Browse Prior Art Database

Tractor-Roller System for Paper Feed

IP.com Disclosure Number: IPCOM000105565D
Original Publication Date: 1993-Aug-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Lee, HC: AUTHOR [+2]

Abstract

In the paper feed system schematically depicted in the figure, a tractor/roller combination is used to increment paper in a low speed printer (such as IBM 4234). Pin-feed tractor assemblies precisely position the paper during forward and reversed paper motion. The high friction pressure rollers become actively engaged with the motor through a one-way clutch only during reversed paper motion. During forward motion, the rollers are rotated by the paper causing rolling friction for providing tension in the paper.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 76% of the total text.

Tractor-Roller System for Paper Feed

      In the paper feed system schematically depicted in the figure,
a tractor/roller combination is used to increment paper in a low
speed printer (such as IBM 4234).  Pin-feed tractor assemblies
precisely position the paper during forward and reversed paper
motion.  The high friction pressure rollers become actively engaged
with the motor through a one-way clutch only during reversed paper
motion.  During forward motion, the rollers are rotated by the paper
causing rolling friction for providing tension in the paper.

      Such systems damage the paper holes due to high tension which
is induced between the tractors and rollers during high acceleration
modes of paper incrementing.  In addition to the inertia of the
paper, rollers and roller shafts, the rolling friction and the
system's inability to quickly disengage the clutch contribute to the
high tension.  The pin hole damage not only degrades the print
quality, but also causes loss of perforation memory that bows the
edges of the paper at the top of the refolding stack upward and leads
to failures in paper stacking.

      This problem is greatly reduced by allowing the paper to slip
with respect to the drive rollers in a controlled manner.  The drive
rollers are provided with a hard surface having stable frictional and
wear characteristics.  The spring force on the low inertia
idle-rollers is used to control the frictional force between the
paper and drive rolle...