JPS58177578A - Magnetic tape cassette - Google Patents

Abstract

PURPOSE:To eliminate extreme disorder of pad pressure and to prevent partial abrasion of a magnetic head, by composing a cassette of an upper half part consisting of a couple of upper arms extending to left and right from an upper base part and a lower half part consisting of a couple of lower arms. CONSTITUTION:The upper base part 2 supporting the upper half part of a tape pad 10 have the upper arms 3a and 3b which flex more than the lower arms 6a and 6b to move out into the cassette (to left in a figure) more than the lower base part 5 according to the attitude of a magnetic head 11. Therefore, the pressure that the tape pad 10 presses a magnetic tape 12 against the magnetic head 11, i.e. pad pressure is uniformed by reducing the pad pressure of a part higher than the center by the moving-out operation of the upper base part 2. Consequently, no large pad pressure is applied to the upper part of the magnetic core 11a of the magnetic head 11 which wears relatively easily to prevent the partial abrasion of the magnetic head 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to magnetic tape cassettes such as compact cassettes.

In a magnetic tape cassette (hereinafter simply referred to as a cassette) such as a compact cassette, a tape pad biased in the direction of the magnetic tape is arranged inside the magnetic tape in the part that contacts the magnetic head, and the tape pad is biased toward the magnetic tape during recording and playback. When the magnetic head of the reproducing device is inserted into the cassette, the magnetic tape is brought into elastic pressure contact with the magnetic head by the action of the tape pad.

In reel-to-reel type tape recorders, the tape path is set so that the magnetic tape comes into pressure contact with the magnetic head to achieve close contact between the tape and the head, but in compact cassettes and other devices, the magnetic tape is placed outside the cassette Since such a tape bus setting is not possible with a cassette that cannot be pulled out, the tape and the head are brought into pressure contact by the tape pad as described above.

The above-mentioned tape pads are generally made of felt, and are fixed to the center of a leaf spring arranged inside the magnetic tape in parallel with the tape, and are pressed against the back side of the magnetic tape by being biased by the leaf spring. However, conventional cassettes using this type of tape pad tend to cause uneven wear of the magnetic head of the recording/reproducing device.

In other words, in the conventional cassette, the leaf spring is formed by punching out an elastic plate material such as phosphor bronze into a shape in which an elongated strip extends left and right from the center of a rectangular pad support, that is, in a cross shape. However, due to distortion during punching, etc., the central pad support part was not formed completely flat, and the upper part of the band-shaped part and the lower part were sometimes bent in slightly different directions. The pad pressure of the tape pad fixed to such a leaf spring naturally causes magnetic spatula. In addition to the shape of the leaf spring, such pad pressure irregularities may also occur due to, for example, a dimensional error on the side of the cassette half supporting the leaf spring, or even an incorrect insertion posture of the magnetic head of the recording/reproducing device. As is well known, most recording and reproducing devices that use cassettes perform bidirectional recording and reproducing of tape, and therefore the magnetic core of the magnetic head is placed one side above or below the magnetic tape. The parts outside the magnetic core of the magnetic core are relatively more likely to wear out than the core part. Therefore,
If the above-mentioned pad pressure irregularity is particularly such that a large pad pressure is applied to a portion outside the core, this portion outside the core will wear out at an accelerated rate.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a cassette that eliminates the extreme pad pressure irregularities described above and does not cause uneven wear of the magnetic head.

The cassette of the present invention includes a plate spring as described above, an upper half consisting of an upper support part supporting the upper half of the tape pad, a pair of upper arms extending in the left-right direction from the upper support part, and Formed by a lower half consisting of a lower support part that supports the lower half of the tape pad, and a pair of lower arms extending from the lower support part in the left-right direction and having both sides connected to both ends of the upper arm. It is characterized by the fact that

When a leaf spring is divided into an upper half and a lower half as shown above, the leaf spring half to which a large force is applied will deflect more independently of the other half, and this half of the leaf spring will be supported. Reduce the pad pressure of the tape pad in the area where the tape pad is located and average the pad pressure. As a result, extremely large pad pressure is not applied to a portion of the magnetic head, and uneven wear of the magnetic head as described above can be prevented.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the tape pad and leaf spring of a cassette according to one embodiment of the present invention.

