Gram load, static attitude and radius geometry adjusting system for magnetic head suspensions

A system for adjusting the gram load, static attitude roll and radius geometry of a suspension with a high degree of accuracy and repeatability includes a clamp, load-engaging member, actuator, laser and control system. The mounting region of the suspension to be adjusted is releasably received and clamped by a clamp. A load beam of the suspension is engaged and supported at adjust positions with respect to the clamp by the load beam-engaging member. The load beam-engaging member is driven and positioned by the actuator. IR light from the laser is directed to the spring region of the suspension by optical fibers. The control system includes a pre-adjust input terminal, memory and a controller. Information representatives of a measured pre-adjust fly height gram load, static attitude roll and radius geometry values of the suspension are received at the pre-adjust input terminal. Adjust data representative of load beam adjust positions which will cause the suspension to have a desired post-adjust fly height gram load, static attitude roll and radius geometry values after the load beam is stressed relieved is stored in the memory. The controller is coupled to the pre-adjust input terminal, actuator, laser and memory, and controls the system by: 1) accessing the memory as a function of the measured pre-adjust fly height gram load, static attitude roll and radius geometry values to determine the load beam adjust position which will cause the suspension to have the desired fly height gram load, roll and radius geometry values after the load beam is stressed relieved, 2) actuating the actuator and causing the load beam-engaging member to position the load beam at the adjust position, 3) actuating the laser to stress relieve the spring region of the load beam while the load beam is positioned at the adjust position, and 4) actuating the actuator and causing the load beam-engaging member to release the load beam after the load beam is stress relieved.

REFERENCE TO RELATED APPLICATIONS 
Reference is hereby made to the following commonly assigned and copending 
applications filed on even date herewith. 
1. U.S. application Ser. No. 08/656,639 entitled GRAM LOAD ADJUSTING SYSTEM 
FOR MAGNETIC HEAD SUSPENSIONS. 
2. U.S. application Ser. No. 08/657,778 entitled GRAM LOAD, STATIC ATTITUDE 
AND RADIUS GEOMETRY ESTABLISHING SYSTEM FOR FLAT MAGNETIC HEAD 
SUSPENSIONS. 
BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention is a machine for adjusting the characteristics of 
suspensions used in rigid magnetic disk drive head gimbal assemblies. In 
particular, the present invention is a machine for adjusting the gram 
load, profile geometry and static attitude of rolled suspensions and head 
gimbal assemblies. 
2. Description of the Related Art 
Head gimbal assemblies (HGAs), also sometimes known as head suspension 
assemblies (HSAs), are commonly used in rigid magnetic disk drives to 
support magnetic heads in close proximity to the rotating disk surfaces. 
One such gimbal assembly 10 is illustrated in FIG. 1. As shown, gimbal 
assembly 10 includes an air bearing head slider assembly 12 mounted to a 
suspension 14. The suspension 14 includes a load beam 16 having a mounting 
region 18 on its proximal end and a gimbal or flexure 20 on its distal 
end. When incorporated into a disk drive (not shown), the mounting region 
18 is configured to be mounted to an actuator or positioning arm which 
supports the gimbal assembly 10 over the rotating disk. A baseplate 21 
which includes a mounting boss 23 is typically welded to the mounting 
region 18 to increase the rigidity of the mounting region and to provide a 
mechanism for securely mounting the gimbal assembly to the positioning 
arm. The load beam 16 is an elongated and often generally 
triangularly-shaped member which includes a spring region 24 adjacent to 
the mounting region 18, and a rigid region 26 which extends from the 
spring region. The spring region 24 of the embodiment shown in FIG. 1 
includes a central aperture which forms the spring region into two legs. 
In this embodiment the flexure 20 is manufactured as a separate member, 
and welded to the distal end of the rigid region 26. The air bearing head 
slider assembly 12 contains a magnetic head (not visible in FIG. 1) and is 
typically bonded to the flexure 20 by adhesive. 
During the manufacture of suspensions 14, elongated carrier strips having a 
plurality of flat and unformed load beam blanks extending therefrom are 
chemically etched from thin sheets of stainless steel or other spring 
material. Carrier strips with flat and unformed flexure blanks are etched 
in a similar manner from sheets of stainless steel. During subsequent 
manufacturing operations any side rails 30, wire lead captures 32, load 
point dimples (not visible) and any other structures which extend upwardly 
or downwardly from the generally planar surface of the load beam 16 (i.e., 
in what is known as the z-height direction), along a z-axis are formed on 
the load beam blanks by mechanical bending procedures. Any structures on 
the flexure blanks requiring z-height deformation (e.g., load point 
dimples, not shown) are formed in a similar manner. After forming, the 
flexures 20 are welded to the distal ends of the load beams 16. The 
carrier strip is then cut or detabbed from the flexures 20. Baseplates 21 
also are welded to the mounting regions 18 of the load beams 16 following 
the forming operations. 
The suspension 14 illustrated and described above is known as a three-piece 
design in that it includes a load beam 16, flexure 20 and baseplate 21, 
all of which are separately fabricated and formed before being welded 
together. In another suspension design known as a two-piece design or 
integrated gimbal suspension (not shown), the flexure is etched in the 
distal end of the rigid region of the load beam. Portions of the 
integrated gimbal which extend from the planar surface of the load beam in 
the z-height direction are formed along with other structures on the load 
beam during the forming operation. A baseplate is typically welded to the 
mounting region after these load beam and integrated gimbal etching and 
forming operations. 
As shown in FIG. 2, the products of these etching, forming and welding 
operations are carrier strips 34 with generally flat suspensions 14 
extending therefrom (i.e., the mounting region 18, spring region 24 and 
rigid region 26 of load beam 16 are generally coplanar and at the same 
z-height). During subsequent manufacturing operations the spring region 24 
of each load beam 16 is rolled around a curved mandrel or otherwise bent 
in such a manner as to plastically bend or deform the spring region. As 
illustrated in FIGS. 3 and 4, this rolling operation imparts a curved 
shape to the spring region 24 and causes the flexure 20 to be offset from 
the mounting region 18 in the z-height direction when the suspension 14 is 
in its unloaded or free state. Equipment and methods for performing these 
rolling operations are generally known and disclosed, for example, in the 
Smith et al. U.S. Pat. No. 4,603,567 and the Hatch et al. U.S. Pat. No. 
5,471,734. 
As noted above, the suspension 14 supports the slider assembly 12 over the 
magnetic disk. In reaction to the air pressure at the surface of the 
spinning disk, the slider assembly 12 develops a hydrodynamic force which 
causes the slider assembly to lift away from and "fly" over the disk 
surface. To counteract this hydrodynamic lifting force, the head gimbal 
assembly 10 is mounted in the disk drive with the suspension 14 in a 
loaded state so the bent spring region 24 of the suspension forces the 
head slider assembly 12 toward the magnetic disk. The height at which the 
slider assembly 12 flies over the disk surface is known as the "fly 
height." The force exerted by the suspension 14 on slider assembly 12 is 
known as the "gram load." High performance disk drive operation requires 
the air bearing head slider assembly 12 to closely follow the rotating 
magnetic disk surface at a constant height and attitude. To meet this 
critical requirement, the gram load of suspensions 14 must be adjusted to 
a relatively tight specification range (defined in terms of upper and 
lower range specification gram loads above and below, respectively, the 
desired or nominal gram load). 
Techniques for adjusting the gram load of suspensions 14 after they have 
been rolled are generally known and disclosed, for example, in the Smith 
et al. U.S. Pat. No. 4,603,567 and the Schones et al. U.S. Pat. No. 
5,297,413. Briefly, one such method is known as a "thermal adjust" or 
"light adjust" technique. A known property of stainless steel members such 
as load beams is that the force they exert in response to attempts to bend 
them can be reduced (stress relieved) through exposure to thermal energy. 
The functional relationship between the amount of force reduction and the 
amount of heat to which a member is exposed can be empirically determined. 
The light adjust method makes use of this empirically determined 
relationship to "downgram" or lower the gram load of load beams that have 
been purposely manufactured (e.g., through rolling operations of the type 
described above) to have an initial gram load greater than the desired 
gram load range. 
Equipment for performing the light adjust method includes a clamp for 
clamping the mounting region 18 of the suspension 14 to a fixed base or 
datum, and a load cell for measuring the gram load of the suspension. A 
computer controlled actuator moves the load cell into engagement with the 
flexure 20 and elevates the flexure to a z-height or offset with respect 
to the datum which corresponds to the specified fly height for the 
suspension (i.e., the gram load is measured at fly height). In practice, 
the measured gram load quickly rises toward its then-current value as the 
flexure 20 is elevated. When the measured gram load reaches an upper range 
specification, the computer actuates or turns on a high intensity infrared 
lamp to apply heat to the load beam 16. Since the applied heat reduces the 
actual gram load of the suspension 14, the measured gram load quickly 
peaks. Continued application of heat causes the measured gram load to 
decrease with time. The computer deactuates or turns off the lamp when the 
measured gram load has decreased to a predetermined set point, typically a 
load between the nominal or desired gram load and the lower range 
specification. Once the lamp has been turned off, the measured decrease in 
gram load quickly slows and reaches its minimum value (often at a gram 
load below the lower range specification) as the heat in the suspension 14 
dissipates. However, as the load beam continues to cool, the measured gram 
load increases and stabilizes at an equilibrium or final load value that 
is preferably well within the specification range, and ideally close to 
the nominal specification. The final gram load is also measured following 
the light adjust procedure. This measurement is used by the computer to 
continually update the stored model (e.g., the setpoint) of the functional 
relationship between the amount of heat applied (e.g., lamp on time) and 
the gram load reduction, to optimize the accuracy of the results obtained 
by the gram adjust procedure. 
Computer controlled mechanical bending procedures are also used to adjust 
the gram load on load beams 16. The mechanical bending method makes use of 
an empirically determined relationship between the amount that the load 
beam 16 is mechanically bent and the associated change in gram load. For a 
range of gram load adjustments that are typically performed by this 
technique, a simple linear regression line has been found to accurately 
describe this relationship. In practice, this technique is implemented by 
a computer coupled to a stepper motor-driven bending mechanism and a load 
cell. A model of the relationship between changes in gram load and the 
number of motor steps (i.e., the associated amount or extent of bending 
required) is stored in the computer. After the then-current gram load of 
the suspension is measured by the load cell, the computer calculates the 
required load correction (i.e., the difference between the measured and 
desired loads). The computer then accesses the model as a function of the 
required correction to determine the number of motor steps required to 
achieve the required load correction, and actuates the stepper motor 
accordingly. Once the load beam has been bent, the then-current gram load 
is again measured and used to update the model. Measured data from a given 
number of the most recently executed mechanical bends is used to recompute 
the regression line data prior to the execution of the next mechanical 
bend. 
The air bearing head slider assemblies 12 are mounted to the flexure 20, 
and the lead wires clamped to the load beam 16, after the gram load of the 
suspension has been initially set using methods such as those described 
above. Unfortunately, the mechanical handling and assembly procedures 
involved in this manufacturing operation sometimes forces the gram loads 
of the assembled head suspension assemblies 10 beyond the specification 
range. Since the gram load specification is so critical to proper disk 
drive operation, these out-of-specification head suspension assemblies 
cannot be used unless the gram load is readjusted to the specification 
range. A machine which uses both the light-adjust and mechanical bending 
procedures described above to "regram" suspensions is shown in the Schones 
et al. U.S. Pat. No. 5,297,413. 
Another critical performance-related criteria of a suspension is specified 
in terms of its resonance characteristics. In order for the head slider 
assembly 12 to be accurately positioned with respect to a desired track on 
the magnetic disk, the suspension 14 must be capable of precisely 
translating or transferring the motion of the positioning arm to the 
slider assembly. An inherent property of moving mechanical systems, 
however, is their tendency to bend and twist in a number of different 
modes when driven back and forth at certain rates known as resonant 
frequencies. Any such bending or twisting of a suspension 14 causes the 
position of the head slider assembly 12 to deviate from its intended 
position with respect to the desired track. Since the head suspension 
assemblies 10 must be driven at high rates of speed in high performance 
disk drives, the resonant frequencies of a suspension should be as high as 
possible. 
As discussed in the Hatch et al. U.S. Pat. No. 5,471,734, the position, 
shape and size of the roll or bend in the spring region 24 of a suspension 
14, sometimes generally referred to as the radius geometry or profile of 
the suspension, can greatly affect its resonance characteristics. The 
radius geometry of a suspension must therefore be accurately controlled 
during manufacture to optimize the resonance characteristics of the part. 
The radius geometry of a suspension is characterized by parameters 
referred to as offset and bump in the Hatch et al. Patent. However, it is 
known to define the radius geometry of a suspension using different 
parameters. By way of example, Hutchinson Technology Incorporated, the 
assignee of the present application, has often characterized the radius 
geometry of suspensions such as 14 using a number of parameters including 
those referred to as "height" and "depth" or "rippel." As shown in FIG. 4, 
the height parameter is the z-height distance between the surfaces of the 
load beam 16 at the mounting region 18 and a point on the rigid region 26. 
The location on the rigid region 26 at which the height is measured is 
referenced to the proximal end of the load beam 16 by a distance parameter 
referred to as the "height location." The depth is the z-height distance 
between the surfaces of the load beam 16 at the mounting region 18 and a 
point on the spring region 24. The location on the spring region 24 at 
which the depth is measured is referenced to the proximal end of the load 
beam 16 by a distance parameter referred to as the "low point location." 
Typically, the low point location is the position at which the depth is at 
its maximum for the suspension 14. 
