JPH05242439A - Rotary drum device - Google Patents

Abstract

PURPOSE:To effective evade the change of a cylindrical degree due to an impact in various directions by forming integrally a first drum abutting surface holding an upper and a lower drums with a circular arc having a radius according to the upper and the lower drums and a second drum abutting surface holding a plane parallel to an upper and a lower end surfaces with a notched part formed on the upper and the lower drums. CONSTITUTION:This rotary drum device is constituted so that a magnetic head 17 is loaded on an intermediate drum 16 provided between the upper and the lower drums 11, 12 and helical-scans a magnetic tape wound around both drums 11, 12. A drum supporter 13 holding both drums 11, 12 is provided with the first drum abutting surface 13A being in contact with and holding both drums 11, 12 by the circular arc surface having a radius according to both drums 11, 12. Then, the second drum abutting surface 13B being in contact with and holding the plane nearly parallel to the upper and the lower end surface by the upper or the lower end surface of both drums 11, 12 or the notched part formed on both drums 11, 12 and the first drum abutting surface 13A are formed integrally.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a rotary drum device,
In particular, it can be applied to a rotary drum device having an upper drum fixing structure.

[0002]

2. Description of the Related Art Conventionally, in a rotary drum device having a so-called upper drum fixing structure in which an upper drum is fixed to a lower drum, a magnetic head is mounted on an intermediate drum arranged between the upper drum and the lower drum. There is. Then, by rotating the middle drum, the magnetic tapes obliquely wound around the peripheral surfaces of the upper and lower drums are helically scanned so that desired video signals and audio signals can be recorded and reproduced.

That is, as shown in FIGS. 6 and 7, a rotary drum device 1 having an upper drum fixing structure has a structure upper drum support 4 for fixing the upper and lower drums 2 and 3. An arc surface having the same curvature as the outer diameter of the drum is formed on the drum contact surface 4A of the drum support 4. By combining the outer diameters of the upper and lower drums 2 and 3 with this arc surface, Also, the peripheral side surfaces of the lower drums 2 and 3 are received by a wide area of the drum contact surface 4A, and the bolt 5
The upper drum 2 is fixed to the lower drum 3 by being fastened with each other.

[0004]

In the case of the rotary drum device 1 having such a structure, however, the drum support 4 receives the upper and lower drums 2 and 3 only by the drum abutting surfaces which are arcuate surfaces. When an impact is applied to the rotary drum device 1 from the lateral direction or each direction as indicated by the arrow a, there is a problem that the holding force falls in a weak direction and the cylindricity changes. As a practical matter, there is a risk that the product may become defective due to the shock during transportation.

Further, in the rotary drum device 1, since the magnetic tape is helically scanned, the upper drum 2 and the lower drum 3 must be attached as a cylindricity having a predetermined offset. As a work for adjusting the cylindricity, for example, a spacer is inserted between the lower drum 3 and the drum support 4, but for this reason, the drum support 4 must be removed from the lower drum 3, which is a troublesome task.

The present invention has been made in consideration of the above points, and it is possible to effectively avoid a change in cylindricity due to an impact from each direction with a simple structure and to easily adjust the cylindricity. Is to be proposed.

[0007]

In order to solve such a problem, in the first invention, the upper drum 11 and the lower drum 1
A rotary drum device 1 in which a magnetic head 17 is mounted on a middle drum 16 disposed between two, and a magnetic tape wound around the peripheral side surfaces of the upper and lower drums 11 and 12 is helically scanned.
At 0, the drum support 13 that holds the upper and lower drums 11 and 12 has a first arc that holds the upper and lower drums 11 and 12 in contact with the upper and lower drums 11 and 12 with an arc surface having a radius corresponding to the upper and lower drums 11 and 12. The drum contact surface 13A and the upper or lower drum 11 or 12 upper or lower end surface, or the notch 12A formed in the upper or lower drum 11 or 12 is held in contact with a plane substantially parallel to the upper or lower end surface. The second drum contact surface 13C is formed integrally.

Further, in the second invention, the drum support 13
In addition to the first drum contact surface 13A and the second drum contact surface 13C, the lower or upper drum 12 or 11 lower or upper end surface not in contact with the second drum contact surface 13C, Alternatively, a notch formed in the lower or upper drum 12 or 11 is provided with a third drum contact surface 30A that holds the lower or upper end surface in contact with a substantially parallel plane.

[0009]

A first drum contact surface 13A for contacting and holding the upper and lower drums 11 and 12 with an arcuate surface having a radius corresponding to the upper and lower drums 11 and 12, and the upper or lower drum 1
1 or 12 upper or lower end surface, or upper or lower drum 1
Since the notch 12A formed in 1 or 12 is integrally molded with the second drum contact surface 13C that holds the upper or lower end surface in contact with a plane substantially parallel to the upper or lower end surface, The change in cylindricity due to impact can be effectively avoided, and the cylindricity can be easily adjusted on the second drum contact surface 13C side.

