JPS5853757Y2 - micro video cassette - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a micro video cassette in which a cylindrical tape winding hub is disposed within a casing consisting of an upper cassette half and a lower cassette half.

In conventional videotape cassettes, a flanged tube was used for winding the tape.

However, not only are flanged hubs difficult to manufacture and store, but the flange must have a certain thickness due to strength issues, so the hub as a whole is quite thick, which makes it difficult to manufacture and store videotape cassettes. This has been one of the major obstacles to miniaturization.

Therefore, in order to realize a downsized videotape cassette, it is conceivable to use a flangeless type cylindrical hub as the tape winding hub.

This flangeless type hub can be made thinner by at least two flanges than a hub with seven flanges, and therefore the cassette as a whole can also be made thinner.

However, in conventional videotape cassettes, in order to prevent the hub from rotating and the tape loosening when the cassette is not in use, teeth are formed on the entire periphery of the flange of the knob, and the teeth are removable. A tape locking mechanism has been provided in which an engaging ratchet pawl is pivotally connected to the casing, but since a flangeless hub does not have a flange, the tape locking mechanism cannot be arranged in the conventional manner. There is a problem.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a miniaturized micro videotape cassette having a flangeless bubble and having a novel locking mechanism.

That is, in the micro video cassette of the present invention, this
- An engagement groove is provided concentrically with the bub, extending from the lower surface of the bub at least midway 1 of its height, while the lower cassette half is provided with an engagement groove extending upward from the inner surface of the lower cassette half and fitting into the engagement groove of the bub. A cylindrical engagement wall is formed that is approximately equal to the height of the engagement groove to be mated, and the height of this cylindrical engagement wall is set such that the bottom surface of the engagement groove and the top surface of this engagement wall are the same as the height of the cassette. are set so that they contact each other when not in use, and the contacting surfaces are provided with projections and depressions that engage with each other so as to prevent the bub from rotating in the unwinding direction, and the bub is urged in the direction in which the two surfaces contact. A biasing means is provided in the casing, and with this structure, when the cassette is not in use, the two surfaces come into contact and prevent the bub from rotating in the loosening direction, thereby preventing the tape from loosening. It is something to do.

Hereinafter, a micro video cassette according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a state in which flangeless type tape winding tabs 2A and 2B are installed in a lower cassette half 1A of a casing of a micro video cassette according to the present invention.

When the cassette is assembled, an upper cassette half IB (see FIG. 2) is placed above the lower cassette half 1A.

For tape winding...B2A. 2B has a bottom surface 3A in its center and a top surface 4A from 3B as shown in FIGS. 1 and 2.
, 4B, the shaft holes 5A and 5B have circular cross-sectional shapes.
is formed.

This shaft hole is used when the cassette is loaded into a video device.
The drive shaft of this video device is inserted into it.

A biasing means 6 (see FIG. 2) such as a leaf spring or a friction sheet for biasing the bubble in the axial direction is provided on the bubble so that the center of the upper surfaces 4A and 4B of the bubble can be pressed. As shown in FIG. 2, the shaft holes 5A and 5B desirably end near the top surface of the bubble and do not penetrate through them.

Due to the presence of the shaft holes 5A, 5B, the bubs 2A, 2B have a substantially cylindrical shape.

The biasing means 6 will be explained in detail later.

The peripheral wall portions 7A, 7B of the bubs 2A, 2B include engagement grooves 8 extending from the lower surfaces 3A, 3B toward the upper surfaces 4A, 4B.
A and 8B are provided concentrically with B.

These engagement grooves 8A, 8B only need to extend at the middle 1 of the height of the bubble, but as shown in FIG.
It is desirable that it extends at 1 near 4B.

The purpose of making the engagement groove deep in this manner is to ensure support of the bub.

On the other hand, the lower cassette half 1A has a cylindrical engagement wall 10 extending upward from the inner surface 9 of the lower cassette half.
A and 10B are provided.

This engagement wall has a thickness that is smaller than the width of the engagement groove so that it can be inserted into each of the above-mentioned engagement grooves 8A and 8B.

Further, it is desirable that its height is approximately equal to the height of the engagement groove.

That is, the engagement wall 10A. The height of 10B is the height of engagement groove 8A.
, 8B bottom surface 11A.

11B and the top surfaces 12A and 12B of the engagement wall are set to come into contact with each other when the cassette is not in use.

Among them, when the cassette is in use, that is, when it is loaded into a video device, the shaft hole 5A of the knob.

The drive shaft of the video device inserted into 5B pushes up the .5B to a specified height and removes contact with it when not in use.

