JPS6334527B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head rotating device for a reverse type tape recorder, and more particularly to an improvement in the mounting position adjustment mechanism of the magnetic head.

Needless to say, in the above tape recorder, the tracks of the tape to be recorded and played back are different in the forward recording/playback mode and the reverse recording/playback mode, so switching between the two modes is performed by rotating the magnetic head 180 degrees.

In principle, the means for reversing and rotating the magnetic head is to attach the magnetic head to a rotatable mounting plate (B) supported on a bearing (A) as shown in the schematic diagram of FIG. However, it is necessary to mount the head on the mounting plate by aligning the center of the head accurately with the rotation center of the mounting plate in order to prevent track displacement during forward and reverse operations. Conventionally, as a means for this purpose, as shown in Japanese Utility Model Publication No. 49-24412, a screw member and a spring member are provided on the top and bottom of the head mounting plate so as to face each other on the same line, and the top and bottom of the magnetic head are sandwiched between the two members. With this structure, when the magnetic head is pressed, the magnetic head is pushed against the elasticity of the spring member by the screw member, and the vertical position is adjusted. There is a problem that the head may tilt forward due to displacement of members, etc., and this is not preferred as a vertical position adjustment mechanism for this type of magnetic head, which requires delicate adjustment accuracy.

Therefore, in this invention, when the magnetic head moves up and down due to the screw threading, the magnetic head is forcibly brought into sliding contact with the abutting guide surface in the tape width direction provided on the mounting plate, thereby causing the magnetic head to tilt. It is designed to always move up and down in a straight line without twisting, making it possible to easily and accurately adjust the up and down position.

First, details of the embodiment will be described with reference to the drawings.

In Fig. 2, 1 is a chassis, and 2 is a base that can be moved left and right in the figure by a recording/playback button (not shown).A head mounting plate 3 is rotatably supported on the base 2, and this mounting plate A magnetic head 4 is attached to the head 3.
A pinion 6 is fixed to the shaft portion 5 of the mounting plate 3, and a sector gear 8 whose base is pivoted to the base 2 by a shaft 7 is meshed with the pinion 6. A swing lever 9 connected to the source is connected.

Therefore, by operating the recording/playback button (not shown), the base 2 moves to the left in the figure, thereby moving the head 4.
contacts the tape in the cassette, which is being scanned, for example, in the forward direction. When the tape is transferred to the end, the base 2 is temporarily returned from the position shown in the figure by an end detection signal, etc., and the head 4 is removed from the cassette. In this removed state, the swing lever 9 swings and the sector gear 8
At the same time, the mounting plate 3 is rotated through 180 degrees, so that the head 4 is switched to the reverse recording/playback mode and reversed. In this inverted state, the base again moves to the left and comes into contact with the tape moving in the reverse direction, which is the general form of this type of device.

Further, as a means for attaching the magnetic head 4 to the mounting plate 3, a bent portion 3a of this plate is provided at the upper center of one side of the mounting plate 3, and a screw member 10 is attached to the bent portion 3a between the mounting plate 3 and the mounting plate 3. The screws protrude in parallel, and
A diagonal portion 11a is provided at the tip of the lower center of one side of the mounting plate 3.
A plate-shaped spring member 11 having
A contact guide surface 3c is formed on the mounting plate surface between the spring member 11 and the screw member 10 in order to move the magnetic head in the tape width direction. The back surface of the magnetic head 4 inserted and held in the magnetic head 4 is brought into contact with the screw member 10, and the tip of the screw member 10 is brought into contact with the slope 4a provided on the upper surface of the magnetic head 4, and the jaw portion 4b provided on the lower part of the magnetic head 4 is brought into contact with the tip of the screw member 10. A diagonal portion 11a of the spring member 11 is provided at the front end.
The inner surface of the holder is in elastic contact with the inner surface of the holder.

Therefore, its action is that when the head 4 is inserted between the screw member 10 and the spring member 11 and the screw member 10 is tightened, the head 4 moves parallel to the mounting plate 3 against the spring member 11. The vertical position of the head 4 with respect to the mounting plate 3 is adjusted, and at the same time, the screw member 10 removes the slope 4a of the head, and the diagonal portion 11a of the spring member 11 presses against the jaw 4b of the head. 4 will move straight up and down with the entire back surface in contact with the contact guide surface 3c.

