JPS61239470A - Head assembly for magnetic disk - Google Patents

Abstract

PURPOSE:To increase the strength of a leaf spring in the direction of the thickness and to hardly resonate by setting the thickness of a plate in the vicinity of a bridging part to one not impeding a rotary motion while enlarging the thickness of the plate in the circumference scarcely relating to the rotating movement. CONSTITUTION:When paying attention to a distribution of the thickness of a plate of a gimbal spring 23 (24), the thickness of the plate w1 in the vicinity of bridging section 34b, 35b is made the same as the conventional one while the thickness w2 of the plate of a section except for that is made 1.5 - several times as thick as it. In this way, by providing a difference in the thickness of the plate, the strength of the gimbal spring 23 in the direction of the thickness can be increased without inpeding of the smooth rotary motion of a magnetic head 24 centering the bridging sections 34b, 35b. Namely, the flexibility followed by a magnetic head 25 with respect to the recording media is not damaged but the strength in the direction of the thickness of the plate is enhanced. When the strength in the direction of the thickness of the plate is increased, the gimbal spring does not resonate.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a head assembly for a magnetic disk drive, and more particularly to an improvement in a flexible leaf spring member (gimbal spring) that movably supports a magnetic head.

"Prior art and its problems" The head assembly of a magnetic recording device that records on a flexible magnetic disk (floppy disk) basically consists of a carriage that moves in a direction across the floppy disk, and a It has an opening/closing arm that can be opened and closed, and a magnetic head that engages with a floppy disk via a gimbal spring (flexible leaf spring means) is attached to at least one of the magnetic head support member on the carriage side and the opening/closing arm. 3 and 4 show specific examples of this, in which the gimbal spring l has a magnetic head fixing part 3 in its center that fixes the magnetic head 2, and this magnetic head On the outside of the fixed part 3, an intermediate base 4 is formed by a groove 4a, and an outer base 5 is formed by a groove 5a. The magnetic head fixing part 3 and the intermediate base part 4 interrupt the groove 4a. They are connected by a pair of bridging parts 4b located on a straight line, and similarly, the intermediate base part 4 and the outer base part 5 are connected by a pair of bridging parts 5b located on a straight line and interrupting the groove 5a.

The direction R-R of the bridging portion 4b and the direction C-C of the bridging portion 5b are orthogonal to each other, and normally the bridging portion 4b is oriented in the radial direction of the floppy disk, and the bridging portion 5b is oriented in the same circumferential direction. It will be done. The outer base 5 is fixed to a magnetic head support member or an opening/closing arm on the carriage side.

According to this gimbal spring l, the magnetic head fixing part 3 can rotate about the axis R-R with respect to the intermediate base 4 by the bridge part 4b, and similarly, the intermediate base 4 can rotate around the axis R-R with respect to the outer base 5.
The bridging portion 5b allows rotation about the axis CC.

Therefore, the magnetic head 2 can be made to follow the waviness and deformation of the floppy disk.

By the way, the conventional gimbal spring 1 has bridge parts 4b and 5-b.
In order to ensure smooth rotation in the
■It is constructed from plate spring materials such as grade 1 stainless steel (for example, 5US304) and beryllium copper. However, such a thin leaf spring material cannot be expected to have much strength in the thickness direction, so the magnetic head 2 cannot be maintained in its position unless it is supported by the pivot 6 from the back side, as shown in Figure 3. This places restrictions on the space and layout before and after the magnetic head, making it difficult to make the head assembly thinner. In addition, a thin leaf spring material with a uniform thickness tends to resonate, sometimes causing so-called gimbal noise. In FIG. 3, 7 indicates a coil, 8 a back core, and 9 a flexible printed circuit board.

``Object of the Invention'' The present invention solves the problems of conventional gimbal springs, and can increase the strength in the thickness direction without impairing the smoothness of rotational movement around the bridge part. Therefore, the object is to obtain a gimbal spring that does not require a pivot that supports a magnetic head from the back and can be made thinner. Another object of the present invention is to obtain a gimbal spring that is difficult to resonate and does not generate gimbal noise.

``Summary of the Invention'' In order to achieve this object, the present invention was made based on the idea of varying the plate thickness of a gimbal spring, which had conventionally had a uniform plate thickness. and,
It is characterized in that the thickness of at least a portion of the portion other than the bridge portion is greater than the thickness of the plate near the bridge portion connecting the outer base. In this way, the plate thickness near the bridge portion is set to a thickness that does not impair rotational motion.

If the thickness of the surrounding plates that are not significantly involved in rotational motion is set to be large, the strength of the plate spring in the thickness direction will be increased, and resonance will be less likely to occur.

``Embodiments of the Invention'' The present invention will be described below with reference to illustrated embodiments. Figure 1,
FIG. 2 shows an embodiment of the invention. The carriage 11 is moved in the direction of arrow X, that is, in the radial direction across the floppy disk F, by means of a guide device and a drive device (not shown).

On this carriage 11, a magnetic head support plate 13 with a leaf spring 12 as a fixed part, a spacer 14, an opening/closing arm 16 with a leaf spring 15 as a fixed part, and a spring retainer 17 are located, and these are secured with a fixing screw 18. , are fixed to one end of the carriage 11 in an overlapping manner to the fixing part 19. The magnetic head support plate l3 and the opening/closing arm 16 are connected to respective leaf springs 12 and 1.
5, it can be opened and closed mainly on the fixed part 19 side. Load springs 21 and 22 are inserted between the carriage 11 and the magnetic head support plate 13, and between the opening/closing arm 16 and the spring retainer 17, respectively, to move the magnetic head supporting plate 13 and the opening/closing arm 16 close together. It is biased in the direction of

At the tips of the magnetic head support plate 13 and the opening/closing arm 16,
Magnetic heads 25,26 are supported via gimbal springs 23,24, each according to the invention.

