JP2000322863A - Tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a tape cassette exhibiting satisfactory size precision and an improved sliding reliability by suppressing deformation of the slider. SOLUTION: A groove (a recessed portion) 25 for creating a reverse-directed resin flow during a molding process to cancel disturbance in the resin flow due to a recessed groove 17 on the rear surface is provided in the vicinity of a raised region 20 that has the height realizing the sliding against a bottom surface of a tape cassette body case 1. Thus, the resin flow becomes smooth and occurrence of 'warp' or the like is suppressed during the molding of a slider 5, thereby allowing the slider 5 having good quality with satisfactory size precision to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an opening on the bottom of a main body case into which a tape loading device of a recording / reproducing apparatus can be inserted, and a slidable slider for opening and closing the opening. Regarding the tape cassette,
More specifically, the present invention relates to an improvement in the structure of the slider.

[0002]

2. Description of the Related Art In a tape cassette of this kind, a hub around which a magnetic tape is wound is housed on the left and right sides of a main body case. The above-mentioned opening is provided so that the loading of. Further, in order to prevent dust and the like from entering from outside through the opening, a slider for closing the above-mentioned bottom opening when not in use slides in the tape cassette loading direction along the bottom side of the main body case. It is movably arranged.

[0003] With respect to the above-mentioned tape cassette, a technique in which a slider installed in a main body case so as to be able to advance and retreat slidably opens and closes in accordance with an operation of loading the tape cassette into a recording / reproducing apparatus is disclosed in, for example, Japanese Unexamined Patent Publication No. 60-1985. No. 129985,
Nos. 60-136078, 60-136079 and 60-175271.

Further, when the slider is slidably mounted on the bottom surface of the main body case, if the slider is brought into sliding contact with the bottom surface of the main body case in a state of being in close contact with the whole surface, a slight manufacturing accuracy error or internal strain or Since the sliding contact resistance becomes excessive due to thermal deformation and the slider malfunctions, a rib-shaped protrusion running in the front-rear direction is provided on the inner surface of the slider. A technique for making contact is disclosed, for example, in Japanese Patent Publication No. 7-19552. In this prior art, a mechanism for locking the slider at an open position and a closed position is provided, and a concave groove for guiding an unlocking member for releasing the locked state is formed on the bottom surface of the slider.

FIG. 13 shows a structural example of a slider 5 in a conventional tape cassette. Although the overall structure will be described later, this slider 5 has through holes 15, 1 for engaging and locking the tip of the elastic locking piece of the main body case 1.
6, a concave groove 17 is provided on the bottom surface for guiding the unlocking member for releasing the engagement, and the upper surface of the slider 5 is in sliding contact with the bottom surface of the lower case 3 (see FIG. 1). The protrusion 20 moves in the slider 5 along the sliding direction.
Are formed in a rib shape from the front end to the rear end over the entire length in the sliding direction. For other structures, the same structures as those shown in FIG. 1 described later are denoted by the same reference numerals, and therefore, the description thereof is to be referred to.

[0006]

By the way, in a tape cassette having a slider as in the prior art, the slider is provided with a projection having a full width in the sliding direction including a substantially rectangular concave groove for guiding an unlocking member. As a result, in the slider, the thick portion and the thin portion are adjacent to each other, so that "warping" is likely to occur in the form after the formation, and the dimensional accuracy may be reduced to cause various adverse effects.

That is, when the slider is formed, the portion where the concave groove for guiding the unlocking member is formed becomes thin, so that the flow of the resin is not smooth and the molded product is partially distorted. For this reason, there is a problem that "warpage" or partial deformation occurs, and problems in appearance, specifically, poor transfer of grain, weld lines, appearance unevenness, sink marks, and the like are likely to occur. .

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tape cassette which suppresses deformation of a slider, has good dimensional accuracy, and has improved sliding reliability of the slider. Is to do.

