Browse Prior Art Database

Method of Sealing Disk Files

IP.com Disclosure Number: IPCOM000100444D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Chainer, TC: AUTHOR [+3]

Abstract

Disclosed is a method of sealing a disk drive to control the chemical environment of the heads and disks while reducing the internal forces which originate from environmental changes.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

Method of Sealing Disk Files

       Disclosed is a method of sealing a disk drive to control
the chemical environment of the heads and disks while reducing the
internal forces which originate from environmental changes.

      In disk drives, it is desirable to seal the head/disk assembly
(HDA) from all outside contaminants.  However, in practice most files
have a "breather" hole to allow the internal pressure of the disk
drive to come to equilibrium with the external ambient pressure.  If
this equalization were not allowed to occur, large forces could build
up in the drive which could cause deformations of the head/disk
assembly, resulting in track misregistration or possible catastrophic
failure.

      The proposed solution is to incorporate a pair of pressure
release valves in the disk drive.  These valves open when the
pressure differential between the file pressure and the atmospheric
pressure is above a set limit. One valve opens when air must be
released from the file and the other vavle opens when air must be let
into the file. Air flow through the valves will pass through filters
before entering the disk file.  An important requirement of the
pressure release valves is that they have inherent hysteresis.  Once
a valve opens (referred to as cracking pressure) it should not
re-close until the file pressure is almost equal to the ambient
pressure.  This insures that the pressure difference between the file
and the external atmosphere is reduced wit...