JPH08180347A - Magnetic head adjustment mechanism - Google Patents

Abstract

PURPOSE: To easily attain three-point adjustment of a fixed magnetic head and to reduce the adjusting man-hour and the number of parts by providing a magnetic head position adjustment means on upper/lower plates bend- processing an elastic plate into a nearly U shape. CONSTITUTION: When through holes 16a, 16b of an attaching piece 16 of a head bracket 11 attaching the magnetic head 14 are inserted into a main shaft 19 of a chassis 25, a bent tongue 17 is touched elastically to the upper surface of the chassis 25, and the bent tongue piece 15 comes into contact with a projection 18 to be positioned temporarily. Then, an adjusting screw 23 with a flange is screwed temporarily into the screw part 19a of the main shaft 19, and the adjusting screws 21, 22 are screwed temporarily into the through holes 12a, 12b. Further, when a nut 24 is screwed into a screw shaft 20, the outer peripheral part of the head 14 comes into contact with the bent tongue piece 18. Then, when the lower plate 13 is fixed in three points, the upper plate 12 is inclined freely, and the magnetic head is slope-adjusted. Thus, the head is adjusted easily by a single bracket without using a spring coil, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position / posture adjusting mechanism for a fixed magnetic head in a magnetic recording / reproducing apparatus such as a video tape recorder (VTR).

[0002]

2. Description of the Related Art As an adjusting mechanism for a fixed magnetic head of this type, for example, Japanese Patent Laid-Open Publication No. 4-69810 (G.
11B 5/56). In the relevant publication, FIG.
As shown in FIG. 3, a bracket 3 integrally formed with a base lower plate 1 and an upper base plate 2 via an elastic connecting portion 1 a, a magnetic head 4 mounted on the base upper plate 2 of the bracket 3, and a magnetic head. The tilt adjusting screw 5 and the magnetic head tilt adjusting screw 6 are provided, and the adjusting screws 5 and 6 are provided between the base lower plate 1 and the base upper plate 2. Reference numeral 7 is a mounting piece for mounting the magnetic head assembly component 8 on a chassis (not shown) and for adjusting the height of the magnetic head (although only the drawings do not explain the components in the publication). is there. In addition, T shows a magnetic tape (tape).

[0003]

In the above structure, the inclination adjustment of the magnetic head with respect to the tape running direction 9 and the contact of the magnetic head with respect to the tape surface, that is, the tilt adjustment can be performed with the screws 5 and 6, respectively. When attaching the head assembly component 8 to the chassis, a spring member such as a spring coil is required between the chassis and the base lower plate 1, and additional attachment means other than the attachment piece 7 is required for the chassis. is there. Also, the mechanism of the VTR is troublesome because it requires adjustment of the distance X from the point where the rotary magnetic head separates from the tape to the fixed magnetic head. Therefore, the present proposal proposes an adjusting mechanism for a fixed magnetic head, which uses as few parts as possible without using a spring coil or the like.

[0004]

Therefore, in the present invention, an elastic plate is bent into a substantially U-shape to form an upper plate and a lower plate, and a magnetic head is mounted on the upper plate. The lower plate has a first bent tongue piece on one side surface of the magnetic head, a mounting piece having a U-shape bent on the rear side of the magnetic head and having a through hole on the opposite surface, and a second bent piece. A bracket integrally formed with a tongue, and a first
A magnetic head position adjusting means (tilt and tilt adjusting screws) is provided on the upper and lower plates, and the upper and lower plates are constituted by a projection that comes into contact with the bent tongue and a chassis having a main shaft that is inserted into the through hole.

Further, the second bent tongue piece is formed in a curved downward shape on both sides of the mounting piece. Further, a third bent tongue piece is formed on the other side surface of the magnetic head on the lower plate, and a screw shaft on which a nut having an elliptical cross-section is screwed to the chassis so as to face the third bent tongue piece. Is provided.