Yet another important performance-related criteria of a suspension 14 is 
known as its static attitude. The attitude of a head slider assembly 12 
refers to the positional orientation of slider assembly with respect to 
the surface of the disk over which it is flying. The head slider assembly 
12 is designed to fly at a predetermined orientation (typically generally 
parallel) with the surface of the disk. Deviations from this parallel 
relationship which result in the front and back edges of the slider being 
at a different heights from the disk (i.e., a rotation about a y-axis 
transverse to the longitudinal x-axis of the suspension) are known as 
pitch errors. Deviations from the parallel relationship which result in 
the opposite sides of the slider being at different heights from the disk 
(i.e., a rotation about the longitudinal x-axis of the suspension) are 
known as roll errors. Any pitch or roll errors in the desired flying 
attitude of the slider can degrade to performance of the disk drive. 
One source of these pitch and roll errors is static attitude errors of the 
suspension. Static attitude errors and the use of static attitude 
compensation dimples or protuberances to minimize these errors are 
disclosed in the Harrison et al. article The Double Dimple Magnetic 
Recording Head Suspension and its Effect on Fly Height Variability. 
There remains a continuing need for improved head suspension adjusting 
equipment and methods. In particular, there is a need for equipment and 
methods for adjusting suspension parameters such as gram load, height or 
other profile characteristics, roll and/or pitch. Equipment and methods 
for adjusting several of these parameters would be especially desirable. 
To be commercially viable, any such equipment and methods must capable of 
achieving a high degree of accuracy and repeatability. 
SUMMARY OF THE INVENTION 
The present invention is a system for adjusting two or more parameters of a 
suspension, such as gram load, static attitude roll and radius geometry, 
with a high degree of accuracy and repeatability. One embodiment of the 
suspension adjusting system includes a load beam-engaging member, an 
actuator, heat source and a control system. The load beam-engaging member 
engages the load beam and supports the head-receiving of the load beam at 
adjust positions with respect to the mounting region. The actuator drives 
and positions the load beam-engaging member. The heat source stress 
relieves at least the spring region of the load beam. The control system 
includes a pre-adjust input terminal, memory and a controller. Information 
representatives of at least two measured pre-adjust parameters values of 
the suspension is received at the pre-adjust input terminal. Parameter 
adjust data representatives of suspension parameter adjust positions which 
will cause the suspension to have desired post-adjust parameter values 
after the load beam is stress relieved is stored in the memory. The 
controller is coupled to the pre-adjust terminal, actuator, heat source 
and memory, and controls the system by: 1) accessing the memory as a 
function of the measured pre-adjust parameter values to determine the 
suspension adjust which will cause the suspension to have the at least two 
desired parameters values after the load beam is stress relieved, 2) 
actuating the actuator and causing the load beam-engaging member to 
position the load beam at the adjust position, and 3) actuating the heat 
source to stress relieve at least the spring region of the load beam while 
the load beam is position at the adjust position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Suspension adjust equipment 100, a first embodiment of the present 
invention, is illustrated generally in FIG. 5. Equipment 100 rolls and 
gram load adjusts generally flat (i.e., unrolled) suspensions. As 
described above in the Background of the Invention section, suspensions of 
these types typically have already been formed and are attached to carrier 
strips at this stage of their manufacture. For purposes of example, 
therefore, the following description of equipment 100 (as well as 
equipment 200, 700 and 900 described below) is provided with reference to 
carrier strips 34 of suspensions 14 such as those described above. 
However, equipment 100 can also be used to roll and gram load adjust 
individual suspensions such as 14 which are not attached to carrier strips 
such as 34. Furthermore, equipment 100 can be used to gram load adjust 
head gimbal assemblies such as 10 (i.e., to adjust or readjust the gram 
load after a head slider assembly such as 12 has been bonded to the 
suspension). 
As shown, equipment 100 includes a walking beam 101 which advances carrier 
strips 34 (not visible in FIG. 5) through the equipment, and sequentially 
positions each suspension 14 at a roll station 102, first gram load 
measure station 104, gram load adjust station 106, second gram load 
measure station 108 and an out-of-specification part detab station (not 
shown). At the roll station 102, the spring region 24 of the suspension 14 
is rolled around a curved mandrel or otherwise bent to impart the desired 
radius geometry to the suspension. At the first gram load measure station 
104, the suspension 14 is elevated to fly height, and the post-roll fly 
height gram load of the suspension measured. As described in greater 
detail below, a gram load adjust procedure is performed at station 106 to 
adjust the gram load of the suspension 14 if the post-roll gram load 
measured at station 104 is outside the desired specification range. The 
post-adjust gram load of the suspension 14 is measured at second gram load 
measure station 108. If the post-adjust gram load of the suspension 14 is 
outside the desired specification range, the suspension is rejected and 
cut from the carrier strip at the out-of-specification detab station. The 
carrier strips 34 with the remaining in-specification suspensions 14 are 
then removed from equipment 100 and transported to a clean, heat treat and 
clean station (not shown). Following the cleaning, heat treating and 
cleaning operations the suspensions are transported to a final detab 
station where all the remaining suspensions 14 are cut from the carrier 
strip 34, and subsequently packaged for shipment to customers. In other 
embodiments, the suspensions 14 are not heat treated following their 
adjustment on equipment 100. 
Walking beam 101 can be any conventional or otherwise known mechanism for 
transporting and positioning suspensions 14 at stations 102, 104, 106 and 
108. By way of example, one such walking beam mechanism is disclosed in 
the Smith et al. U.S. Pat. No. 4,603,567. The walking beam 101 and 
stations 102, 104,106 and 108 are mounted to a base 103. 
Rolling station 102 can be any conventional or otherwise known mechanism 
for bending the spring region 24 of suspension 14 to the desired profile. 
Rolling stations such as 102 are generally known and disclosed, for 
example, in the Smith et al. U.S. Pat. No. 4,603,567 and the Hatch et al. 
U.S. Pat. No. 5,371,734. Briefly, the embodiment of rolling station 102 
shown in FIG. 5 includes a base clamp and radius block mechanism 110, 
radius block slide 112 and a stepper motor 114 for raising and lowering a 
roller (not visible). After each suspension 14 is advanced to rolling 
station 102 by the walking beam 101, the base clamp and radius block 
mechanism 110 functionally clamps the baseplate 21 of the suspension to a 
base (not visible) with the spring region 24 positioned under a curved 
mandrel (also not visible). The curved mandrel has a profile which will 
impart the desired profile to the spring region of the suspension. Stepper 
motor 114 is then actuated to raise and drive the roller through a rolling 
stroke during which the roller engages and rolls the spring region 24 over 
the mandrel. The extent to which the spring region is rolled over the 
mandrel (i.e., the length of the rolling stroke) affects the gram load of 
the suspension 14. In one embodiment of equipment 100, the roll station 
102 rolls each suspension 14 a constant predetermined amount. Using an 
interface terminal of the equipment control system (not shown), an 
operator sets up the roll station 102 to achieve the desired post-roll 
gram load (typically a percentage of the desired nominal gram load) in the 
suspensions 14 emerging from roll station 102. The position of the mandrel 
with respect to the base clamp, and therefore the position of the roll on 
the spring region 24, a parameter that affects the resonance 
characteristics of the suspension, can be adjusted by radius block slide 
112. Following the rolling procedure the base clamp is opened to release 
the suspension 14, and the suspension is subsequently transported to first 
measure station 104 by walking beam 101. 
First and second gram load measure stations 104 and 108, respectively, can 
be any conventional or otherwise known mechanism for measuring the gram 
load of suspensions 14 at fly height. One such gram load measure station 
is disclosed, for example, in the Smith et al. U.S. Pat. No. 4,603,567. 
The embodiment of measure station 104 shown in FIG. 5 includes load cell 
120, elevator 122, elevator actuator 124, stepper motor 126 and base clamp 
128. Measure station 108 can be identical to station 104, and similar 
features are illustrated with identical but primed reference numbers 
(i.e., "x'"). 
Briefly, after the suspension 14 is advanced to measure station 104 by the 
walking beam 101, the base clamp 128 rigidly functionally clamps the 
baseplate 21 of the suspension to a base (not visible) with the load beam 
16 and flexure 20 of the suspension positioned below load cell 120 and 
elevator 122. Stepper motor 126 is then actuated to simultaneously lower 
load cell 120 and elevator 122 from a retracted position (shown in FIG. 
6A) to an extended position (shown in FIG. 6B) at which the load cell is 
located at a relative z-height measurement position with respect to the 
base which is equal to the specification fly-height of the suspension 14. 
As shown in FIG. 6A, when in its retracted position the elevator 122 
extends downwardly a greater distance than the load cell 120. As the load 
cell 120 and elevator 122 are lowered, the elevator will therefore engage 
the suspension 14 (typically at a location on the rigid region 26 adjacent 
to flexure 20) before the load cell, and elevate the suspension to a 
z-height beyond the fly height. After the load cell 120 is lowered to the 
fly height position, elevator actuator 124 is actuated to lift the 
elevator 122 and gently position flexure 20 of the suspension 14 on the 
load cell (shown in FIG. 6C) for the gram load measurement. This procedure 
is then repeated in the reverse order to return the suspension 14 to its 
free state. Other embodiments of measurement stations 104 and 108 (not 
shown) do not include an elevator 122 or elevator actuator 124, and 
instead use the load cell 120 to elevate the suspension to the fly-height 
measurement position. Following the gram load measurement procedure the 
base clamp 128 is opened to release the suspension 14, and allow the 
suspension to be transported to the next station by walking beam 101. 
Gram load adjust station 106 can be described in greater detail with 
reference to FIGS. 5 and 7-10. As shown, the station 106 includes a clamp 
assembly 130, stepper motor 132 and suspension positioning assembly 134. 
Clamp assembly 130 includes a fixed base 136 and a moving clamping member 
138. Base 136 is rigidly mounted with respect to the walking beam 101 and 
has a surface configured to receive and register the baseplate 21 of 
suspension 14. Clamping member 138 is reciprocally driven between closed 
and open positions with respect to base 136 in synchronization with the 
motion of walking beam 101. At the beginning of a gram adjust procedure, 
clamping member 138 is in its open position (not shown) spaced from base 
136. The walking beam 101 then advances the suspension 14 to be adjusted 
into the clamp assembly 130. After the baseplate 21 has been aligned with 
the base 136 by the walking beam 101, clamping member 138 is driven to the 
closed position shown in FIG. 7, functionally clamping the baseplate 21 
against the base 136. The mounting region 18 of the suspension 14 is 
thereby functionally clamped and rigidly held in the adjust station 106 
throughout the gram adjust procedure. Following the completion of the gram 
adjust procedure the clamping member 138 is driven to its open position to 
release the suspension 14 and allow the suspension to be advanced from the 
station 106 by walking beam 101. 
Stepper motor 132 and suspension positioning assembly 134 are mounted to a 
fixed base 140. The stepper motor 132 is fixedly mounted to an upper 
portion of the base 140. The suspension positioning assembly 134 includes 
a slide mount 142, a support arm 144 and a positioning bar assembly 146. 
Slide mount 142 is mounted to the base 140 for reciprocal motion in a 
direction generally parallel to the direction the clamped suspension 14 
can be flexed about its spring region 24 (e.g., about a vertical or z-axis 
in the illustrated embodiment). Support arm 144 is mounted to and extends 
from slide mount 142. Positioning bar assembly 146 is mounted to an end of 
support arm 144 opposite the slide mount 142, and is positioned adjacent 
to the clamp assembly 130. Stepper motor 132 is mechanically connected to 
and drives the slide mount 142 through its range of reciprocal motion. 
Positioning bar assembly 146 includes a pair of spaced and generally 
C-shaped plates 148 having longitudinally extending gaps 150 which open 
toward clamp assembly 130. An upper positioning bar 152 extends 
horizontally between plates 148 above gap 150. Similarly, a lower 
positioning bar 154 extends horizontally between plates 148 below gap 150 
and bar 152. Bars 152 and 154 are positioned on assembly 146 at locations 
above and below the distal end of the load beam 16 of suspensions 14 
clamped at and extending from clamp assembly 130. The positioning bar 
assembly 146 is shown at a suspension clamping position in FIG. 7. In this 
suspension clamping position gap 150 is aligned with the clamp assembly 
130 enabling suspensions 14 to be advanced into and out of the clamp 
assembly with the load beam 16 extending between bars 152 and 154. 
An optical fiber bracket 156 is fixedly mounted adjacent to the base 136 of 
clamp assembly 130. Bracket 156 is configured to receive and hold one or 
more optical fibers 158 with the ends 160 of the fibers positioned at 
locations directly above the spring region 24 of suspensions 14 clamped at 
clamp assembly 130. A laser 177 or other source of infrared light (shown 
in FIG. 9) is coupled to the opposite ends of optical fibers 158. The 
illustrated embodiment of station 106 includes two optical fibers 158 
which are mounted within bracket 156 in such a manner that their ends 160 
are positioned above the spaced legs of the spring region 24. In general, 
the ends 160 of fibers 158 are positioned to direct a relatively uniform 
intensity of infrared light (i.e., heat) over the spring region 24 of the 
suspension 14. One embodiment of the present invention uses a ten watt 
laser diode from SDL of San Jose, Calif., for laser 177. 
A control system 170 for controlling the operation of gram load adjust 
station 106 is illustrated in FIG. 9. As shown, the control system 170 
includes a digital processor 172 coupled to program memory 174 and 
interface terminal 176. The processor 172 is also interfaced to stepper 
motor 114 of roll station 102, stepper motor 126, elevator actuator 124 
and load cell 120 of gram load measure station 104, stepper motor 132 and 
a laser 177 of gram load adjust station 106, and stepper motor 126', 
elevator actuator 124' and load cell 120' of gram load measure station 
108. A gram adjust program executed by processor 172 to perform gram load 
adjust procedures is stored in memory 174. Interface terminal 176, which 
includes a monitor and keypad (not separately shown) is used by an 
operator to set up equipment 100 and to monitor the operation of the 
equipment during production operations. 
