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Pneumatic Switching to Cool Motor Armatures

IP.com Disclosure Number: IPCOM000121438D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 3 page(s) / 101K

Publishing Venue

IBM

Related People

DeLessio, AP: AUTHOR [+3]

Abstract

It is known in the state of the art that tape drives can vent pressurized air between the read 10 and write 11 modules of the magnetic head (Figure 1) to lift the tape 12 off the magnetic head when the tape is not moving and no read/write operations are taking place [*]. The name given to the combination of a head and a hydrostatic air bearing is a tape lifter head. This creation of a temporary hydrostatic air bearing when the tape is stationary is done to prevent the magnetic tape from sticking to the head. Such tape stick can occur with aged tape or tape exposed to hot and wet environments.

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Pneumatic Switching to Cool Motor Armatures

      It is known in the state of the art that tape drives
can vent pressurized air between the read 10 and write 11 modules of
the magnetic head (Figure 1) to lift the tape 12 off the magnetic
head when the tape is not moving and no read/write operations are
taking place [*].  The name given to the combination of a head and a
hydrostatic air bearing is a tape lifter head.  This creation of a
temporary hydrostatic air bearing when the tape is stationary is done
to prevent the magnetic tape from sticking to the head. Such tape
stick can occur with aged tape or tape exposed to hot and wet
environments.

      When the transference of data is required, the flow of
pressurized air to the magnetic head must terminate while the tape is
accelerating to its streaming velocity.  This cessation of air flow
to the head is required to allow the tape to assume a close proximity
or flying height over the magnetic head through the formation of a
hydrodynamic air bearing.

      This article proposes that when tape motion ensues, that the
air flow no longer desired for the tape lifter head be selectively
ducted to cool either the supply reel 21 or the take-up reel 22 motor
of the tape drive.

      In Fig. 1, a multi-port solenoid valve 30 is activated by the
microprocessor 40 controlled power supply 41.  When the tape is
stationary, the solenoid valve is positioned to duct air from the air
supply 42 through the flexible tube 43 to the fitting 44.  This
fitting channels the air between the read and write modules to form a
hydrostatic air bearing underneath the magnetic tape.

      When the tape is moving, the solenoid valve is positioned to
duct air to the motor receiving the most current.  As shown in Figure
2, the decision as to which motor receives the cooling air is based
on a c...