[0009]

In order to solve the above problems, a tape cassette according to the present invention is provided with an opening in a bottom surface of a main body case so that a tape loading device can be inserted therein. , Slidable sliders for opening and closing the opening are disposed facing each other, and one or more elastic lock pieces having an engagement head capable of swinging up and down are provided on the bottom surface of the main body case. The slider is formed with a through hole for engaging the engaging head of the elastic locking piece so that the slider is locked in a state where the opening is opened and a state where the opening is closed. Further, the surface of the slider not facing the main body case is brought into contact with the engaging head of the elastic lock piece engaged with the through-hole, and the recording / reproducing device for releasing the locked state is provided. Provided A substantially rectangular concave groove for guiding the unlocking member is formed in a longitudinal shape in the tape cassette loading direction, and the axis in the longitudinal direction is the same as the axis of the elastic lock piece in the tape cassette loading direction. In a tape cassette molded with a resin formed at a substantially overlapping position, on the back side of the substantially rectangular concave groove of the slider, near the portion corresponding to the substantially rectangular concave groove, A concave groove extending in the sliding direction is provided.

The shape of the concave groove has at least a length corresponding to the substantially rectangular concave groove in the sliding direction of the slider, and takes various shapes such as a slit shape and a groove shape. be able to. The depth of the concave groove is
The thickness is preferably 10 to 70% of the total thickness of the slider. Furthermore, various shapes such as a uniform shape, a shape that changes continuously in the sliding direction of the slider, and a shape that changes in the same step can be applied to the shape of the concave groove in the length direction. is there. The length of the concave groove is preferably equal to or longer than the length of the concave groove in the sliding direction of the slider.

In the tape cassette according to the present invention,
A new “warp” is generated by the concave groove as described above, but the occurrence of the “warp” cancels out the “warp” as a whole.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail based on a preferred embodiment shown in the drawings. FIG.
FIG. 2 is a schematic exploded perspective view of a tape cassette according to an embodiment of the present invention, FIG. 2 is a bottom perspective view of the slider, and FIG. 3 is a sectional view of the tape cassette.

The tape cassette includes an upper case (hereinafter, referred to as an upper half) 2 and a lower case (hereinafter, referred to as a lower half) 3
And a slider case 5 slidably mounted on the lower surface side of the main body case 1.

A magnetic tape is wound around and housed in hubs (not shown) on both sides inside the main body case 1, and a bottom surface 3 a formed on the lower half 3 is oriented in a direction D to be loaded into the recording / reproducing apparatus. The center of the bottom of the front portion is removed together with the front portion to form an opening 4 for tape loading. The front part of the upper half 2 is also opened at the front part, and a front lid 7 is disposed in front of the front opening part so as to be able to move up and down, and is opened and closed with the loading of the recording / reproducing apparatus. You.

A tape loading device (not shown) of a recording / reproducing device is provided in an opening 4 on the bottom surface of the lower half 3.
Can be inserted from below, and the tape is pulled out to perform recording and reproduction. In the lower half 3, drive shaft insertion holes 3b are opened on both sides.

The slider 5 opens and closes the bottom opening 4 of the lower half 3 of the main body case 1 as the tape cassette advances and retreats along the loading direction D of the tape cassette. Plate portion 5 parallel to bottom surface 3a
a and a side wall 5b standing on both sides, and the whole is integrally formed of synthetic resin.

The side wall portion 5b is provided with a retaining piece 11 extending upward, as shown in FIG. 3, which is inserted into a slit 12 formed in a joint portion between the upper half 2 and the lower half 3, and It is slidable and the amount of movement is restricted.

The length of the slider 5 in the sliding direction of the flat plate portion 5a is formed shorter than the length of the main body case 1 in the front-rear direction, and the front end thereof coincides with the front end position of the main body case 1 when moving forward. The above-mentioned opening 4 is closed, and the opening 4 is fully opened when it retreats.
At this time, a drive shaft insertion hole 5c is also opened in the slider 5 at a position corresponding to the drive shaft insertion hole 3b of the lower half 3. The center position of the drive shaft insertion hole 5c is aligned with a center line S perpendicular to the sliding direction of the slider 5.
It is formed so as to be offset more rearward.

The lower half 3 is provided with a lock mechanism for locking the slider 5 between an open position and a closed position. The lock mechanism includes an elastic lock piece 14 of the lower half 3 and through holes 15 and 16 of the slider 5. The elastic lock piece 14 is provided on the bottom surface 3 of the lower half 3.
a, one or more places (one on each side in the case shown),
It is molded integrally.

As shown in FIG. 4, the elastic lock piece 14 has a base connected to the lower half 3 and a distal end connected to the lower half 3.
The hook-shaped engaging head 14a, which is elastically deformable and can be vertically swung, is formed downward at its tip. The engaging head 14a is provided so as to protrude further downward from the bottom surface 3a of the lower half 3, and can be engaged with the through holes 15, 16 of the slider 5.

