JPS6235141Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an azimuth adjustment device for a magnetic head that is most suitable for application to an auto-reverse machine in a magnetic recording/reproducing device such as a tape recorder.

As is well known, this type of azimuth adjustment device adjusts the gap of the magnetic head relative to the tape center when the tape is running in the forward direction (hereinafter referred to as normal running) and when the tape is running in the reverse direction (hereinafter referred to as reverse running). It is designed to adjust the verticality, and various ideas have been made in the past. For example, a rotating head system in which the magnetic head is reversed 180 degrees during normal driving and reverse driving, and the azimuth can be adjusted independently using a pair of adjustment screws. A dual head system in which two independent magnetic heads are attached to a single head mounting plate and used as a fixed head, and the azimuth can be adjusted independently using a pair of adjustment screws to correspond to normal running and reverse running. There is. However, in the former case, the structure for rotating the magnetic head is complicated and requires precision, and is expensive, as well as having a bad space factor. In addition, the latter uses two independent magnetic heads, and due to problems such as tilting of these magnetic heads, precision in mounting the magnetic head to the head mounting plate and precision in processing and assembling the head mounting plate itself is required, which reduces yield. However, there are some flaws that make it expensive.

Note that Japanese Patent Publication No. 54-9045 is a known technique that can correct the above defects to some extent. In this known technique, one end of a head mounting plate, on which a magnetic head is mounted, is supported by a mounting screw via a spring, and a pair of adjustment screws are mounted downward on the other end of the head mounting plate. A sliding plate is placed below the adjustment screw, and the other end of the head mounting plate is pulled downward by a tension spring, and the sharp tips of the pair of adjustment screws are pressed onto the sliding plate. , the sliding plate is provided with a pair of bent parts corresponding to a pair of adjustment screws and having different phases in the sliding direction, and the sliding plate is slid in conjunction with the reversal of normal running and reverse running of the tape. By moving the adjustment screws, the sharp ends of the pair of adjustment screws are brought into contact with and slid on the sliding plate alternately, so that the azimuth can be adjusted independently with each of the pair of adjustment screws. It is something.

However, with the above structure, the sliding plate is subjected to strong frictional resistance and cannot be lightly slid. The moving mechanism is very complicated, and the azimuth is likely to be out of alignment. That is, the structure is such that the magnetic head is fixed in each azimuth state by the spring force that pulls the other end of the head mounting plate downward by a tension spring.
It is necessary to make the tension spring's spring force very strong. On the other hand, due to the strong spring force, the sharp tips of the pair of adjustment screws alternately come into contact with and slide on the sliding plate, so strong frictional resistance acts every time the sliding plate slides. do. In addition, since the sliding plate is frequently slid in conjunction with the automatic reversal operation of the tape running direction, the top surface of the sliding plate and the sharp tips of the pair of adjustment screws are likely to wear out quickly. In addition to easily causing scratches in the sliding motion, the adjusted azimuth is also likely to be distorted, resulting in a lack of reliability.

The present invention attempts to provide a device that can correct the above-mentioned deficiencies.

An embodiment in which the present invention is applied to an auto-reverse machine for a tape recorder will be described below with reference to the drawings.

First, the structure of the azimuth adjustment device will be explained with reference to FIGS. 1 to 7.