The gram load adjust procedure is based upon the discovery that the gram 
load of a suspension can be predictably adjusted to a high degree of 
accuracy, repeatability and stability if the spring region 24 of the 
suspension 14 is stressed by lifting or lowering the load beam 16 from its 
free state (depending on whether it is desired to upgram or downgram the 
suspension) to a predetermined position, and to relieve the stresses by 
heating the spring region (e.g., through the application of an infrared 
laser beam) while the load beam is held in the predetermined position. The 
magnitude of the gram load change generated by this process is dependent 
upon the amount of the stress to which the spring region 24 is subjected 
before being stress relieved, and this stress level can be controlled by 
the position of the load beam 16 with respect to its free state position. 
Accordingly, adjust data representative of desired fly height gram load 
changes as a function load beam adjust positions is stored in memory 174. 
The load beam adjust positions are positions to which the load beam 16 of 
suspension 14 is driven upwardly by bar 154 or downwardly by bar 152 from 
its free state position. In a preferred embodiment the adjust data 
characterizes a linear equation describing gram load changes as a function 
of load beam adjust positions. The load beam adjust positions can be 
correlated to the number of steps motor 132 must be driven to raise or 
lower positioning bar assembly 146 from its clamping position to position 
the bars 154 and 152 at the desired load beam adjust positions. Also 
stored in memory 174 is data representative of the nominal or desired gram 
load of suspension 14. 
FIG. 10 is a flow diagram illustrating the gram load adjust procedure 
performed by station 106. The adjust procedure begins with the receipt of 
data from first gram load measurement station 104 representative of the 
post-roll gram load of the suspension 14 to be gram load adjusted (step 
180). The difference between the measured post-roll gram load and the 
nominal gram load is then computed to determine the desired gram load 
change (i.e., the amount of the gram load adjustment to be made by station 
106) (step 182). Processor 172 then accesses the adjust data as a function 
of the desired gram load change to determine the load beam adjust position 
which will produce the desired gram load change. In the embodiment 
described above in which the adjust data is a linear equation, processor 
172 computes the load beam adjust position in terms of the required number 
of steps that motor 176 must be driven to raise or lower the positioning 
bar assembly 146 (step 184). Stepper motor 132 is then actuated by 
processor 172 in such a manner as to drive the positioning bar assembly 
146 and cause one of the bars 152 or 154 to position the load beam 16 at 
the computed adjust position (step 186). With the load beam 16 held at the 
adjust position, processor 172 actuates laser 177 for an exposure time 
period and causes the spring region 24 to be heated and stress relieved by 
the application infrared light directed to the spring region through 
optical fibers 158 (step 188). To complete the adjust procedure, processor 
172 turns off laser 177 at the end of the exposure period and allows the 
suspension 14 to cool to ambient temperature (less than one second is 
usually sufficient) (step 190) before again actuating motor 132 and 
driving the positioning bar assembly 146 back to the clamping position 
(step 192). 
Control system 170 is set up by an operator through the use of interface 
terminal 176. In one embodiment, the exposure period of laser 177 is set 
by observing the physical effects of the infrared light on a test 
suspension 14. In particular, during exposure trials the exposure period 
is increased until the applied heat is sufficiently great to oxidize the 
suspension 14, resulting in a "browning" effect on the suspension. This 
procedure is known as determining the browning threshold. The exposure 
period is then set to a period which is a predetermined length of time 
(e.g., 50 msec.) less than the browning threshold. This set-up procedure 
will result in the spring region 24 being heated to a temperature between 
about 600.degree.-900.degree. F. (315.degree.-482.degree. C.) during the 
exposure period. 
The gram load adjust data (e.g., the linear equation coefficients for the 
preferred embodiment described above) is initially established during 
set-up procedure in which a number of suspensions 14 having known 
post-roll gram loads (measured at first gram load measurement station 104) 
are driven to different set-up adjust positions and stress relieved at 
adjust station 106. The post-adjust gram loads of the suspensions 14 are 
then measured at second gram load measurement station 108, and used by 
processor 172 to compute the changes in gram load induced by the adjust 
station 106 at these set-up adjust positions. Processor 172 then generates 
the gram load adjust data by computing a least squares fit (e.g., a 
Gaussian method) to the measured gram load changes and corresponding 
set-up adjust positions. In a similar manner, the adjust data can be 
periodically or continually updated by processor 172 during normal 
operation of adjust station 106 on the basis of measured differences 
between the actual post-adjust gram loads and the nominal gram load. 
Suspension adjust equipment 200, a second embodiment of the present 
invention, is illustrated generally in FIG. 11. Equipment 200 rolls and 
adjusts the gram load, radius geometry and static attitude (both pitch and 
roll) of generally flat (i.e., unrolled) suspensions. As described above 
in the Background of the Invention section, suspensions of these types 
typically have already been formed and are attached to carrier strips at 
this stage of their manufacture. For purposes of example, therefore, the 
following description of equipment 200 is provided with reference to 
carrier strips 34 of suspensions 14 such as those described above. 
Portions of equipment 200 are similar to those of equipment 100 described 
above, and these portions are described with reference to identical but 
twice primed (i.e., "x"") reference numerals. 
As shown, suspension adjust equipment 200 includes a walking beam 101" 
which advances carrier strips 34 (not visible in FIG. 11) through the 
equipment. The walking beam 101" sequentially positions each suspension 14 
at a roll station 102", backbend station 202, gram load and profile 
measure station 204, static attitude measure and pitch adjust station 206, 
laser adjust station 208, static attitude measure station 210 and an 
out-of-specification part detab station (not shown). 
At roll station 102', the baseplate 21 of the suspension 14 is clamped at 
the base clamp and radius block mechanism 110", and the spring region 24 
rolled around a curved mandrel to bend the spring region to the desired 
profile and impart a desired post-roll gram load to the suspension. Upon 
the completion of the rolling operation, the suspension 14 is released 
from the mechanism 110 ' and transported to backbend station 202 where the 
suspension is backbent to reduce its gram load a predetermined amount 
(i.e., bent a predetermined amount beyond its range of elastic deformation 
in a direction opposite that in which it was rolled). 
Any conventional or otherwise known backbending mechanism can be 
incorporated into station 202. In the embodiment shown in FIG. 11, 
backbend station 202 is structurally similar to gram load measure station 
104 described above with reference to adjust equipment 100, but does not 
include a load cell. As shown, backbend station 202 includes an elevator 
222, elevator actuator 224, stepper motor 226 and base clamp 228. After 
the suspension 14 is advanced to backbend station 202 by the walking beam 
101", the base clamp 228 functionally clamps the baseplate 21 of the 
suspension to a base (not visible) with the load beam 16 and flexure 20 of 
the suspension positioned below elevator 222. Stepper motor 226 is then 
actuated to drive the elevator 222 through a backbend stroke by lowering 
the elevator from a retracted position to an extended position. As it is 
driven to the extended position the elevator 222 will engage the 
suspension 14 (typically at a location on the rigid region 26 adjacent to 
flexure 20), and elevate the suspension in a direction opposite to the 
direction that it was rolled. During the backbend operation the load beam 
16 is elevated beyond its range of elastic deformation (i.e., beyond the 
point at which it will "spring back" or return to its original free state 
when released from the elevator) to bend or plastically deform the spring 
region 24 and reduce the then-current gram load. The amount of plastic 
deformation imparted to the load beam 16 during the backbend operation, 
and therefore the induced gram load reduction, is controlled by the extent 
to which the load beam is backbent (i.e., the length of the backbend 
stroke of elevator 222). In one embodiment of adjust equipment 200, the 
backbend station 202 backbends each suspension 14 a constant predetermined 
amount (e.g. 0.3 grams for a suspension having a nominal gram load of two 
to five grams). Using an interface terminal (FIG. 25) an operator set up 
the backbend station 202 to achieve the desired post-backbend gram load in 
the suspensions 14 emerging from backbend station. Following the 
backbending procedures the base clamp 228 is opened to release the 
suspension 14, and allow the suspension to be transported to the next 
station by walking beam 101''. 
Gram load and profile measure station 204 includes a gram load measurement 
instrument 230 and a z-height measurement instrument 232. Gram load 
measurement instrument 230 is structurally similar to gram load measure 
station 104 described above with reference to adjust equipment 100, but 
does not include an elevator or elevator actuator. As shown, gram load 
measurement instrument 230 includes a load cell 234, stepper motor 236 and 
base clamp 238. After the suspension 14 is advanced to station 204 by the 
walking beam 101'', the base clamp 238 functionally clamps the baseplate 
21 of the suspension to a base (not visible) with the load beam 16 and 
flexure 20 of the suspension positioned below load cell 234. Stepper motor 
226 is then actuated to drive the load cell 234 into engagement with the 
flexure 20 and to elevate the suspension 14 to its specification fly 
height. A measurement of the post-backbend gram load of the suspension 14 
can then be provided by load cell 234. 
Z-height measurement instrument 232 is positioned and configured to measure 
the height parameter of suspensions 14 clamped at base clamp 238. As 
described above in the Background of the Invention section, the height 
parameter of the suspension 14 can be used to describe the profile 
geometry and therefore resonance characteristics of the suspension. In the 
embodiment shown, instrument 232 is an optical point range sensor mounted 
to station 204 between base clamp 238 and load cell 234, and above 
suspensions 14 clamped at the base clamp. Optical point range sensors are 
generally known and commercially available from a number of suppliers 
including WYKO Corporation of Tucson, Ariz. Briefly, point range sensors 
of this type generate a light beam which is directed to a measurement 
target at a non-perpendicular angle. The light beam is then reflected from 
the target and directed to a detector. The position at which the reflected 
light beam strikes the detector will vary as a function of the distance 
between the instrument 232 and the measurement target. On station 204, the 
instrument 232 is positioned to direct the light beam to the location on 
the rigid region 26 of suspension 14 at which the height parameter is to 
be measured (e.g., the height location). Z-height measurement instrument 
232 can then provide a height parameter measurement of the suspension 14 
when the suspension is elevated to fly height by the load cell 234. 
Although not shown, station 204 can include alternative measurement 
instruments for measuring the height parameter of suspensions 14. 
Furthermore, additional and/or alternative parameters to height can be 
used to characterize the profile geometry of the suspensions 14. 
After the gram load and height parameter of the suspension 14 are measured, 
stepper motor 236 is actuated to raise the load cell 234 to its retracted 
position and return the suspension 14 to its free state. The base clamp 
238 is opened to release the suspension 14, and allow the suspension to be 
transported to the next station by walking beam 101". 
Static attitude measure and pitch adjust station 206 includes suspension 
clamp assembly 240, pitch adjust mechanism 242 and static attitude 
measurement instrument 244. After the suspension 14 is advanced to station 
206 by walking beam 101", clamp assembly 240 is actuated and driven from 
its open position to a baseplate clamping position at which the baseplate 
21 of the suspension is functionally clamped and the suspension elevated 
to fly height. The static attitude of the flexure 20 (both pitch and roll 
in the illustrated embodiment) is then measured by instrument 244. After 
the static attitude is measured, clamp assembly 240 is again actuated and 
driven from the baseplate clamping position to a load beam clamping 
position. At the load beam clamping position clamp assembly 240 fixedly 
clamps the rigid region 26 of the load beam 16. Pitch adjust mechanism 242 
is then actuated to engage and adjust the pitch of the flexure 20. 
Following these static attitude measurement and pitch adjust procedures, 
clamp assembly 240 is opened to release the suspension 14, and allow the 
suspension to be transported to the next station by walking beam 101". In 
other embodiments (not shown), pitch adjust mechanism 242 is configured to 
engage and bend the distal end of load beam 16 to include pitch changes. 
As shown generally in FIGS. 12 and 13A-13C, suspension clamp assembly 240 
includes a base assembly 246, baseplate clamp assembly 248 and load beam 
clamp assembly 250. Base assembly 246 can be described in greater detail 
with reference to FIGS. 14-16, and includes a base 252 and a fly height 
adjustment stop assembly 254. Base 252 is a machined member with an upper 
surface which includes a clamp assembly guide region 256, baseplate 
clamping region 258 and load beam clamping region 260. An elongated 
channel 262 extends into the clamp assembly guide region 256. Channel 262 
has a longitudinal axis which is generally parallel to an axis extending 
through clamping regions 258 and 260, a lower surface 264 which slopes 
downwardly with increasing distance from the clamping regions, and a pair 
of semicircular bearing channels 266 which extend transversely across the 
channel at spaced locations. Fly height adjustment stop assembly 254 
includes a pair of roller bearings 268 mounted within bearing channels 
266, stop block 270, spring 272 and height adjustment control 274. Stop 
block 270 has a lower surface 276 which is generally parallel to the lower 
surface 264 of channel 262, an upper surface 278 which is generally 
parallel to the surface of clamp assembly guide region 256, and a central 
opening 280 which extends between the upper and lower surfaces. The lower 
surface 276 of stop block 270 is positioned on roller bearings 268 to 
enable the stop block to slide within channel 262, and thereby vary the 
position of the upper surface 278 (i.e., the height of the upper surface) 
with respect to the surface of base 252. A lower end of spring 272 is 
hooked around pin 282 which is mounted to base 252. An upper end of the 
spring 272 extends through opening 280 and is hooked around a pin 284 
which is mounted to the stop block 270. Spring 272 therefore biases the 
stop block 270 in a direction away from clamping regions 258 and 260. 
