Magnetic disk file head suspension assembly mounting means

The head suspension assembly of a magnetic disk file is mounted to the disk file`s rigid actuator arm by means of an intermediate, arm-encircling, low profile, mounting band. A number of different mounting bands are disclosed for use in securing the head suspension assembly to the actuator arm. A head suspension assembly is permanently attached to the mounting band during a subassembly manufacturing procedure. The unitary mounting-band/head-suspension subassembly is then removably mounted on the end of the actuator arm by use of the mounting band.

DESCRIPTION 
1. Field of the Invention 
This invention relates to the field of magnetic disk files or drives, and 
more specifically to means for mechanically mounting the head suspension 
assembly, or assemblies, to the rigid actuator arm(s) of the disk file. 
2. Backqround of the Invention 
The art of magnetic disk files or drives provides for a magnetic 
transducing head(s) that closely follow the surface of a rotation magnetic 
disk(s). The disk is provided with a plurality of recording tracks. A head 
actuator means operates to move a rigid actuator arm(s) to which the 
head(s) is mounted by way of a flexible head suspension assembly. In this 
way, the head is positioned in transducing relation to a desired disk 
track. The head actuator means usually comprises a linear motor or a 
rotary motor. 
Disk files with which the present invention finds utility, without 
limitation thereto, may comprise one or more rigid disks having flying 
heads, or one or more floppy disks having in-contact heads. 
While the present invention will be described with reference to a head 
suspension assembly having particular utility in a rigid disk file, the 
invention is not to be limited thereto. In addition, the invention will be 
described with reference to a single actuator arm, recognizing that those 
skilled in the art will understand that the invention has utility where 
the head actuator means operates to move multiple actuator arms in 
relation to multiple disk surfaces. 
U.S. Pat. No. 4,167,765 is incorporated herein by reference for the purpose 
of showing the background of the invention. This patent shows a flying 
head. The head is carried on a head suspension assembly that is directly 
mounted onto the end of a rigid actuator arm. More specifically, the head 
suspension assembly is directly mounted to the arm by the use of screws or 
welds. 
While the prior head suspension assembly direct attachment means has been 
satisfactory in the past, it is not adaptable to actuator designs using a 
single piece actuator armature that includes head suspension carrying arms 
formed integral therewith. This type actuator hub or armature is lower in 
cost and provides better thermal characteristics than prior stacked arm 
actuators. However, such an actuator design does not permit access to the 
major surfaces of the arm to insert screws or use other common attachment 
techniques. This condition is made more difficult as spacings between 
disks and consequently the spacing between adjacent actuator arms is 
decreased to increase the storage capability per unit volume of the disk 
drive. The technique used with such actuator designs must be capable of 
assembly from the end of the arm and attachment using access from the side 
of the arm rather than along the major arm surfaces which are closely 
adjacent the next adjoining arm. The technique must also meet the usual 
objectives of low cost, ease of assembly and capability of rework where 
necessary 
While in its broad aspects the present invention is not to be limited 
thereto, the invention has particular utility as an aid to providing 
higher data storage capacity in a given physical volume. The desire to 
provide a higher storage capacity in any given volume leads to the design 
of a disk drive where a number of disks are stacked close together, 
leaving little space therebetween for the plurality of disk actuator arms. 
As a result, a number of thin, non-removable, disk actuating arms (three 
of which are shown at 10, 1O' and 1O" of FIG. 1) must be located in close 
spatial relation. 
This desirable compact mechanical configuration of a disk file leads to the 
need for a convenient, low cost, mounting means whereby each 
head-suspension subassembly (one of which is shown at 16 in FIG. 1) may be 
mounted to the end of the arm, without requiring an attachment means, such 
as screw means or welding means, to be inserted into the confined space 
between the arms as the subassembly is mounted onto the end of the arm. 
The tube-like mounting means of the present invention solves this mounting 
problem by providing a mounting means having a low spatial profile, thus 
facilitating the ease of mounting/replacement of the head-suspension 
subassembly in the confined space that exists between the actuator arms of 
such a high capacity disk drive. 