The through-holes 15 and 16 are formed in a rectangular shape by penetrating two at the left, right, front and back of the flat plate portion 5a of the slider 5. That is, the front through-hole 15 engages with the engaging head 14a at a position where the slider 5 opens the opening 4 and moves backward, and an engaging head 14a at a position where the slider 5 closes the opening 4 and moves forward. Rear through hole 1 that engages with
6 are provided, and the movement of the slider 5 is locked by the engagement of the two at each position.

The release of the locked state by the engagement between the engaging head 14a of the elastic lock piece 14 and the through holes 15 and 16 is performed by a lock release member 30 provided in a recording / reproducing apparatus into which the tape cassette is loaded. Push-up piece 31 (see FIG. 4)
Done by The unlocking member 30 is guided by a concave groove 17 having a substantially rectangular cross section formed on the bottom surface of the slider 5, and is engaged with the through holes 15, 16 opened corresponding to the concave groove 17. The upwardly-moving push-up piece 31 comes into contact with the engaging head 14a of the lock piece 14 to release the engagement. The front end of the concave groove 17 is formed so as to expand in the left-right direction (see FIG. 2).

The concave groove 17 is formed in a longitudinal shape along the loading direction D of the tape cassette, and the longitudinal axis is formed at a position substantially overlapping the axis of the elastic lock piece 14 along the loading direction D. . The rear end of the concave groove 17 is located at a position forward of the center of the drive shaft insertion hole 5c.
In particular, it is provided forward of a center line S (see FIG. 2) perpendicular to the sliding direction of the slider 5.

Further, the through holes 15 and 16 and the concave groove 1 are formed so as to surround a portion where the concave groove 17 is projected.
7. The flat plate portion 5a of the slider 5 in the peripheral portion including the forming range of 7
, The bottom surface 3a of the lower half 3 of the slider 5
A convex region 20 having a height that is in sliding contact with the back surface (the lower surface in the figure) of the bottom surface 3a of the lower half 3 is formed on the surface on the side opposite to. Then, the slider 5 comes into sliding contact with the back surface of the bottom surface 3a of the lower half 3 via the convex region 20.

The convex region 20 extends radially from the front end of the slider 5 to the side or obliquely rearward, for example, around the resin injection gate 40 in the form of a plurality of convex lines. The formation range is such that the rear extension end 20a of the convex region 20 does not exceed the center line S in a direction perpendicular to the sliding direction of the slider 5 (FIG. 1).
reference). Further, the convex region 20 includes a portion where the substantially rectangular concave groove 17 is projected.

Due to the formation of the convex region 20, the thickness of the flat plate portion 5a of the slider 5 becomes thicker in the peripheral portion except the concave groove 17 than in other portions, and thinner in the concave groove 17 portion. In order to prevent deformation of the slider 5 such as "warping" due to such a change in thickness, the tape cassette according to the present embodiment is provided with a concave portion for preventing "warping" as described below. I have.

That is, as shown in FIGS. 1 to 3, the back surface of the surface provided with the concave groove 17 (that is, FIGS.
A concave portion (groove) 25 having a triangular cross section is provided on a thin portion of the upper surface in FIG.
Are provided over the entire width in the sliding direction. Such a groove 2
Providing 5 cancels out the “warpage” of the slider 5 due to the change in thickness at the concave groove 17 described above, so that a molded product without “warpage” as a whole can be obtained.

The tip of the engaging head 14a engaged with the through holes 15 and 16 is located in the concave groove 17 (in the height direction) so as not to protrude below the lower surface of the slider 5. It has become. At the center of the front end of the slider 5, a locking member 18 having a resin injection gate 40 at the time of molding and a spring (not shown) for urging the slider 5 in the closing direction is provided.

Further, on the upper surface of the slider 5 near the rear end portion, auxiliary projections 21 are formed on the left and right sides of which the front end can contact the bottom surface of the lower half 3 so as to prevent rattling during sliding. ing. The auxiliary protrusion 21 has the same height as the convex region 20. The tip of the auxiliary projection 21 may be a flat surface or a curved surface such as a sphere. The height of the protruding region 20 is, for example, about 0.05 to 0.3 mm so that the amount of protrusion from the periphery is about 0.05 to 0.3 mm.

