JPH0450621Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is most suitable for application to tape cassettes for video tape recorders, for example, and is particularly suitable for application to tape cassettes for video tape recorders. The present invention relates to a tape cassette in which cassette information is detected by switching the vertical position.

[Summary of the idea]

In the present invention, a plug is arranged in a through-hole of a cassette case so as to be movable up and down, and a compression coil spring that presses and biases the plug upward is connected to a spring abutting part of the plug and a spring abutting part in the through-hole. In the tape cassette inserted between This is designed to prevent the lower end of the compression coil spring from getting caught in the gap between the through hole and the plug when switching the vertical position of the plug within the through hole.

[Conventional technology]

Conventionally, a plug has been placed in a through-hole provided in a cassette housing so that its vertical position can be switched, and when a tape cassette is installed in a video tape recorder, etc., the vertical position of the plug is determined by the information detection means on the equipment side. There are tape cassettes that are designed to detect various types of cassette information such as prevention of erroneous erasure.

Therefore, a conventional example of this type of tape cassette will be explained with reference to FIGS. 3 and 4.

First, as shown in FIG. 4, the cassette housing 1 is made up of upper and lower halves 2 and 3 connected to each other from above and below, and cylindrical parts 4 and 5 integrally molded vertically to the upper and lower halves 2 and 3. A through hole 6 is formed vertically in the cassette housing 1 by abutting against each other. A plug 8 is disposed within the through hole 6 so as to be movable up and down and rotatable around the vertical axis. This cylindrical plug 8 has a large-diameter head 9 formed at its upper part, and a pair of horizontally protruding pins 10 at its lower part. A compression coil spring 12 is attached to the outer periphery of the plug 8.
is inserted, and the upper end 12a of the compression coil spring 12 is brought into contact with the annular spring contact part 14, which is the lower end of the head 9 of the plug 8. The lower end portion 12 b of the compression coil spring 12 is in contact with the annular spring contact portion 15 .

The plug 8, which is pressed upward by the compression coil spring 12, has a pair of pins 10 at the locking portion 17, which is the lower end of the cylindrical portion 4, as shown by the dashed line.
It is positioned at the upper stage position by being locked at. When the tape cassette is inserted into the video tape recorder in this state, the detection pin 20 of the information detection means provided on the video tape recorder side
does not come into contact with the lower end of the plug 8, and information detection is off. On the other hand, insert a tool such as a screwdriver into the groove 9a provided on the top surface of the head 9 of the plug 8, press the plug 8 downward against the compression coil spring 12, and then rotate the plug 8 by 90 degrees. Release the pressure on the plug 8. Then, the plug 8 is pressed upward by the compression coil spring 12, and the pair of pins 10 are locked by the locking part 18 formed in the cylindrical part 5, as shown by the solid line, and the plug 8 is moved to the lower stage. Positioned by position. When the tape cassette is inserted into the video tape recorder in this state, the detection pin 20 is brought into contact with the lower end of the plug 8, and information detection is turned on.

[Problem that the invention attempts to solve]

However, the conventional tape cassette described above has the following problems.

That is, when assembling the tape cassette, when inserting the plug 8 into the through hole 6, as shown in FIG.
2 is inserted into the through hole 6 together with the plug 8 while pressing the compression coil spring 12. However, at this time, if the compression coil spring 12 is hooked by the plug 8, the lower end 12b of the compression coil spring 12 will come into contact with the spring because the spring contact portion 15 of the through hole 6 is a flat surface. Part 1
5 and was often caught in the gap 22 between the through hole 6 and the plug 8. Therefore, it is necessary to carefully insert the plug 8 into the through hole 6, and it is extremely troublesome because it must be done carefully by hand. Note that if the dimensional difference between the outer diameter of the plug 8 and the inner diameter of the through hole 6 is set strictly so that the gap 22 is small, the above-mentioned entanglement of the compression coil spring 12 can be prevented to some extent, but the dimensions should not be set too strictly. If it is too much, there is a risk that the plug 8 and the through hole 6 will bite into each other.

Further, when using a tape cassette, when switching the vertical position of the plug 8 in the through hole 6 while pressing the compression coil spring 12, the compression coil spring 12 may be caught in the same way as described above. Ta. In particular, since the plug 8 is rotated when changing the vertical position, when the rotation direction coincides with the winding direction of the compression coil spring 12, the diameter of the compression coil spring 12 becomes smaller and it becomes easier to slip into the gap 22. In this state, the plug 8 becomes immovable in the middle between the upper and lower positions, resulting in a problem that the detection of cassette information by the detection pin 20 malfunctions.

Therefore, the present invention prevents the lower end of the compression coil spring from getting caught in the gap between the through hole and the plug when inserting the plug into the through hole or switching the vertical position of the plug inside the through hole. This is to enable prevention.

[Means for solving problems]

The present invention provides the above-mentioned tape cassette.
An annular spring receiving groove is provided in the spring contacting portion in the through hole, and the lower end of the compression coil spring is engaged in the spring receiving groove.