The back surface of the mounting plate 3 is brought into contact with a reference surface consisting of a ring-shaped jetty provided on the base 2 as shown in the figure, so that the verticality of the mounting plate 3 can be maintained accurately.

As described above, according to the present invention, the magnetic head can be moved against the spring member by the spiral operation of the screw member, and the vertical position can be adjusted. When the head moves,
The magnetic head is forcibly moved by sliding contact with the contact guide surface provided on the mounting plate, so the magnetic head can be moved straight and accurately along the contact guide surface without tilting. By aligning the center of the head and the rotation center of the mounting plate to the optimum tape track position, the adjustment can be made much more accurate and easier.

In addition, since there is no need to pursue the precision of individual parts, it is suitable for low-cost mass production, and has excellent features that cannot be expected with conventional devices of this type.

The head 4 in this example is one whose outside is integrally covered with a holder as shown in the figure.
Therefore, the slope 4a and the jaw portion 4b are formed into a holder.

Further, in this example, the head 4 is provided with an engaging protrusion 4e having upper and lower inclined surfaces 4c, 4d on one side thereof, and the inclined surfaces 4c, 4d of this protrusion 4e are connected to the head 4.
When the head 4 is reversed from the state shown in FIG. One inclined surface 4c of 4e comes into contact with the spring plate 13 on the right side in the figure.
This contact action involves maintaining the inverted state of the head with pressure, pressing the head toward the mounting plate 3 side, and further pressing the head 4 upward to press it against one side of the mounting plate 3. A protrusion 3b provided at the top is brought into contact with an azimuth adjustment screw 14. Note that this adjustment screw 14 is screwed into a projecting piece 2a provided on the base 2.

Furthermore, as shown in FIG.
The bent portion 3a is interposed within the notch 4f, and both side edges of the bent portion 3a are brought into contact with the opposing edges of the notch 4f, thereby ensuring left and right positioning of the head.

Furthermore, the pin 12 fixing the spring member 11
are also interposed within another notch-shaped guide 4g provided in the head to ensure left and right positioning of the head. Further, the left and right play in the guides 4f and 4g is shifted in one direction by slightly shifting the center of the screw member 10 and the center n of the guide 4g.

FIG. 4 shows a partial modification in which the tip of the screw member 10 is formed into a tapered shape, and this taper presses a jaw 4h provided on the head 4, thereby pressing the head toward the surface of the mounting plate 3.

5 and 6 show modified examples of the spring member 11. In this example, a spring retaining piece 15 with a U-shape facing upward from the front is attached to the mounting plate 3, and a wire spring is attached to the U-shaped portion of the retaining piece 15. 16 is bridged, and this wire spring 16 is made to come into elastic contact with an inclined jaw 17 provided at the lower part of the head 4. In addition, in this example, the screw member 10
Of course, the head 4 and the head 4 are in a slope-like abutting relationship.

As is clear from the above, in the present invention, the spring member and the screw member are placed in contact with the pressing surface provided on the member or the head so that the head is pressed against the mounting plate surface by the screw member. Since they are in contact with each other, the head can be easily adjusted up and down.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional general example, Fig. 2 is a side sectional view of the main part of the present invention, Fig. 3 is a front view from above, and Fig. 4 is a side view showing a modification of the screw member portion. FIG. 5 is a side view of a modified example of the spring member portion, and FIG. 6 is a front view. 2...Base, 3...Head mounting plate, 4...Magnetic head, 10...Screw member, 11...Spring member,
11a, 4a... Pressing surface.

Claims (1)

[Claims] 1. A head mounting plate is provided on the base which is rotated 180 degrees when the tape running direction is changed, and the upper and lower sides of the magnetic head are arranged between the screw member and the spring member provided on the mounting plate. In a rotating device for a magnetic head that is clamped and supported in a vertically adjustable manner by threading a screw member, the threading of the screw member forces the magnetic head onto an abutting guide surface in the tape width direction provided on a mounting plate. A head attachment position adjusting mechanism in a magnetic head rotating device, characterized in that a pressing surface provided on the spring member and the screw member is brought into contact with the magnetic head so as to be in sliding contact with the magnetic head.