Height adjustment control 274 includes mounting member 286, threaded 
insert 288, threaded rod 290 and knob 292. Mounting member 286 is 
positioned on the rear side of base 252 adjacent the position into which 
the channel 262 opens, and includes a bore 294 aligned with the channel. 
Threaded insert 288 is mounted within the bore 295. Shaft 290 is 
threadedly mounted within insert 288 and has a stop end 295 which extends 
into channel 262. Shaft 290 thereby limits the motion of stop block 270 
within the channel 262. The height of the upper surface 278 of stop block 
270 can therefore be adjusted and set using knob 292 to rotate shaft 290. 
Baseplate clamping region 258 and load beam clamping region 260 of the base 
252 can be described in greater detail with reference to FIGS. 14, 16 and 
17. The baseplate clamping region 260 includes a baseplate clamp pad 300, 
guide pads 302 on opposite sides of the clamp pad and guide ridges 304 
between the guide pads and the sides of base 252. Baseplate clamp pad 300 
is elevated from the surrounding portions of the base 252, and has a 
generally planar upper surface which is configured to receive the 
baseplate 21 of suspensions 14. The guide pads 300 have surfaces which 
slope upwardly toward the clamp pad 300 to guide the baseplate 21 of 
suspensions 14 being advanced to and from the clamp pad by the walking 
beam 101''. Similarly, the guide ridges 304 have surfaces which slope 
upwardly toward clamp pad 300 and guide suspensions 14 being advanced to 
and from the clamp pad. 
A registration bore 306 extends into clamp pad 300 and is sized to receive 
the mounting boss 23 of suspension 14 clamped to the clamp pad. A rod 308 
is mounted within the bore 306 for reciprocal motion, and is biased 
upwardly by spring assembly 310. In the embodiment shown, spring assembly 
310 includes springs 312 and 314 and plunger 316 which are retained in a 
bore 318 below aperture 306 by screw 320. Spring 314 is positioned between 
screw 320 and plunger 316. Spring 312 is positioned between the plunger 
316 and rod 308. As shown in FIG. 17, spring assembly 310 is configured 
and positioned within bore 318 in such a manner that in its uncompressed 
or free state the upper surface of rod 308 is generally coplanar with the 
upper surface of clamp pad 300. When baseplates 21 of suspensions 14 are 
clamped to the clamp pad 300 by the baseplate clamp assembly 248, the 
mounting boss 23 will extend into bore 306 to accurately position the 
suspension on the clamp pad. This motion forces rod 308 downwardly and 
compresses springs 312 and 314. When the baseplate 21 of the suspension 14 
is subsequently released by the baseplate clamp assembly 248, spring 
assembly 310 forces rod 308 upwardly, thereby lifting the mounting boss 23 
out of bore 306 to allow the suspension to be advanced from the clamp pad 
300 by walking beam 101". 
Load beam clamping region 260 includes a clamp surface 322 and a pair of 
guide pads 324 which are positioned on opposite sides of the clamp 
surface. The guide pads 324 have surfaces which slope upwardly toward the 
clamp surface 322 to guide the rigid region 26 of suspensions 14 being 
advanced to and from the clamp surface by the walking beam 101". Clamp 
surface 322 is recessed from the surfaces of guide pads 324 and includes a 
bore 326. As shown in FIG. 17, at shoulder 328 the bore 326 extends into a 
larger diameter bore 330. A plunger 332 which includes a rod 334 and 
piston 336 is mounted for reciprocal motion within bores 326 and 330, and 
is biased upwardly by spring assembly 338. Spring assembly 338 includes 
spring 340, washer 342 and screw 344. Spring 340 is retained within bore 
330 in a compressed state to force plunger 332 upwardly to the extended 
position shown in FIG. 17 at which piston 336 is engaged with shoulder 328 
and the rod 334 extends from aperture 326 to a height above the clamp 
surface 322. When the rigid region 26 of suspensions 14 are clamped to the 
clamp surface 322 by the load beam clamp assembly 250, the plunger rod 334 
will be forced into bore 326 by the rigid region of the suspension. When 
the rigid region 26 of the suspension 14 is subsequently released by the 
load beam clamp assembly 250, spring assembly 338 forces plunger 332 
upwardly, thereby lifting the rigid region of the suspension from the 
clamp surface 322 to allow the suspension to be advanced by walking beam 
101''. 
Baseplate clamp assembly 248 and load beam clamp assembly 250 can be 
described generally with reference to FIGS. 12, 13A-13C, 14, 15, and 
18-22. The baseplate clamp assembly 248 includes a support frame 350, 
clamping frame assembly 352 and pneumatic actuator 354. Support frame 350 
supports both the baseplate clamp assembly 248 and load beam clamp 
assembly 250 above the base assembly 246 and includes a pair of vertically 
oriented side members 356 and a cross member 358 which is supported by the 
side members. Actuator 354 is mounted to the upper surface of the cross 
member 358 and includes an actuator arm 360 which extends through an 
aperture (not visible) in the cross member. Clamping frame assembly 352 
includes frame plate 362, yoke 364, elevator assembly 366, guide shafts 
368 and clamp pad assembly 370. Yoke 364 is mounted to the upper surface 
of frame plate 362 by screws 372 and has a slot 374 which is sized to 
receive rod 376. The upper end of rod 376 is fastened to actuator arm 360 
by nuts 378, while the lower end of the rod is fastened to yoke 364 by 
rings 380 and 382 which extend from and engage the rod at positions above 
and below the yoke. 
Guide shafts 368 extend from the lower surface of frame plate 362 and are 
positioned for reciprocal motion in linear bearings 384 which are mounted 
within apertures 386 in the base 252. In the embodiment shown, two guide 
shafts 368 are located on opposite sides at the back of the frame plate 
362, while one guide shaft 362 is centrally located in a tongue 388 
extending from the front of the frame plate. A pair of spaced and 
elongated ridges 390 extend downwardly from the surrounding lower surface 
of the frame plate 362. As perhaps best shown in FIG. 18, ridges 390 
extend between the opposite sides of the frame plate 362, with one of the 
ridges being positioned between the pair of guide shafts 368 at the back 
of the frame plate and the other located rearwardly of the tongue 388. The 
guide shafts 368 cooperate with linear bearings 384 to guide frame plate 
362 and other components of clamping frame assembly 352 through reciprocal 
baseplate clamping strokes. 
Clamp pad assembly 370 can be described with reference to FIGS. 23A and 
23B. As shown, the clamp pad assembly 370 is mounted within a chamber 392 
centrally located in the front of the tongue 388 of frame plate 362. 
Chamber 392 is circular in cross section and has an upper portion 393 and 
a reduced diameter lower portion 395 which are separated by shoulder 397. 
The clamp pad assembly 370 includes outer tube 394, inner tube 396, spring 
398, jewel ring 400 and clamp pad 402. Outer tube 394 is concentrically 
mounted for reciprocal motion within lower portion 395 of chamber 392 and 
has an outwardly extending lip 404 on its upper end and an inwardly 
extending lip 406 at a position spaced from its lower end. Lip 404 extends 
into upper portion 393 of the chamber 392 and engages shoulder 397 to 
limit the downward motion of outer tube 394. Inner tube 396 is mounted 
within outer tube 394 and has an outwardly extending lip 408 on its lower 
edge. Inner tube 396 is positioned with its lip 408 within outer tube 394 
and below the inwardly extending lip 406 of the outer tube. The upward 
motion of the inner tube 396 is thereby limited when its lip 408 engages 
the lip 406 of outer tube 394. Spring 398 is concentrically mounted around 
the inner tube 396 and extends between the inwardly extending lip 406 of 
the outer tube 394 and a cover plate 410. Cover plate 410 is secured to 
frame plate 362 by screws 412 (FIG. 19). Spring 398 biases the tubes 394 
and 396 and clamp pad 402 to the extended position shown in FIGS. 18 and 
23A at which the lower edge of tube 394 projects below the lower surface 
of frame plate 362. 
Clamp pad 402 includes a clamp ball 414, mounting pin 416 and nut 420. The 
clamp ball 414 is a semi-spherical member having a flat clamping surface. 
Pin 416 is fixedly mounted to the semi-spherical surface of the clamp ball 
414 and extends upwardly through ring 400 and into the inner tube 396. Nut 
420 is fastened to the end of pin 416 to hold the pin in the inner tube 
396 with the semi-spherical surface of clamp ball 414 engaged with the 
ring 400 and the flat clamping surface extending below the lower edge of 
tube 394. As shown in FIGS. 23A and 23B, the outer diameter of the 
mounting pin 416 is sufficiently less than the inner diameter of the inner 
tube 396 to enable the pin to rock or swing within the tube while the 
semi-spherical surface of the clamp ball 414 rotates within the ring 400. 
Ring 400 and the other components of clamp pad assembly 370 thereby 
securely engage the clamp ball 414 while allowing the flat clamping 
surface of the clamp ball to engage the mounting regions 18 of suspensions 
14 which lack parallelism with the baseplate clamp pad 300 (FIG. 14) when 
the suspensions are positioned on the clamp pad (e.g., due to tolerance 
variations). 
A pair of locating pins 422 having tapered lower edges project from the 
lower surface of frame plate 362. Locating pins 422 are positioned 
rearwardly and on opposite sides of the clamp pad assembly 370, and are 
sized to extend through apertures 35 in carrier strips 34 (FIG. 2) and 
into holes 424 of base 252. 
Elevator assembly 366 can be described with reference to FIGS. 19 and 22. 
As shown, the assembly 366 includes bracket 440 and elevator pin 442. 
Bracket 440 is fastened to the forward edge of the frame plate tongue 388 
by screws 444. Elevator pin 442 is mounted within an aperture in the 
bracket 440 by screw 446, and extends downwardly from the bracket. 
As shown in FIGS. 12, 13A-13C, 14, 15, and 18-22, load beam clamp assembly 
250 includes adjustment frame 450, guide shafts 452 and pneumatic 
actuators 454. Frame 450 is a generally rectangularly shaped member having 
a central opening. A clamp base 456 is mounted to the front of frame 450. 
Guide shafts 452 extend from the lower surface of frame 450 and are 
positioned for reciprocal motion in linear bearings 458 which are mounted 
within apertures 460 in the base 252. The adjustment frame 450 is 
positioned below the frame plate 362 of clamping frame assembly 352 and 
includes a pair of spaced recesses 462 in the upper surface of both sides. 
The guide shafts 368 of the clamping frame assembly 352 extend through the 
central opening of adjustment frame 450 enabling reciprocal motion of the 
adjustment frame with respect to the clamping frame assembly. A pair of 
spaced recesses 464 are located in the lower surface of both sides of the 
frame plate 362 of the clamping frame assembly 352, directly above the 
recesses 462 in the adjustment frame 450. 
Actuators 454 are mounted to the upper surface of frame plate 362 of 
clamping frame assembly 352 on its opposite sides between recesses 464, 
and include actuator arms 466 which extend downwardly through the frame 
plate and into apertures 468 in adjustment frame 450. Ends of the actuator 
arms 466 are secured to adjustment frame 450 by screws 470. Springs 472 
are mounted in associated recesses 462 and 464 to bias adjustment frame 
450 downwardly from the frame plate 362 of the clamping frame assembly 
352. 
Clamp base 456 includes a load beam clamp pad 474 and guide pads 476 on 
opposite sides of the clamp pad. The load beam clamp pad 474 is elevated 
from the surrounding portions of base 456, and has a generally planar 
surface with a central bore 478. The planar surface of clamp pad 474 is 
configured to engage the rigid region 26 of suspensions 14. The guide pads 
476 have surfaces which slope towards the load beam clamp pad 474 to guide 
the load beam 16 of suspensions 14 being advanced to and from the clamp 
pad by the walking beam 101". As shown in FIGS. 13A-13C and 22, bore 478 
extends through the load beam clamp pad 474 and base 456, and is aligned 
with the elevator pin 442. Clamp base 456 also includes an aperture 480 in 
front of the load beam clamp pad 474. As described below, aperture 480 
functions as a shutter for the light beam used to measure the static 
attitude of suspensions 14 clamped by clamp assembly 240. 
Static attitude measurement instrument 244 is fixedly mounted to a support 
frame 484 at a position directly above the aperture 480 in clamp base 456. 
In the embodiment shown, instrument 244 is an autocollimator. 
Autocollimators are generally known and commercially available from a 
number of sources including Sight Systems of Newburry Park, Calif. and 
WYKO of Tucson Ariz. Briefly, autocollimator instruments of this type 
generate a collimated beam of light which is directed to a measurement 
target. The light beam is then reflected from the measurement target and 
directed to a detector. The incident angle at which the reflected light 
beam strikes the detector will vary as a function of the orientation of 
the surface of the target (i.e., its angle) with respect to the light 
beam. At station 206, instrument 244 is positioned to direct the 
collimated light beam to the flexure 20 of suspension 14 through aperture 
480. Instrument 244 can then provide a measurement of the static attitude 
of the flexure 20 when suspension 14 is elevated to fly height by 
baseplate clamp assembly 248 in the manner described below. Although not 
shown, station 206 can include alternative measurement instruments for 
measuring the static attitude of flexures 20. 
Pitch adjust mechanism 242 includes stepper motor 488 and flexure bending 
assembly 490. As shown in FIG. 11, the stepper motor 488 is fixedly 
mounted with respect to base 103' adjacent to suspension clamp assembly 
240. As shown in FIGS. 13A-13C, 22 and 24, bending assembly 490 includes 
an arm 492 which is mounted to and driven by the stepper motor 488. A 
generally C-shaped member 494 is located on the end of arm 492 and 
includes a pair of flexure-engaging pins 496. One of pins 496 extends 
upwardly from the lower surface of member 494, while the other extends 
downwardly from the upper surface of the member. The flexure bending 
assembly 490 is shown at a suspension transfer position in FIG. 13A. In 
this transfer position the gap between the ends of pins 496 is aligned 
with the upper surface of rod 334 enabling suspensions 14 to be advanced 
into and out of clamp assembly 240 with the flexures 20 extending between 
the pins. 