[Effect]

According to the present invention, even if the compression coil spring is hooked by the plug when the plug is inserted into the through hole while pressing the compression coil spring and the plug is switched between the vertical positions, The lower end of the compression coil spring is engaged in the annular spring receiving groove of the spring abutting part and is securely fixed, so the lower end of the compression coil spring may slip from the spring abutting part and be between the through hole and the plug. Don't get caught up in the gap.

〔Example〕

An embodiment in which the present invention is applied to a tape cassette for a video tape recorder is shown in Figs. 1 and 2 below.
This will be explained using figures. Note that the same parts as those of the conventional example described in the [Prior Art] section are given the same reference numerals, and the explanation thereof will be omitted.

First, as shown in FIG. 2, a cassette housing 1 of a tape cassette consists of upper and lower halves 2 and 3, and inside this cassette housing 1 there is a magnetic tape (not shown).
A pair of left and right reels 24 wound with are rotatably housed. Further, a front cover 25 is rotatably attached to the front end of the cassette housing 1. The through hole 6 is provided vertically in a space at the center of the rear side of the cassette housing 1, avoiding both reels 24.

Next, in the present invention, as shown in Figure 1,
A spring receiving groove 30 having a substantially V-shaped cross section is provided in an annular shape in an annular spring contact portion 15 formed of a stepped portion provided on the inner periphery of the through hole 6 . Note that the cross-sectional shape may be approximately U-shaped, approximately U-shaped opening upward, or the like. Further, the depth of the spring receiving groove 30 is preferably larger than the wire diameter of the compression coil spring 12. The lower end portion 12b of the compression coil spring 12 is engaged within the spring receiving groove 30.

According to the tape cassette configured as described above, the plug 8 is pressed while pressing the compression coil spring 12.
Even if the compression coil spring 12 is hooked by the plug 8 when inserting the compression coil spring 12 into the through hole 6 from above, the lower end 12 of the compression coil spring 12
b is engaged in the spring receiving groove 30 and is securely fixed, so that its lower end 12b is connected to the spring contact portion 1.
Gap 2 between through hole 6 and plug 8
Don't get caught up in 2.

Also, when the plug 8 is pressed downward against the compression coil spring 12 to switch from the upper position shown by the dashed line to the lower position shown by the solid line, the lower end 12b of the compression coil spring 12 gets caught in the gap 22. There is no need to worry about the plug 8 getting stuck between the upper position and the lower position. In particular, when the plug 8 rotates, even if the rotation direction matches the winding direction of the compression coil spring 12, the reduction in the diameter of the lower end portion 12b of the compression coil spring 12 is regulated by the spring receiving groove 30. .

Although one embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and various effective modifications can be made based on the technical concept of the present invention.

For example, in the embodiment, the pair of pins of the plug are locked by the upper and lower locking parts.
This positioning structure can be modified in various ways, and may be switched to have three or more upper and lower stages.

The present invention is not limited to tape cassettes for video tape recorders, but can be applied to various tape cassettes.

[Effect of idea]

In the present invention, the lower end of the compression coil spring is engaged in the annular spring receiving groove provided in the spring contact part of the through hole, so the plug is inserted into the through hole while pressing the compression coil spring. When the compression coil spring is inserted into the plug, the lower end of the compression coil spring can be prevented from being caught in the gap between the through hole and the plug. Therefore, the work of inserting the plug into the through hole can be performed extremely easily, and it is also possible to easily handle automatic assembly using an automatic machine, thereby greatly increasing work efficiency.

Furthermore, when using a tape cassette, when switching the plug's vertical position while pressing the compression coil spring, the above-mentioned entanglement will not occur, so the plug will not be able to move while switching between the vertical position. There is no accident in which the detection of cassette information malfunctions, and reliability can be significantly improved.

[Brief explanation of the drawing]

1 and 2 show an embodiment in which the present invention is applied to a tape cassette for a video tape recorder, and FIG. 1 shows a main part showing switching of the vertical position of the plug in the through hole. The longitudinal sectional view and FIG. 2 are perspective views of the tape cassette. 3 and 4 show a conventional example of a tape cassette for a video tape recorder, in which FIG. 3 is a vertical sectional view of the main part showing switching of the vertical position of the plug in the through hole, and FIG. The figure is a longitudinal sectional view of the main part showing the winding of the compression coil spring. In addition, in the symbols used in the drawings, 1...Cassette housing, 6...Through hole, 8...Plug, 10...
Pin, 12... Compression coil spring, 12b... Lower end, 14... Spring contact part, 15... Spring contact part,
17...Locking portion, 18...Locking portion, 22...Gap, 30...Spring receiving groove.

Claims (1)

[Scope of Claim for Utility Model Registration] A plug is arranged in a through hole provided in a cassette casing so as to be movable up and down, and between a spring abutting part provided on the plug and a spring abutting part provided in the through hole. A compression coil spring is inserted into the cassette, and a plug that is pressed upward by the compression coil spring is positioned at multiple vertical positions within the through hole, and cassette information is detected by switching the vertical position of this plug. The tape cassette configured as above is characterized in that an annular spring receiving groove is provided in the spring contacting part in the through hole, and the lower end of the compression coil spring is engaged in the spring receiving groove. tape cassette.