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Browse Prior Art Database

Frictionally Constrained Shock Isolator for Direct Access Storage Device

IP.com Disclosure Number: IPCOM000119117D
Original Publication Date: 1997-Dec-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 4 page(s) / 94K

Publishing Venue

IBM

Related People

Khanna, VD: AUTHOR [+3]

Abstract

Disclosed is a device of frictional pads which is used to constrain small motions that are induced by the internal vibrations of an operating Direct Storage Access Device (DASD), without hampering the large motions needed by soft shock isolators to attenuate large input shocks. This device allows an increase in shock protection without impacting DASD performance.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Frictionally Constrained Shock Isolator for Direct Access Storage
Device

      Disclosed is a device of frictional pads which is used to
constrain small motions that are induced by the internal vibrations
of an operating Direct Storage Access Device (DASD), without
hampering the large motions needed by soft shock isolators to
attenuate large input shocks.  This device allows an increase in
shock protection without impacting DASD performance.

      Small form factor DASDs are being used in a variety of portable
applications, the most common of which is laptop computers.  Some
other applications which are becoming increasingly popular are
personal storage  devices (which are portable, externally attached
hard drives) and removable storage for digital video cameras.  The
DASDs used in these environments have to be able to withstand high
shock loads in the event  they are mishandled or dropped.  To reduce
the input shocks from such abuse to values for which their internal
components can be designed to  withstand, the DASDs are generally
provided with shock isolation via some  form of compliant mount
between it and its enclosure.  The more compliant  the mount, the
greater the shock isolation that can be provided.

      Unfortunately, along with increasing the compliance, comes the
problem of increasing Track-Mis-Registration (TMR).  It is caused by
angular vibrations in the DASD unit which make it more difficult for
the actuator servo system to keep the head on track.  Such vibrations
are mostly due to mass imbalances in the moving parts of the DASD or
its reaction to actuator motion.  The softer the mounts, the greater
the vibration and the worse the TMR.  Thus, there is a limit to how
compliant the mounts can be made and the degree of shock isolation
that can be provided.

  ...