Browse Prior Art Database

Actuator Alignment Tool

IP.com Disclosure Number: IPCOM000111818D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 6 page(s) / 183K

Publishing Venue

IBM

Related People

Barenboim, M: AUTHOR [+4]

Abstract

The need existed for a tool capable of aligning to extremely close tolerances the Read/Write (R/W) heads of magnetic tape drives for the IBM 3490 cartridge. In prior art, all heads for this type of cartridge used stationary R/W heads with 18 or 36 pairs of elements. This severely limited the track recording density that could be achieved with these cartridges and left a significant amount of the tape area on each cartridge unused.

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This is the abbreviated version, containing approximately 40% of the total text.

Actuator Alignment Tool

      The need existed for a tool capable of aligning to extremely
close tolerances the Read/Write (R/W) heads of magnetic tape drives
for the IBM 3490 cartridge.  In prior art, all heads for this type of
cartridge used stationary R/W heads with 18 or 36 pairs of elements.
This severely limited the track recording density that could be
achieved with these cartridges and left a significant amount of the
tape area on each cartridge unused.

      The Actuator Alignment Tool (AAT) is designed for use with a
magnetic tape drive whose R/W head is built into an actuator that
permits the head to step into several additional positions.  While
use of the actuator considerably increases the track density of the
1/2-inch tape, it requires three critical, close-tolerance
adjustments:

o   Each R/W pair must be adjusted along the tape length parallel to
    the fixed tape guide within 3 microns.

o   The head gap line for each pair must be adjusted perpendicular to
    the tape fixed guide within 5 minutes of an arc.

o   The head penetration must be adjusted to within 50 microns of the
    tape drive "D"-bearings (the surface the tape rides on).

      The AAT design disclosed herein satisfies the requirements for
precise alignment of the actuator, resulting in greatly increased
efficiency of tape usage.

TOOL DESCRIPTION

      Fig. 1 shows magnetic tape drive 1 with base mount 2, actuator
3, two "D"-bearings 4 (left) and 5 (right), tape fixed guides 6, and
tape stops 7.  Two locating holes 8 are used for positioning the tape
drive within the AAT.

      Actuator 3 has a load beam 9 with either front pad 10, or datum
"A", and two side pads 11 and 12, or datum "B".  The load beam and
head assembly 13 are moved up and down by a voice coil (not shown for
clarity) which is energized via cable leads 14.  The actuator is
attached to the base 2 by its central pin 15 (shown in Fig. 5), which
is also used for adjustment of the actuator.

      Fig. 2 shows the actuator alignment tool 16 which consists of
top 17 and bottom 18 assemblies.

      Top plate 19 of top assembly 17 rides on three ball bearing
supports 20.  Either the magnetic tape drive 1 or a setup gauge
(shown in Fig. 3) rests on three pads 21, and is located by a set of
pins 22.  Both the tape drive and a setup gauge are clamped to the
top plate by three spring-loaded clamps 23.  A micrometer-type
adjustment tool 24 is used to adjust the lateral head position
relative to the "D"-bearings 4 and 5 (penetration adjustment).  Two
clamps 25 clamp the entire top assembly with locking screws 26 at the
loading position (toward the operator), shown in Fig. 2, or at the
working and adjusting position, shown in Figs. 4 and 5.

      Bottom assembly 18 has a spring-loaded handle 27 which he
operator hold the top assembly 17 in working position when clamping
it.  Two stops 28 and 29 keep the drive on its "D"-bearings 4 and 5
(Fig. 1). ...