A control system 500 for controlling the operation of adjust equipment 200 
is illustrated generally in FIG. 25. As shown, the control system 500 
includes a digital processor 502 coupled to program memory 504 and 
interface terminal 506. The processor 502 is also interfaced to the 
electrical subsystems (i.e., the electrical components) of each station 
102", 202, 204, 206, 208 and 210. In particular, processor 502 is 
interfaced to roll station electrical subsystem 501, backbend station 
electrical subsystem 503, gram load and profile measure station electrical 
subsystem 505, static attitude measure and pitch adjust station electrical 
subsystem 507, laser adjust station electrical subsystem 509 and static 
attitude measure station electrical subsystem 511. FIG. 26 illustrates in 
greater detail the electrical subsystems 505 and 507 of the gram load and 
profile measure station 204 and static attitude measure and pitch adjust 
station 206, respectively. As shown, the electrical subsystem 505 of the 
gram load and profile measure station 204 includes Z-height measurement 
instrument 232, load cell 234 and stepper motor 236. The electrical 
subsystem 507 of the static attitude measure and pitch adjust station 206 
includes static attitude measurement instrument 244, stepper motor 488, 
baseplate clamp pneumatic valve 508 and load beam clamp pneumatic valve 
510. 
A static attitude adjust program executed by the processor 502 to perform 
static attitude measure and pitch adjust procedures is stored in memory 
504. Baseplate clamp valve 508 couples a source of pressurized air (not 
shown) to pneumatic actuator 345 through fittings such as 512 (FIG. 12) 
and hoses such as 514 (not shown in FIG. 12). Similarly, load beam clamp 
valve 510 couples the source of pressurized air to pneumatic actuators 454 
through fittings such as 516 and hoses such as 518. 
The pitch adjust procedures are based upon the knowledge that the pitch of 
a flexure 20 of a suspension 14 can be predictably adjusted to a high 
degree of accuracy, repeatability and stability by bending the flexure 
upwardly or downwardly a predetermined amount beyond its range of elastic 
deformation (i.e., plastic deformation) with respect to the adjacent rigid 
region 26 of the load beam 16. The magnitude of the change in pitch 
generated by this procedure is dependent upon the distance or degree to 
which the flexure 20 is bent within its range of plastic deformation. 
Accordingly, suspension adjust data representative of desired pitch angle 
changes as a function of flexure bend positions is stored in memory 504. 
The flexure bend positions are positions to which the flexure 20 (or load 
beam 16) of a suspension 14 is driven upwardly or downwardly by pitch 
adjust mechanism 242 from its then-current position. The flexure bend 
positions can be correlated to the number of steps motor 488 must be 
driven to raise or lower bending assembly 490 from its clamping position 
to position the pins 496 at the desired bend positions. Also stored in 
memory is data representative of the nominal or desired pitch of flexure 
20. 
FIG. 27 is a flow diagram illustrating the static attitude measure and 
pitch adjust procedures performed by station 206. The procedure begins 
with the transfer of a suspension 14 to be measured and pitch adjusted 
into the suspension clamp assembly 240 while the clamp assembly is in the 
suspension transfer position shown in FIG. 13A (step 510). Processor 502 
causes the clamp assembly 240 to be in the suspension transfer position by 
actuating baseplate clamp valve 508 in such a manner that pneumatic 
actuator 354 retracts its actuator arm 360 and drives baseplate clamp 
assembly 248 upwardly to a retracted position. Simultaneously, processor 
502 actuates load beam clamp valve 510 in such a manner that pneumatic 
actuators 454 retract their actuator arms 466 and drive load beam clamp 
assembly 250 upwardly to a retracted position against the bias forces of 
springs 472. When the baseplate clamp assembly 248 is in the retracted 
position the clamp pad assembly 370 will be biased to its extended 
position shown in FIG. 23A, while the spring assembly 310 will bias rod 
308 at the baseplate clamping region 258 on the base 252 to the extended 
position shown in FIG. 17. The lower surface and ridges 390 of the 
baseplate clamp assembly frame plate 362 are spaced from the upper surface 
of the base assembly stop block 270 when the baseplate clamp assembly 248 
is in the retracted position. When the load beam clamp assembly 250 is in 
its retracted position the elevator pin 442 extends through bore 478 and 
beyond the load beam clamp pad 474. Spring assembly 338 biases plunger 332 
upwardly to an extended position shown in FIG. 17 at which it projects 
beyond the clamp surface 322 when the load beam clamp assembly 250 is in 
the retracted position. As shown in FIG. 13A, when the clamp assembly 240 
is in its retracted position there is sufficient clearance between the 
baseplate clamp ball 414 and the baseplate clamp pad 300, and between the 
load beam clamp pad 474 and the load beam plunger 332, to allow 
suspensions 14 to be advanced into and out of the clamp assembly. 
After a suspension 14 to be measured and adjusted has been advanced into 
the clamp assembly 240, processor 502 actuates baseplate clamp valve 508 
in such a manner as to cause pneumatic actuator 354 to extend its actuator 
arm 360 and drive baseplate clamp frame assembly 352 downwardly through a 
baseplate clamping stroke to the baseplate clamping position shown in FIG. 
13B (step 512). Locating pins 422 extend downwardly from the functional 
clamp assembly frame plate 362 a greater distance than the clamp pad 
assembly 370 in its extended position, so as the baseplate clamp frame 
assembly 352 is moving downwardly, the locating pins will enter apertures 
35 in the suspension carrier strip 34 and register the suspension 14 over 
the baseplate clamp pad 300. With continued downward motion of the clamp 
frame assembly 352, the flat lower surface of clamp ball 414 will engage 
the mounting region 18 of the suspension 14 and force the mounting boss 23 
into the registration bore 306, thereby forcing rod 308 downwardly against 
the bias force of spring assembly 310 and urging the baseplate 21 of the 
suspension into contact with the planar surface of the baseplate clamp pad 
300. With still further downward motion of the clamp frame assembly the 
clamp pad assembly 370 is forced toward its retracted position within the 
frame plate 362 against the bias force of spring 398 (FIG. 23B) to 
securely clamp the mounting region 18 of the suspension 14 to the 
baseplate clamp pad 300 (i.e., functionally clamp). This downward motion 
also causes the elevator pin 442 to engage the rigid region 26 of the load 
beam 16 and elevate the load beam from its free state. 
When the clamp frame assembly 352 is in the baseplate clamping position the 
ridges 390 on the lower surface of the baseplate clamp assembly frame 
plate 362 are engaged with the upper surface of the base assembly stop 
block 270. By adjusting the height of the stop block 270 with respect to 
the base 252, the position of the tip of elevator pin 442 can be set so 
the elevator pin drives the suspension 14 to fly height when the clamp 
frame assembly 352 is in the baseplate clamping position. 
After the baseplate 21 of the suspension 14 is functionally clamped to base 
252 and flexure 20 elevated to fly height processor 502 actuates static 
attitude measurement instrument 244. As shown in FIG. 13B, static attitude 
measurement instrument 244 generates and directs a light beam 514 onto the 
flexure 20 of the suspension. In the embodiment shown the light beam 514 
passes through aperture 480 so that only light reflected off the flexure 
20 of the suspension 14 is directed back to the instrument 244. Static 
attitude data, including both roll data characteristic of the pre-adjust 
fly height roll of the flexure 20 and pitch data representative of the 
pre-adjust fly height pitch of the flexure is thereby provided to 
processor 502 by the instrument 244 (step 516). 
After the static attitude measurement is completed, processor 502 actuates 
load beam clamp valve 510 in such a manner as to cause pneumatic actuators 
454 to release their actuator arms 466 and allow springs 472 to force the 
adjustment frame 450 downwardly through a load beam clamping stroke to the 
load beam clamping position shown in FIG. 13C (step 518). As the 
adjustment frame 450 moves through its clamping stroke the load beam clamp 
pad 474 engages the rigid region 26 of suspension 14 and forces the rigid 
region downwardly from the fly height position at which it was held by the 
elevator pin 442 and into engagement with the upper surface of ejector rod 
334. With continued motion of the adjustment frame 450 the clamp pad 474 
clamps the rigid region 26 of the suspension 14 into clamp surface 322 of 
the base 252. Ejector rod 334 is forced to a retracted position within 
base 252 when the rigid region 26 of the suspension 14 is clamped to 
surface 322. 
Following the static attitude measurement, processor 502 also computes the 
difference between the measured pre-adjust pitch and the nominal pitch to 
determine the desired pitch change (Dpitch) (i.e., the amount of pitch 
adjustment to be made by station 206) (step 520). Processor 502 then 
accesses the suspension adjust data as a function of the desired pitch 
change to compute or otherwise determine a position referred to as "Bump." 
Bump is the flexure bend position which will produce the desired pitch 
change (step 522). As described in greater detail below, Bump is 
functionally related to the desired changes in the height (Dheight), roll 
(Droll) and gram load (Dgram) as well as Dpitch. The mathematical 
algorithm used by processor 502 therefore computes Bump as a function of 
Pitch, Dheight, Droll and Dgram. In the embodiment described herein, 
processor 502 computes Bump in terms of the required number of steps that 
stepper motor 488 must be driven to raise or lower the bending assembly 
490 from its transfer position. Stepper motor 488 is then actuated by 
processor 502 in such a manner to drive the bending assembly 490 and 
position the tips of pins 496 at the desired flexure bend positions (step 
524). Stepper motor 488 is then actuated to drive bending assembly 490 
back to the transfer position to complete the pitch adjust procedure (step 
526). Flexure 20 is thereby bent to a position that will (after the laser 
adjust procedure performed at station 208 and described below) provide the 
flexure with the desired or nominal pitch angle when the flexure is 
elevated to fly height. 
The static attitude measurement and pitch adjust procedure is completed 
when the baseplate clamp valve 508 and load beam clamp valve 510 are again 
actuated by processor 502 to drive suspension clamp assembly 240 back to 
its suspension transfer position by retracting the clamp frame assembly 
352 and the adjustment frame 450 (step 510). As the adjustment frame 450 
is retracted from its clamping position the spring assembly 338 will 
return to its extended position and force plunger 332 upwardly to lift the 
rigid region 26 of the suspension 14 from the clamp surface 322 of base 
252. Similarly, as the clamp frame assembly 352 is retracted from its 
baseplate clamping position the spring assembly 310 will force rod 308 
upwardly to lift the suspension baseplate boss 23 from the bore 306 and 
release the suspension 14 from the clamp assembly 240. The static 
attitude-measured and pitch-adjusted suspension 14 can then be advanced 
from the clamp assembly 240. The static attitude measurement and pitch 
adjust procedure described above can then be repeated on another 
suspension 14. 
Laser adjust station 208 can be described with reference to FIGS. 11 and 
28-31. As shown, laser adjust station 208 includes a baseplate clamp 
assembly 540, load beam positioning assembly 542, load beam clamping 
assembly 544, optical fibers 546, Z-height measurement instrument 548 and 
gram load measurement assembly 550. Baseplate clamp assembly 540 includes 
a fixed base 552 and a moving clamping member 554. Base 552 is rigidly 
mounted with respect to the walking beam 101'' and has a baseplate clamp 
pad 556 configured to receive and register the baseplate 21 of suspension 
14. A spring-biased plunger 558 is located in the center of the clamp pad 
556. Moving clamping member 554 includes a clamp pad 560 and is 
reciprocally driven between transfer (open) and clamping (closed) 
positions with respect to base 552 in synchronization with the motion of 
walking beam 101". At the beginning of a laser adjust procedure, clamping 
member 554 is in its transfer position (not shown) spaced from base 552. 
The walking beam 101" then advances the suspension 14 to be adjusted into 
clamp assembly 540. After the suspension baseplate 21 is aligned with the 
clamp pad 556 by the walking beam 101", clamping member 554 is driven to 
the clamping position shown in FIGS. 28 and 30, functionally clamping the 
baseplate between clamp pads 556 and 560. The mounting region of the 
suspension 14 is thereby clamped and rigidly held in the laser adjust 
station 208 throughout the laser adjust procedure. Following the 
completion of the laser adjust procedure and post-adjust Z-height and gram 
load measurements, the clamping member 554 is driven to its transfer 
position to release the suspension 14 and allow the suspension to be 
advanced from the laser adjust station 208 by the walking beam 101". 
Z-height measurement instrument 548 can be identical to the instrument 232 
described above with reference to gram load and profile measure station 
204, and is positioned and configured to measure the height parameter of 
suspensions 14 clamped at clamping assembly 540. Gram load measurement 
assembly 550 includes a load cell 562 having a measurement probe 582. 
Drive assembly 564 includes an arm assembly 566, arm mount 568 and 
pneumatic actuator 570. Arm mount 568 is supported by a frame 572. 
Pneumatic actuator 570 is mounted to a frame 574 at a location above the 
arm mount 568, and includes a piston (not visible) connected by collar 576 
to a rod 578 which extends through the arm mount. The end of arm assembly 
566 which is located below arm mount 568 is fixedly connected to rod 578 
and includes guide shafts 580 which extend upwardly into linear bearings 
(not visible) in the arm mount. Load cell 562 is mounted to the end of arm 
assembly 566 adjacent to clamping assembly 540 to position the measurement 
probe 582 of the load cell above the flexure 20 of suspensions 14 clamped 
to the clamping assembly. 
