U.S. patent application number 09/254572 was filed with the patent office on 2001-08-09 for suspension assembly.
Invention is credited to HARAKO, FUJIO, INOUE, HIROO, MATSUDA, HIROSHI, TAKAHASHI, KEISHI.
Application Number | 20010012181 09/254572 |
Document ID | / |
Family ID | 26541914 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010012181 |
Kind Code |
A1 |
INOUE, HIROO ; et
al. |
August 9, 2001 |
SUSPENSION ASSEMBLY
Abstract
A head support assembly for a disk drive is comprised of a head
suspension assembly connected to an actuator arm at one end and
supporting a head at the other end, wherein a projection is formed
on a flexure closely fixed on a thin-plate load beam, said
projection projecting toward a disk surface and having a smooth
surface. The projection is formed at a region somewhat close to the
head supporting end from the hinge portion of the load beam. When
shock is applied to the disk drive, bending occurs around the hinge
portion of the load beam. During such bending, the projection
having a smooth round surface is caused to contact the disk,
whereby the disk surface is prevented from being damaged.
Inventors: |
INOUE, HIROO; (FUJISAWA-SHI,
JP) ; TAKAHASHI, KEISHI; (FUJISAWA-SHI, JP) ;
MATSUDA, HIROSHI; (ZAMA-SHI, JP) ; HARAKO, FUJIO;
(KANAGAWA-KEN, JP) |
Correspondence
Address: |
DOUGLAS R MILLETT
IBM CORP INTELLECTUAL PROPERTY LAW
5600 COTTLE ROAD
L2PA 0142
SAN JOSE
CA
95193
|
Family ID: |
26541914 |
Appl. No.: |
09/254572 |
Filed: |
March 4, 1999 |
PCT Filed: |
September 25, 1997 |
PCT NO: |
PCT/JP97/03425 |
Current U.S.
Class: |
360/244.2 ;
360/245; 360/245.3; G9B/21.026; G9B/5.153 |
Current CPC
Class: |
G11B 21/21 20130101;
G11B 5/4833 20130101 |
Class at
Publication: |
360/244.2 ;
360/245; 360/245.3 |
International
Class: |
G11B 005/48 |
Claims
We claim:
1. A suspension assembly comprising: a suspension having a
thin-plate load beam; and a flexure fixed on said load beam, said
flexure contains a projection having a round surface and projecting
toward a disk surface.
2. A suspension assembly as set forth in claim 1, wherein said
projection is formed at the vicinity of a hinge portion of said
load beam.
3. A suspension assembly as set forth in claim 1, wherein said
projection is formed by plasticly deforming the flexure.
4. A suspension assembly as set forth in claim 1, wherein a coating
with elasticity is formed on the surface of said projection facing
to a disk surface.
5. A head suspension assembly comprising: a head having a
transducer; a suspension having a thin-plate load beam; and a
flexure fixed on said load beam, said flexure contains a projection
having a round surface and projecting toward a disk surface.
6. A head stack assembly comprising: a head suspension assembly
comprising a head having a transducer; a suspension having a
thin-plate load beam; and a flexure fixed on said load beam;
wherein said flexure contains a projection having a round surface
and projecting toward a disk surface; and a carriage for supporting
said head suspension assembly.
7. A storage disk drive comprising; a head suspension assembly
comprising a head having a transducer; a suspension having a
thin-plate load beam; and a flexure fixed on said load beam;
wherein said flexure contains a projection having a round surface
and projecting toward a disk surface; a carriage for supporting
said head suspension assembly; a storage disk from or on which data
is read or written by said transducer; and a motor for rotating
said storage disk.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a disk storage device, and,
more particularly, to a structure of a suspension assembly on one
end of which a magnetic head is mounted.
