Appeal No. 97-2421
Application 08/202,411
5 and 15 mm/sec. (specification, page 50). Carteau discloses using a cam CAM and a cam follower
P to raise and lower the head T. The cam follower P is part of a spring plate LRS mounted on
supporting arm BS. Under the influence of cam follower P, the spring plate LRS exerts/releases a
force on wire F which in turn exerts/releases a tensile force on loading plate LAM to adjust the height
of head T above the plane of the disk DISC. The cam has three sections to divide the loading
(unlocking and lowering the head to the disk) and unloading (raising the head from the disk to the
locked position) operations into three phases. Two breakpoints, A and B, divide the three sections
and sudden changes in acceleration of system SCT occur when pin P reaches the break points
(column 12, lines 28-30). If the velocity of the moving arm is less than a predetermined velocity at
the second breakpoint B, there is a likelihood that the cam follower will travel backward away from
the second breakpoint, while if the velocity is greater than a predetermined value, the arm is likely to
accelerate and cause the head to crash onto the disk (e.g., column 3, line 63 to column 4, line 7).
Carteau controls the motor current so that as the cam follower P passes the breakpoint B the arm is
driven to a zero velocity and then is driven to a predetermined velocity without substantial overshoot
(column 4, lines 36-62). The motor current waveforms during loading (lowering) are shown in
figures 5A to 5C.
Kitagawa discloses a device to load and unload a magnetic head slider. Head sliders 3a and
3b are installed to actuator arms 6a and 6b via suspensions 4a and 4b on both surfaces of the
magnetic disk 1. Head lifters 7a and 7b are attached to support stand 11 via plate springs 10a and
10b so that head lift arms 8a and 8b which are attached to 7a and 7b are installed between the
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Last modified: November 3, 2007