Pneumatic actuator 570 is actuated by control system 500 to drive arm 
assembly 566 and load cell 562 between a retracted position and an 
extended or measurement position. In the retracted position the load cell 
562 is raised above the load beam positioning assembly 542 to provide 
sufficient clearance for the suspensions 14 to be advanced into and out of 
the laser adjust station 208 by the walking beam 101". In the measurement 
position the load cell 562 is driven downwardly to engage the measurement 
probe 582 with the flexure 20 of the suspension 14 and elevate the 
suspension to fly height. The extent of the downward motion of load cell 
562 is limited by the engagement of the collar 576 with a stop block 584 
on the top of arm mount 568. The vertical position of the stop block 584 
with respect to arm mount 568, and therefore the fly height to which 
suspensions 14 are elevated when the load cell 562 is driven to its 
extended position, can be adjusted through the use of micrometer 586. 
Load beam clamping assembly 544 includes pneumatic actuator 590, arm 592 
and bracket 594. Pneumatic actuator 590 is fixedly mounted to frame 596 
and includes a piston 598 mounted to an end of arm 592 by collar 600. 
Bracket 594 is mounted to the end of arm 592 opposite collar 600. Optical 
fibers 546 and load beam clamp pad assembly 602 are mounted to bracket 
594. In the embodiment shown, load beam clamp pad assembly 602 includes 
three pogo pins 604 which are biased downwardly toward the load beam 
positioning assembly 542 by springs 606. As perhaps best shown in FIG. 28, 
optical fibers 546 are mounted to bracket 594 in such a manner as to 
position the ends of the fibers above the legs of the spring region 24 of 
the suspension 14 clamped at station 208. Clamp pad assembly 602 is 
mounted to the bracket 594 in such a manner as to position the assembly 
above the rigid region 26 of the suspension 14 clamped at station 208. 
Pneumatic actuator 590 is actuated by control system 500 and drives the 
arm 592, optical fibers 546 and clamp pad assembly 602 between a retracted 
position and an extended or load beam clamping position. 
Load beam positioning assembly 542 includes stepper motors 610A-610C and 
positioning pin assemblies 612A-612C which are driven by the motors. 
Positioning pin assemblies 612A-612C include arms 614A-614C connected to 
the respective motors 610A-610C, and positioning pins 616A-616C which are 
mounted to and extend upwardly from the ends of the arms. As perhaps best 
shown in FIGS. 29 and 31, the arms 614A-614C are configured to position 
the pins 616A-616C below the rigid region 26 of suspensions 14 clamped at 
station 208. In the particular embodiment shown, pins 616A and 616B are 
positioned below a central portion of the rigid region 26 along a 
generally transverse load beam axis, and symmetrically spaced from the 
central longitudinal load beam axis. Pin 616C is positioned on the central 
longitudinal axis below a rear portion of the rigid region 26 and adjacent 
to the spring region 24. Stepper motors 610A-610C drive positioning pin 
assemblies 612A-612C between retracted positions and extended adjust 
positions. When in the retracted positions, positioning pins 616A-616C are 
at positions which provide sufficient clearance for suspensions 14 to be 
advanced into and out of station 208. 
The electrical subsystem 509 of laser adjust station 208 is illustrated 
generally in FIG. 32. As shown, the electrical subsystem 509 includes 
stepper motors 610A-610C, load cell 562, Z-height measurement instrument 
548, load beam clamp valve 618, load cell elevator valve 620 and diode 
laser 622. Load beam clamp valve 618 couples a source of pressurized air 
(not shown) to pneumatic actuator 590 through hoses such as 624 (FIG. 11). 
Similarly, valve 620 couples the source of pressurized air to pneumatic 
actuator 570 through the hoses 624. 
The laser adjust procedure performed by station 208 is based upon the 
discovery that the Z-height, roll and gram load of suspension 14 can be 
predictably adjusted to a high degree of accuracy, repeatability and 
stability by driving the rigid region 26 to a predetermined position and 
orientation from its free state to stress the spring region 24, and to 
relieve the stresses by heating the spring region (e.g., through the 
application of an infrared laser beam) while the load beam is held in the 
predetermined position and orientation. The magnitude of the Z-height, 
roll and gram load change generated or induced by this process is 
dependent upon the amounts and distribution of the stress to which the 
spring region 24 is subjected before being stress relieved, and this 
stress level and distribution can be controlled by the position and 
orientation of the load beam with respect to its free state position and 
orientation. 
Accordingly, adjust data representative of desired fly height gram load, 
height and roll changes as a function of load beam adjust positions and 
orientations is stored in the memory 504 of control system 500. The load 
beam adjust positions and orientations are positions and orientations to 
which the load beam 26 is driven by positioning assembly 542 from its free 
state position. In the preferred embodiment described herein the adjust 
data characterizes a series of linear and nonlinear equations describing 
gram load, height and roll changes as a function of adjust positions and 
orientations. The load beam adjust positions are planar positions 
established by the positioning pins 616A-616C. Stated another way, in the 
embodiment described herein the positioning pins 616A-616C are driven to 
positions which support the load beam 26 of suspensions 14 in planar 
positions and orientations during the laser adjust procedures. The adjust 
position of each pin 616A-616C can be correlated to the number of steps 
motors 610A-610C, respectively, are driven from their retracted positions 
to position the pins at the desired adjust positions. Data representative 
of desired or nominal values of fly height gram load, height and roll for 
suspensions 14 are also stored in memory 504. 
FIG. 33 is a flow diagram illustrating the laser adjust procedure performed 
by station 208 on suspensions 14 clamped at clamping assembly 540. The 
procedure begins with the transfer of a suspension 14 to be height, gram 
load and roll adjusted into the clamping assembly 540 when the clamping 
member 554 is in its transfer position, and closing the clamping member to 
functionally clamp the mounting region 18 to base 552 between clamp pads 
560 and 556 (step 630). The differences (i.e., desired changes) between 
the measured pre-adjust and desired or nominal gram load, height, roll and 
pitch values (Dgram, Dheight, Droll and Pitch, respectively) are computed 
by processor 502 (step 632). Processor 502 then accesses the adjust data 
as a function of the desired changes in gram load, height, roll and pitch 
to compute or otherwise determine the adjust positions of pins 616A-616C 
(step 634). Stepper motors 610A-610C are then actuated by processor 502 in 
such a manner as to drive the positioning pin assemblies 612A-612C 
upwardly and position the pins 616A-616C at the adjust positions (step 
636). 
After the positioning pin assemblies 612A-612C are driven to their adjust 
positions, processor 502 actuates load beam clamp valve 618 in such a 
manner as to cause pneumatic actuator 590 to drive arm 592 and the load 
beam clamp pad assembly 602 on the end thereof from its retracted position 
to the load beam clamping position shown in FIGS. 28 and 30 (step 638). 
The pogo pins 604 of clamp pad assembly 602 are located directly above 
positioning pins 616A-616C. As the clamp pad assembly 602 is lowered from 
its retracted position the pogo pins 604 will engage the upper surface of 
the rigid region 26 of suspension 14 and force suspension into the adjust 
position with the lower surface of the rigid region engaged with the tips 
of positioning pins 616A-616C. The springs 606 apply a sufficiently great 
bias force to the pogo pins 604 that the pogo pins will force the rigid 
region 26 of the suspension 14 into engagement with positioning pins 
616A-616C. With continued downward motion of the clamp pad assembly 602 
after the pogo pins have forced the load beam 16 into the adjust position, 
the pogo pins will retract into bracket 594 against the bias force of the 
springs 606. 
With the load beam 26 held at the adjust position, processor 502 actuates 
laser 622 for an exposure time period and causes the spring region 24 to 
be heated and stress relieved by the application of infrared light 
directed to the spring region through the optical fibers 546 (step 640). 
Laser 622 is turned off by the processor 502 at the end of the exposure 
period and the suspension allowed to cool (about 30 msec. in one 
embodiment) (step 642). To complete this laser adjust procedure processor 
502 actuates load beam clamp valve 618 and stepper motors 610A-610C to 
drive the clamp pad assembly 602 and positioning pin assemblies 612A-612C 
to their retracted positions (step 644). 
Post-adjust gram load and z-height (for profile geometry characterization) 
measurements are taken at station 208 following the laser adjust 
procedure. Following the laser adjust procedure the elevator valve 620 is 
actuated by processor 502 to drive load cell 562 downwardly to the 
measurement position at which the suspension 14 is elevated to fly height. 
Processor 502 then takes a post-adjust fly height gram load measurement 
from the load cell 562 (step 646). With the suspension elevated to fly 
height processor 502 also actuates the Z-height measurement instrument and 
takes a post-adjust radius region profile measurement (step 648). 
Following these post-adjust measurements the processor 502 actuates the 
elevator valve 620 to drive the load cell back to its retracted position 
(step 650). Clamping member 554 is then driven to its transfer position 
(opened) to allow the adjusted and measured suspension 14 to be advanced 
out of the clamping assembly 540 by walking beam 101" (step 652). 
Static attitude measurement station 210 can be described with reference to 
FIGS. 11, 34 and 35. As shown, station 210 includes suspension clamp 
assembly 660 and static attitude measurement instrument 662. Static 
attitude measurement instrument 662 can be identical in structure, 
function and operation to instrument 244 described above with reference to 
station 206. With the exception of the differences described immediately 
below, suspension clamp assembly 660 can be identical in structure, 
function and operation to suspension clamp assembly 240 described above 
with reference to station 206, and similar features are identified by 
common but primed (i.e., "x'") reference numerals. The differences between 
clamp assemblies 660 and 240 are due to the fact that no flexure pitch 
adjustment is performed at static attitude measurement station. No load 
beam or adjustment clamping operations are therefore performed by clamp 
assembly 660, so the adjustment frame 450' is not used and is fixedly 
mounted to the frame plate 362' of clamping frame assembly 352' by bolts 
664. Unlike suspension clamp assembly 240 of station 206, suspension clamp 
assembly 660 does not include pneumatic actuators such as 454 or biasing 
springs such as 472 for driving the frame plate 450' to a load beam 
clamping position. 
FIG. 36 is a block diagram of the electrical subsystem 511 of static 
attitude measurement station 210. As shown, electrical subsystem 511 
includes static attitude measurement instrument 662 and functional clamp 
valve 666, both of which are interfaced to processor 502. 
FIG. 37 is a flow diagram illustrating the static attitude measurement 
procedure performed by station 260. The procedure begins with the transfer 
of a suspension 14 to be measured into the suspension clamp assembly 660 
while the clamp assembly is in the suspension transfer position (not 
shown) (step 668). Processor 502 causes the clamp assembly 660 to be in 
the suspension transfer position by actuating load beam clamp valve 666 in 
such a manner that pneumatic actuator 354' retracts its actuator arm 360' 
and drives load beam clamp assembly 248' upwardly to a retracted position. 
After a suspension 14 to be measured has been advanced into the clamp 
assembly 660, processor 502 actuates load beam clamp valve 666 in such a 
manner as to cause pneumatic actuator 354' to extend its actuator arm 360' 
and drive load beam clamp frame assembly 352' downwardly to the baseplate 
clamping position shown in FIG. 35 (step 670). When the clamp frame 
assembly 352' is at its clamping position the elevator pin 442' engages 
the rigid region 26 of the load beam 16 and elevates the load beam 16 from 
its free state to fly height. 
After the baseplate 21 of the suspension 14 is functionally clamped to base 
252' and its flexure 20 elevated to fly height processor 502 actuates 
static attitude measurement instrument 662. As shown in FIG. 35, 
instrument 662 generates and directs a light beam onto the flexure 20 
through aperture 480'. Post-adjust static attitude data, including both 
roll data characteristic of the post-adjust fly height roll of the flexure 
20 and pitch data representative of the post-adjust fly height pitch of 
the flexure is thereby provided to processor 502 by the instrument 662 
(step 672). The post-adjust static attitude measurement is completed when 
the load beam clamp valve 666 is again actuated by processor 502 to drive 
suspension clamp assembly 660 back to its suspension transfer position by 
retracting the clamp frame assembly 352' (step 668). The static 
attitude-measured suspension 14 can then be advanced from the clamp 
assembly 660, and the static attitude measurement procedure described 
above repeated on the next suspension. 
If the post-adjust gram load, height and static attitude of the suspension 
14 is outside the desired specification ranges, the suspension is rejected 
and cut from the carrier strip at the out-of-specification detab station. 
The carrier strips 34 with the remaining in-specification suspensions 14 
are then removed from equipment 200 and transported to a cleaning station 
(not shown). Following the cleaning operations the suspensions 14 are 
transported to a final detab station where all the remaining suspensions 
14 are cut from the carrier strip 34, and subsequently packaged for 
shipment to customers. In other embodiments, the suspensions 14 are also 
heat treated following their adjustment on equipment 200. 
A detailed description of the algorithm executed by processor 502 to 
control the pitch adjust procedure at station 206 and the gram load, 
height and roll adjust procedure (i.e., the laser adjust procedure) at 
station 208 follows. The mathematical equations included in the algorithm 
and referred to below are set out in FIG. 38. As mentioned above, the 
changes in pitch, gram load, height and roll that made at stations 206 and 
208 are designated Pitch, Dgram, Dheight and Droll, respectively. These 
parameters are computed by processor 502 in accordance with Equations 1-4. 
The embodiment of the algorithm described herein makes use of four 
response variables designated "Load," "Bias," "Pivot" and "Bump." These 
response variables are defined in Equations 5-9 in terms of the relative 
pin positions of the pitch adjust mechanism 242 of station 206 and the 
load beam positioning assembly 542 of station 208 to minimize the amount 
of coupling or dependence. 