[0003] 2. Description of the Prior Art
[0004] Recent magnetic disk drives are being reduced in size, more
particularly, in thickness, and various measures are being taken to
accommodate such circumstances. They include, for example, reducing
the size of the structure of a load beam. The load beam is a
support structure for the magnetic head, for mounting it on an
actuator, and the mounting structure for the magnetic head. A
typical structure for supporting the magnetic head comprises, as
shown in FIG. 1, a mount plate 10 connected to an actuator arm, a
load beam 12 coupled to the mount plate 10, and a flexure 14
coupled to the load beam 12, wherein the magnetic head is supported
on the flexure 14 with a gimbal structure. A signal line 16 from
the head is fixed on the side of the load beam 12.
[0005] FIG. 2 shows an exploded view of the mount plate 10, the
load beam 12, and the flexure 14. Each component is worked into the
predetermined shape, and then coupled and fixed to each other. The
load beam 12 or the flexure 14 is manufactured under precise
control on its material and thickness so as to provide
predetermined mechanical characteristics such as natural frequency
and stiffness. The load beam and the flexure are typically made of
stainless steel. The mount plate 10 is coupled to the load beam 12
with welding at a plurality of welding points 18 shown in FIG. 1.
The load beam 12 and the flexure 14 are also coupled by welding at
a plurality of welding points 19.
[0006] As the disk drive is made smaller and smaller, the clearance
between disks is narrowed down. Accordingly, there is an increased
possibility that a head assembly disposed between the disks will
collide with the surface of a disk due to some external impact or
vibration. If the load beam or the flexure on the head mount
contacts a disk surface, the disk surface may be damaged, leading
to damage or loss of data. It is believed that, since the load beam
or flexure is generally made of stainless steel as described above,
and a sharp edge is formed on such stainless steel member, when the
edge hits the disk surface, the disk surface tends to be easily
scratched.
[0007] FIGS. 3 and 4 schematically show a variation of the load
beam. The load beam is in the form of a thin plate, and is deformed
as shown in FIG. 3 or 4 under an external impact. Consequently, the
edge of the load beam (31 in FIG. 3, and 41 in FIG. 4) collides
with the disk surface, so that the disk surface may be damaged,
leading to damage or loss of data.
[0008] The present invention is intended to provide a head support
structure which can prevent damage on the disk surface which may be
caused by contact between the disk surface and the head
assembly.
[0009] Furthermore, the present invention is intended to provide a
disk drive with excellent impact resistance without impairing its
low profile.
SUMMARY OF THE INVENTION
[0010] To attain the above objects, a head support assembly for a
disk drive according to the present invention comprises a head
suspension assembly connected to an actuator arm at one end and
supporting a head at the other end, wherein a projection is formed
on a flexure closely fixed on a thin-plate load beam, said
projection projecting toward a disk surface and having a smooth
surface.
[0011] According to one aspect of the present invention, the
projection is formed at the vicinity of a hinge portion of the load
beam, but at a position offset therefrom.
[0012] For a fuller understanding of the nature and advantages of
the present invention, reference should be made to the following
detailed description taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic view showing the arrangement of a
typical head suspension assembly;
[0014] FIG. 2 is an exploded view of the typical head suspension
assembly;
[0015] FIG. 3 is a view showing deformation of the typical load
beam;
[0016] FIG. 4 is a view showing deformation of the typical head
suspension assembly;
[0017] FIG. 5 is a schematic view showing the arrangement of a head
suspension assembly according to the present invention;
[0018] FIG. 6 is a sectional view of the load beam of the present
invention at a region where projections are formed; and
[0019] FIG. 7 is an enlarged sectional view of the load beam at a
region where the projection is formed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The suspension assembly according to the present invention
is usually used for a storage disk drive known as a hard disk
drive. The storage disk drive comprises a storage disk, a motor for
rotating the storage disk, and a head stack assembly or actuator
for reading or writing information from or to the storage disk. The
head stack assembly comprises a head suspension assembly, and a
carriage for supporting the head suspension assembly. The head
suspension assembly comprises a head having a transducer, a
suspension having a thin-plate load beam, and a flexure fixed on
the load beam.
