JP2548682Y2 - Magnetic tape cassette - Google Patents

Description

[Detailed description of the invention]

[0001]

In the present invention, a pair of tape winding bodies for winding a magnetic tape are housed in a cassette case composed of upper and lower half cases, and each of the tape winding bodies is pressed downward by a leaf spring by a leaf spring. More particularly, the present invention relates to a structure for integrally molding the leaf spring with the half case.

[0002]

2. Description of the Related Art Conventionally, in audio equipment and video equipment, a magnetic tape wound around a pair of reels (or hubs) is movably supported in a cassette case to perform recording and reproduction. Many cassettes are used. Among these magnetic tape cassettes, a magnetic tape cassette used for video equipment such as a VHS system, a β system, and an 8 mm video is a magnetic tape wound around an upper and lower half cassette integrally formed of a synthetic resin such as an ABS resin. A pair of tape-wrapped bodies is rotatably held. The tape winding body is configured to be pressed downward by the leaf spring attached to the upper half case.

FIGS. 5 and 6 are a plan view showing the inner surface of an upper half case and a perspective view of a leaf spring in a VHS type magnetic tape cassette. The leaf spring 60 is a metal plate-like member that has an arm 62 that extends symmetrically from the center fixing portion 61 and that is appropriately curved and protrudes.
As shown in FIG. 5, the leaf spring 60 has a projection 64 provided at a central portion of the inner wall surface of the upper half case 2, for example.
The arm 62 is fixed so as to protrude inward (downward) of the cassette by inserting a hole 63 formed in the fixing portion 61 and melting the top of the projection 64 by ultrasonic welding. Therefore, when the cassette is assembled, the fixing portion 61 of the leaf spring 60 is fixed to the central portion of the upper half case 2, and both ends of the arm 62 are mounted on a tape reel which is a pair of tape winding bodies. The central portion of the end face is pressed downward of the cassette.

[0004]

[Problems to be Solved by the Invention] One of the current social backgrounds is the treatment and reuse of waste. Considering the case where the magnetic tape cassette is discarded, the half case 2 is made of a synthetic resin, and the leaf spring 60 is a metal plate. In other words, it is desired that the leaf spring 60, which is a metal plate, and the half case 2, which is a synthetic resin, are easily separated. However, if the conventional mounting structure as described above is used, the leaf spring 60 may be attached to the upper half case 2. 2 has a disadvantage that it is difficult to remove the half case, and it is difficult to process the half case. Furthermore, when the assembly process is taken into consideration, the process management and inventory management become complicated due to the large number of parts, and an ultrasonic welding device is required for performing the ultrasonic welding. In addition, there are various problems such as an increase in man-hours and difficulty in improving production efficiency. The present invention has been made in view of the above problems, and an object of the present invention is to form a leaf spring integrally with a half case formed of a synthetic resin so that the number of parts and work steps can be reduced, and disposal and recycling can be easily performed. The present invention provides a magnetic tape cassette configured as described above.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to form a pair of tape reels for winding a magnetic tape up and down.
Housed in a cassette case consisting of
A leaf bar that pushes a pair of tape reels down the cassette
At a substantially central portion of the inner surface of the upper half case,
Magnetic tape cassette integrally formed with the half case
The leaf spring and the tape reel.
The thickness corresponding to the rotation axis direction, the tape from the base
It gradually decreases in the rotation axis direction of the reel,
A protrusion located at the center of the upper end surface of the tail reel at the tip
The side opposite to is concave so as to rotate and support the projection.
Magnetic tape cassette and magnetism characterized by depression
Place the pair of tape reels around which the tape is wound
Stored in a cassette case made of
A leaf spring that pushes the prill down the cassette
At the approximate center of the inner surface of the half case,
To the magnetic tape cassette integrally molded with the
And the leaf spring moves from the base thereof to the tape library.
Part extending toward the axis of rotation of the
A protrusion located at the center of the upper end surface of the tape reel at the end
And a part for supporting the rotation is molded in two colors.
The parts are made of wear-resistant synthetic resin
Characterized by a magnetic tape cassette and achieved by
You.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view of a magnetic tape cassette, and FIG. 2 is a cross-sectional view of a main part of an upper half case. . Magnetic tape cassette 1
Is a combination of an upper half case 2 and a lower half case 3, and a magnetic tape (both not shown) wound around a pair of tape reels is externally connected to a tape draw-out opening provided in front of the cassette case. It is configured so that it can be pulled out. The tape draw-out opening is normally closed by a guard panel 4 as shown in FIG.