The leaf spring 1 includes a rectangular upper support part 2 and a rectangular upper support part 2.
A pair of upper arms 3a, 3 extending left and right downward from the upper end.
an upper half 4 consisting of b, a lower support part 5 and a lower arm 6;
a, 6b, and has a lower half 7 formed symmetrically with the upper half 4, and includes upper arms 3a, 3b and a lower arm 6.
a and 6b are connected at their respective ends. Further outer ends of the joint portions of the upper arms 3a, 3b and the lower arms 6a, 6b are respectively bent at right angles to form support portions 8a, 8b. The plate spring 1 is made of an elastic plate material such as phosphor bronze, nickel silver, or stainless steel, like the plate spring of a conventional cassette.

The upper support part 2 and the lower support part 5 are separated from each other with a slit 9 between them, and one tape pad 10 is attached to the upper support part 2 and the lower support part 5. . That is, the upper support part 2 is the upper half of the tape pad 10,
The lower support part 5 supports the lower half of the tape pad 10. This tape pad 10 is made of felt or the like, similar to the tape pad of a conventional cassette.

The leaf spring 1 to which the tape pad 10 as described above is fixed is
The supporting parts 8a and 8b are held in the cassette half by being combined with both ends of the shield plate.

FIG. 2 shows that the cassette of this embodiment having the above-mentioned leaf spring 11 and tape pad 10 is installed and used in a recording/reproducing snowmaking machine in which the magnetic head 11 cannot be inserted perpendicularly to the magnetic tape 12 of the cassette. It indicates the condition.

The magnetic head 11 is inserted into the cassette with the upper side tilted forward, and comes into contact with the magnetic tape 12 pressed from the back side by the tape pad 10 biased by the leaf spring 1. At this time, the upper support part 2 supporting the upper half of the tape pad 10 has upper arms 3a, 3b and lower arms 6a, 6b.
By bending more sharply than in the figure, the magnetic head 11 moves toward the inside of the cassette (to the left in the figure) from the lower support part 5 in accordance with the attitude of the magnetic head 11, as shown in the figure. Therefore, the pressure with which the tape pad 10 presses the magnetic tape 12 against the magnetic head 11, that is, the pad pressure, would normally be greater at the upper part of the tape pad 10, but due to the withdrawal of the side support part 2, the pad pressure is increased from the center to the upper part. reduced and equalized. Therefore, -FT of the magnetic core lla of the magnetic head 11
Undue pad pressure is not applied to the relatively easily worn portion of the magnetic head 11, and uneven wear of the magnetic head 11 is prevented.

tJ, the mechanism for compensating for pad pressure irregularities due to incorrect insertion posture of the upper magnetic head 11 has been explained.
Of course, pad pressure irregularities that occur due to the plate spring 1 being distorted or being disposed obliquely due to manufacturing errors in the plate spring support portion such as the shield plate can also be compensated for in the same manner.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a part of a cassette according to an embodiment of the present invention, and FIG. 2 is a side sectional view showing the state in which the embodiment of FIG. 1 is used. 1...Plate spring 2...Upper support part 3a, 3
b... Upper arm 4... Upper half of leaf spring 5
...Lower support part 5a, 6b...Lower arm 7
... Lower half of leaf spring 10 ... Tape pad 12
...Magnetic tape vs I Figure 2 Figure 1

Claims (1)

[Claims] In a magnetic tape cassette, the plate spring is arranged inside a magnetic tape stretched in a cassette opening, and has a plate spring arranged substantially parallel to the tape, and a tape pad fixed to the plate spring. an upper half portion comprising an upper support portion supporting the upper half of the pad and a pair of upper arms extending in the left-right direction from the upper support portion; and a lower support portion supporting the lower half of the tape pad; A magnetic tape cassette comprising a lower half portion comprising a pair of lower arms extending from the lower support portion in the left-right direction and having both ends connected to both ends of the upper arm.