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Belt Tensioner for Serial Matrix Printers

IP.com Disclosure Number: IPCOM000112466D
Original Publication Date: 1994-May-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Harris, RH: AUTHOR [+2]

Abstract

In low cost personal computer and Point-of-Sale printers, a timing belt is the preferred means of driving the print head across the document. Timing belts require a method to keep the belt under tension. The tensioning method must accommodate tolerances and temperature variations. Most existing methods either require adjustment or elaborate camming schemes. Disclosed is a simple tensioner that also simplifies belt attachment to the printhead carrier.

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This is the abbreviated version, containing approximately 73% of the total text.

Belt Tensioner for Serial Matrix Printers

      In low cost personal computer and Point-of-Sale printers, a
timing belt is the preferred means of driving the print head across
the document.  Timing belts require a method to keep the belt under
tension.  The tensioning method must accommodate tolerances and
temperature variations.  Most existing methods either require
adjustment or elaborate camming schemes.  Disclosed is a simple
tensioner that also simplifies belt attachment to the printhead
carrier.

      Current methods tension the belt by cutting the belt and
inserting a tension spring in line with the belt, installing a cam
and spring arrangement that cams the idler pulley, or high tension
springs placed on the idler pulley shaft.  The designs that allow the
idler pulley to move are exposed to undesirable backlash as the belt
changes directions.  Designs with a spring in line with the belt act
differently, depending on which way the belt is being driven, because
one direction pulls the carrier only with the belt, and the other
direction pulls through the spring.  All known designs require a
separate mechanism to attach the belt to the printhead carrier.

      Disclosed is a tensioner and belt attachment means combined in
a simple, low-cost design.  As the sole figure shows, the tensioner
consists of a Spring loaded Shoe, which forces an uncut belt into a
recess in the printhead carrier.  The Shoe pivots about a point such
that tension from either...