A distinguishing feature of the present invention is that the disk file's 
head suspension assembly is directly connected or mounted onto an 
intermediate mounting means, to form a subassembly. Later, the completed 
mounting-means/ head-suspension subassembly is mounted onto the disk 
file's actuator arm. 
SUMMARY OF THE INVENTION 
The present invention provides an apparatus and method whereby a 
subassembly (also called a head suspension assembly herein), made up of 
(1) a head-suspension means (2) and a mounting means, is first fabricated. 
In this fabrication step, the head-suspension means is preferably 
permanently attached to the mounting means. In preferred embodiments the 
mounting means is in the form of a hollow mounting band. In its broader 
aspects, the present invention is not to be limited to this preferred 
construction and arrangement. 
Once the head-suspension/mounting-means subassembly is fabricated, the 
mounting means portion of the subassembly is used to indirectly mount the 
head-suspension onto a disk file's actuator arm means. 
In this way, fabrication of the relatively fragile subassembly is separated 
from fabrication of the disk file. The later mounting of the subassembly 
to the disk file's actuator arm, by virtue of the subassembly's mounting 
means portion, can now be accomplished much more readily than in the prior 
art where the head-suspension was directly mounted onto the actuator arm. 
As an additional feature of the invention, mounting of the head-suspension 
to its mounting means may comprise using a permanent mounting means, 
whereas mounting of the subassembly's mounting means to the actuator arm 
may comprise using a releasable mounting means. This feature of the 
invention facilitate later repair and the like of the disk file. 
In its broader aspects the method of the present invention comprises 
manufacturing the actuator-arm / head-suspension portion of a disk file by 
providing head-suspension means, and actuator-arm means that includes a 
mounting portion to which said head-suspension means is to be mounted, 
providing an intermediate mounting member having a first portion adapted 
to receive said head-suspension means and having a second portion adapted 
to cooperate with the mounting portion of said actuator-arm means, 
securing said head-suspension means to the first portion of said mounting 
member to thereby form a sub assembly, and mounting the subassembly to 
said actuator-arm means by securing the second portion of said mounting 
member to the mounting portion of the actuator-arm means. 
In its broader aspects the apparatus of the present invention comprises a 
disk file having a rotatable recording disk having at least one planar 
recording surface, actuator means operable to move a transducing head to a 
desired location on the disk's surface, head-suspension means mounting a 
transducing head at one portion thereof and having a mounting portion 
spaced therefrom, actuator-arm means having a drive portion connected to 
the actuator means and having a mounting portion spaced therefrom, an 
intermediate mounting member having a first portion adapted to mount the 
head-suspension means and having a second portion adapted to cooperate 
with the mounting portion of the actuator-arm means, means securing the 
mounting portion of the head-suspension means to the first portion of the 
mounting member to thereby form a subassembly, and means securing the 
subassembly to the mounting portion of the actuator-arm means by the use 
of the second portion of the mounting member, to thereby indirectly mount 
the head-suspension means onto the actuator-arm means. 
The present invention provides a disk file having a relatively thick and 
rigid head actuator arm that is operable to support a transducing head 
relative a recording disk. A hollow tube member is provide, having an 
internal surface that conforms generally to the shape of the arm's 
head-supporting end. 
A relatively thin and flexible head-suspension blade member mounts the 
transducing head at one end thereof, and has its other end secured to the 
external surface of the tube member. These members comprise a head 
suspension subassembly. 
Tube securing means is provided to secure the tube member to the 
head-supporting end of said actuator arm, with the internal surface of the 
tube member being located closely adjacent the external surface of the 
head-supporting end of the actuator arm. 
In exemplary embodiments, the tube securing means is selected from the 
group adhesive means, elastomer means, solder means, or deformable 
metallic means, some of which means may be heat activated. 
The above mentioned deformable metallic securing means may comprise notch 
means formed in the head-supporting end of the arm, and correspondingly 
located deformable portions of the tube member that are deformed into the 
arm's notch means. 