The general operation of the tape cassette as described above is as follows. First, before loading into the recording / reproducing apparatus, the slider 5 is at the forward position and closes the bottom opening 4. In this state, the engaging head 14a of the elastic locking piece 14 is locked so as not to engage with the rear through hole 16 to perform the opening operation.

With the loading into the recording / reproducing apparatus, the unlocking member 30 is inserted from the front end of the concave groove 17 and
The engaging head 1 engaged with the rear through-hole 16 by the operation of 1
The engagement of the slider 4a is released, the slider 5 is made movable, and the slider 5 is moved rearward relative to the main body case 1 in accordance with the loading operation to open the bottom opening 4, and the elastic lock is provided at the retracted position. The engaging head 14a of the piece 14 is
To lock the open position. The tape loading device is inserted into the opened opening 4 and the tape is pulled out forward to enable recording and reproduction.

When the tape cassette is taken out after use, the unlocking member 30 moves relatively forward and engages with the engaging head 14a of the elastic locking piece 14 engaged with the front through hole 15. Is released by the operation of the push-up piece 31, the slider 5 moves in the closing direction by the urging force of the spring, and closes the opening 4. In the movement of the slider 5 as described above, the formation of the grooves 25, the convex regions 20, and the auxiliary projections 21 eliminates the problem such as "warpage" during molding, and ensures good sliding characteristics.

That is, first, the convex region 20 is thickened around the concave groove 17 due to the formation of the convex region 20 around the concave groove 17. Inflow. Therefore, problems of molding defects such as distortion and “warpage” due to poor flow can be reduced.

If the groove 25 is not provided, the resin injection gate 40 is formed when the slider 5 is formed.
Resin flows from the groove 5 so as to circumvent this portion because the portion of the concave groove 17 is thin, and the flow of the resin changes greatly here, and the subsequent flow is greatly disturbed. The groove 2 was
It is considered that the provision of 5 has an effect of canceling the disturbance of the resin flow due to the concave groove 17.

FIG. 5 shows another embodiment, in which the shape of the groove (25a) is rectangular, and the other points are the same as those in the above-described embodiment. In this embodiment, the same portions are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 6 shows still another embodiment, in which the shape of the groove (25b) is a semicircle, and the rest is the same as the above-described embodiment. Note that, also in the present embodiment, the same portions are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 7 shows still another embodiment, in which a groove 25 similar to that shown in FIG. 1 is provided in the slider 5 shown in FIG. Note that, also in the present embodiment, the same portions are denoted by the same reference numerals, and description thereof will be omitted.

In the above embodiment, the grooves 25 (25a, 25a,
25b) is provided over the entire width of the slider 5 in the sliding direction. However, the present invention is not limited to this. For example, the grooves 25 (25a, 25b) may be provided in the sliding direction of the slider 5. The length may be a length corresponding to the portion where the concave groove 17 exists.

The groove 2 shown in FIGS. 1 to 3 and FIG.
5, the groove 25a shown in FIG. 5 and the groove 25b shown in FIG. 6 can be implemented in various forms as shown in the sectional views of FIGS. That is, the one in which the depth is uniform as shown in FIG. 8, the one in which the depth changes at a constant rate as shown in FIG. 9, and the one in which the depth changes stepwise as shown in FIG. Etc. can be used effectively.

In this case, the groove is deep on the front side and shallow on the rear side in the loading direction D into the recording / reproducing apparatus. In addition, when the fukusa is changed stepwise, taking into account the fluidity of the resin at the time of molding, for example, in the case of dividing into three steps shown in FIG. The position q at which the second step is provided at the rear end of the convex region 20 (see FIGS. 1, 5 and 6)
It is good to set it to the rear end (the same) of c.

In addition to the specific examples shown in FIGS. 8 to 10, those in which the depth changes in a curved line may be used, or the number of steps and the setting of the height in the case of a stepwise configuration may be used. ,
Various choices are possible. Also, needless to say, various shapes in which these are combined in an appropriate form can be applied in consideration of the fluidity of the resin at the time of molding.

In FIG. 1 to FIG. 6, what is indicated by reference numeral 26 is the deformation after molding of the side wall portions 5b on both sides of the slider 5 (normally, since the side walls 5b fall inward, they are referred to as "falling"). This is a fall prevention groove for reducing the height. The shape of the fall prevention groove 26 is not limited to the circular shape shown in the figure, but may be a somewhat angular shape.