The magnetic head 1 is fixed on a head mounting plate 2 made of a leaf spring.
One end 2a is attached to a mounting base 4 fixed to a reciprocating head board 3 by means of a mounting screw 5. Note that a groove 6 is formed on the other end 2b side of the head mounting plate 2. Other end 2 of head mounting plate 2
A fulcrum shaft 7 is vertically fixed on the head substrate 3 on the b side. This fulcrum shaft 7 has a rotating lever 8 having a substantially U-shaped cross section with a pair of upper and lower through holes 9a,
9b, and this rotary lever 8
is configured to be horizontally rotatable around the axial center of the fulcrum shaft 7, and also to be slidable up and down in the axial direction. On the same circumference of the top plate 8a of the rotary lever 8, there are a pair of adjustment screws 11 for adjusting the azimuth.
12 are both mounted facing downward. These adjustment screws 11 and 12 are screwed into a pair of screw holes 13 and 14 provided in the upper surface plate 8a and penetrated downward, and the outer peripheries of these adjustment screws 11 and 12 are provided with their heads. Compression springs 15 and 16 for preventing loosening are interposed between the top plate 8a and the top plate 8a in a pre-compressed state. The other end 2b of the head mounting plate 2 is brought into contact with the tip of the bottom plate 8b of the rotary lever 8. A height reference shaft 18 inserted into the groove 6 of the head mounting plate 2 is vertically fixed onto the head board 3, and its upper end surface forms a height reference surface 19. A washer 20 is fitted to the upper end of this height reference shaft 18, and between the washer 20 and the other end 2b of the head mounting plate 2, the outer periphery of this height reference shaft 18 is used for pressing the head mounting plate. A compression spring 21 is interposed in a pre-compressed state. A thin leaf spring 22 is interposed between the tips (lower ends) of both adjustment screws 11 and 12 and the height reference surface 19 at the upper end of the height reference shaft 18. This leaf spring 22 is approximately L
The engagement hole 25 is formed at the tip of the top plate 8a of the rotary lever 8, and has a projection 24 that is formed into a letter shape and is inserted into the fulcrum shaft 7 through a through hole 23 at one end, and is integrally provided at the other end. The rotary lever 8 is engaged with the rotary lever 8 and rotated together with the rotary lever 8. Note that the tip of an interlocking lever 26, which will be described later, is connected to a part of the lower plate 8b of the rotary lever 8 via a pin 27.

Next, the azimuth adjustment operation of the magnetic head 1 will be explained.

First, FIGS. 2 to 4 show the state in which the magnetic tape 29 in contact with the magnetic head 1 is normally running in the direction of arrow a. During this normal running, the magnetic head 1 is aligned with the vertical reference line P as shown in FIG. ₁ at an angle θ ₁ in the direction of arrow b, thereby making the magnetic tape 29 perpendicular to the tape center P ₂ P ₃
At the top, the gap of the magnetic head 1 is adjusted (verticality adjustment).

That is, during normal running of the magnetic tape 29, the interlocking lever 26 is moved in the direction of arrow c in FIG.
The rotation lever 8 is rotated in the direction of arrow d. As a result, as shown in Figs. 3 and 4, one adjustment screw 1
1 is brought into contact with the height reference surface 19 at the upper end of the height reference shaft 18 via the leaf spring 22, and the rotary lever 8 is moved along the fulcrum shaft 7 in the direction of arrow e in FIG. It is slid by a compression spring 21. At the tip of the bottom plate 8b of the rotary lever 8, the other end 2b of the head mounting plate 2 is connected to its own elastic and compression spring 21.
3, the head mounting plate 2 is bent by a predetermined angle θ ₃ in the direction of the arrow f in FIG.
is tilted at an angle θ ₁ . Note that by adjusting the adjustment screw 11 in this normal running state, the rotation lever 8 can be moved to the fulcrum shaft 7 by working together with the compression spring 21.
The azimuth adjustment (adjustment of the verticality of the gap) of the magnetic head 1 can be performed by adjusting the deflection angle of the head mounting plate 2 by moving it up and down along the magnetic head 1.

Next, in FIGS. 5 to 7, the magnetic tape 29 is
During this reverse running, the magnetic head 1 is tilted at an angle θ ₂ in the direction of the arrow h with respect to the vertical reference line P ₁ as shown in FIG. The gap of the magnetic head 1 is adjusted (verticality adjustment) on a line _P4 perpendicular to _P2 .

That is, when the magnetic tape 29 runs in reverse, the interlocking lever 26 is moved in the direction of arrow i in FIG.
Rotation lever 8 is adjusted to rotate in the direction of arrow j. As a result, as shown in Figs. 6 and 7, the other adjustment screw 1
2 is brought into contact with the height reference surface 19 at the upper end of the height reference shaft 18 via the leaf spring 22, and the rotary lever 8 is rotated along the fulcrum shaft 7 in the direction of arrow k in FIG. It is slid against the compression spring 21. At this time, the leaf spring 22 is bent as shown in FIG. As the lower surface plate 8b of the rotary lever 8 moves, the other end 2b side of the head mounting plate 2 is moved by its own elasticity and compression spring 21.
6, the head mounting plate 2 is bent by a predetermined angle _θ4 in the direction of arrow l in FIG.
is tilted at an angle θ ₂ . Note that by adjusting the adjustment screw 12 in this normal running state, the rotation lever 8 can be moved to the fulcrum shaft 7 by working together with the compression spring 21.
The azimuth adjustment (adjustment of the verticality of the gap) of the magnetic head 1 can be performed by adjusting the deflection angle of the head mounting plate 2 by moving it up and down along the magnetic head 1.