In certain embodiments of the invention the actuator arm is split, to 
thereby form two side-by-side end portions whose shape generally conforms 
to, but is somewhat larger than, the internal shape of the tube member. In 
this case, the tube securing means may comprise the side-by-side end 
portions flexed together, to thereby receive the tube member over the 
flexed end portions. This tube securing means may include an adhesive 
means, for example, an adhesive that is heat activated. 
In certain embodiments, the actuator arm is split to form two side-by-side 
end portions whose shape generally conforms to, and is somewhat smaller 
than, the internal shape of the tube member. In this case, the tube 
securing means may comprise cam means operable to flexing the arm's 
side-by-side end portions apart and against the inner surface of the tube 
member. 
In other embodiments, the head-supporting end of the actuator arm is 
somewhat smaller than the internal shape of the tube member, such that a 
space exists between the outer surface of the arm and the inner surface of 
the tube member, to thereby define a cavity. In these embodiments, the 
tube securing means may comprise means operable to fill the cavity, the 
means being selected from the group solder means, elastomer means, spring 
means or deformable means carried by the tube member, for example. 
An object of the invention is to provide an intermediate mounting means for 
use in mounting a head suspension assembly to an actuator arm, said 
mounting means improving the assembly procedure of a disk file, and 
improving the ability to rework a disk file that does not meet 
manufacturing specifications. 
It is a further object of the invention to provide a means for mounting a 
head suspension assembly to an actuator arm, which means does not make use 
of direct attachment, such as direct screw attachment or direct high 
temperature weld attachment, of the head suspension assembly to the disk 
file's actuator arm. 
Another object of the invention is to provide a one-piece, pre-assembled, 
mounting-means / head-suspension subassembly, the subassembly including a 
mounting-means that is easily mounted onto the end of the disk file's 
actuator arm. 
These and other objects and advantages of the invention will be apparent to 
those of skill in the art upon reference to the following enabling 
description of preferred embodiments of the invention, with reference 
being made to the drawing.

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 is an exploded perspective view of the actuator-arm / 
head-suspension portion of a disk file that is constructed and arranged in 
accordance with a generic aspect of the present invention. 
In this figure, a number of actuator arms 10, 10', 10" are birotationally 
movable in the direction indicated by arrow 11. The portion 12 of each arm 
10 is connected to a rotary actuator, or perhaps to a linear actuator, not 
shown for purposes of simplicity, but well known to those of skill in the 
art. The end 13 of each arm 10 is adapted to mount the disk drive's 
read/write transducing head(s). 
While the invention is not to be limited thereto, each arm 10 is a 
relatively thin, rigid, metallic or plastic arm. Aluminum or magnesium are 
exemplary materials for arm 10. By way of example, the end portion 13 of 
the arm is rectangular in cross section, the major axis of the rectangular 
cross section being about 8.0 mm in length, and the minor axis of the 
rectangular cross section being about 1.0 mm in length. The length 
dimension 14 of end portion 13 is about 8.0 mm, for example. 
In an embodiment of the invention, the multiplicity of actuator arms 10, 
10', 10", etc, were constructed integrally with the actuating motor. These 
arms were closely spaced, one above the other, and were non-removable from 
the actuating motor. This actuating structure can be fabricated by 
machining, by casting, or by plastic molding. The remaining figures, 
showing other embodiments of the invention, will show only one such arm 
10. However, it is to be understood that a plurality of closely stacked 
arms can be provided, as is desired. 
As will be more fully shown in other figures, arm portion 13 includes a 
raised location surface portion 15 against which the invention's 
mounting-means / head-suspension subassembly is pressed or located when 
the subassembly is mounted onto the end 13 of arm 10. Surface 15 
accurately locates the subassembly relative arm 10. 
Reference numeral 16 identifies the above mentioned mounting-means / 
head-suspension subassembly. This subassembly includes a mounting-means in 
the form of a hollow mounting band tube 17. Band 17 is preferably formed 
of a thin, flexible, metal. For example, stainless steel may be used. The 
dimensional shape of band 17 closely conforms to the shape of arm end 13. 
In this way, band 17 may be fitted onto this end of the arm. The manner of 
mounting band 17 onto arm 13 is not critical to the invention, and various 
means will be described relative other figures. Band 17 may be made of 
metal about 0.15 mm thick, for example. 