An opening 5 formed on the upper surface of the cassette
Has an opening at a substantially central portion of the upper cassette half 2 so that the overhanging portion of a leaf spring 21 integrally formed with the half 2 can be seen. A transparent window member 6 is fitted into the opening 5 and is appropriately fixed and integrated with the upper half case 2. The figure is shown for the sake of showing the shape of a leaf spring 21 to be described later and for convenience of explanation. 1
Is shown with the window member 6 removed. In the present embodiment, the window member 6 has a shape corresponding to the opening 5 formed in the upper half case 2, and is a member for closing the opening 5. And the structure is a transparent window 6
A, a bonding margin 6B for bonding to the lower side of the edge of the opening 5;
The leaf spring 21 includes a non-transparent cover that covers the upper part. The cover part is a cover part 6C,
It is composed of a cover 6D fitted into the label area 7, and the like.

Next, referring to FIG.
The structure of will be described. Since the opening 5 and the leaf spring 21 have a symmetrical structure in the left-right direction of the cassette, only one of them is shown in FIG. The leaf spring 21 and the upper half case 2 are, for example, PS
It is integrally formed using resin or the like. The leaf spring 2
The first base 21A is a substantially central portion of the upper half case 2, and is integrated with the half case 2 inside the label area 7, and protrudes downward from the base thereof in the cassette left-right direction (right direction in the figure) and downward. The tip portion 21B extends in a tongue shape toward the center of the opening 5. In addition,
The entire length of the leaf spring 21 is set so as to press a central portion of a tape reel (not shown) positioned below the opening 5. A step 5A is formed on the lower side surface of the edge of the opening 5, and is used for bonding by attaching a bonding margin 6B of the window member 6.

Next, a method of forming the upper half case 2 and the leaf spring 21 will be described. An injection gap formed by combining an upper mold 31 shown by a two-dot chain line in FIG. 2 and a lower mold 32 shown by a one-dot chain line is configured. That is, in the upper mold 31, the leaf spring forming portion 31 which protrudes downward in the drawing in the opening 5 is shown.
a, and the lower mold 32 is formed with a recess corresponding to the leaf spring forming portion 31a. With such a structure, the upper half case 2 and the leaf spring 2
There is formed an injection space in which one can be molded at a time. Then, by injecting, for example, a PS resin, an ABS resin, or the like into the molding gap, the upper half case 2 and the leaf case 21 excluding the opening 5 are integrally formed as shown in a sectional structure in FIG. Is done. With the structure in which the upper half wall surface of the portion corresponding to the protruding portion of the leaf spring 21 is thus opened, undercutting is not required under the leaf spring 21 during half case molding, and one molding, that is, The leaf spring 2 is formed by a single color molding method.
1 can be formed integrally with the half case. Therefore, the structure of the upper mold 31 and the lower mold 32 can be simplified as compared with a mold employing two-color molding or the like.

Next, a first embodiment of the present invention will be described with reference to FIG. The feature of this embodiment is that the thickness and the shape of the leaf spring are modified. That is, the leaf spring 41 shown in FIG. 3 is formed gradually thinner from the vicinity of the base 41A, the tip 41B is formed thicker, and a gentle arc-shaped recess 41C is formed on the lower surface of the tip 41B. Are devised so that the protrusion at the center of the upper end surface of the tape reel, which is omitted, can be effectively pressed without displacement. The leaf spring 41 includes a base 41A.
Because it is formed into a thin shape to the tip of the elastic different compared to the prior SL leaf spring 21.

The leaf spring 41 can be easily formed by changing the gap between the dies 31, 32 described with reference to FIG. Therefore, according to the present invention, the force for pressing the tape reel can be easily adjusted by changing the thickness and shape of the leaf spring 41. In addition, the adjustment of the pressing force can be easily and uniformly set by setting the gap between the dies 31, 32, so that the uneven pressing force can be eliminated and the rotation of the tape reel can be made smooth.