According to the azimuth adjusting device described above, by adjusting the rotation of the rotary lever 8, the pair of adjustment screws 11 and 12 are adjusted to the height reference plane 19 while sliding the rotary lever 8 up and down along the fulcrum shaft 7. The magnetic head 1 is configured to selectively ride on the magnetic head 1 to regulate the height of the rotating lever 8, and accordingly swing the head mounting plate 2 up and down to adjust the azimuth of the magnetic head 1. Therefore, the rotational resistance of the rotary lever 8 is very small, and the rotation of the rotary lever 8 can be constantly and easily adjusted with a very weak force. At this time, the leaf spring 22 guides the pair of adjustment screws 11 and 12 to ride on the height reference surface 19, and allows the pair of adjustment screws 11 and 12 to ride on the height reference surface 19 smoothly with even less resistance. Moreover, it is a method in which the head mounting plate 2 is swung up and down by adjusting the height of the rotary lever 8.
The tip of the lower plate 8b of the rotary lever 8 always acts on the other end 2b of the head mounting plate 2 at a constant position to swing the head mounting plate 2 up and down. Therefore, in both normal running and reverse running, the point of action P ₅ between the rotary lever 8 and the head mounting plate 2 shown in FIGS. 3 and 6, and the fulcrum position P ₆ of the head mounting plate 2 shown in FIGS.
_The distance L _between the two and
and θ ₄ . As a result, unreasonable force is rarely applied to the head mounting plate 2, and it can be easily swung, and the elastic force of the head mounting plate 2 can be easily adjusted and designed.
The problem of tilting of the magnetic head 1 with respect to the magnetic tape 29 does not occur at all.

Next, FIG. 8 shows an interlocking mechanism between an azimuth adjusting device and a tape running direction reversing mechanism in a dual-capstan type auto-reverse machine.

First, the motor pulley 42 of the motor 41, the pulleys 45, 46 of the pair of capstans 43, 44,
A belt 48 is wound around the intermediate pulley 47, and the pair of capstans 43, 44 are driven by forward and reverse rotation of the motor 41 in the direction of the arrow m or the direction of the arrow n.
is configured to be selectively rotationally driven in the direction of the arrow a' or the direction of the arrow g'. and a pair of notches 4
9a and 49b is selectively engaged with the drive gear 51 driven by the intermediate pulley 47 by a mechanical trigger mechanism (not shown), so that the arrow m of the drive gear 47 Depending on the forward/reverse rotation in the 'direction' or 'n' direction, the direction of the arrow m'' or
It is driven half a rotation in the n″ direction.Then, the partially toothed gear 5
0 drives the pinch roller drive lever 54 through the elongated hole 53, and the pinch roller drive lever 54 moves within the angular range shown by the solid line and the imaginary line around the fulcrum shaft 55. The pair of pinch rollers 56 and 57 are swung in the direction of the arrow o or the direction of the arrow p, so that the pair of pinch rollers 56 and 57 are
3 and 44, and the magnetic tape 29 is configured to run normally or in reverse in the direction of arrow a or g. At this time, when the pinch roller drive lever 54 is rotated in the direction of the arrow o, its protrusion 58 escapes from one pinch roller lever 59, so that the pinch roller lever 59 rotates around the fulcrum shaft 55. It is rotated in the direction of arrow q by the compression spring 60. On the other hand, as the pinch roller drive lever 54 rotates in the direction of the arrow o, the seesaw lever 62 is rotated in the direction of the arrow r around the fulcrum shaft 61 at its tip, and the tip of the seesaw lever 62 rotates in the direction of the arrow r with the tip of the lever 62 rotating in the direction of the arrow r. Press the pin 64 to move this pinch roller lever 63 to the fulcrum shaft 6.
5 in the direction of arrow s against the compression spring 66. On the other hand, the pinch roller drive lever 5
4 is rotated in the direction of arrow P, one pinch roller lever 59 is rotated by the protrusion 58 in the direction of arrow t against the compression spring 60, while the seesaw lever 62 is rotated in the direction of arrow U. The other pinch roller lever 63 is rotated in the direction of the pressure spring 6.
6 in the direction of arrow v.

