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Print Band Transducer with Magnetic Band Biasing Force

IP.com Disclosure Number: IPCOM000106628D
Original Publication Date: 1993-Dec-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Ergler, JM: AUTHOR [+4]

Abstract

The reliability of a magnetic timing mark transducer is improved by ensuring the correct position of the band within the transducer housing by the use of a magnetic biasing force.

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Print Band Transducer with Magnetic Band Biasing Force

      The reliability of a magnetic timing mark transducer is
improved by ensuring the correct position of the band within the
transducer housing by the use of a magnetic biasing force.

      Fully formed engraved character printers utilize a magnetic
transducer assembly to detect the velocity and position of print
characters on a magnetic steel print band by using raised timing
marks which are located below each print character.  The Figure shows
a cross sectional side view of the print band (11) and transducer
assembly having a permanent magnet (12) located below and in line
with the outer surface of band support bearing (13).

      The magnetic biasing forces produced by permanent magnet (12)
attract band (11) into line contact with band support bearing (13)
thus preventing the band from moving away from bearing (13) and
causing wear to the pole face (14) of magnetic transducer (15)
subsequently causing errors.  The band (11) is supported by a drive
pulley and idler pulley (not shown).

      Without the permanent magnet it has been shown that dimensional
tolerance variations as well as dirt and debris on the band and
pulleys have caused the band to tip away from bearing (13).  However,
the permanent magnet produces an attractive force toward the magnet
and bearing thus preventing the described tipping condition.