JPH0416282Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to a spiral-wound magnetic recording and reproducing device that uses a mainspring as a driving source to drive a magnetic disk and a magnetic head.

(Background of the invention) A magnetic disk is rotated by the release elasticity of a tightly wound mainspring, and a magnetic head in contact with the disk is moved in the radial direction of the disk in conjunction with the rotation of the magnetic disk, thereby recording and playing. If this is done, it is desirable that the rotational speed of the magnetic disk is always constant during the recording/playback operation. A speed governor that operates in conjunction with the drive shaft of the magnetic disk is effective in stabilizing the rotation of the magnetic disk. This speed governor includes a worm that can be rotated at high speed by the release elasticity of a mainspring, and a rotating body provided on the worm.

The magnetic disk driving force is transmitted to the worm constituting the speed governor only when the magnetic disk is rotationally driven by the mainspring, and when the mainspring is wound, the winding force of the mainspring is not transmitted to the worm. If you do not do this, you will not be able to quickly and lightly tighten the mainspring. This connection of rotational motion transmission to the worm is
This can be done by a connecting means using a ratchet mechanism consisting of a row of serrated protrusions that transmit rotation of the magnetic disk drive shaft in only one direction to the worm gear, and an engaging pawl that engages and disengages from the serrated protrusions. In the case of this connecting means, a phase difference occurs between the rotating body having the protrusion row and the rotating body having the engagement claw each time the connecting member is connected. On the other hand, when using a mainspring as a drive source, it is difficult to obtain appropriate stability in the rotation of the magnetic disk even if a speed governor is used, but under the same conditions as the rotation of the magnetic disk during recording. If the magnetic disk is rotated during playback, it should be possible to always keep the rotation of the magnetic disk under the same conditions during recording and playback.
The purpose is to keep the meshing position between the rotation transmission gears including the worm unchanged during recording and playback, but when using the above-mentioned connecting means,
Since a phase difference occurs, there is a problem that the meshing position between the rotation transmission gears changes between recording and playback.

(Purpose of the invention) The object of the invention is to solve the above-mentioned problems and provide a magnetic recording and reproducing apparatus in which a magnetic disk and a magnetic head are driven under the same conditions during recording and reproduction.

(Means for solving the problem) A rotation transmission gear that drives a worm constituting a speed governor has one engaging pawl, and the engaging pawl engages only when the magnetic disk is driven by a mainspring. A one-way rotation transmission mechanism including one engaged portion that is integrated with the engaging claw is provided.

(Operation and Effect) According to this invention, the speed governor is actuated via a one-way rotation transmission mechanism having a connecting function and consisting of one engaging pawl and one engaged portion that engages and disengages from the engaging pawl. Therefore, the meshing position of the rotation transmission system during recording and playback, especially the meshing position between the worm and the worm gear, remains unchanged, and the rotation conditions of the magnetic disk during recording and playback are the same, resulting in good playback. It will be done.

(Embodiment) A magnetic head drive gear 2, a magnetic disk drive gear 3, and a mainspring winding pulley 4 are fixed to a mainspring shaft to which the inner end of the mainspring 1 is fixed. The outer end 1a of the mainspring 1 is fixed to an immovable member of the device, and by pulling the knob 6 of the string 5 wound around the pulley 4, the pulley 4 is moved in the direction indicated by the arrow A.
The mainspring 1 can be wound tightly by rotating it in the direction shown in FIG.

A rack 8 formed on an arm 7a integrally extending from the magnetic head support 7 is meshed with the gear 2. The magnetic head support 7 is provided with a recording/reproducing head 10 and an erasing head 11 (hereinafter referred to as "magnetic heads") that contact the magnetic surface formed on the back surface of the magnetic disk 9. The magnetic head support 7 is appropriately guided by a guide member so that the magnetic head moves approximately in the radial direction of the magnetic disk 9.

The magnetic disk 9 has its center portion engaged with one end of the magnetic disk drive shaft 12 and rotates integrally with the drive shaft 12.

A gear 14 that drives a speed governor 13 and a gear 15 that meshes with the magnetic disk drive gear 3 are fixed to the magnetic disk drive shaft 12 . Gear 14
A small gear 16 of a rotation transmission gear 18 consisting of a small gear 16 and a worm gear 17 is engaged with the
The worm gear 17 has a regulating rotating body 19 at one end.
The worms 20 are engaged with each other.

