JPH0348771Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic disk device generally called a floppy disk drive device, and more specifically, the present invention relates to a magnetic disk device that is generally called a floppy disk drive device, and more specifically, a magnetic disk device that uses both main surfaces of a flexible magnetic disk. The present invention relates to a magnetic head support mechanism for recording or reproducing signals.

[Conventional technology]

In a double-sided magnetic disk device, one magnetic head is attached to a carriage, the other magnetic head is attached to an arm, the arm is rotatably attached to the carriage with a hinge leaf spring, and the other magnetic head is attached to the disk. A configuration in which a biasing force in the contact direction is applied to the arm by a torsion spring is known.

In the above-mentioned apparatus, when the disk is rotated, the arm supporting the magnetic head resonates due to friction between the head and the disk, causing a problem such as noise and accelerated wear of the disk.
In order to solve the above-mentioned problems, it was proposed in 1983 that a rigid body be placed above the arm via an elastic body.
It is disclosed in the specification and drawings of No. 42263 (Utility Model Application Publication No. 58-144660).

[Problem that the invention attempts to solve]

By the way, the above-mentioned Utility Application No. 57-42263 (Utility Application No. 1983)
No. 144660) The specification does not disclose a structure for making the magnetic disk device thinner. That is, in the embodiment of the above application, an elastic body is disposed between the shield plate of the magnetic head and the arm. Since the shield plate is mounted near the tip of the arm, if an elastic body is placed below it, the upper surface of the shield plate will inevitably be raised higher, making it difficult to make the magnetic disk device thinner.

In addition, in conventional magnetic disk drives, in order to stably obtain contact pressure between the other magnetic head and the disk using the torsion spring, the torsion spring is used to press a position on the arm as close to the other magnetic head as possible. It is desirable to place one end.
However, the shaft that supports the torsion spring is inevitably located near the hinge plate spring that supports the arm, so if you try to press the vicinity of the other magnetic head, it is necessary to increase the length of one end of the torsion spring. This causes one end of the torsion spring to easily deform. As a result, the required biasing force may not be obtained, or one end of the torsion spring may come into contact with the lead wire led out from the magnetic head.

Therefore, the purpose of the present invention is to reduce the thickness of the device and obtain a stable biasing force even if one end of the torsion spring is relatively short, even though it has a resonance prevention function for the arm that supports the magnetic head. The object of the present invention is to provide a magnetic disk device that can perform the following functions.

[Means for solving problems]

To achieve the above-mentioned objects, the present invention is a device for converting signals using both main surfaces of a flexible magnetic disk. first contact
a magnetic head; a carriage supporting the first magnetic head; a second magnetic head disposed opposite to the first magnetic head and in contact with the other main surface of the disk; a first arm supporting the head near its tip;
a hinge plate spring having one end fixed to the first arm and the other end fixed to the carriage for rotatably supporting the arm; and a hinge plate spring extending parallel to the first arm. It has a central portion that covers at least a portion of the first arm, a tip portion that presses the first arm, and a support portion that is rotatably supported by the carriage, and the tip portion covers the first arm. the second in the first arm;
a second arm that is located closer to the leaf spring than the attachment portion of the magnetic head and has rigidity, and between the tip portion of the second arm and the first arm; an elastic body disposed therein; a shaft supported by the carriage and disposed near a portion of the leaf spring fixed to the carriage; and an elastic body wound around the shaft in the same direction as the first and second arms. The central portion of the second arm is pressed at or near the tip of the one end to apply a biasing force in the direction in which the second magnetic head contacts the disk. The present invention relates to a magnetic disk device characterized in that it includes a torsion spring applied to the first arm via an arm, and a mechanism for moving the carriage in the radial direction of the disk.

[Effect]

In the above invention, since the elastic body is disposed between the second arm and the first arm, it is not necessary to specifically dispose a rigid body on top of the elastic body to prevent resonance. The above-mentioned Utility Application No. 57-42263
144660) also uses a shield plate as a rigid body, so there is almost no difference from the present invention in terms of the cost for preventing resonance. However, with the device disclosed in the above-mentioned application, it is difficult to make the magnetic disk device thinner. On the other hand, in the present application, since the elastic body is inserted under the second arm which is formed so as not to cover the attachment part of the second magnetic head of the first arm, the height of the head support arm portion is reduced. The increase can be suppressed.

Further, in the device of the present invention, when the second arm is pressed by a torsion spring, the first arm is pressed via the second arm. Since the second arm has high rigidity, it does not substantially bend even if its tip extends along the first arm to the vicinity of the second magnetic head. Therefore, the force of the torsion spring is stably transmitted to the first arm. Furthermore, since the second arm is rotatably supported, the force of the torsion spring can be transmitted to the first arm with little loss. In the end, there is no problem even if the length of one end of the torsion spring is shortened, and the problem of bending of the one end of the torsion spring is reduced. As a result, sufficient biasing force can be stably obtained.

