JPH0521739Y2 - - 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.

[Prior art]

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 magnetic tape cassettes used in such PCM recording and reproducing devices, if index marks or dust get on the magnetic tape, a dropout will occur in the playback signal, so to prevent this, the magnetic tape should be 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. Also, during storage, an elastic lock piece is provided at the bottom of the case so that the magnetic tape is sealed between the slider, front cover, and cassette case, and its head is inserted into the through hole of the slider to maintain the locked state. It is usually configured as follows.

That is, as shown in FIG. 7, the head 4 provided at one end of the elastic lock is fitted into the through hole 2 of the slider 1 to maintain the locked state, and as shown in FIG.
When trying to push up and release the head 4 from the locked state with the lock piece release protrusion b on the cassette deck side as shown in ~D, for example, the sloped portion a of the lock piece head 4 will move against the lock piece release protrusion b. While making contact, the lock is gradually released (Fig. 8A).
Furthermore, the locking piece releasing protrusion b is pressed against the slope c of the slider 1, so that the locking piece 5 and the slider 1 come into contact, and the head 4 is placed on the slider 1 through the position B in FIG. When the lock release is completed (Fig. 8C), the slider 1 moves further and with the slider 1 open (Fig. 8D), the head 4 is inserted into the other through hole ₂₁ and the open state is maintained. be done. In these cases, when loading the cassette into the deck, please refer to Figure 9A.
As shown in , slider 1 is moved in the first operation (pushing operation).
is opened, and loading is normally completed by the second operation (pushing down operation) as shown in FIG. 9B.

[Problem that the invention attempts to solve]

In this conventional cassette, the elastic locking piece is formed into a plate-like shape with a uniform thickness, and the mechanism that accompanies the opening and closing movement of the slider is performed when loading the cassette, and when the cassette is taken out, the mechanism is operated at the same time. The reverse operation is performed, but when loading and unloading the cassette is repeated, the lock piece 5, which has a nearly uniform wall thickness as in the past, deforms near the fulcrum and eventually loses its springiness. Sometimes the slider could not be locked. Another cause of this phenomenon is that if the cassette is left under high temperature conditions for a long time, the elastic locking piece 5 may be similarly deformed and the slider may no longer be locked. The particular problem here is that
When loading a cassette, the cassette is pushed into a compartment (not shown) in the cassette deck in a first motion, as shown in FIG. Normally, loading is completed after the opening operation of the slider 1 is completed and the pushing operation is completed as shown in FIG. 9B, but as mentioned above, the elastic lock piece 5 deforms and the slider cannot be locked If it becomes, the 9th
When trying to perform the operation shown in Figure A, the slider 1 opens and is not locked (position D in Figure 8), and the cassette is pushed back toward you, making it impossible to complete this operation. Therefore, since it is not possible to proceed to the operation shown in Figure 9B, it is impossible to load the cassette, and even if it were possible to load the cassette,
Problems occur when removing the cassette.

Furthermore, in the state shown in FIG. 8B, the slider 1 is locked by a slider locking part (not shown) provided in the compartment of the cassette deck, so there is no fear that it will close. When moving to the operation, the slider locking part provided in the compartment is released and the slider 1 is held in the open position by the slider lock of the cassette itself, and the cassette moves to the position shown in Figure 8A and is removed. but if the slider lock is disabled,
Almost at the same time as the cassette starts moving from the state shown in Fig. 8B, the reel shaft insertion hole 8 of the slider 1 gets caught in the reel shaft 12 of the deck, making it impossible to take out the cassette. Then, there was a problem that not only could the cassette not be removed, but there was even a risk of breaking the deck.

The present invention attempts to eliminate these conventional problems and aims to provide a magnetic tape cassette with a fully functional locking mechanism that is simple in construction and easy to manufacture.

[Means for solving problems]

The present invention has a slider 1 attached to a cassette case 3 so as to be able to freely open and close a space for inserting guides by sliding over the bottom and side surfaces of the cassette case, and a through hole 2 in the bottom of the slider 1. _{. ​}
In a magnetic tape cassette having an elastic locking piece 5 having a head 4 that is inserted into the magnetic tape cassette ₁ and locked, the thickness of the elastic locking piece 5 is made thinner as it moves toward the head 4 from the base that serves as its fulcrum, and the cross-sectional area of the elastic locking piece 5 is reduced. This magnetic tape cassette is characterized in that the magnetic tape cassette gradually decreases toward the head 4.

〔Example〕

An embodiment of the present invention will be explained with reference to FIGS. 1 to 3. The cassette case 3 has a structure in which an upper case 3 ₁ and a lower case _{3 2} are combined. It has a slider 1 which is mounted so as to be able to open and close a space for inserting guides by moving the slider 1. Through holes 2, ₂₁ are formed in the bottom surface of the slider 1, and the through holes 2, 21 are formed in the bottom surface of the cassette case 3. A magnetic tape cassette having an elastic locking piece 5 having a head 4 fitted and locked into the through-holes 2, 2-1 when the slider ₁ is closed and opened, at a position corresponding to the holes 2 _, 2-1. and an elastic locking piece 5 when the slider 1 is opened and closed.
The thickness is changed from t1 _{to t2} in the distal direction so that the arm portion of the elastic locking piece 5 formed by the slit 15 is elastically deformed so that the head 4 can be inserted into the through holes _{2, 21 and} locked. It has a structure that is gradually made thinner.
That is, the shape of the arm portion of the elastic locking piece 5, which has a biasing means for fitting the head 4 into the through hole 2 of the slider and pushing it outward to prevent it from coming off, is such that the plate thickness near the fulcrum is thicker than the head 4. The wall gets thinner as it gets closer, for example, the cross-sectional area or wall thickness near the fulcrum
When set to 100%, gradually change the cross-sectional area or wall thickness near the head of the leading example to a range of 20% to 80%, or change the cross-sectional area or wall thickness in a stepwise manner, 20% or less If the thickness is 80% or more, the effect of changing the wall thickness will be lost, so this should be taken into consideration. Fourth
In the illustrated example, the wall thickness of the elastic locking piece 5 is gradually reduced, and the width direction is also gradually reduced to form a tapered plate-like arm portion. Note that the head 4 of the elastic lock piece 5 is arranged in correspondence with a stopper 6 that restricts movement inward of the case.