Further, the first drum contact surface 13A and the second drum contact surface 13A
Of the lower or upper drum 12 or 11 not in contact with the second drum contact surface 13C of the second drum contact surface 13C.
Lower or upper end surface, or lower or upper drum 12 or 11
By providing the third drum contact surface 30A which is held in contact with the lower or upper end surface in a plane substantially parallel to the lower or upper end surface by the notch formed in the above, it is possible to further effectively change the cylindricity due to the impact from each direction. It can be avoided.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.

(1) Overall Configuration of Rotating Drum Device In FIG. 3, reference numeral 10 generally indicates the overall configuration of a rotating drum device to which the present invention is applied, in which an upper drum 11 and a lower drum 12 are fixed by a drum support 13. It has an upper drum fixing structure. Upper and lower drums 11 and 1
Reference numerals 2 are cylindrical shapes each having the same outer diameter, are formed with a predetermined space inside, and are fastened with a bolt or the like through a drum support 13 so as to have a predetermined gap in the vertical direction.

Inside the upper and lower drums 11 and 12, there is disposed a middle drum 16 which is driven by a motor 15 communicating with a drum shaft 14 to rotate, and a magnetic head 17 is mounted on the middle drum 16. There is. The magnetic head 17 has its tip slightly protruding from the gap between the upper and lower drums 11 and 12, and the rotation of the motor 15 causes the middle drum 16 to rotate.
A magnetic tape (not shown) wound obliquely around the peripheral side surfaces of Nos. 12 and 12 is helically scanned so that desired video signals and audio signals can be recorded and reproduced.

The drum shaft 14 has a cylindrical bearing portion formed inside the lower drum 12 and a housing of a motor 15 disposed below the lower drum 12, which has bearings 1 respectively.
It is rotatably attached via 8. Further, the middle drum 16 is attached to the drum shaft 14 via a flange 20 in which, for example, rotary transformers 19A and 19B for 8 channels are integrally arranged at the top and bottom. Further, stator assembly portions 21A and 21B of the rotary transformer are arranged so as to face the rotary transformers 19A and 19B.

An amplifier circuit and the like are arranged on the upper portion of the middle drum 16, and an amplifier board 22 that rotates together with the middle drum 16 is attached. With this, a reproduction signal obtained from the magnetic head 17 is amplified, and the rotary transformers 19A and 19A, respectively.
9B and the stator assembling parts 21A and 21B are sent to an external signal processing circuit, and conversely, the recording signals inputted from the external signal processing circuit through the stator assembling parts 21A and 21B and the rotary transformers 19A and 19B, respectively. The signal is amplified and supplied to the magnetic head 17.

Further, in this rotary drum device 10,
A slip ring 23 is arranged below the motor 15, whereby a bimorph consisting of a piezoelectric element is used as the magnetic head 17, and the drum shaft 1 of the magnetic head 17 is used.
The control voltage in the case of using the DT head for variably controlling the height in four directions can be supplied from the outside.

(2) Rotating Drum Device of the Embodiment Here, in the case of the rotating drum device 10 of this embodiment, as shown in FIGS. 1 and 2 in which parts corresponding to those in FIG. Is contacted with the upper and lower drums 11 and 12 by an arc-shaped first drum contact surface 13A having a radius corresponding to the cylindrical shape of the upper and lower drums 11 and 12, and is fastened with a bolt. ..

In addition to this, a collar portion 13B is integrally formed on the lower portion of the drum support 13, and this collar portion 13 is formed.
B is inserted into the notch 12A formed at the lower end of the lower drum 12 to be attached, and is brought into contact with the lower drum 12 from below by the second drum contact surface 13C which is a flat surface formed on the flange 13B, and is fastened with a bolt. It is designed to do.

In the case of this rotary drum device 1, the cylindricity of the upper and lower drums 11 and 12 is adjusted when the lower drum 12 is attached to the flange portion 13B of the drum support 13. Therefore, compared with the conventional cylindricity adjustment work using spacers, the work of removing the drum support 13 from the upper and lower drums 11 and 12 each time adjustment is not necessary, and the adjustment process can be simplified accordingly.

In this way, the upper and lower drums 11 and 12 fixed to the drum support 13 can withstand the impact from each direction, and the change in the cylindricity can be prevented accordingly. It is possible to improve the quality as a result.

According to the above construction, the flange portion 13B is provided on the drum support 13 and is held in contact with the upper and lower drums 11 and 12 by the arcuate surface having the radius corresponding to the upper and lower drums 11 and 12. Since the first drum abutting surface 13A and the second drum abutting surface 13C that contacts and holds the notch 12A formed in the lower drum 12 are integrally molded, the impact from each direction is generated. It is possible to realize a rotary drum device that can effectively avoid a change in cylindricity and easily adjust the cylindricity.