[0021] FIGS. 5 and 7 show an embodiment of the present invention.
Referring to FIG. 5, there is shown a plan view of the head
suspension assembly according to the present invention. It consists
of a mount plate 10 to be coupled to the actuator arm, a load beam
12 coupled to the mount plate 10, and a flexure 14 coupled to the
load beam 12. The magnetic head is supported on the flexure 14 with
a gimbal support structure. A signal line 16 from the head is fixed
on the side of the load beam 12. The mount plate 10 is coupled to
the load beam 12 with welding at a plurality of welding points 18.
The load beam 12 and the flexure 14 are also coupled by welding at
a plurality of welding points 19.
[0022] The following is materials and thickness of respective
components of the head suspension assembly according to the present
invention.
[0023] Mount plate 10: Stainless steel (SUS 304), 0.25 mm thick
[0024] Load beam 12: Stainless steel (SUS 304), 0.062 mm thick
[0025] Flexure 14: Stainless steel (SUS 304), 0.030 mm thick
[0026] FIG. 6 is a sectional view taken along line A-A' in FIG. 5.
It is an enlarged sectional view of the projection formed on the
load beam. Referring to FIG. 5, the load beam 12 is coupled to the
mount plate 10 at one end, and supports the head at the other end.
The hinge portion 45 is located substantially at the center of
these ends. When shock is exerted on the disk drive, bending as
described with reference to FIG. 3 or 4 occurs at the hinge portion
45 as the bending point.
[0027] The flexure of the present invention is formed with two
projections 47 at regions somewhat close to the head supporting end
from the hinge portion 45. FIG. 6 shows section A-A' where the
projections are formed. As shown in FIG. 6, the projection 47 has a
smooth round surface. By making a portion of the load beam to
contact the disk surface when the load beam is deformed by external
shock the region where this projection is formed, the edge of the
load beam can be prevented from colliding with the disk
surface.
[0028] FIG. 6 shows an enlarged sectional view of the projection
47. In this embodiment, the projection 47 is formed to have a
radius 1.35 mm, and a height 0.06 mm from the load beam. Such shape
and size of the projection is determined by taking into account the
spacing between disks, stiffness of the load beam, and the location
where the projection is formed. The projections 47 may be formed by
plasticly deforming the flexure 45 with a stamping tool.
[0029] The projections 47 formed on the flexure 14 is arranged to
become the region contacting the disk due to deformation of the
load beam when the disk drive is subjected to external shock or the
like. Since the projection 47 has a gradual round surface, it does
not scratch the disk surface even if it contacts the disk surface.
In addition, contacting of the projection can prevent the edge of
the load beam from contacting the disk surface.
[0030] While damage on the disk surface can be avoided because the
projection has a round surface, an alternative embodiment forms a
coating consisting of elastic material such as resin or plastics on
the surface of the projection in order to reduce shock on the
disk.
[0031] In addition, as can be seen from the comparison between FIG.
5 showing the embodiment of the present invention and FIG. 1
showing a prior art, in the embodiment of the present invention
provided with the projection 47, a welding point for the load beam
12 and the flexure 14 is not formed on the region where the
projection 47 is formed. Accordingly, the flexure 14 is in a free
state from the load beam 12 to the region where the projection 47
is provided. With such free arrangement, the projection 47 is
designed to be more easily close to the disk surface than the edge
of the load beam when the load beam is deformed, whereby the edge
is prevented from collision.
[0032] In the head suspension assembly according to the present
invention, even if the load beam collides with the disk surface
when it is deformed by external shock, the projection with smooth
round surface formed on the flexure contacts the disk surface,
whereby it can prevent the edge of the load beam from colliding
with the disk, and effectively prevent data recorded on the disk
surface from being lost.
[0033] While the preferred embodiments of the present invention
have been illustrated in detail it should be apparent that
modifications and adaptations to those embodiments may occur to one
skilled in the art without departing from the scope of the present
invention as set forth in the following claims.
* * * * *