Next, a second embodiment will be described with reference to FIG. The feature of the present embodiment is that the leaf spring is provided with wear resistance. That is, the distal end portion 51A of the leaf spring 51 is formed of a wear-resistant synthetic resin such as polyexmethylene. The tip 51
A has a high degree of wear because it presses the center of the rotating tape reel. However, by molding with a synthetic resin having abrasion resistance as in the present embodiment, abrasion can be reduced and reliability of the magnetic tape cassette 1 can be improved. The molding of the tip 51A is performed by two-color molding . In this case, a mold for forming the distal end portion 51A is required for the molds 31 and 32. However, since the opening 5 is provided, complication of the mold can be avoided.

As described above, in the magnetic tape cassette to which the present invention is applied, since the upper half case and the leaf spring are integrally formed, it is not necessary to separately prepare a separately manufactured leaf spring. The man-hour can be reduced. Moreover, since different kinds of members such as metal leaf springs are not used as the cassette case, it is possible to adopt a configuration that meets the demands of the era, such as easy disposal and recycling.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, as in the case of applying the wear-resistant structure shown in the second embodiment to the leaf spring shown in the first embodiment, a structure in which the respective embodiments are appropriately combined may be used .

[0015]

As described above, in the magnetic tape cassette according to the present invention, at least the extension of the leaf spring is provided on the upper surface of the half case in order to integrally form the leaf spring substantially at the center of the inner surface of the upper half case. An opening corresponding to the portion is formed, and a closing member for closing the opening is provided in a window member attached to the upper half case. That is, according to the present invention, the half case and the leaf spring are integrally formed, and the opening provided for inserting the mold required for the integral molding is closed by the closing member (window member). In addition, the work for fixing the leaf spring and the device for fixing the leaf spring are not required for assembling the cassette. Further, regarding the disposal and recycling of the magnetic tape cassette, since a structure in which different kinds of members are fixed by ultrasonic welding, such as a metal leaf spring, is not used as in the related art, it is easy to perform both disposal and recycling. Meet current social demands for industrial products.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic tape cassette showing a first outline of the present invention.

FIG. 2 is a sectional view of a main part of an upper half case in the magnetic tape cassette shown in FIG. 1;

FIG. 3 is a sectional view of a main part showing the first embodiment of the present invention.

FIG. 4 is a sectional view of a main part showing a second embodiment of the present invention.

FIG. 5 is a plan view showing an example of a conventional leaf spring.

FIG. 6 is a perspective view showing an example of a conventional leaf spring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic tape cassette 2, 3 Half case 4 Guard panel 5 Opening 5A Step 6 Window member 6A Window 6B Adhesive margin 6C Cover 6D Label area cover 7 Label area 21, 41, 51, 60 Leaf spring 21A, 41A Base 31, 32 Mold 21B, 41B Tip 41C Recess 51A Tip of different resin

Claims (2)

(57) [Scope of request for utility model registration] 1. A pair of tape reels for winding a magnetic tape are housed in a cassette case composed of upper and lower half cases, and the pair of tape reels is pressed downward of the cassette.
The leaf spring is located substantially at the center of the inner surface of the upper half case.
In the magnetic tape cassette integrally formed with the half case, the leaf spring may
The thickness corresponding to the rotation axis direction of the prill is
When gradually decreasing in the direction of the rotation axis of the tape reel,
At the center of the top end of the tail reel,
The side opposite to the projection to be placed supports the projection in rotation.
A magnetic tape cassette having a concave shape. 2. A pair of tape reels for winding a magnetic tape are housed in a cassette case composed of upper and lower half cases, and a leaf spring for pressing the pair of tape reels downward of the cassette is provided on an inner surface of the upper half case. In a magnetic tape cassette integrally formed with the half case at a substantially central portion, a portion where the leaf spring extends from a base portion thereof in a rotation axis direction of the tape reel, and a tape reel at a tip end thereof. A magnetic tape cassette, wherein a portion for instructing rotation of a protrusion located at the center of the upper end surface is formed in two colors, and the front end portion is formed of a synthetic resin having wear resistance.