formed with the lower half 3. The lock plate ribs 30 are made thinner to reduce the manufacturing cost by reducing the amount of resin used.

However, if the thickness is simply reduced, cracks, cracks, and the like are generated under external influences such as transportation, a drop test, and a high-temperature environment, and the lock plate is sufficiently held to fulfill its role. You will not be able to do it. Therefore,
The lock plate ribs 30 of the present invention include, in addition to the thinned main ribs 31, a vertically elongated rib 32 which intersects vertically with the main rib 31 and extends from the bottom at substantially the same height as the main rib 31, and a main rib 3.
The main ribs 31 are integrally formed with the longitudinal ribs 32 so as to include longitudinally short ribs 33 that extend shortly from the bottom surface on the side opposite to the longitudinally extending ribs 32. Main rib 31, Long rib 32, Short rib 3
3 is formed to be substantially the same as the wall thickness of the partition wall 50 in the reel area, but about 0.7 mm and about 0.8 m, respectively.
m, preferably about 0.8 mm. By reducing the thickness of the lock plate ribs, the problem of wall thickness imbalance, which was an obstacle due to the reduction of the thickness of all the halves, is solved. It also solves the problem of sink on the product surface.

Also, as shown in FIG.
Is not formed at the same height as the main ribs 31 and the longitudinal ribs 32 for the purpose of not obstructing the movement of the lock plate. This is because the inclination can be prevented, and the strength of the portion above it can be sufficiently maintained only by the longitudinal ribs 32.

FIG. 5 is a side view of the lock plate rib 30 taken along the line CC in FIG. 3A. As can be seen from this figure, the main rib 31 has a lock plate A concave portion 35 for regulating the position of the shaft is provided. This limits the horizontal movement of the shaft of the lock plate.

[0013]

According to the above construction of the present invention, it is possible to supply a tape cassette which fully satisfies the function of holding the lock plate even under an external situation and does not cause sink marks on the appearance. The above object can be achieved. In addition, productivity is remarkably improved because fine adjustment of molding conditions and the need for pins of a slide mold are required.

While the preferred embodiment of the invention has been illustrated and described, what is presently considered, those skilled in the art will appreciate that
It will be apparent that various changes and modifications can be made without departing from the spirit of the invention. All such changes and modifications are to be included in the spirit of the present invention.

[Brief description of the drawings]

FIG. 1 is an exploded view of a general tape cassette.

FIG. 2 is an enlarged perspective view of a lock plate housing portion indicated by an instruction number 9 in FIG.

FIG. 3A is an enlarged plan view of a lock plate housing portion including a lock plate bearing rib according to the present invention,
(B) is a side view by the line AA in (a).

FIG. 4A is an enlarged plan view of a lock plate housing portion including a conventional lock plate bearing rib, and FIG.
FIG. 4 is a side view taken along line BB in FIG.

FIG. 5 is a side view including a partial cross section taken along line CC in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper half 3 Lower half 5 Reel 7 Front lid 8 Lock plate 9 Lock plate accommodation part 10 Lock plate shaft 11, 30, 40 Lock plate bearing rib 12 Lower half bottom wall 31 Main rib 32 Vertical rib 33 Vertical short rib 35 Lock plate bearing recess 50 Partition wall in reel area

Continuation of the front page (56) References JP-A-63-44287 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B 23/087 521

Claims (3)

(57) [Claims] 1. A cassette half containing a pair of tape reels wound with a magnetic tape, the cassette half having a front cover that can be opened and closed, and a lock plate that regulates a closing direction of the front cover. In the tape cassette, the holding rib for holding the shaft of the lock plate is a cross-shaped rib. 2. The tape cassette according to claim 1, wherein said holding rib has a thickness substantially equal to a thickness of a partition wall in a reel area. 3. The tape cassette according to claim 1, wherein the height of the cross rib is reduced so that the holding rib does not interfere with the rocking plate.