JPH02826Y2 - - Google Patents

Description

[Detailed description of the invention] <Technical field of the invention> This invention relates to a spring switch that can be used, for example, as a switch to detect the presence or absence of an accidental erasure prevention claw on a video cassette. It is an object of the present invention to provide a spring switch which does not require force to be applied and causes no accidents in which the switch is damaged or the video cassette cannot be removed.

<Technical background of the invention> The video cassette has a claw to prevent accidental erasure, and by breaking off the claw to prevent accidental erasure, the video cassette is structured so that it will not operate in recording mode when it is installed.

A spring switch as shown in FIGS. 1 and 2 has been considered as a switch for detecting the presence or absence of this erroneous erasure prevention claw. This spring switch is made up of a pair of plates 1a, 1 whose surfaces are opposite to each other.
A support 1 formed by b and this support 1
A lever 2 rotatably supported by a shaft, a first spring contact piece 3 that biases the lever 2 in a direction away from its pivot position, and a first spring contact piece 3 arranged opposite to the first spring contact piece 3. , a second spring contact piece 3 that comes into contact with and separates from the first spring contact piece 3;
It is constituted by a spring contact piece 4.

In other words, the lever 2 is the plate 1a that constitutes the support body 1,
It is pivotally supported by a shaft 5 protruding from the mutually opposing plate surfaces of 1b, and has a surface 6 at a position away from this shaft support position. A case is shown in which the first spring contact piece 3 is brought into pressure contact with this surface 6, and the lever 2 is elastically supported in a state in which it projects in a direction orthogonal to the support body 1 in this example. The second spring contact piece 4 is arranged closer to the shaft 5 side than the first spring contact piece 3, and constitutes a switch that is turned on when the lever 2 is rotated.

In such a spring switch, when the video cassette 7 is lowered along the support 1 as shown in FIG. 2, the lever 2 engages the lower end of the cassette 7 and is rotated in the direction of the arrow 8. With the cassette 7 abutting against the positioning pin 9 and stopped, move the lever 2.
is the erroneous erasure prevention determination means 11 formed in the cassette 7.
Opposite the position of. Erroneous erasure prevention determination means 11 includes a recessed hole 11a and a claw 1 provided on the opening surface of this recessed hole 11a.
1b. To prevent erasure, the claw 11b is broken off. When the claw 11b is broken off, the lever 2 becomes free within the recessed hole 11a and is in an OFF state. In this state, operation to record mode is blocked. If the claw 11b is present, the lever 2
is held in a rotated state in the direction of arrow 8, and the switch is held in an on state. In this state, recording and playback can be performed freely.

<Defects of the structure shown in FIGS. 1 and 2> The following drawbacks occur when using the structure of the spring switch described above. That is, as shown in FIG. 3, there may be cases where it is desired to erase the contents stored in the cassette 7 even though the claw 11b of the erroneous erasure prevention means 11 has been broken off. A method often used in such cases is to attach adhesive tape 12 to the opening of the recessed hole 11a.
There is a way to paste it. Due to a problem with the method of attaching the adhesive tape 12, as shown in FIG.
If the lever 2 becomes depressed in the recessed hole 11a due to the biasing force of the lever 2, when the cassette 7 is pulled out, the lever 2 will catch on the edge of the recessed hole 11a and an unreasonable force will be applied to the lever 2. Then, there is a possibility that the cassette 7 cannot be pulled out.

<Purpose of the invention> The purpose of this invention is to provide a spring switch that can easily pull out the cassette 7 even if the situation is as shown in FIG.

<Summary of the invention> This invention has a structure in which the lever 2 can be moved in the longitudinal direction with respect to the support 1.

With this structure, when a force is applied to the lever 2 in the longitudinal direction of the lever 2, the lever 2 can escape in the longitudinal direction against the force, and this escape allows the cassette 7 to be pulled out without difficulty.

<Example of the invention> Fig. 4 shows an example of the invention. In this invention, a means is provided which allows the lever 2 to rotate freely relative to the support 1 and also allows the lever 2 to move in its longitudinal direction.

In the example shown in FIG.
3 is formed, and this elongated hole 13 is engaged with a shaft 5 protruding from the support body 1, and the elongated hole 13 constitutes a means for allowing movement in the longitudinal direction. The other structures are the same as in FIGS. 1 and 2.

With this structure, the lever 2 is elastically supported with its longitudinal direction perpendicular to the extending direction of the support body 1 by the biasing force of the first spring contact piece 3. Therefore, at this time, the shaft 5 is attached to one end 13 of the elongated hole 13.
It is engaged with a.

When loading the cassette, lever 2 is rotated in the direction of arrow 8. At this time, if the cassette's erroneous erasure determination means 11 (see FIG. 2) does not have the claw 11b, the lever 2 will move into the recessed hole 11 constituting the erroneous erasure determination means 11.
The switch is turned off and enters erasure prevention mode. When the claw 11b is present, the lever 2 is kept rotated in the direction of the arrow 8, keeping the switch in the on state. At this time as well, the biasing force of the first spring contact piece 3 acts on the lever 2, and the lever 2
is biased toward its free end. Therefore, the shaft 5 is in contact with one end 13a of the elongated hole 13.

