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Ribbon Re-inking Rate Compensation by Varying Ribbon Speed

IP.com Disclosure Number: IPCOM000109875D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 3 page(s) / 118K

Publishing Venue

IBM

Related People

Wilson III, JT: AUTHOR [+2]

Abstract

Fig. 1 depicts a rotating sponge re-inking system. Ribbon 3 is wound on spools 1 and 2. A stepping motor rotates spool 1 in a counter-clockwise direction to unwind ribbon from spool 2, passes it along the print line, and rewinds it on spool 1. Ink-saturated sponge rolls 5 and 6 rotate on axles and press on transfer rolls 7 and 8, respectively. Motion of ribbon 1, which wraps around a sector of the periphery of each transfer roll, rotates the transfer rolls which in turn rotate sponge rolls 5 and 6. This motion of the ribbon transfers ink from the sponge rolls to the transfer rolls and thence to the ribbon where it is available for printing.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Ribbon Re-inking Rate Compensation by Varying Ribbon Speed

       Fig. 1 depicts a rotating sponge re-inking system.
Ribbon 3 is wound on spools 1 and 2.  A stepping motor rotates spool
1 in a counter-clockwise direction to unwind ribbon from spool 2,
passes it along the print line, and rewinds it on spool 1.
Ink-saturated sponge rolls 5 and 6 rotate on axles and press on
transfer rolls 7 and 8, respectively.  Motion of ribbon 1, which
wraps around a sector of the periphery of each transfer roll, rotates
the transfer rolls which in turn rotate sponge rolls 5 and 6.  This
motion of the ribbon transfers ink from the sponge rolls to the
transfer rolls and thence to the ribbon where it is available for
printing.

      The printing rate, which is usually expressed in characters per
second (CPS), is the primary factor in determining the
ink-consumption rate.  Type font design and size, and hammer contact
force have secondary effects on the ink-consumption rate.  The
ink-transfer rate from the sponge to the ribbon is affected primarily
by the following factors: the ribbon velocity; the sponge ink release
rate (which is determined by the porosity of the sponge and the
amount of ink remaining in the sponge); the ink viscosity which is
affected by the temperature of the sponge; and the contact force
between the sponge and transfer roll.

      Described below is a means to match the ink-transfer rate with
the ink-consumption rate by varying the ribbon velocity.

      The velocity (v) of the ribbon, which is caused by rotation of
the spools, can be determined from the following parameters:  R1 and
R2, the maximum and minimum radius of the ribbon on spools 1 and 2,
respectively, and the period of rotation of spools 1 and 2.  These
parameters can also be used to determine a new motor rotation time
(T) that will yield a desired velocity (V).  The reciprocal of the
motor rotation time (T) is proportional to the stepping rate of a
stepping motor or the RPM of a DC motor.  Thus, ribbon speed control
can be obtained by varying the stepping rate or the voltage,
respectively.

      Tests have demonstrated that increasing the ribbon speed will
increa...