Now, when the string 5 is pulled to tighten the mainspring 1 and the knob 6 is released, the magnetic disk 9 is fixed by the gear 3 due to the release elasticity of the mainspring, and the magnetic heads 10 and 11 are Recording or reproduction is performed by moving from the outer periphery of the magnetic disk 9 toward the center.

The above-mentioned recording/playback device is incorporated into a case and used in toys, etc., but the details of the configuration of this device are disclosed in Japanese Patent Application No. 59-128958 (Japanese Unexamined Patent Publication No. 59-128958).
No.).

As shown in FIGS. 2 to 4, the rotation transmission gear 18 has a structure in which a small gear 16 is rotatably fitted onto the shaft 17a of the worm gear 17.
At the base of the pinion 16, an elastic arm 16a having a length extending approximately half the circumference is integrally formed with the pinion 16, and this arm 16a is inserted into a recess 21 provided in the worm gear 17. It is stored. An engaging pawl 16b is provided at the free end of the arm 16a, and an engaged portion 22 that engages with and disengages from the engaging pawl 16b is provided on a portion of the inner peripheral wall of the recess 21 of the worm gear 17.

The pinion 16 rotates clockwise in FIG. 3 when the magnetic disk is driven by the mainspring, that is, when recording or playback is performed, and rotates in the opposite direction when the mainspring is wound. Rotate. The engagement claw 16b is connected to the small gear 16.
When rotating clockwise in FIG. 3, that is, during recording or reproduction, the worm 20 engages with the engaged portion 22 and pushes the worm gear 17 in the same direction, causing the worm 20 to rotate at high speed. When the small gear 16 rotates counterclockwise in FIG. 3, that is, when the mainspring is wound up, the engagement claw 1
6b has its back surface 16c pushed inward by the slope 21a of the inner circumferential wall of the recess 21 and idles relative to the worm gear 17, and the rotation of the pinion 16 is as follows:
There is no transmission to the worm gear 17 and therefore to the worm 20.

The small gear 16 and the worm gear 17 are connected to transmit rotation through one engaging pawl and one engaged part, so that the engaging pawl does not engage with the engaged part. Accordingly, the worm gear 1 is rotated by the pinion 16.
The phases of both gears when gear 7 is driven are always constant. In addition, since the meshing position between the worm gear 17 and the worm 20 remains unchanged, even if the rotation transmission to the speed governor by the mainspring is cut off during the winding process of the mainspring, the magnetic disk driven by the mainspring will not be able to record. , always rotates under the same conditions regardless of playback.

Therefore, even if there is unevenness in the rotation speed of the magnetic disk caused by the mainspring, this rotational unevenness will be the same during recording and playback, and there will be good wow and flutter during recording and playback. , the reproduction is close to the real sound.

As shown in FIG. 5, the gear 14 and the worm 20
When two stages of speed-increasing rotation transmission gears 28 and 38 are provided between the two stages, one of them is provided with a one-way rotation transmission mechanism consisting of one engaging pawl and one engaged part. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a magnetic recording device showing an embodiment of the present invention, FIG. 2 is a side view showing only the rotation transmission gear, and FIG. 3 is a sectional view taken along line A-A in FIG.
4 is a longitudinal sectional view of FIG. 2, and FIG. 5 is a perspective view showing the rotation transmission gear train. 1... Spring, 9... Magnetic disk, 10,
DESCRIPTION OF SYMBOLS 11... Magnetic head, 12... Magnetic disk drive shaft, 16b... Engaging claw, 18, 28, 38... Rotation transmission gear, 19... Speed governing rotating body, 20... Worm, 22... Target Engagement part.

Claims (1)

[Scope of utility model registration request] A magnetic disk drive shaft that rotationally drives a magnetic disk, a mainspring that drives this drive shaft, and a magnetic head drive device that moves a magnetic head in a direction in which the diameter of the magnetic disk changes in conjunction with the magnetic disk drive shaft. , a speed governor including a rotation transmission gear that interlocks a worm having a speed governing rotary body and the magnetic disk drive shaft, one engaging pawl, and the magnetic disk drive shaft driven by the mainspring. The rotation transmitting gear is provided with a one-way rotation transmission mechanism comprising an engaged portion that engages the engaging pawl and integrates the engaging pawl in the rotational direction only when the engaging pawl is rotated. Features a magnetic recording and playback device.