The other end of the interlocking lever 26 is connected to the tip of the pinch roller drive lever 54 via a pin 68.
By rotating in the direction of the arrow o or p, the magnetic head 1 is moved in the direction of the arrow c or i as described above, and the azimuth of the magnetic head 1 is adjusted. At this time, as mentioned above, since the rotational resistance of the rotary lever 8 is very small, the load applied to the tape running direction reversing mechanism is very small. Therefore, the reversal operation of the tape running direction can always be carried out very easily and quickly with an extremely simple mechanism, and a device with few failures and high durability and reliability can be obtained.

Although the embodiments of the present invention have been described above, various modifications can be made based on the technical idea of the present invention.

For example, the head mounting plate 2 does not need to be composed of a leaf spring, and may simply have the function of being able to swing up and down using one end 2a as a fulcrum.

Further, in the embodiment, the head mounting plate 2 and the rotary lever 8 are commonly moved and biased downward by one compression spring 21, but they are moved downward by using separate springs. It can be moved and energized, and in this case, it is not necessarily necessary to use a compression spring, and a tension spring can also perform the same function.

As described above, according to the present invention, the azimuth of the magnetic head can be adjusted by rotating the rotary lever extremely easily according to the running direction of the tape, so that the azimuth of the magnetic head can be adjusted. The interlocking azimuth adjustment operation can be performed extremely easily with an extremely simple mechanism. In addition, there are no problems such as wear, no deviation in the adjusted azimuth, no problems with tilt, etc., and extremely high durability and reliability can be obtained.

[Brief explanation of the drawing]

The drawing shows an embodiment in which the present invention is applied to an auto-reverse machine for a tape recorder.
Figure 1 is a perspective view of the azimuth adjustment device, Figure 2 is a plan view of the magnetic tape during normal running, and Figure 3 is a perspective view of the azimuth adjustment device.
The figure is Fig. 2 - Line sectional view, Fig. 4 is Fig. 2 -
Figure 5 is a plan view when traveling in reverse, Figure 6 is a cross-sectional view taken from Figure 5, Figure 7 is a cross-sectional view taken from Figure 5, and Figure 8 is a dual capstan type auto. FIG. 3 is a plan view showing an interlocking mechanism between a tape running direction reversing mechanism and an azimuth adjustment device in a reversing machine. In addition, in the symbols used in the drawings, 1...magnetic head, 2...head mounting plate, 7...fulcrum shaft,
8... Rotating lever, 8a... Top plate of rotating lever, 8b... Bottom plate of rotating lever, 11, 12...
... Adjustment screw, 18 ... Height reference axis, 19 ... Height reference plane, 21 ... Compression spring, 26 ... Interlocking lever, 29 ... Magnetic tape, 43, 44 ... Capstan, 54 ... Pinch roller Drive lever, 5
6, 57...Pinch roller.

Claims (1)

[Scope of utility model registration request] A rotary lever that is rotatable around the axial center of the fulcrum shaft and slidable in the direction of the axial center, and a pair of adjustment screws for azimuth adjustment installed at a distance on the same circumference of the rotary lever. a height reference surface on which the pair of adjustment screws are selectively abutted by adjusting the rotation of the rotary lever; and a height reference surface on which the magnetic head is attached and engaged with the rotary lever, and the fulcrum shaft of the rotary lever. and a head mounting plate adapted to adjust the azimuth of the magnetic head by sliding in the axial direction of the head, and adjust the azimuth of the magnetic head by rotating the rotary lever according to the running direction of the magnetic tape. A magnetic head azimuth adjustment device configured to adjust the magnetic head.