〔Example〕

Next, a magnetic disk device for recording or reproducing data using a flexible magnetic disk cartridge (floppy disk) according to an embodiment of the present invention shown in FIGS. 1 to 5 will be described.

In this magnetic disk device, a flexible magnetic disk 1 is rotated by a rotation mechanism 2, a first magnetic head 3 is brought into sliding contact with the lower surface of the disk 1, and a second magnetic head 4 is brought into sliding contact with the upper surface of the disk 1, thereby transmitting a signal. The device is configured to record or play back. The first magnetic head 3 is attached to a carriage 6 via a gimbal spring plate 5. The second magnetic head 4 has a gimbal spring plate 7
It is attached to the vicinity of the tip of the first arm 8 made of synthetic resin via. The first and second magnetic heads 3 and 4 have mirror-finished gap surfaces.

As is clear from FIG. 4, one end of a leaf spring 9 for obtaining a hinge function is fixed to the first arm 8, and the other end of this leaf spring 9 is fixed to the protrusion 6a of the carriage 6 with a screw 10. Therefore, the first arm 8 can rotate or swing freely using the leaf spring 9 as a hinge. In this embodiment, the carriage 6 and the first arm 8 are made of polyphenylene sulfide (PPS) resin, which has high hardness and low elongation.

11 is a second arm made of stainless steel and has great rigidity. This second arm 11 has a central portion 12 arranged parallel to the first arm 8, a tip portion 13 for pressing the first arm 8, and a pair of tip portions for rotatably supporting the first arm 8. It consists of supporting parts 14, 15. A pair of holes 16, 17 are provided in a pair of support portions 14, 15 that are perpendicular to the central portion 12, into which a pair of shafts 18, 19 provided on the protruding portion 6a of the carriage 6 are inserted. has been done. Since the second arm 11 is interposed between the torsion spring 20 and the first arm 8, a recess 22 for stably receiving one end 21 of the torsion spring 20 is provided in the central portion 12 of the second arm 11. We are prepared. Since the second arm 11 is less elastically deformable than the torsion spring 20, it does not substantially deform even when pressed by the torsion spring 20, and only the bent portion 23 of the tip portion 13 presses the first arm 8. Therefore, the torsion spring 20
The first arm 8 is positioned closer to the second head 4 than the point where the one end 21 presses the second arm 11.
can be pressed. As a result, torsion spring 2
The same effect can be obtained by making one end 21 of 0 longer. In other words, even with a short torsion spring 20, it is possible to press a point close to the magnetic head 4, and the stability of the contact between the magnetic head 4 and the disk 1 is improved.

Note that the tip portion 13 of the second arm 11 is
The arm 8 extends above the attachment portion of the second magnetic head 4, and is located closer to the leaf spring 9 than this.

The coil portion 24 of the torsion spring 20 is connected to the carriage 6.
It is wound around a shaft 26 provided on a metal fitting 25 which is fixed with a screw 10, and the other end 27 is locked to the metal fitting 25.

A magnetic shield plate 28 is placed over the tip of the first arm 8 so as to cover the second magnetic head 4. The distal end portion of the first arm 8 having the shield plate 28 is made thinner as it goes forward in order to make the device thinner.

The carriage 6 is provided with a hole 30 through which a guide rod 29 for guiding the carriage 6 in the radial direction of the disk 1 is inserted. The carriage 6 is moved in the radial direction of the disk 1 by a moving mechanism consisting of a stepping motor 31 and a lead screw 31a.

When inserting the disk 1, the first arm 8 must be moved to the position shown by the chain line in FIG. For this reason, as shown in FIGS. 2 and 5, a protrusion 32 is provided on the first arm 8. When the disk 1 is not inserted, a head displacement mechanism (not shown) engages the protrusion 32 and lifts the protrusion 32, thereby releasing the torsion spring 20.
The first arm 8 is held in the position indicated by the dotted line in FIG. 1 against the leaf spring 9. When the disk 1 is inserted, the restriction by the protrusion 32 is released and the first arm 8 is in the head load position shown in FIG.

At the center of the first arm 8, a recess 33 is provided for passing the lead wire of the second magnetic head 4, as shown in FIG. As shown by the chain line in FIG. 2, a lead wire 34 led out from the first arm 8
is guided through a notch 35 provided in the second arm 11 to a lead wire holding recess 36 of the metal fitting 25. Since the magnetic head 4 includes an erasing head as well as a signal conversion head, the lead wires 34 usually consist of four. As in this embodiment, when the second arm 11 is provided to cover the first arm 8, the second arm 11 functions as a cover for the lead wire 34,
It is possible to prevent the torsion spring 20 from coming into contact with the lead wire 34. If the torsion spring 20 comes into contact with the lead wire 34, the lead wire 34 may be damaged or
There is a possibility that an appropriate biasing force by the torsion spring 20 may not be obtained.