When band 17 is mounted on end 13 of arm 10, the band is pressed onto the 
arm until it encounters and is stopped by the arm's locating surface 
portion 15. 
Subassembly 16 also includes thin, flexible, metallic blades 18 and 19, 
made of stainless steel for example. Blades 18,19 may be 0.08 mm thick, 
for example. The two free ends 20 of blades 18,19 each support a 
transducing head, for example by way of a flexure mount, in the manner 
shown in above mentioned U.S. Pat. No. 4,167,765. These elements comprise 
the head-suspension portion of subassembly 16. It is to be understood that 
the details of construction and arrangement of the head-suspension portion 
of subassembly 16 are not critical to the invention. 
In accordance with a feature of the invention, blades 18,19 are permanently 
mounted to band 17, as by welding, whereas band 17 is removably mounted to 
the end 13 of actuator arm 10, for example by the various mounting means 
to be described. 
As is well known to those of skill in the art, the upper transducing head 
of subassembly 16 cooperates with the lower recording surface of a disk 
(not shown) that is located immediately above the subassembly, whereas the 
lower transducing head that is supported by subassembly 16 cooperates with 
the upper surface of a disk (not shown) that is located immediately below 
the subassembly. In this way, each of the subassembly's two transducing 
heads cooperate with a disk recording surface, and operate to transduce 
the magnetic recording tracks of a disk, as movement 11 positions the 
heads at desired disk tracks. 
Those skilled in the art will note that the angular arrangement of FIG. 1 
suggests use of a rotary actuator to move arms 10, 10' and 10". This is 
for convenience of illustration only, and the invention is not to be 
limited thereto. 
FIGS. 2 and 3 show an embodiment of the invention where actuator arm 10 
includes two flexible end portions 25 and 26. The free-state of end 
portions 25 and 26 is such that tube or band 17 will not fit over the end 
of arm 00. Attachment of tube 17 to arm 10 is accomplished by flexing arm 
portions 25,26 inward toward one another, sliding tube 17 over arm 
portions 25,26, to a registered position against surface 15, and then 
releasing arm portions 25,26. The side surfaces 27, 28 and 29 of the arm 
are shaped to provide three symmetrical pressure points against which the 
inside surface of tube 17 is consistently and securely seated. 
As will be appreciated, this construction and arrangement provides for 
quick, unencumbered and inexpensive attachment and/or replacement of the 
above mentioned subassembly. In addition, since tube 17 is symmetrical, 
the tube can be easily oriented in a manufacturing fixture. 
After the tube has been mechanically positioned on the arm, against points 
15, 27,28 and 29, in this and other embodiments of the invention, a 
vibrational input force may be applied to the tube, thereby ensuring a 
firm seating of the tube against these alignment points. In the event that 
minute foreign particles are present on the arm or on the tube, these 
particles will be dislodged by such a force, and final accurate seating of 
the tube will be achieved. 
If desired, a laser weld can be provided once tube 17 is correctly 
positioned on the end 13 of arm 10. As shown at 30, blades 18,19 may be 
welded to tube 17 during fabrication of the subassembly. 
FIGS. 4 and 5 show an embodiment of the invention wherein the mounting tube 
or band 17 is secured to the end 13 of arm 10 by the use of a metal spring 
lock member 31. While not specifically shown, it is to be understood that 
band 17 carries blades 18,19 as above described. In this embodiment the 
dimension of arm end 13 is such that band 17 snugly fits over the arm end. 
Attachment of band 17 to arm 10 is effected by sliding the band onto the 
end 13 of the arm, and then inserting spring lock 31 into the space 
between the edge of arm 10 and the corresponding inner surface of band 17. 
Replacement is effected by sliding band 17 off of arm 10, and then 
installing a new subassembly and its spring lock. One side of arm 10 
includes two pressure points 33 and 34. These two pressure points 
cooperate with the curved shape of spring lock 31 to form three pressure 
points, for the reasons above mentioned. Spring lock 31 is designed to 
yield, without fracture, for all gap sizes between arm 10 and the inside 
surface of band 17 that result from normal manufacturing parts tolerances. 