27 is an opening arm for opening the opening/closing arm 20 against the force of the load spring 22. This opening arm 27 engages with an opening mechanism (not shown), which normally opens the opening/closing arm 16 when no floppy disk °F is loaded, and when the opening mechanism releases the opening arm 27, the force of the load spring 21.22 , the opening/closing arm 16 and the magnetic head support plate 13 approach the floppy disk, and the magnetic heads 25, 26 engage with the magnetic recording medium of the floppy disk.

The planar structure of the gimbal springs 23 and 24 according to the present invention is the same as that of the conventional product shown in FIG. magnetic head fixing part 3 fixing the magnetic head 25;
3, and a groove 34 is formed on the outside of this magnetic head fixing part 33.
An intermediate base 34 is formed by a, and an outer base 35 is formed by a groove 35a. The magnetic head fixing portion 33 and the intermediate base 34 are connected by a pair of bridging portions 34b located in a straight line, which interrupt the groove 34a. They are connected by a pair of bridge portions 35b located on a straight line that interrupt the groove 35a. The direction RR of the bridging part 34b' and the direction C-C of the bridging part 35b are perpendicular to each other, and the bridging part 34b is oriented in the radial direction of the floppy disk, and the bridging part 35b is oriented in the circumferential direction. ing. The outer base 5 is fixed to the magnetic head support plate 13 or the opening/closing arm 16.

However, when paying attention to the plate thickness distribution of the gimbal spring 23 (24) of the present invention, the plate thickness w1 near the bridge portions 34b and 35b is approximately the same as that of the conventional product, for example, 0.05++.
n), and the thickness w2 of the other parts is 1 of this.
．． It is about 5 to several times larger (for example, 0.08 to 0.3 mm), and is different from conventional products in this point. Bridge section 3
The thickness of the plates other than the bridge parts 34b and 35b may be uniform for all parts, but the plate thickness may be varied in parts other than the bridge parts 34b and 35b, such as by increasing the thickness only in the parts where the strength is particularly poor. Good too.

When the plate thickness is made different in this way, the bridge parts 34b and 35
The strength of the gimbal spring 23 in the thickness direction can be increased without impeding the smooth rotational movement of the magnetic head 24 about b. That is, the flexibility of the magnetic head 25 to follow the magnetic recording medium is not impaired, and the strength in the thickness direction is improved. When the strength in the plate thickness direction increases, the gimbal spring rest 3 does not resonate.

Specifically, the gimbal spring 23 of the present invention can be processed, for example, by photo-etching.

In the above embodiment, the present invention is applied to a gimbal spring having bridging portions in two orthogonal axes directions. Furthermore, the present invention can be similarly applied to a leaf spring member having only one base connected by a bridge portion. Furthermore, although the above embodiment applies the present invention to a single-sided recording type magnetic disk device, the present invention is of course applicable to a single-sided recording type in which the magnetic head is provided only on either the carriage side or the opening/closing arm side. It is possible.

[Effects of the Invention] As described above, according to the present invention, the strength in the thickness direction of the flexible leaf spring member that enables the magnetic head to follow the floppy disk can be increased.

Therefore, the pivot that supports the magnetic head from the back side of the leaf spring material can be omitted or made smaller, which is effective for making the head assembly smaller and thinner. Furthermore, since the strength of the leaf spring member is increased, resonance that causes gimbal noise (head noise) can be suppressed.

[Brief explanation of the drawing]

1 shows an embodiment of the flexible leaf spring member used in the head assembly of the present invention, (a) is a plan view, (b)
) is a cross-sectional view taken along line bb in (a), (C) is a cross-sectional view taken along line c-c in (a), and Figure 2 is a head incorporating the flexible leaf spring member in Figure 1. There are an exploded perspective view of the assembly, FIG. 3 is a side view of the main parts of a conventional helad assembly, and FIG. 4 is a plan view of FIG. 3 viewed from below. F...Magnetic disk, IT...Carriage, 13.
... Magnetic head support plate, 16... Opening/closing arm, 23.
24... Gimbal spring (flexible leaf spring member), 25.2
6...Magnetic head, 33...Magnetic head fixing part, 3
4... Intermediate base, 34a... Groove, 34b... Bridge portion, "' 35... Base, 35a... Groove, 35b... Bridge portion. 1st @ Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) A flexible plate spring member is connected to at least one of a magnetic head support member on the carriage side that moves in a direction across a flexible magnetic disk and an opening/closing arm provided on the carriage so as to be openable and closable. A head assembly supporting a magnetic head that engages with a magnetic disk,
The flexible leaf spring member has a central magnetic head fixing part and at least one base part located outside the magnetic head fixing part and supported by the carriage side magnetic head supporting member or the opening/closing arm. In a head assembly of a magnetic disk drive in which a magnetic head fixing part and a base are connected by a pair of bridging parts located in a straight line, the plate thickness of the flexible plate spring member is varied, and the bridging part is 1. A head assembly for a magnetic disk drive, characterized in that at least a portion of the plate other than the bridge portion is thicker than a portion near the bridge portion. (2) In claim 1, the flexible leaf spring member includes a central magnetic head fixing section, an intermediate base located outside the magnetic head fixing section, and an intermediate base located further outside the intermediate base. and an outer base supported by the carriage-side magnetic head support member or opening/closing arm, and the magnetic head fixing part and the intermediate base, and the intermediate base and the outer base are each a pair of bridges that are orthogonal to each other and located on a straight line. head assembly of a magnetic disk drive connected to the