(3) Other Embodiments (3-1) In the above embodiment, the case where the drum support 13 is provided with the flange portion 13B to hold the upper and lower drums 11 and 12 has been described. In addition, as shown in FIGS. 4 and 5, the upper surface of the drum support 13 and the upper drum 1
A drum supporting member 30 may be used, which is in contact with and held by the upper end surface of the drum 1 by a flat drum contact surface 30A.

By doing so, also in the upper drum 11, the drum contact surface 1 formed by the arcuate surface of the drum support 13 is formed.
In addition to 3A, the drum contact surface 30A, which is a flat surface of the drum support member 30, makes contact and is fastened, so that a change in cylindricity due to an impact from each direction can be more effectively avoided.

(3-2) In the above-described embodiment, the case where the collar portion is integrally formed in the lower portion of the drum support and the collar portion is inserted into the notch portion formed in the lower drum to be mounted is described. Alternatively, the same effect as that of the above-described embodiment can be realized by integrally forming the flange portion on the drum support and forming the cutout portion on the upper drum, and inserting the flange portion into the cutout portion. it can. Further, in this case, if the drum supporting member 30 described above with reference to FIGS. 4 and 5 is brought into contact with the lower drum 12, the same effect as described above can be realized.

(3-3) In the above embodiment, the case where the drum support is integrally formed with the collar portion and the collar portion is inserted into the notch portion formed in the upper or lower drum to be mounted, is described. Alternatively, the collar portion may be attached to the upper or lower end surface of the upper or lower drum.

[0026]

As described above, according to the present invention, the first drum contact surface for contacting and holding the upper and lower drums with the circular arc surface having the radius corresponding to the upper and lower drums, and the upper or lower drum contact surface. The upper or lower end surface of the drum, or the notch formed in the upper or lower drum is integrally formed with the second drum contact surface that holds the upper or lower end surface in contact with a plane substantially parallel to the upper or lower end surface. As a result, it is possible to realize a rotary drum device that can effectively avoid a change in cylindricity due to an impact from each direction and that can easily adjust the cylindricity on the second drum contact surface side.

Further, in addition to the first and second drum abutting surfaces, the lower or upper surface of the lower or upper drum which is not in contact with the second drum abutting surface, or the lower or upper drum. By providing a third drum contact surface that holds in contact with a substantially parallel plane on the lower or upper end surface at the notch formed in the drum, it is possible to more effectively change the cylindricity due to impact from each direction. A rotatable drum device that can be avoided can be realized.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a rotary drum device according to the present invention.

FIG. 2 is a schematic perspective view showing a drum support of the rotary drum device of FIG.

FIG. 3 is a side view showing an overall configuration of a rotary drum device to which the present invention is applied, with a partial cross section.

FIG. 4 is a schematic perspective view showing another embodiment of the rotary drum device according to the present invention.

5 is a schematic perspective view showing a drum support and a drum support member of the rotary drum device of FIG.

FIG. 6 is a schematic perspective view showing a conventional rotary drum device.

FIG. 7 is a schematic side view of the rotary drum device of FIG.

[Explanation of symbols]

1, 10 ... rotating drum device, 2, 11 ... upper drum,
3, 12 ... Lower drum, 12A ... Notch, 4, 13 ...
... Drum support 4A, 13A, 30A ... Drum contact surface, 14 ... Drum shaft, 15 ... Motor, 16 ... Middle drum, 17 ... Magnetic head, 18 ... Bearing, 19
A, 19B ... Rotary transformer, 20 ... Flange, 21
A, 21B ... Rotor transformer stator assembly 22 ...
… Amplifier board, 23 …… Bolt, 30 …… Drum support member.

Claims (2)

[Claims] 1. A rotary drum device in which a magnetic head is mounted on a middle drum disposed between an upper drum and a lower drum, and a magnetic tape wound around the peripheral side surfaces of the upper and lower drums is helically scanned. And a drum support for holding the lower drum, a first drum contact surface for contacting and holding the upper and lower drums with an arc surface having a radius corresponding to the upper and lower drums, and The upper or lower end surface, or a notch formed in the upper or lower drum is integrally formed with a second drum contact surface that holds in contact with a plane substantially parallel to the upper or lower end surface. A rotary drum device characterized in that 2. The drum support includes, in addition to the first drum contact surface and the second drum contact surface, the lower or upper drum that is not in contact with the second drum contact surface. A lower or upper end surface, or a third drum abutting surface for holding in contact with a plane substantially parallel to the lower or upper end surface by a notch formed in the lower or upper drum. The rotary drum device according to Item 1.