This results in a consistent normal force that resists relative slipping 
movement between the band and the arm. 
FIGS. 6, 7 and 8 show another embodiment of the invention that utilizes a 
split-end actuator arm 10. In this embodiment, hollow tube or band 17 is 
of an internal dimension so as to easily slide over the split end 13 of 
arm 10, since the free-state width of split end 13 is less than the 
corresponding internal dimension of band 17. The end 13 of the arm 
includes a relatively inflexible wide portion 35, and a relatively 
flexible narrow portion 36. Two band-engaging pressure points 37 and 38 
are provided on wide arm portion 38, whereas a single band-engaging 
pressure point 39 is provided on narrow arm portion 36. 
Band 17 includes a pair of symmetrically located holes 40, 4Oa into one of 
which a rotatable cam disk 41 is positioned once band 17 has been slipped 
onto the split end 13 of arm 10, thereby loosely positioning the band over 
and in encircling relation to arm portions 35,36. As can be seen, hole 40 
is in general alignment with the split that is formed in the end 13 of arm 
10. Subsequent 90-degree manual rotation of cam disk 41, to a high cam 
dwell position (not shown) that is provided on the cam disk, as by the use 
of the FIG. 8 tool, effects a spreading movement of the arm's narrow 
portion 36 away from the arm's wide portion 35, and effects the locking, 
mounting, or press fitting of band 17 onto arm 10. 
Of course, subsequent opposite direction rotation of cam disk 41, away from 
its high dwell position, allows the subassembly to be replaced. 
FIG. 9 show another embodiment of the invention that utilizes a split-end 
actuator arm 10. In this embodiment, hollow tube or band 17 is of an 
internal dimension so that arm portions 50 and 51 must be pressed 
together, in the manner of the FIGS. 2,3 embodiment, in order to easily 
slide band 17 over the split end 13 of arm 10, since the free-state width 
of split end 13 is greater than the corresponding internal dimension of 
band 17. Multiple internal pressure points (not shown) may be used to 
control the proper locating of band 17 onto the end 13 of arm 10. 
In this embodiment, double-sided adhesive strips 52 and 53 are pre-bonded 
to the sides of the split-end portion 13 of arm 10. By way of example, 
strips 52,53 may include a heat-activated adhesive that is not in an 
adhesive state at room temperature. The use of such an adhesive 
facilitates the ease of part handling, and the positioning of band 17 over 
the end of the arm. 
As with the FIG. 2,3 embodiment, band 17 of the subassembly is positioned 
over the ends 50,51 of arm 10 when these ends are flexed together. 
Subsequent release of ends 50,51 causes the exposed adhesive side of 
strips 52,53 to engage the inner side of tube 17, and effects a mounting 
of the subassembly onto arm 10. When heat-activated adhesive is used, heat 
is applied to band 17 to effect subassembly mounting. 
The adhesive of this embodiment of the invention provides a bonded 
interface between each side of the tube and the arm, thereby providing the 
proper locating of the tube on the arm. 
When a heat activated adhesive is used, subassembly replacement is 
accomplished by heating the end 13 of arm 10, flexing the split end 
together, and then removing the subassembly. 
FIGS. 10 and 11 show an embodiment of the invention wherein compression of 
an elastomeric locking member operates to secure subassembly band 17 to 
the end 13 of arm 10. 
In this embodiment, the width of arm end 13 is less than the corresponding 
dimension of band 17, see FIG. 10. Thus, band 17 can be easily slid over 
the end 13 of the arm. Once the band is so positioned, and accurately 
located against registration surface 15, elastomeric locking member 60, in 
the form of a solid fiber, thread or tube, is threaded between the edge of 
arm end 13 and the adjacent, internal, narrow edge 61 of band 17. When a 
full length of member 60 has been located in the space between band 17 and 
the edge of arm 10, the exposed ends of member 60 are cut off, see FIG. 
11. 