[0006]

With the above structure, when the mounting piece of the bracket on which the magnetic head is mounted is inserted into the main shaft of the chassis, the first
The bent tongue contacts the protrusion of the chassis, and the second bent tongue elastically contacts the upper surface of the chassis. Furthermore, the third bent tongue contacts the elliptical nut, and the position of the bracket is regulated. Therefore, the height of the magnetic head is adjusted by adjusting the screw screwed to the main shaft, the tilt and tilt of the magnetic head are adjusted by the two adjusting screws on the bracket, and the X distance is adjusted by the elliptical nut. Be seen.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the present invention will be described below with reference to the drawings. 1 is an exploded perspective view, FIG. 2 is an assembled external perspective view, FIG. 3 is a plan view, FIG. 4 is a front view, and FIG. 5 is a side partial sectional view.

In the figure, 11 is a head bracket composed of an upper plate 12 and a lower plate 13 formed by pressing a strong elastic thin plate, for example, a phosphor bronze plate into a U-shape, and the upper plate 12 of the bracket 11 is Through holes 12a and 12b are provided, and the magnetic head 14 for audio control is attached by welding or screwing. On the lower plate 13, a first bent tongue piece 15 for adjusting the X distance is provided on one side surface of the magnetic head 14, and a mounting piece 16 is formed in a U shape on the rear surface side of the magnetic head 14. The second bent tongues 17 and 17 curved downward on both sides of the mounting piece 16 and the third bent tongue 18 on the other side surface side of the magnetic head 14 (in FIG. It is bent into a shape) is integrally provided. The mounting piece 16 has through-holes 16 which are burred outwardly on the upper and lower facing surfaces of the U-shaped bent portion.
a, 16b are provided, and the lower plate 12 has through holes 12a, 12a.
Through holes 13a and 13b, which are burred downward and tapped, are provided at positions facing b.

Reference numeral 25 is a mechanism chassis (or it may be a sub-chassis mounted on the mechanism chassis). The chassis 25 includes a projection 26 that abuts the first bent tongue piece 15 and a mounting piece 16. Curling through hole 16a,
A male screw shaft 20 is fixedly planted at a position facing the main shaft 19 inserted through 16b and the third bent tongue piece 18. Spindle 1
The upper part of 9 is provided with a female screw portion 19a. 21 is an azimuth adjusting screw, 22 is a tilt adjusting screw, and 23 is a collar portion 2.
3a is a head height adjusting screw for attaching the head bracket 11 having 3a. Reference numeral 24 denotes a nut having an outer shape of an elliptic cylinder.

Next, the assembling method of the present invention will be described.
The through holes 16a and 16b of the mounting piece 16 of the head bracket 11 to which the magnetic head 14 is attached are fitted to the spindle 1 of the chassis 25.
When the second bent tongue pieces 17 and 17 are inserted into the upper part of the chassis 25, the curved second bent tongue pieces 17 and 17 are elastically contacted with the upper surface of the chassis 25, and the first bent tongue piece 15 is brought into contact with the protrusion 18 for temporary positioning. The adjusting screw 23 with a collar is screwed and temporarily fixed to the screw portion 19a of the main shaft 19.
The adjusting screws 21 and 22 are screwed and temporarily fixed to the through holes 12a and 12b. Further, when the nut 24 is screwed onto the screw shaft 20, the outer peripheral portion of the nut 24 comes into contact with the third bent tongue piece 18. That is, the state shown in FIG. 2 or 3 is obtained.

As shown in FIG.
When fixed at the points, the upper plate 12 can be freely tilted, so the tilt of the magnetic head is adjusted. Further, by twisting the upper plate 12, the magnetic head 1
4. Adjust the tilt. Further, for the X distance adjustment, the elasticity of the head bracket 11 is used to utilize the above-described first and second bent tongue pieces 15 and 18 as leaf springs, and the chassis 2
5 is pressed against the projection 26 and the nut 24 to make a slight distance adjustment. The height of the magnetic head 14 can also be adjusted by attaching the second bent tongue piece 17 which is bent downward to the chassis 25 while pressing the second bent tongue piece 17 against the head bracket 11 due to a reaction. Becomes