In the figure, 7 is a guide elongated hole provided in the slider 1, 8 is a reel shaft insertion hole, 9 is a front cover, 10 is a concave part that allows the slider 1 to move, 11 is an opening for inserting the guide, and 20 is a finger hook operation part. are formed on both sides of the upper case ₃₁ .

The surface of the head 4 of the elastic locking piece 5 that comes into contact with the slider when it is opened and closed is a sloped surface, but it is also preferable to form it with a flat or curved surface, with the top rounded or in the shape of a chevron with the flat surface remaining. Preferably, the height of the top formed by both sloped portions is at least larger than the depth of the through holes 2, ₂₁ .
The elastic locking piece 5 is edged with a slit 15 so that one end becomes a free end, and the base serving as a fulcrum is integrally connected to the lower case ₃₂ , and the upper and lower surfaces are thinned in the thickness direction or width direction. It is preferable to use an elastic locking piece 5 that provides a spring action.

However, during storage, the head 4 of the elastic lock piece 5
is inserted into the through hole 2 of the slider 1, the slider 1 is locked, the front cover is closed, and the cassette case 3 is closed.
The magnetic tape is safely sealed inside (Figures 2 and 3). When the cassette case 3 is automatically loaded into the cassette deck, the lock piece release protrusion on the cassette deck side contacts the head 4, and the elastic lock piece 5 is gradually pushed up and released at the top position, allowing the slider 1 to slide forward. The lid 9 is also opened and the magnetic tape is exposed for use. When the cassette case 3 is returned, the lock piece releasing convex portion first comes into contact with the head 4 of the elastic lock piece 5 while the cassette case 3 is being held open, pushing up the elastic lock piece 5 so that the slider 1 can be returned to the state shown in FIG. It will be preserved as a.

In this case, as shown in Fig. 5, the amount of deformation can be greatly improved as shown in the conventional example and the data of the present invention when the loading and unloading operations of the cassette are repeated 500 times, and even during storage, the amount of deformation can be improved as shown in Fig. 6. As shown, its usefulness was also confirmed by the data on the difference in deformation between the conventional example and the present example when stored for 72 hours in an environment of 70°C.

[Effect of idea]

In the present invention, the cross-sectional area of the elastic lock piece with the head is gradually reduced toward the head so that it is elastically deformed, so that the elastic lock piece does not deform even if the loading and unloading operations of the cassette are repeated. Furthermore, even if the cassette is left under high temperature conditions for a long time, the elastic lock piece will not be deformed. In particular, there is almost no large deformation near the fulcrum, which eliminates loading failures due to slider inability to lock and the need for unloading, making it possible to produce magnetic tape cassettes of excellent quality that are less affected by thermal fluctuations and are easy to mold. The slider can be operated smoothly and easily, making it easy to handle, and the various drawbacks of the conventional method can be accurately eliminated.The lock when opening and closing the slider is strong, and the maintenance of the sealed storage state is highly stable and reliable. This has practical effects such as making it easier to make the deck more compact.

[Brief explanation of drawings]

Fig. 1 is an overall perspective view of the embodiment of the present invention seen from the bottom side, Fig. 2 is a bottom view, Fig. 3 is a vertical sectional view, Fig. 4 is a bottom view of the lower case, and Fig. 5 is Figure 6 is a diagram showing the relationship between the number of loading and unloading operations of the cassette and the amount of lock piece deformation. Figure 6 is a diagram showing the relationship between the amount of lock piece deformation and storage time. Figure 7 is a conventional example and corresponds to the position on the line in Figure 1. 8A to 8D are sectional views illustrating its operation, and FIGS. 9A and 9B are sectional views illustrating the operating state when loading a deck. 1...Slider, 2, 2 ₁ ...Through hole, 3...Cassette case, 3 ₁ ...Upper case, 3 ₂ ...Lower case, 4...Head, 5...Elastic lock piece, 6... Stopper, 7... Guide long hole.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The slider 1 is attached to the cassette case 3 so as to cover the bottom and side surfaces of the cassette case 3 and slide to open and close the space for inserting guides.
Through-holes 2, ₂₁ are bored in the bottom surface of the slider 1, and the slider 1 is placed in the closed state and in the open state at positions corresponding to the through-holes 2, ₂₁ in the bottom surface of the cassette case 3. In the magnetic tape cassette, the elastic lock piece 5 has a head 4 that is inserted into the through holes 2, ₂₁ and locked in the magnetic tape cassette. Once the thickness was reduced,
A magnetic tape cassette characterized in that the cross-sectional area is configured to gradually decrease toward the head 4 and to be elastically deformed. (2) The above-mentioned elastic lock piece 5 is integrally connected to the cassette case 3 and is tapered in the width direction toward the head 4 from a base serving as a fulcrum. magnetic tape cassette. (3) The elastic locking piece 5 has a cross-sectional area of 80 to 80% of the cross-sectional area of the base with the cross-sectional area of the tip of the head 4 as a fulcrum.
2. A magnetic tape cassette according to claim 1 or 2 of the claims for utility model registration, which is gradually reduced to within a range of 20%.