A preferred physical shape for elastomeric locking member 60 is that the 
end thereof that is first threaded between the edge of arm end 13 and the 
adjacent, internal, narrow edge 61 of band 17 is of a small dimension, to 
thereby facilitate initial threading, whereas the opposite end of the 
locking member tapers to a large dimension that will fully occupy the 
space between the arm end and the band. With the tube completely located 
in an operative position on the arm, the small end of the locking member 
is threaded into the opening that then exists between the arm and the 
tube. Subsequent pulling on the small end of the locking member pulls the 
large portion thereof into this opening. Subsequent stretching of the 
locking member, by continuing to pull on its small end, stretches the 
locking member and reduces the diameter of its large end, This enables the 
locking member to be pulled into the opening between the arm and the tube. 
When the large portion of the locking member has been stretched by pulling 
it a sufficient distance into this opening, i.e. far enough to fill the 
opening, the locking member is released. Releasing the locking member 
allows it to try to restore to its original large, unstressed shape, and 
thereby fills the opening and provides a tube locking force. 
Subassembly removal and replacement is accomplished by forcing band 17 off 
of arm end 13. 
As can be seen in FIG. 11, the side edge 62 of arm end 13 has two spaced 
band pressure point surfaces, whereas the other side 63 of this arm end 
has two spaced bumps that cooperate with a dimple 64 that is formed in the 
narrow edge 61 of band 17. When elastomeric locking member 60 is in its 
FIG. 11 position, the locking member essentially fills the cavity between 
the edge of arm end 13 and the internal surface of band 17. This effects a 
press fit mounting of the subassembly onto arm 10. This filling of the 
cavity by elastomer 60 also seats the band against the two locating 
surfaces that are carried by edge 62 of the arm. As can be seen in FIG. 
11, for tube 17 to move axially it must compress elastomeric number 60 
between dimple 64 and either of the associated arm bumps within the 
elastomeric cavity. This feature along with the press fit effect, provided 
by the elastomeric member, hold the tube securely to the arm. 
FIGS. 12 through 15 show embodiments of the invention wherein portions of 
tube 17 are mechanically deformed or bent into recesses or notches that 
are carried by the end 13 of arm 10, in order to effect a mounting of the 
subassembly onto the arm. 
With reference to FIG. 12, the end 13 of arm 10 is provided with a pair of 
leading-edge notches 70. Band 17 includes correspondingly placed tangs 71. 
The dimension of arm end 13 is such that band 17 may be easily placed over 
the arm end 13, perhaps with a press fit. Once band 17 is so located, 
tangs 71 are deformed inward, into notches 70, for example by the use of a 
tool 72, see FIG. 13. 
For removal of a subassembly, it is necessary to bend tangs 71 to their 
original FIG. 12 position, and then pull band 17 off of arm 10. 
The embodiment of FIGS. 14,15 is somewhat similar in that the end 13 of arm 
10 is provided with a pair of center-disposed notches 73, and band 17 is 
provided with correspondingly located deformable edge portions 74. As with 
the prior embodiment, band 17 is mounted onto the end 13 of arm 10 by 
operation of punches 75, see FIG. 15. 
For removal of a subassembly, it is necessary to bend band edge portions 74 
to their original FIG. 14 position, and then pull band 17 off of arm 10. 
FIGS. 16 and 17 show an embodiment of the invention that is somewhat 
similar to the fillable-cavity embodiment of FIGS. 10,11, wherein a cavity 
space 80 that exists between arm 10 and tube 17, is filled with a 
heat-activated material such as solder 81, using two small holes that are 
formed in the corresponding edge of band 17, see FIG. 17, after band 17 
has been located on the end 13 of arm 10. 
The dimensional size of arm end 13 is such that band 17 may be easily slid 
over the arm end 13, perhaps with a press fit. Once band 17 is so located, 
the cavity is filled with solder 81. 
For removal of a subassembly, it is necessary to heat solder 81, and then 
pull band 17 off of arm 10. 
The present invention has been described with reference to various 
embodiments thereof. This description of the invention will enable those 
skilled in the art to visualize yet other embodiments of the invention. 
Thus, the scope and content of the invention is to be limited only by the 
scope and content of the following claims.