Equations 9-12 are used to calculate Pivot, Bias, Load and Bump, 
respectively. As described in FIG. 38, in addition to the desired changes 
in pitch, gram load, height and roll, Equations 9-12 make use of weight 
factors "A"-"N" as well as computed constants "Constant", ".alpha." "p", 
"q", "Det", "u" and "v" which are set out in Equations 13-19. The 
numerical system represented by Equations 1-19 has been formatted so that 
there is only one set of real roots, and two pair of conjugate imaginary 
sets. This numerical system can be solved directly using a convolute 
transform, eliminating the need for any type of convergence computational 
technique. 
It has been observed that there are subtle differences in the way that 
different types or designs of suspensions 14 respond to the pitch adjust 
procedure performed at station 206. To account for these differences, the 
exponent in Equation 12 used to calculate Bump includes the variable 
"Power". This variable Power is set for each type of suspension 14 during 
a setup procedure performed by processor 502. For example, when adjusting 
a Type 850 suspension 14 available from Hutchinson Technology 
Incorporated, Power is set equal to three. When adjusting a Type 1650 
suspension 14 available from Hutchinson Technology Incorporated, Power is 
set equal to thirteen. 
During the setup procedure processor 502 executes a teach routine to 
establish weight factors A-N. Processor 502 performs a full factorial with 
Load, Bias and Pivot during the setup procedure. Bump is varied 
independently of Load, Bias and Pivot during this setup procedure. During 
this setup procedure measured pre-adjust and post-adjust values of gram 
load, height, pitch and roll, as well as the associated adjust positions 
are stored and processed by Gaussian regression to compute initial values 
of weight factors A-N. By way of example, representative numerical values 
of weight factors A-N for a Hutchinson Technology Incorporated Type 850 
suspension are listed below in Table 1. Weight factors A-N, and therefore 
the computed constants as well, are also updated on the basis of the 
differences between the desired gram load, height, pitch and roll of the 
suspensions 14, and the measured post-adjust values of gram load, height, 
pitch and roll, respectively, and on the basis of the associated adjust 
positions (i.e., correlation data). In one embodiment, the weight factors 
A-N are continually updated following the adjustment and post-adjust 
measurement of each suspension 14 using the historical correlation data 
from a predetermined number (e.g., eighty in one embodiment) of the most 
recently processed suspensions 14. 
Table 1 
A=9.59655.times.10.sup.2 
B=4.224 
C=-33.378 
D=18.357 
E=-5.73643.times.10.sup.2 
F=-94.246 
G=-56.948 
H=-0.6379 
I=11.59 
J=-0.05835 
K=0.1114 
L=0.57972 
M=-3.457 
N=5.304 
Suspension adjust equipment 700, another embodiment of the present 
invention, is illustrated generally in FIG. 39. As shown, equipment 700 
includes a roll module 702 and an adjust module 704. Roll module 702 
includes a pitch stabilize station 706, roll station 708 and backbend and 
gram load measure station 710, all of which are interfaced to control 
system 712. Adjust module 704 includes gram load and height measure 
station 714, static attitude measure station 715, pitch adjust station 
716, laser adjust station 717, static attitude measurement station 718 and 
gram load and height measure station 719, all of which are interfaced to 
control system 726. 
A walking beam (not shown in FIG. 39) such as that described above with 
respect to suspension adjust equipment 100 advances carrier strips 34 of 
formed suspensions 14 (also not shown) through the roll module 702, and 
sequentially positions each suspension 14 at stations 706, 708 and 710. 
After being positioned at each station 706, 708 and 710 the baseplate 21 
of suspension 14 is functionally clamped at its mounting region 18 and 
processed before being unclamped and advanced to the subsequent station. 
The overall operation of the roll module 702, as well as that of its 
stations 706, 708 and 710, is coordinated and controlled by control system 
712. 
At the pitch stabilization station 706 the flexure 20 of the suspension 14 
is heated to relieve any residual stresses. In one embodiment (the 
individual components of which are not shown), this stress relieving 
heating operation is performed by subjecting the flexure 20 to infrared 
light generated by a laser diode and directed to the flexure by one or 
more optical fibers. Control system 712 can be set up in a manner similar 
to that of station 106 of adjusting equipment 100 described above to apply 
sufficient stress relieving heat, but not brown, the flexure 20. The rigid 
region 26 of the suspension 14 can also be heated to relieve residual 
stresses in a manner similar to that of the flexure 20. 
At roll station 708 the spring region 24 of the suspension 14 is rolled 
around a curved mandrel to form the spring region. Rolling station 708 can 
be structurally and functionally similar to the rolling station 102 of 
adjust equipment 100 described above. 
At backbend and gram load measurement station 710 the suspension 14 is 
backbent a predetermined set amount to reduce and thereby help stabilize 
the gram load of the suspension. The backbending mechanism (not separately 
shown) at station 710 can be structurally and functionally similar to the 
mechanism used to perform the backbend operation at backbend station 202 
of adjust equipment 200 described above. Station 710 also includes a gram 
load measurement instrument (not separately shown in FIG. 40) for 
measuring the post-roll gram load of the suspensions 14. The post-roll 
gram load measurements made at station 710 are used during the roll 
station 708 setup procedure. The gram load measurement instrument at 
station 708 can be structurally and functionally similar to that at 
station 714 and described in greater detail below. 
Adjust module 704 also includes a walking beam (not shown) for advancing 
the carrier strips 34 of suspensions 14 (also not shown) through the 
module and for sequentially positioning each suspension at stations 
714-719. After being positioned at each station 714-719 the suspension 14 
is functionally clamped at its mounting region 18 and processed before 
being unclamped and advanced to the subsequent station. The overall 
operation of the adjust module 704, as well as that of its stations 
714-719 is coordinated and controlled by control system 726. 
At the gram load and height measure station 714 the suspension 14 is 
elevated to fly height. The pre-adjust height (i.e., a profile geometry 
parameter) and pre-adjust gram load of the suspension 14 are then measured 
through the use of a load cell and Z-height measurement instrument (not 
shown in FIG. 39), respectively. 
At the static attitude measure station 715 the suspension is again elevated 
to fly height. The pre-adjust static attitude of the flexure 20 (both roll 
and pitch) are then measured through the use of a static attitude 
measurement instrument (not shown in FIG. 39). 
At the pitch adjust station 716 the rigid region 26 of the suspension 14 is 
rigidly clamped. The flexure 20 is then plastically bent upwardly or 
downwardly by a pitch adjust mechanism (not shown in FIG. 39) to adjust 
the pitch of the flexure. The pitch adjust mechanism can be structurally 
and functionally similar to pitch adjust mechanism 242 of adjust equipment 
200 described above. 
At the laser adjust station 717 a load beam positioning assembly (not shown 
in FIG. 39) orients and positions the rigid region 26 of the suspension 14 
at an adjust position to stress the spring region 24. The spring region 24 
is then stress relieved by the application of infrared light generated by 
a laser and directed to the spring region through optical fibers. The gram 
load, height and roll of the suspension 14 are thereby adjusted. The load 
beam positioning assembly can be structurally and functionally similar to 
load beam positioning assembly 542 of adjust equipment 200 described 
above. The laser and optical fibers can be similar to the fibers 546 and 
laser 622 of adjust equipment 200. The algorithm used by control system 
726 to control the pitch adjust procedure performed at station 716 and the 
gram load, height and roll adjust procedure at station 717, and to update 
the adjust data, can be similar to the algorithm implemented by processor 
502 of adjust equipment 200 described above. 
At the static attitude measure station 718 the suspension 14 is again 
elevated to fly height. The post-adjust static attitude of the flexure 20 
(both roll and pitch) are then measured through the use of a static 
attitude measurement instrument (not shown in FIG. 39). Static attitude 
measurement station 718 can be structurally and functionally similar to 
station 715. 
At the gram load and height measure station 719 the suspension 14 is 
elevated to fly height. The post-adjust height and post-adjust gram load 
of the suspension 14 are then measured through the use of a load cell and 
Z-height measurement instrument (not shown in FIG. 39), respectively. Gram 
load and height measure station 724 can be functionally and structurally 
similar to station 714. 
Although not shown in FIG. 39, adjust module 704 also includes a reject 
suspension detab station to which the suspensions 14 are advanced by the 
walking beam after being measured at station 719. The reject suspension 
detab station is interfaced to and controlled by control system 726. 
Out-of-specification suspensions 14 (i.e., suspensions with measured 
post-adjust static attitude, height or gram load outside a predetermined 
range of the desired static attitude, height and gram load) are cut from 
the carrier strip 34 at this station. Detab stations of this type are 
known and disclosed, for example in the Smith et al. U.S. Pat. No. 
4,603,567. The carrier strips 34 with the in-specification suspensions 14 
are then manually removed from the walking beam at the gram load and 
height measure station 719 and transported to a final detab station. All 
the remaining suspensions 14 are cut from the carrier strips 34 at the 
final detab station, and subsequently packaged for shipment to customers. 
Gram load and height measure station 714 can be described in greater detail 
with reference to FIG. 40. As shown, station 714 includes a suspension 
clamp/actuator assembly 728, gram load measurement assembly 730 and 
Z-height measurement instrument 732. Gram load measurement assembly 730 is 
mounted to a support frame 736 on base 734 and includes stepper motor 738, 
slide mount 740, support arm 742 and load cell 744. Slide mount 740 is 
mounted with respect to the support frame 736 for reciprocal motion along 
a vertical axis and is driven through its range of motion by stepper motor 
738. Support arm 742 is mounted to and extends from the slide mount 740. 
Load cell 744 is mounted to and extends downwardly from the end of the 
support arm 742, and is positioned directly above the flexure 20 of 
suspensions 14 clamped at clamp/actuator assembly 728. In response to 
control signals from control system 726 (FIG. 39), stepper motor 738 
drives the load cell 744 between a retracted or transfer position and a 
fly height measurement position. In the transfer position the load cell 
744 is raised sufficiently high that it does not interfere with 
suspensions 14 being advanced into and out of the suspension 
clamp/actuator assembly 728. When lowered to the measurement position the 
load cell 744 engages the flexure 20 and elevates the suspension 14 to fly 
height to enable fly height gram load measurements by the load cell. 
Adjustment mechanism 746 can be used to adjust the measurement position of 
the load cell 744. 
Z-height measurement instrument 732 is mounted to base 734 at a position 
below the rigid region 26 of suspensions 14 clamped at clamp/actuator 
assembly 728. Instrument 732 is positioned and configured to measure the 
height parameter of suspensions 14 after the suspensions have been 
elevated to fly height by the gram load measurement assembly 730. Optical 
point range sensors such as instrument 232 described above with reference 
to adjust equipment 200 can be used for this purpose. In one embodiment, 
instrument 732 is an LC 2430 point range sensor available from Keyence of 
Osaka, Japan. 
Suspension clamp/actuator assembly 728 can be described with reference to 
FIGS. 40-43. As shown, the assembly 728 is mounted above the walking beam 
feed shaft 729 and includes base assembly 750, locating pin block assembly 
752, functional clamping block assembly 754, load beam actuator block 
assembly 756 and cam assembly 758. Base assembly 750 include a rigidly 
mounted base 760 with a baseplate clamping region which includes a 
baseplate clamp pad 762. A registration bore 766 extends into the clamp 
pad 762 and is sized to receive the mounting boss 23 of a suspension 14 
clamped to the clamp pad. A lifting rod 764 is mounted within the bore 766 
for reciprocal motion, and is biased upwardly by spring 768. Guide rods 
770 are rigidly mounted to base assembly 750 and extend upwardly and 
downwardly from the base 760. 
Cam assembly 758 includes a splined shaft 776 mounted for rotation within 
base assembly 750. A locating cam 778, clamping cam 780 and actuator cam 
782 are spline mounted to and rotated by shaft 776. 
Locating pin block assembly 752 is positioned below the base assembly 750 
and includes a guide block 772 mounted for reciprocal vertical motion on 
guide rods 770 by linear bearings 774. The upper surface of guide block 
772 includes a recess 784 in which a cam follower 786 is rotatably mounted 
to the guide block. The cam follower 786 is positioned for engagement by 
the locating cam 778 of cam assembly 758. Tension springs (not shown) on 
the opposite sides of the guide block 772 are connected between the guide 
block 772 and base assembly 750 to force the locating pin block assembly 
752 upwardly and its cam follower 786 into engagement with the locating 
cam 778. 
A locating pin assembly 788 including support arm 790 and pins 792 (only 
one is visible in FIGS. 40, 41 and 43) is mounted to the front of guide 
block 772. Pins 792 extend upwardly through apertures in base 760 which 
are aligned with the apertures 35 in the suspension carrier strip 34 when 
the baseplate 21 of the suspension is positioned over the clamp pad 762. 
The support arm 790 and pins 792 are driven through a carrier strip 
locating stroke between extended and retracted positions in response to 
the rotation of shaft 776. Locating cam 778 and cam follower 786 cooperate 
to control the position of pins 792 within their locating stroke. 
Functional clamping block assembly 754 is positioned immediately above the 
base assembly 750 and includes a guide block 794 mounted for reciprocal 
vertical motion on guide rods 770 by linear bearings 796. The lower 
surface of the guide block 794 includes a recess 798 in which a cam 
follower 800 is rotatably mounted to the guide block. The cam follower 800 
is positioned for engagement by the clamping cam 780 of cam assembly 758. 
Tension springs 802 on the opposite sides of the guide block 794 are 
connected between the guide block 794 and base assembly 750 to force the 
clamping block assembly 754 downwardly and its cam follower 800 into 
engagement with the clamping cam 780. 
