JPH0544939Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a magnetic tape cassette (DAT) suitable for use in recording digital signals, such as PCM signals.

[Conventional technology]

BACKGROUND ART Currently, a PCM recording and reproducing apparatus has been proposed that converts an analog signal such as an acoustic signal into a digital signal, such as a PCM signal, and records (or reproduces) the converted signal on a magnetic tape. Some PCM recording and reproducing apparatuses use a rotating head to achieve a relatively high recording density. Using this rotating head
In a PCM recording/reproducing apparatus, during recording or reproduction, a magnetic tape is pulled out from a magnetic tape cassette and wound around a rotating drum provided with a rotating head.

By the way, in the magnetic tape cassettes used in such PCM recording/playback devices, if fingerprints or dust get on the magnetic tape, dropouts will occur in the playback signal. , must be sealed inside a magnetic tape cassette case. Furthermore, the cassette case requires a space for inserting guides so that the magnetic tape can be pulled out during recording or reproduction.

For this reason, conventional cassette cases are difficult to assemble and manufacture.
It consists of a combination of upper and lower cases, and includes a slider placed on the outer side of the lower case that opens and closes the space by sliding in the front and back directions of the cassette, and a slider that is allowed to rotate by the sliding of the slider. Accordingly, magnetic tape cassettes have been proposed that have a rotatable front cover that covers the front surface of the cassette. In such a magnetic tape cassette, during recording or playback, the front cover is rotated from the front of the cassette to an almost right angle position toward the upper case, exposing the magnetic tape at the front of the cassette, and the slider slides rearward. Thus, a space for inserting a guide or the like is provided on the exposed back side of the magnetic tape. Furthermore, during storage, the magnetic tape is sealed by the slider, front cover, and cassette case.

In this conventional cassette, as shown in FIGS. 6 and 7, a torsion spring 20 is passed through a boss 10 protruding from the side surface of the front cover 9, and connected to a retaining portion 11 that receives a spring end ₂₀₁ so that the torsion spring 20 works. death,
When the front cover 9 is assembled into the upper and lower cases, the other end 20
It is configured so that it can be opened and closed by a force P generated at ₂ .

[Problem that the invention attempts to solve]

However, in this conventional structure, when attaching the torsion spring 20 to the front cover 9, even if the spring end ₂₀₁ is engaged with the engagement part 11, it comes off immediately. No efforts had been made to do so.

Therefore, when assembling the magnetic tape cassette, there is a problem that the torsion spring 20 comes off from the side boss 10 of the front cover 9 during transportation from the time when the torsion spring 20 is assembled to the front cover 9 to the time when it is assembled into the upper and lower cases.

Furthermore, as a means for holding the torsion spring 20 on the front cover 9, it is possible to use claws 12 protruding from both sides of the spring end ₂₀₁ of the torsion spring 20 as shown in FIG. 7B. The torsion spring 20 rotates in the direction of the arrow shown in FIG. 7B when it is assembled into the front cover 9 and transported, and when it is assembled into the upper case, the position of the tip of the torsion spring 20 is not constant, which significantly worsens the assembly work. At the same time, front cover side boss 1
There is a high risk that the value will deviate from 0, and as with the previous example, it is not possible to completely eliminate the problem, which is problematic.

The present invention aims to eliminate these conventional problems. When assembling a magnetic tape cassette with a front lid that can be opened and closed, the torsion spring can be securely held in the front lid, and the torsion spring can be easily removed from the front lid during transportation. The object of the present invention is to provide a magnetic tape cassette which can greatly improve assembly efficiency by eliminating the problems caused by the magnetic tape cassette, and which has a simple structure using existing parts and is easy to manufacture.

[Means for solving problems]

In the present invention, a front cover 9 that covers the front surface of a cassette case consisting of an upper case 1 and a lower case 2 is rotatably attached to the case, and a torsion spring 8 that operates when the front cover 9 is opened and closed is attached to the case and the front cover. 9, the free end of the torsion spring 8 attached to the boss 10 and the engaging portion 11 provided on the side surface of the front cover 9 is formed into a substantially U-shaped support portion 7; The front lid 9 is provided with a holding part 13 which is a convex part and has an abutting surface facing the engaging part 11, and the supporting part 7 of the torsion spring 8 is disposed between the holding part 13 and the engaging part 11. This magnetic tape cassette is characterized by being held by being elastically deformed so that the width of the groove is reduced.

