JPS6327339Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape cassette, and more particularly to an opening/closing mechanism for a guard panel that protects the entire surface of a magnetic tape cassette.

A magnetic tape cassette, such as a video tape cassette, houses a pair of tape winding hubs, the magnetic tape is fed out from one hub, the magnetic tape is pulled out to the front of the cassette by a guide roller, and then wound through the front of the cassette to the hub on the opposite side. It's summery. Since the magnetic tape is exposed at the front of the cassette, if it is stored as is, dust will adhere to the magnetic tape surface and cause problems such as dropouts. A guard panel 2 that covers the front surface of the cassette is attached to the cassette case so that it can be opened and closed. Since it is desirable that the opening/closing operation be performed elastically between the open position and the closed position and be stable in these positions, various opening/closing mechanisms have been proposed.

The cassette shown in FIGS. 2 and 3 shows a guard panel opening/closing mechanism of a magnetic tape cassette attempted by the inventor of the present invention, in which a guide groove 3 is formed on at least one side of the cassette case 1, and a slidable presser foot is formed therein. A plate that engages the lever 4, has its front end selectively contact two substantially right-angled surfaces of the projecting plate 5 that supports the pivot joint of the guard panel 2, and is held in a U-shaped recess on the side of the case. The presser lever is configured to be pressed against the projecting plate 5 by a spring 6. In this way, when the guard panel 2 is operated with a finger or the finger of a recorder, the presser lever 4 slides against the leaf spring 6, so that the guard panel 2 can be moved to the closed position shown in FIG. 2 and to the open position shown in FIG. 3. It moves explosively between and stops at two positions.

However, it has been found that the opening/closing mechanism shown in FIGS. 2 and 3 has a drawback in that the presser lever is likely to come off due to mechanical impact from the outside. A dovetail groove could be considered as a structure to prevent this lever from falling off, but the structure of the mold for forming case 1 from plastic would be extremely complicated, and the durability of the formed case and the appearance of the product would be affected. There are problems such as easy occurrence of this problem, which is not desirable.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic tape cassette having a guard panel opening/closing mechanism that does not have the above-mentioned drawbacks and has a structure to prevent the presser lever from falling off without the need for a dovetail groove.

The present invention provides a guard panel opening/closing mechanism that does not interfere with the rotation of the guard panel or its pivot shaft, and also prevents the presser lever from falling off due to external mechanical shocks such as accidentally dropping a magnetic tape cassette. .

The present invention achieves the above object by having the tip of the presser lever have a thin protrusion extending between the projecting plate having the pivot portion of the guard panel and the side surface of the cassette case. By extending the thin protrusion close to the periphery of the pivot portion, the effect of preventing the presser lever from falling off can be further enhanced. The invention will be explained in detail below in conjunction with the drawings.

In the following description, an example will be described in which an opening/closing mechanism is provided on only one side of the front portion of the magnetic tape cassette, but a similar opening/closing mechanism may be provided on the other side. Now, FIGS. 4, 5 and 6 are enlarged views of essential parts of the guard panel opening/closing mechanism of the magnetic tape cassette of the present invention. The basic structure of this embodiment is almost the same as that shown in FIGS. 2 and 3, so common parts are indicated by the same reference symbols and detailed explanation will be omitted.

The groove 3 of the cassette case 1 is formed diagonally, and the presser lever 4 pushed by a leaf spring (see Figs. 2 and 3) is constantly displaced to the upper right (in Fig. 4) and presses one side of the guard panel 2. The projecting plate 5 is selectively engaged with substantially perpendicular end surfaces 7 and 8 of the protruding plate 5 extending from the side thereof to the side of the case. The illustrated position is the closed position, in which the presser lever 4 is engaged with the end surface 7 of the projecting plate 5. The projecting plate 5 has a pivot shaft 9 on its inner surface, and this pivot shaft is engaged with a pivot hole on the case 1 side. As shown in FIGS. 5 and 6, the inner surface of the projecting plate 5 is cut into a thin section near the presser lever, into which a thin protrusion 10 protruding from the tip of the presser lever 4 extends and enters.
As shown in FIG. 4, a portion 11 of the thin protrusion 10
extends to at least the center position of the pivot shaft 9. The cut portion of the inner surface of the projecting plate 5 is formed so as not to interfere with the thin protrusion 10 during rotation during opening and closing, and has a contour as shown by line 12, for example. Further, it is sufficient that the thickness of the protrusion 10 is about one-third of the total thickness of the presser lever.

With the above configuration, the guard panel of the magnetic tape cassette of the present invention can be opened and closed smoothly.
Not only can the guard panel be kept stationary in each open/close position, but it can also prevent the tip of the presser lever 4 from separating greatly from the projecting plate 5 of the guard panel as shown in Fig. 7 due to a large mechanical shock caused by an accident such as a falling cassette. Even if there is a problem, the engagement of the thin protrusion 10, the extension part 11, etc. with the projecting plate 4 is maintained, so there is no possibility that the presser lever will fall off. moreover,
Since the guide groove 3 may be a normal square groove, there will be no difficulty in forming it as with a dovetail groove.

As described above, the present invention has provided a magnetic tape cassette equipped with an excellent guide panel opening/closing mechanism. It will be apparent to those skilled in the art that many variations are possible within the scope of the invention.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional magnetic tape cassette with a guard panel, Figure 2 is a front view of the guard panel opening/closing mechanism when the guard panel is closed, and Figure 3 is a perspective view of a conventional magnetic tape cassette with a guard panel.
The figure is a similar front view when opened, and Figure 4 is a front view showing the guard panel opening/closing mechanism according to the embodiment of the present invention.
5 is a plan view of the same, FIG. 6 is a sectional view taken along the line AA in FIG. 4, and FIG. 7 is a front view of the opening/closing mechanism of the present invention showing the state at the time of impact. The main parts in the figure are as follows. 1: Cassette case, 2: Guard panel, 3:
Guide groove, 4: Presser lever, 5: Projection plate, 6: Leaf spring, 7, 8: End face, 9: Pivot shaft, 10: Thin protrusion, 11: Extension part, 12: Resection part contour.

Claims (1)

[Scope of utility model registration request] a case for storing a magnetic tape; a guard panel pivotally attached to both sides of the front part of the case to open and close a magnetic tape running path on the entire surface of the case;
A projecting plate extending along both front sides of the case and having a pivot shaft or a pivot hole that engages with a pivot hole or pivot shaft of the case; a groove formed in at least one side and extending toward the projecting plate; an elastically displaced presser lever that is slidably engaged with the groove and presses the protrusion in the opening/closing position; and the presser lever is connected to the projecting plate. A magnetic tape cassette comprising a thin-walled portion extending at least toward the pivot shaft between the magnetic tape cassette and the side surface of the case, the thin-walled portion integrally having a thin-walled protrusion extending to at least approximately the center position of the pivot shaft. A magnetic tape cassette characterized by: