Dynamic magnetic information storage or retrieval – Head mounting – Disk record
Reexamination Certificate
1996-11-04
2001-05-01
Miller, Brian E. (Department: 2754)
Dynamic magnetic information storage or retrieval
Head mounting
Disk record
C360S266100
Reexamination Certificate
active
06226152
ABSTRACT:
TECHNICAL FIELD
This invention relates to not only a joined metal-resin body in which a constant positional relationship between a resin plate and a metal plate joined thereto can be maintained with the aid of a joining member without causing play or backlash, but also a swing-type actuator made using therein said joined body, and it also relates to productng them. The swing-type actuator is used, for example, in a magnetic, optical, or optomagnetic disk drive, wherein the joined metal-resin plate body can be used as a joined body made by joining a head arm with a head support spring for supporting the head of the disk drive.
BACKGROUND ART
FIGS. 10 and 11
are plan and side views, respectively, of a conventional actuator. As shown in these figures, this actuator has head suspensions (support springs)
23
each supporting a magnetic head
21
at one end thereof and fixing arms
25
each having the other end of the head suspension
23
fixed thereto, and is provided with a carriage
27
attached to a disk unit in such a way as to be turnable around a shaft hole
28
. A moving coil
29
disposed in the magnetic circuit of the disk unit for giving a turning force to the carriage
27
according to the applied electric current is fixed to the carriage
27
. The head suspensions
23
are fixed to the corresponding fixed arms
25
with the aid of fixing members
31
, respectively. The fixing arms
25
are made of a metal such as aluminum, while the head suspensions
23
are made of stainless steel.
As shown in
FIG. 12
, each fixing member
31
has a cylindrical portion
33
thrusted through the through-holes of both the head suspension
23
and the fixing arm
25
, and a collar
35
provided at one end thereof. The head suspension
23
is fixed to the fixing arm
25
by outwardly bending the end portion of the cylindrical portion
33
as shown in
FIG. 12
, or by pressing the inner wall of the cylindrical portion
33
toward the inner wall of the through-hole of the fixing arm
25
in the direction of the arrows as shown in FIG.
13
. The collar
35
fixes the head suspension
23
toward the fixing arm
25
.
In the foregoing conventional example, the head suspension
23
, the fixing arm
25
and the cylindrical portion
33
are each made of a metal, and the diameter of the cylindrical portion
33
is only a little smaller than the diameter of the through-hole of the fixing arm
25
. Accordingly, the head suspension
23
can be easily and strongly superposed on and joined to the fixing arm
25
even though the cylindrical portion
33
is pressed from the inner side thereof to deform the wall of the cylindrical portion
33
as shown in FIG.
13
.
On the other hand, for example, U.S. Pat. No. 5,382,851 discloses an actuator wherein a read/write head is installed in an aperture of a metallic insert member of a flat plate form embedded in a resin arm molded by insert molding with the insert member being inserted into the resin arm. Only the end portion of this insert member, opposite to the head, is embedded in the arm.
In general, an injected molten resin is of course brought into contact with an insert member in the case of insert molding. Since, however, a resin generally exhibits no affinity for a metal, causes shrinkage at the time of solidification of the resin in a molten state and has other inconvenient properties, gaps will sometimes be formed between the insert member and the resin when the resulting molding is solidified. The gaps prevent close adhesion of the resin to the insert member to cause backlash or play of the insert member. Such backlash, in other words, relative positional deviation between the insert member and the resin, is usually slight. Depending on the characteristics required of an apparatus wherein such a molding is used, however, such backlash poses problems in some cases.
Among others, when only one end portion of the insert member is embedded in the resin as in the actuator of the above-mentioned U.S. Patent, the influences of the gaps are large because the gaps between the resin and the insert member are localized only in that one end portion. Such gaps may cause an error in the relative position of the head fixed in the insert member as against the arm. The accuracy of the position of the head is an important factor required of the actuator as a precision device.
Further, in the case of the above-mentioned U.S. Patent, the head is directly installed in the aperture of the insert member positioned at the tip of the resin arm. This involves a fear of making accurate read/write difficult because the contact pressure of the head to a disk is not constant.
Although it would also be possible to attach the head to the resin arm by utilizing a through-hole provided in the resin arm instead of using the insert member, direct joining of a metal to a resin does inevitably not attain an essentially strong bond unless an adhesive or the like is used therebetween.
In view of the foregoing problems of the prior art, an object of this invention is to enable joining between a metal plate and a resin plate with the aid of a fixing member to maintain a backlash-free accurate relative positional relationship between the metal plate and the resin plate. Another object of this invention is to provide a lightweight and high-precision swing-type actuator that does not cause any backlash between arms and head suspensions even when the arms are made of a resin. A further object of this invention is to enable the contact pressure of the head to a disk in a disk unit to be maintained constant.
DISCLOSURE OF THE INVENTION
In order to attain the foregoing objects, the joined metal-resin plate body of this invention is characterized by comprising a metal plate; a resin plate; an insert member having a through-hole, embedded in the resin plate, and brought into close contact with the resin of the resin plate in the periphery thereof except for the faces thereof where the through-hole opens; a metallic joining member fitted into the through-hole and adhered to the metal plate to join the resin plate and the metal plate in a superposed state; wherein the insert member and the surrounding resin have respective elastic stresses enough to give rise to sufficient bonding forces among the jointing member, the insert member and the resin plate, and the stress of the surrounding resin is one due to elastic deformation, the amount of which is smaller than the amount of deformation of the insert member which can give rise to the elastic stress of the insert member.
The swing-type actuator of this invention is characterized by further comprising swingably supported resin arms; and metal support springs (support arms) each having one end thereof joined to the resin arm and the other end having a head fixed thereto; wherein the joined body composed of the arm and the support spring constitutes the above joined metal-resin plate body. This actuator is usually provided with a coil for swinging the arms and a turnable carriage having the coil and the arms fixed thereto.
Further, the process for producing a joined metal-resin plate body of this invention is characterized by comprising the step of molding a resin plate by insert molding in such a way that an insert member having a through-hole therein is embedded in a resin with the outer periphery of the member being covered by the resin except for the faces thereof where the through-hole opens; the step of fitting a metallic joining member having a hollow portion therein and adhered to a metal plate, into the through-hole to superpose the resin plate on the metal plate; and the step of joining the joining member and the insert member with a sufficient bond strength by pressing the sidewall of the hollow portion to deform the joining member, the insert member and the resin plate in amounts of deformation enough to join the joining member and the insert member with a sufficient bond strength, enough to vanish gaps formed between the insert member and the surrounding resin during the insert molding and enough to be fallen within the ranges wherein the d
Motoi Ken
Tanaka Kenji
Fielder Kenneth W.
Hollander Law Firm, P.L.C.
Miller Brian E.
Nippon Petrochemicals Co. Ltd.
LandOfFree
Joined metal-resin plate body, swing-type actuator made... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Joined metal-resin plate body, swing-type actuator made..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Joined metal-resin plate body, swing-type actuator made... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2458131