Browse Prior Art Database

Radial-Push Assist to Startup Using Autolock

IP.com Disclosure Number: IPCOM000104156D
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Mosbrucker, JM: AUTHOR

Abstract

A method to assist startup of a direct access storage device is disclosed. The method involves the use of a permanent magnet and an electromagnet to generate a radial force to overcome stiction at the head disk interface. The magnets also serve the function of a home latch to lock the actuator in place when the file is shut off.

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Radial-Push Assist to Startup Using Autolock

      A method to assist startup of a direct access storage device is
disclosed.  The method involves the use of a permanent magnet and an
electromagnet to generate a radial force to overcome stiction at the
head disk interface.  The magnets also serve the function of a home
latch to lock the actuator in place when the file is shut off.

      Many direct access storage devices use magnetic latches to hold
the actuator in place when stopped.  The latch holds the heads in a
predetermined landing zone on the disk when the file is stopped.
This invention uses a permanent magnet as well as an electromagnet
for the latch device (see the figure).  When the disk file is
started, the electromagnet is energized so that the magnet has
opposite polarity to the permanent magnet.  This force of repulsion
from the magnets provides a radial push force that assists the
spindle motor in overcoming stiction forces at the head disk
interface.  The electromagnet can also be pulsed to set up a resonant
vibration with the actuator suspension system to create even larger
forces.