A baseplate clamping assembly 804 including support arm 806 and clamp pad 
assembly 808 is mounted to the front of guide block 794. Clamp pad 
assembly 808 is mounted within a chamber 810 in the support arm 806 at a 
position directly above the clamp pad 762 on base 760. As perhaps best 
shown in FIG. 43, the clamp pad assembly 808 includes a spring 812, jewel 
ring 814 and clamp pad 816. Clamp pad assembly 808 is structurally and 
functionally similar to the clamp pad assembly 370 of adjust equipment 200 
described above. The clamp pad assembly 808 is driven through a clamping 
stroke between a transfer position and a baseplate clamping position in 
response to the rotation of shaft 776. Clamping cam 780 and cam follower 
800 cooperate to control the position of the clamp pad assembly 808 within 
its clamping stroke. 
Load beam actuator block assembly 756 is positioned immediately above the 
functional clamping block assembly 754 and includes a guide block 820 
mounted for reciprocal vertical motion on guide rods 770 by linear 
bearings 822. The lower surface of the guide block 820 includes a recess 
824 in which a cam follower 826 is rotatably mounted to the guide block. 
The cam follower 826 is positioned for engagement by the actuator cam 782 
of cam assembly 758. Tension springs 828 on the opposite sides of the 
guide block 820 are connected between the guide block 820 and base 
assembly 750 to force the actuator block assembly 756 downwardly and its 
cam follower 826 into engagement with the actuator cam 782. 
A load beam actuating member or assembly such as elevator assembly 830 is 
mounted to the front of guide block 820. Elevator assembly 830 includes a 
support arm 832 which extends from the guide block 820 and positions 
elevator pin 834 over the rigid region 26 of suspensions 14 clamped 
between the clamp pad 762 and the clamp pad assembly 808. The elevator 
assembly 830 is driven through an elevator stroke between a retracted 
position and an elevated position in response to the rotation of shaft 
776. Actuator cam 782 and cam follower 826 cooperate to control the 
position of the elevator assembly 830 within its elevator stroke. 
As shown diagrammatically in FIG. 40, suspension clamp/actuator assembly 
728 includes a control system 840 which interfaces the walking beam feed 
shaft 729 to the cam assembly 758. The control system 840 is shown in 
greater detail in FIG. 44 to include optical encoder 842, motor controller 
844 and motor 846. The optical encoder 842 is optically coupled to walking 
beam feed shaft 729 in a conventional manner and generates electrical 
position signals representative of the position of the feed shaft. Motor 
controller 844 is a conventional programmable motor controller which is 
configured to receive the position signals from encoder 842. As shown, 
motor controller 844 is also interfaced to the control system 726 of the 
adjust module 704. The control system 726 provides control commands to 
motor controller 844 and receives information from the motor controller. 
The control system 726 can thereby synchronize the operation of the 
functions it controls (i.e, the operation of gram load measurement 
assembly 730 and Z-height measurement instrument 732 at station 714) to 
the operation of suspension clamp/actuator assembly 728. 
Motor controller 844 is programmed to generate motor drive signals as a 
function of the position signals received from encoder 842 and control 
commands received from control system 726. The motor drive signals 
generated by the controller 844 are applied to motor 846 in a conventional 
manner (e.g., through a motor driver, not shown). The rotation of cam 
shaft 776, and therefore the carrier strip guiding operations performed by 
locating pin block assembly 752, the baseplate clamping operation 
performed by functional clamping block assembly 754, and the load beam 
elevating operation performed by load beam actuator block assembly 756 are 
thereby synchronized to the rotation of feed shaft 729. The relative 
motion and timing of the carrier strip guiding operations performed by 
locating block assembly 752, the baseplate clamping operation performed by 
functional clamping block assembly 754 and the load beam elevating 
operation performed by load beam actuator block assembly 756 are 
synchronized by the locating cam 778, clamping cam 780 and actuator cam 
782. Since the speed at which suspensions 14 are advanced through the 
stations 714-719 of the adjust module 704 is directly related to the speed 
at which the walking beam feed shaft 729 is rotated, the control system 
840 of station 714 and the control system 726 of the adjust module 704, 
and the operations controlled by these control systems, are effectively 
synchronized to the speed at which suspensions 14 are being advanced 
through the adjust module. 
Gram load and height measure station 714 operates in the following manner. 
As the walking beam is advancing a suspension 14 into the suspension 
clamp/actuator assembly 728, control system 840 causes the shaft 776 to be 
rotated to a position at which cams 778, 780 and 782 drive the locating 
pin block assembly 752, clamping block assembly 754 and the load beam 
actuator block assembly 756, respectively, to their extended positions. 
After the mounting region 18 of the suspension 14 is positioned over the 
clamp pad 762, and with continued rotation of shaft 776 the locating cam 
778 causes the pins 792 are driven through a carrier strip locating stroke 
toward its extended position. Simultaneously, the clamping cam 780 causes 
the clamp pad assembly 808 to be driven through its clamping stroke toward 
the clamping position. The motion of the locating pins 792 leads the 
motion of the clamp pad assembly 808 so the pins extend through the 
apertures 35 of the carrier strip 34, and thereby locate the carrier strip 
with the baseplate 21 of the suspension 14 aligned with the clamp pad 762, 
before the clamp pad assembly 808 engages the mounting region 18 of the 
suspension. After the suspension 14 has been located and the clamp pad 
assembly 808 engaged with the mounting region 18, the locating cam 778 and 
clamping cam 780 cause the pins 792 and clamp pad assembly to be driven to 
and held at their extended positions. The mounting region 18 and baseplate 
21 of the suspension 14 are thereby rigidly clamped to base 760 between 
the clamp pad 762 and clamp pad assembly 808. 
Actuator cam 782 causes the elevator assembly 830 to be driven through its 
elevator stroke toward the elevated position while the clamp pad assembly 
808 is being driven toward its clamping position, but the motion of the 
elevator assembly lags the motion of the clamp pad assembly. After the 
suspension 14 is clamped, the elevator pin 834 will engage the load beam 
16 and elevate the load beam to a position slightly beyond fly height when 
the elevator pin has been driven to its elevated position. As the elevator 
pin 834 is being driven to its elevated position the motor controller 844 
provides instructions to control system 726 of the adjust module 704. In 
response to the instructions the control system 726 generates control 
signals which cause the stepper motor 738 to drive the load cell 744 its 
fly height measurement position. Once the load cell 744 is at the fly 
height measurement position the actuator cam 782 causes the elevator pin 
834 to be driven a short distance toward its retracted position to gently 
position the flexure 20 of the suspension 14 onto the load cell. A 
measurement of the fly height gram load of the suspension 14 is then 
taken. Control system 726 also causes the Z-height measurement instrument 
732 to initiate a measurement of the Z-height of the suspension 14 while 
the suspension is elevated to fly height by the load cell 744. With 
further rotation of the shaft 776 following the fly height gram load and 
Z-height measurements, the above-described actions of the locating block 
assembly 752, clamping block assembly 754 and load beam actuator block 
assembly 756 are effectively repeated in reverse order to return the 
locating pins 792, clamp pad assembly 808 and load cell 744 to their 
retracted positions. The measured suspension 14 can then be advanced to 
the static attitude measure station 715, and another suspension advanced 
into the gram load and height measure station 714. 
Suspension clamp/actuator assemblies and associated control systems similar 
to those described immediately above (i.e., similar to assembly 728 and 
system 840) can be included in the other stations of roll module 702 and 
adjust module 704. One embodiment of adjust system 700, for example, 
includes suspension clamp/actuator assemblies and control systems similar 
to 728 and 840, respectively, at stations 710 and 714-719. Given the 
modular characteristics of the suspension clamp/actuator assembly 728 and 
control system 840, they can be efficiently adapted for use in the other 
stations of adjust system 700. For example, the suspension clamp/actuator 
assembly 728 can be adapted for use in other stations by mounting 
different cams such as 778, 780 and 782 on shaft 776 to accommodate 
varying timing requirements. The control system 840 can also be programmed 
to accommodate the requirements of the other stations. 
The load beam actuator block assembly 756 of the suspension clamp/actuator 
assembly 728 can also be adapted for use on the other stations of adjust 
equipment 700. For example, in place of the elevator assembly 830, the 
embodiment of the suspension clamp/actuator assembly of the pitch adjust 
station 716 includes a load beam actuator block assembly having a load 
beam clamp pad functionally similar to the clamp pad 474 of station 206 of 
adjust equipment 200. The base assembly of the suspension clamp/actuator 
assembly of the pitch adjust station 716 includes an adjustment clamping 
region, plunger and spring assembly functionally similar to the clamping 
region 260, plunger 332 and spring assembly 338 of the station 206 of 
adjust equipment 200. The load beam actuator block and base of the 
suspension clamp/actuator assembly of station 716 are thereby configured 
to rigidly clamp the rigid region 26 of suspensions 14 during the pitch 
adjust procedures performed by the station. 
In place of the elevator assembly 830, the embodiment of the suspension 
clamp/actuator assembly of the laser adjust station 717 includes a load 
beam actuator block assembly having a clamp pad assembly structurally and 
functionally similar to the clamp pad assembly 602 of the laser adjust 
station 208 of adjust equipment 200. The load beam actuator block of the 
suspension clamp/actuator assembly of station 714 is thereby configured to 
cooperate with the load beam positioning assembly of station 720. In this 
embodiment of laser adjust station 717, the optical fibers are fixedly 
mounted to base at a location directly below the spring region 24 of 
suspensions 14 clamped at the station. 
Suspension adjust equipment 900, another embodiment of the present 
invention, is illustrated generally in FIG. 45. As shown, equipment 900 
includes static attitude measure station 901, pitch adjust station 902, 
laser adjust station 903, static attitude measure station 904 and gram 
load and height measure station 905, all of which are interfaced to 
control station 906. A walking beam (not shown in FIG. 45) such as that 
described above with respect to suspension adjust equipment 100 advances 
carrier strips 34 of formed suspensions 14 (also not shown) through 
equipment 900, and sequentially positions each suspension 14 at stations 
901-905. After being positioned at each station 901-905 the suspension 14 
is functionally clamped at its mounting region 18 and processed before 
being unclamped and advanced to the subsequent station. The overall 
operation of stations 901-905 is coordinated and controlled by control 
system 906. 
At the static attitude measurement station 901 the suspension 14 is 
elevated to fly height. The pre-adjust static attitude of the flexure 20 
(both pitch and roll) is then measured through the use of a static 
attitude measurement instrument (not shown in FIG. 45). Static attitude 
measure station 901 can be structurally and functionally similar to 
station 715 of the suspension adjust equipment 700 described above. 
At the pitch adjust station 902 the rigid region 26 of the suspension 14 is 
rigidly clamped. The flexure 20 is then plastically bent upwardly or 
downwardly by a pitch adjust mechanism (not shown in FIG. 45) to adjust 
the pitch of the flexure. Pitch adjust station can be structurally and 
functionally similar to station 716 of the suspension adjust equipment 700 
described above. 
At the laser adjust station 903 a load beam positioning assembly (not shown 
in FIG. 45) orients and positions the rigid region 26 of the suspension 14 
at an adjust position to stress the spring region 24. The spring region 24 
is then stress relieved by the application of infrared light generated by 
a laser and directed to the spring region through optical fibers. Since 
the suspension was not rolled (i.e., was not processed at a roll station 
such as 708 of adjust equipment 700), a gram load and height are imparted 
to the suspension 14 at laser adjust station 903. In effect, the laser 
adjust station 903 induces a radius into the spring region 24. The roll of 
the suspension 14 is also adjusted at station 903. With the exception of 
changes in the algorithm used to perform the laser adjust procedure and 
described below, laser adjust station 903 can be structurally and 
functionally similar to station 717 of the suspension adjust equipment 700 
described above. 
At the static attitude measure station 904 the suspension 14 is again 
elevated to fly height. The post-adjust static attitude of the flexure 20 
(both roll and pitch) is then measured through the use of a static 
attitude measurement instrument (not shown in FIG. 45). Static attitude 
measure station 904 can be structurally and functionally similar to 
station 901. 
At the gram load and height measure station 905 the suspension 14 is again 
elevated to fly height. The post-adjust gram load and post-adjust height 
(i.e., a profile geometry characteristic) of the suspension 14 are then 
measured through the use of a load cell and Z-height measurement 
instrument, respectively (not shown in FIG. 45). Gram load and height 
measurement station 905 can be structurally and functionally similar to 
station 719 of adjust equipment 700. 
The control system 906 of adjust system 900 can be similar in structure and 
operation to the control system 500 of adjust equipment 200. Accordingly, 
the algorithm executed by control system 906 is similar to the algorithm 
executed by control system 500. The main difference between the algorithm 
executed by control system 900 is that unlike control system 500, the 
algorithm does not make use of a pre-adjust gram load or a pre-adjust 
height since stations 902 and 903 process unrolled suspensions 14. The 
measured pre-adjust gram load and pre-adjust height used by the algorithm 
(i.e., through Equations 2 and 3 in FIG. 38) are therefore effectively 
zero. 
The suspension adjust equipment of the present invention offers important 
advantages. In particular, suspension characteristics such as gram load, 
static attitude and profile geometry can be efficiently established and/or 
adjust to a high degree of accuracy and repeatability. The characteristics 
of suspensions processed by the invention also exhibit a high degree of 
stability. 
Although the present invention has been described with reference to 
preferred embodiments, those skilled in the art will recognize that 
changes can be made if form and detail without departing from the spirit 
and scope of the invention. In particular, systems 100, 200, 700 and 900 
can be used to adjust individual suspensions and head gimbal assemblies.