Reference numeral 37 denotes a resonance prevention elastic body made of neoprene rubber, and in this example, it is formed into a cylindrical shape.
This elastic body 37 is arranged between the first arm 8 and the tip portion 13 of the second arm 11.
In order to ensure a thin device and to stably hold the elastic body 37, the first arm 8 is provided with a recess 38, into which one end of the elastic body 37 is inserted.
It is fixed with adhesive. The upper surface of the elastic body 37 is in contact with the lower surface of the tip portion 13 of the second arm 11. The height of this elastic body 37 is the same as that of the second arm 1.
Since it is larger than the height of the bent portion 23 of No. 1,
The second arm 11 is connected to the first arm through only the elastic body 37.
The elastic body 37 presses the first arm 8 only with the elastic body 37. The elastic body 37 has a different natural frequency from the first arm 8. Therefore, it is possible to shift the resonance point of the system of the first arm 8 without intervening this. That is, since the head 4 has a mirror finish, a phenomenon occurs in which it comes into close contact with the disk R, and even when the disk 1 is rotated, a stick-slip condition occurs, and the support arm 8 vibrates, the elastic body 37 and Second arm 11 having rigidity
The vibration system consisting of the head support arm 8 resonates, and the vibration of this system consumes the energy of the vibration of the head support arm 8 system, suppressing the resonance phenomenon of the head support arm 8 system and preventing squealing.

When the elastic body 37 is provided, the upper surface position of the second arm 11 will inevitably become higher, but the height position near this tip when the first arm 8 is rotated to the position shown by the chain line in FIG. can be kept lower than. In short, the thickness is significantly reduced compared to the case where the elastic body 37 is placed under the shield plate 28.

The present invention is not limited to the embodiments described above, but may be modified. For example, the carriage 6 may be configured to be driven by a belt. It is also applicable to a case where one or both of the spring plates 5, 7 supporting the first and second magnetic heads 3, 4 have a non-gimbal configuration. It is also applicable to cases where one or both of the first and second magnetic heads 3, 4 are fixedly mounted. Further, the elastic body 37 may be made of sponge. Also,
The upper surface of the elastic body 37 may be fixed to the second arm 11 with an adhesive. Alternatively, the elastic body 37 may be simply placed between the first arm 8 and the second arm 11 without being bonded at all.

[Effect of idea]

As is clear from the above, according to the present invention, since the elastic body is inserted under the second arm, the magnetic disk device can be made thinner. Also, the second
By providing the arm, the lead wire of the second magnetic head is protected and the point of action of the torsion spring 20 is moved in a direction closer to the second magnetic head.

[Brief explanation of drawings]

1 is a front view showing a part of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a plan view of a part of the magnetic disk device shown in FIG. 1, and FIG.
4 is a perspective view of the magnetic head portion of FIG. 1, and FIG. 5 is an exploded perspective view of FIG. 1. 1... Disk, 2... Rotating mechanism, 3... First
magnetic head, 4... second magnetic head, 8...
First arm, 9...Plate spring, 11...Second arm, 12...Central portion, 13...Tip portion, 1
4, 15... Support portion, 20... Torsion spring, 37
...Elastic body, 38...Concavity.

Claims (1)

[Claims for Utility Model Registration] A device for converting signals using both main surfaces of a flexible magnetic disk, comprising: a rotating mechanism for the disk; and a first magnetic disk that contacts one of the main surfaces of the disk. a magnetic head; a carriage supporting the first magnetic head; a second magnetic head disposed opposite to the first magnetic head and in contact with the other main surface of the disk; and the second magnetic head. a first arm supporting the first arm near its tip; and a hinge having one end fixed to the first arm and the other end fixed to the carriage in order to rotatably support the first arm. a leaf spring; a central portion extending parallel to the first arm and covering at least a portion of the first arm; a tip portion for pressing the first arm; and a leaf spring rotatably attached to the carriage. a rigid support portion, the distal end portion being located closer to the leaf spring than the attachment portion of the second magnetic head on the first arm; an elastic body disposed between the distal end portion of the second arm and the first arm; an elastic body supported by the carriage and located near a portion of the leaf spring fixed to the carriage; a shaft arranged around the shaft; and one end wound around the shaft and extending in the same direction as the first and second arms, the central portion of the second arm at or near the tip of the one end. a torsion spring that applies a biasing force to the first arm via the second arm in a direction in which the second magnetic head contacts the disk; What is claimed is: 1. A magnetic disk device comprising a mechanism for causing