The substantially rectangular concave groove as described above is provided also in another magnetic tape cassette, for example, a β cam cassette (L type) used in a broadcasting station. Like the cassette, it is used for positioning with a device for recording and reproduction.

As for the β cam cassette, the problem described above arises in the formation of such a groove, so that the configuration of the present invention can be applied. FIG.
FIG. 2 is an exploded external view of the β cam cassette. FIG.
Is a plan view of the lower half, (a) is a top view,
(B) is a bottom view. Symbol 17a in FIG.
Are grooves corresponding to the concave grooves 17 described above.

[0045]

As described above in detail, according to the present invention, the turbulence of the resin flow at the time of molding due to the concave groove on the back surface is located in the vicinity of the convex region having a height which is in sliding contact with the bottom surface of the main body case. By providing a groove (concave portion) that creates a reverse flow that counteracts the flow of the resin, the flow of the resin becomes smooth,
It is possible to suppress the occurrence of "warpage" or the like at the time of molding the slider, and it is possible to obtain a slider with good dimensional accuracy and good quality. The shape of the above-mentioned concave groove can be selected in a wide range.

Further, by providing the convex region having a height which is in sliding contact with the bottom surface of the main body case within a range not exceeding a center line in a direction perpendicular to the sliding direction, the flow of the resin around the concave groove is reduced. Becomes smoother and “warpage” when molding the slider
And the like can be suppressed, and a slider with good dimensional accuracy and good quality can be obtained. In addition, the opening and closing operation can be reliably performed in assembling with the main body case, so that a functional obstacle such as an abnormal sliding contact of the slider with the main body case does not occur.

[Brief description of the drawings]

FIG. 1 is a schematic exploded perspective view of a tape cassette according to one embodiment of the present invention.

FIG. 2 is a bottom perspective view of the slider of FIG. 1;

FIG. 3 is a cross-sectional view of a combined state of a main body case and a slider.

FIG. 4 is an enlarged sectional view of a main part showing an engaged state of an elastic lock piece.

FIG. 5 is a perspective view of a slider according to another embodiment.

FIG. 6 is a perspective view of a slider according to still another embodiment.

FIG. 7 is a perspective view of a slider according to still another embodiment.

8 is a cross-sectional view for explaining a change in a depth direction of a groove 25 of the slider according to the embodiment shown in FIGS.

FIG. 9 shows a groove 2 of the slider according to the embodiment shown in FIG.
It is sectional drawing explaining the change of the depth direction of 5a.

10 is a cross-sectional view illustrating a change in the depth direction of a groove 25b of the slider according to the embodiment shown in FIG.

FIG. 11 is an external exploded view of a β cam cassette shown for reference.

12A and 12B are plan views of the lower half of the β cam cassette shown in FIG.

FIG. 13 is a perspective view showing a structural example of a slider in a conventional tape cassette.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body case 2 Upper half 3 Lower half 3a Bottom surface 4 Opening 5 Slider 14 Elastic lock piece 14a Engagement head 15, 16 Through hole 17 Concave groove 20, 22 Convex area 20a Rear extension end 21 Auxiliary projection 25, 25a, 25b Groove (concave portion) 26 Fall prevention groove 30 Lock release member D Tape cassette loading direction

Claims (1)

[Claims] An opening is provided on a bottom surface of a main body case so that a tape loading device can be inserted, and slidable sliders for opening and closing the opening are disposed on both outer sides of the bottom surface so as to face each other. On the bottom surface of the main body case, at least one elastic lock piece having an engagement head capable of swinging up and down is formed, and the slider has a state in which the slider has opened the opening. A through-hole for engaging the engaging head of the elastic lock piece is formed so as to be locked in a closed state, and further, on the surface of the slider that does not face the main body case, The tape cassette has a substantially rectangular concave groove which contacts an engaging head of the elastic lock piece engaged with the through hole and guides an unlocking member provided in the recording / reproducing apparatus for releasing the locked state. Loading direction In a tape cassette molded with a synthetic resin, the elastic lock piece is formed at a position substantially overlapping the axis of the elastic lock piece in the tape cassette loading direction. A surface facing the bottom surface of the main body case of the slider, near the portion where the ridge line of the substantially rectangular concave groove is projected, extends in the sliding direction of the slider in parallel with the ridge line. A tape cassette having a concave groove.