The above-mentioned contacting surfaces, that is, the engagement groove 8A.

8B bottom surfaces 11A, 11B and the top surface 12A of the engagement wall.

12B is provided with projections and depressions that engage with each other so as to prevent the bub from rotating in the unwinding direction.

It is desirable that the unevenness be in the shape of a sawtooth used in a face ratchet, for example, as typically shown by the top surfaces 12A, 12B of the engaging walls 10A, 10B in FIG.

Similar serrations are formed on the other side in opposite directions to interlock with each other.

It is desirable that the teeth be oriented such that they can rotate in the tightening direction but cannot rotate in the loosening direction.

A leaf spring serving as the biasing means 6 is attached to the upper cassette 71B, and this leaf spring causes the bubble 2A to
, 2B are pressed downward so that the serrations engage with each other.

When the cassette is loaded into the video device, the shaft hole 5A.

By the drive shaft of the video device inserted in 5B, the bubble 2
A and 2B are lifted to a specified height against the leaf spring of the biasing means 6, and the saw teeth are disengaged, allowing them to rotate freely in any direction.

The above-mentioned unevenness may be formed by continuously providing chevron-shaped teeth as shown in FIG.

The size of these teeth is selected to be 5° to 20P1, preferably 10°, which is the value obtained by dividing the circumference (3600).

If the tooth is too small, it will not be able to function as a rotation prevention means, and if it is too large, it will cause rattling and will be difficult to release, so it is necessary to select it within the above range.

Also, it is desirable that the sizes of the teeth that engage with each other are the same, but within the above size range, one is 1/1/2 of the other.
It may be 3 to 2 times.

As the biasing means 6, instead of a leaf spring, a friction sheet having a curl or the like so as to be able to elastically press the bub downward may be used.

In the micro video cassette according to the present invention, since a thin flangeless type bubble is used as the tape winding bubble, the entire cassette can be made smaller.

In addition, since the bub can be held in a predetermined position on the lower cassette by the engagement of the relatively deep retaining groove and the relatively large engagement wall, the knob can be easily removed from this predetermined position. Therefore, even if the knob is assembled into the lower cassette in advance during the cassette assembly work, handling becomes easy and the ease of assembly is significantly improved.

Furthermore, the means for preventing the rotation of the... when not in use is...
・Since everything is placed inside the room, space can be used effectively.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the main parts of the micro video cassette according to the present invention that are buttoned, including the lower force ceratonnope 7 and the tape winding bubble. A longitudinal sectional view showing how the tape winding flap is supported by the mating wall. FIG. 3 is an enlarged perspective view of the mating wall shown in FIG. 2, and FIG. It is a perspective view which shows the modification of the engagement wall shown in the figure. 1A...lower cassette no.-f, 1B...upper cassette half, 2A, 2B...tape winding bubble, 3A
. 3B... Lower surface of the bubble, 4A, 4B... Upper surface of the knob, 5A, 5B... Opening, 6... Biasing means, 7A, 7
B... Peripheral wall portion of the bub, 8A, 8B... Engagement groove, 9.
... Inner surface of the cassette, 10A, 10B... Engagement wall, 11A, 11B... Bottom surface of the engagement groove, 12A,
12B...Top surface of the holding wall.

Claims (2)

[Scope of utility model registration request] (1) A flangeless type cylindrical tape winding hub is disposed within a casing consisting of an upper cassette half and a lower cassette half, and the hub has a flangeless type cylindrical tape winding hub within the circumferential wall of the hub at least the height from the bottom surface of the hub. An engagement groove extending in the middle 1 is provided concentrically with the hub, and the lower cassette half has an engagement groove extending upwardly from the inner surface of the lower cassette half and fitting into the engagement groove of the lower cassette half. A cylindrical engagement wall is formed that is approximately equal in height to the engagement groove.
The height of the cylindrical engagement wall is set such that the bottom surface of the engagement groove and the top surface of the engagement wall contact each other when the cassette is not in use, and the contacting surfaces include: The hub is provided with projections and depressions that engage with each other so as to prevent rotation of the hub at least in the unwinding direction, and a biasing means is provided in the casing for biasing the hub in a direction in which both surfaces of the hub come into contact with each other. Further, the hub is provided so as to be pushed upward against the biasing force of the biasing means when the cassette is in use, and when the cassette is not in use, the two surfaces contact and the hub is unwound in the direction of unwinding. A micro video cassette characterized by anti-rotation. (2) The micro video cassette according to claim 1, wherein the unevenness formed on the contacting surfaces has a sawtooth shape.