When pulling out the cassette 7 with the claw 11b broken off, the lever 2 rotates counterclockwise about the shaft 5, allowing the cassette 7 to be pulled out.

The operation up to this point is exactly the same as that of the spring switch having the structure explained in FIGS. 1 and 2.

<Operation of the invention> According to the spring switch according to this invention, if the fifth
As shown in the figure, when the cassette 7 is pulled out with the adhesive tape 12 recessed into the recessed hole 11a, the lever 2 can escape in the longitudinal direction of the lever 2 through the elongated hole 13. If the amount of escape, that is, the length of the elongated hole 13 is selected to be sufficiently large, the lever 2 can be rotated without difficulty, and the cassette 7 can be pulled out without difficulty. The longer the length of the elongated hole, the safer it is, but at least the lever 2 should be able to rotate in a direction perpendicular to the longitudinal direction of the support 1 when the cassette 7 is pulled out with the lever 2 hooked by the adhesive tape 12. It is sufficient if the lever 2 escapes in the longitudinal direction.

<Effects of the invention> As described above, according to this invention, even if the tip of the lever 2 is caught by the adhesive tape 12 attached to the erroneous erasure determination means 11 of the cassette 7, the cassette 7 can be pulled out. Since the lever 2 itself can escape in the longitudinal direction, the lever 2 can be rotated without difficulty. As a result, the cassette 7 can be pulled out without difficulty. Therefore, the cassette 7 does not fall into a state where it cannot be pulled out, and reliability can be improved. Furthermore, there is no risk of damaging the spring switch itself, and reliability can be improved in this respect as well.

<Another embodiment of the invention> Fig. 6 shows another embodiment of the invention. In this example, a recess 13b is formed at one end 13a of the elongated hole 13 in the direction in which the cassette 7 is inserted.

By providing this recess 13b, the cassette 7
When the lever 2 is inserted, the lever 2 generates a torque using the first spring contact piece 3 as a fulcrum, so the shaft 5 is pressed against the recess 13b and rotates. Therefore, when the lever 2 rotates in the direction of the arrow 8, the shaft 5 always moves into the recess 13b.
As a result, the rotation radius of the lever 2 can always be kept at the maximum value, and a sufficient amount of rotation bias can be given to the first spring contact piece 3.

On the other hand, when pulling out the cassette 7, especially the claw 11
When b is being folded, the lever 2 is rotated counterclockwise. When the lever 2 rotates counterclockwise, the shaft 5 receives a biasing force in the direction of being removed from the recess 13b. Therefore, the engagement point between the elongated hole 13 and the shaft 5 of the shaft 5 tends to move toward the center of the elongated hole 13, and as a result, the lever 2 escapes toward the support 1, and the cassette 7 The tendency can be to facilitate the withdrawal of the material.

FIG. 7 shows yet another embodiment of this invention. In this example, a long and narrow recess 14 is formed in the support body 1, and a round bar-shaped shaft 5 is formed in the lever 2. The longitudinal direction of the elongated recess 4 is inclined as shown in FIG. The shaft 5 normally engages with the lower end 14a of this elongated recess by the biasing force of the first spring contact piece 3.

Even with this structure, even if the tip of the lever 2 engages with the cassette 7 and gets caught, the lever 2 can retreat along the slope of the recess 14 and escape due to the force of pulling out the cassette 7. Therefore, the same effects as the embodiment shown in FIG. 4 can be achieved.

In the above description, the first spring contact piece 3 comes into contact with the second spring contact piece 4 when the lever 2 is rotated. It is also possible to configure a switch that is disposed in the switch and turns off when the lever 2 is rotated. It is also possible to provide a switch with two second spring contact pieces to obtain on and off contact outputs at the same time. Further, although the above description has been given of an example in which the present invention is applied to an erroneous erasure detection switch for a video cassette, it is easy to understand that other applications are possible.

[Brief explanation of the drawing]

Fig. 1 is a perspective view for explaining a conventionally considered spring switch, Fig. 2 is a sectional view for explaining the internal structure of the spring switch shown in Fig. 1, and Fig. 3 is a diagram of Figs. 1 and 2. FIG. 4 is a cross-sectional view to explain an embodiment of this device, FIG. 5 is a cross-sectional view to explain the operation of this device, and FIG. FIG. 7 and FIG. 7 are cross-sectional views for explaining another embodiment of this invention. 1: Support body, 2: Lever, 3: First spring contact piece,
4: second spring contact piece, 5: shaft, 7: video cassette, 11: erroneous erasure determination means, 13: elongated hole constituting means for allowing the lever to move in the longitudinal direction, 14: allowing the lever to move in the longitudinal direction. an elongated recess that constitutes a means of allowing;

Claims (1)

[Claims for Utility Model Registration] A: A lever pivotally supported by a support; B: A first spring contact piece that biases the lever in a direction away from the shaft support; C: Opposed to the first spring contact piece. D; a second spring contact piece that is arranged so as to move toward and away from the first spring contact piece when the lever is rotated and the first spring contact piece is biased toward the shaft support portion; A spring switch comprising: means provided on either one of the branch parts for allowing the lever to move in the longitudinal direction.