Since the head bracket 11 temporarily fixed as shown in FIG. 4 is in a state of being pressed against the protrusion 26, it tries to rotate counterclockwise about the main shaft 19 in FIG. The bent tongue piece 18 is restricted by the elliptical nut 24. Therefore, the X distance of the magnetic head 14 is adjusted by rotating the elliptical nut 24. Next, to adjust the height of the magnetic head 14, the adjustment screw 23 may be rotated. As shown in FIG. 5, the height L of the main shaft 19 is
The height of the tip of the burring through hole 16a of the head bracket 11 is lower than the lower limit value of the design movable range of the mounting piece 16.
Since it is set lower by about 0.5 mm, the gap 11 is secured. Therefore, by rotating the adjusting screw 17, the head bracket 11 moves up and down, and the height of the magnetic head 14 can be adjusted.

Further, azimuth adjustment and tilt adjustment will be described. When preparing the head bracket 11 alone, as shown in FIGS. 6A and 6B, the upper plate 12 has θ.
The slopes of 1 and θ2 are provided first. This tilt angle is
Depending on the verticality of the main shaft 19 and the accuracy of the head bracket 11, it is set to about 10 to 15 °. By doing so, in the present proposal using only the elasticity of the head bracket 11, the azimuth adjustment and the tilt adjustment can be performed only by rotating the adjustment screw 21 and the adjustment screw 22 clockwise and tightening them. Since the elasticity of the head bracket 11 is used during the adjustment and tilt adjustment, the actual deflection of the head bracket 11 is a quadratic curve of y = aX2 + bX + c, but since it is used in the elastic range, the actual adjustment is performed. Then there is no problem. In addition, a, b, and c are constants.

The position of the azimuth adjusting screw 21 is
As shown in FIG. 3, it is desirable to place the head bracket 11 on a straight line 27 that passes through the gap center of the magnetic head 11 at right angles to the vertical portion of the U-shaped bend. Further, the tilt adjusting screw 22 is also preferably placed on a straight line 28 passing through the gap center of the main shaft 19 and the magnetic head 14.

[0015]

With the above structure, three-point adjustment of a fixed magnetic head in a magnetic recording / reproducing apparatus such as a VTR, that is, head height, azimuth, and tilt adjustment is performed by processing one strong elastic plate. With a single bracket, this is easily possible, and there is the effect of reducing the adjustment man-hours and the number of parts, thus reducing costs.

[Brief description of drawings]

FIG. 1 is an exploded perspective view.

FIG. 2 is an external perspective view of assembly.

FIG. 3 is a plan view.

FIG. 4 is a front view.

FIG. 5 is a side partial sectional view.

FIG. 6 is a front view and a side view of a head bracket.

FIG. 7 is an external perspective view of a conventional example.

[Explanation of symbols]

 11 bracket 12 upper plate 13 lower plate 14 magnetic head 15 first bent tongue 16 mounting piece 17 second bent tongue 19 main shaft 25 chassis 26 protrusion

Claims (4)

[Claims] 1. An elastic plate is bent into a substantially U-shape to form an upper plate and a lower plate, and a magnetic head is mounted on the upper plate, and the magnetic head of the lower plate is mounted. A first bent tongue piece is integrally formed on one side surface of the magnetic head, a mounting piece having a through hole on the opposite surface formed in a U-shape on the rear side of the magnetic head, and a second bent tongue piece. And a chassis having a protrusion that abuts the first bent tongue and a main shaft that is inserted into the through hole, and the magnetic head position adjusting means is provided on the upper plate and the lower plate. A magnetic head adjusting mechanism characterized by being provided with. 2. The magnetic head position adjusting means includes a through hole formed in the upper plate, a female screw portion formed in the lower plate facing the through hole by burring, the through hole, and 2. The magnetic head adjusting mechanism according to claim 1, wherein the adjusting screw is an adjusting screw screwed into the female screw portion. 3. The magnetic head adjusting mechanism according to claim 1, wherein the second bent tongue piece is formed in a curved downward shape on both sides of the mounting piece. 4. A third bent tongue piece is formed on the other side surface of the magnetic head on the lower plate, and an oval nut having a cross section is formed on the chassis so as to face the third bent tongue piece. 4. A screw shaft to be screwed is provided, wherein the screw shaft is provided.
Magnetic head adjustment mechanism.