〔Example〕

An embodiment of the present invention will be explained with reference to FIGS. 1 to 3. The cassette case has a combination structure of an upper case 1 and a lower case 2, and is attached to the lower case 1 so that it can be opened and closed by sliding over the bottom and side surfaces. slider 3
A front cover 9 that covers the front of the cassette case is pivotably attached to the case, and a torsion spring 8 that operates when the front cover 9 is opened and closed is connected to the upper case 1 and the front cover 9.
One free end of the torsion spring 8 attached to the boss 10 and the engaging portion 11 provided on the side surface of the front lid 9 is formed into a substantially U-shaped support portion 7, and Holding part 1 for fitting support part 7
3 is provided on the front cover 9. This torsion spring 8
The support part 7 at one end of the ring part passed through the boss 10 and extended through the engaging part 11 is brought into contact with the holding part 13, and this holding part 13 is provided facing and isolated from the said engaging part 11. It is a convex portion having an abutment surface for keeping the support portion 7 in a held state, and is protruded from the front lid side plate portion. Moreover, this convex portion is approximately U of the torsion spring 8 as shown in FIGS.
A protrusion 14 that holds the support part 7 from both sides in a letter-like shape.
may be provided. Furthermore, the holding portion 13 may have a convex portion with a concave portion on which the support portion 7 of the torsion spring 8 is placed.

In the figure, 4 is a reel regulating rib, 5 is a window, and 6 is a finger operation part. P is the force generated when the front cover is assembled into the upper and lower cases.

In order to attach the torsion spring 8 to the front cover 9 when assembling the front cover 9 into the upper case, the support part 7 formed in a substantially U-shape is attached to the torsion spring 8 to the engaging part 1.
1 and the holding part 13 so that the U-shaped groove becomes narrower, that is, the supporting part 7 is elastically deformed so that the width is reduced, and the torsion spring 8 can be temporarily fixed by its own elastic force. At the time of storage, the slider 3 is locked and the front cover 9 is closed by the biasing force of the torsion spring 8, thereby safely sealing the magnetic tape in the cassette case. When this cassette case is automatically loaded onto a cassette deck, the slider 3 is slidable on the cassette deck side, and the front cover 9 is also opened to expose the magnetic tape for use.

Since the holding part 13 can be used as an engaging part of the hub brake, and the engaging part 11 can be used as a rib for preventing the hub brake arm from lifting up, the structure does not become complicated.
Costs can also be reduced.

[Effect of idea]

In the present invention, the free end of the torsion spring 8 that is attached to the boss 10 and the engagement part 11 provided on the side surface of the front cover 9 is formed into a substantially U-shaped support part 7, and the engagement part 11 is attached to the front cover 9. The holding part 13 is provided oppositely, and the supporting part 7 of the torsion spring 8 is elastically deformed and held between the engaging part 11 and the holding part 13 so that the width of the U-shaped groove becomes narrower, so that the structure can be opened and closed freely. When assembling a magnetic tape cassette with a front lid, the torsion spring can be securely held on the front lid, and the torsion spring can be temporarily fixed during transportation, eliminating the problem of it coming off from the front lid, greatly increasing assembly efficiency. It is easy to handle, the various drawbacks of the conventional method can be properly eliminated, and the front lid is strong when closed, making it highly safe to maintain a sealed storage state, which has practical effects.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view showing an embodiment of the present invention;
Figure 2 is an enlarged cutaway side view taken along the line in Figure 1;
Fig. 3 is a rear view of the conventional example, Fig. 4 is an enlarged cutaway side view of another embodiment, Fig. 5 is a rear view thereof, Fig. 6 is an enlarged cutaway side view of the conventional example, and Figs. 7A and B respectively. ,
FIG. 6 is a rear view of an example different from the example shown in FIG. 6; DESCRIPTION OF SYMBOLS 1... Upper case, 2... Lower case, 3... Slider, 7... Support part, 8... Torsion spring, 9
... Front cover, 10 ... Boss, 11 ... Branch, 13
...Holding part, 14...Protrusion.

Claims (1)

[Claims for Utility Model Registration] 1. A front cover 9 that covers the front of a cassette case consisting of an upper case 1 and a lower case 2 is pivotably attached to the case, and a torsion spring 8 operates when the front cover 9 is opened and closed. In this magnetic tape cassette, the free end of the torsion spring 8 attached to the boss 10 and the engagement part 11 provided on the side surface of the front cover 9 is attached to a substantially U-shaped support part 7. At the same time, a holding portion 13 consisting of a convex portion having an abutting surface is provided on the front lid 9 facing the engaging portion 11, and the torsion spring 8 is formed between the holding portion 13 and the engaging portion 11. A magnetic tape cassette characterized in that a substantially U-shaped support portion 7 is elastically deformed to reduce its width and held. 2. The magnetic tape cassette according to claim 1, wherein the convex portion has a protrusion 14 at its outer end.