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Ribbon Detent And Static Tension Control With One Motor Driver

IP.com Disclosure Number: IPCOM000119329D
Original Publication Date: 1991-Jan-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Jessen, RF: AUTHOR [+2]

Abstract

This article describes a means of using just one motor driver to simultaneously power two stepper motors by selectively placing the motors in parallel. The intended application is to maintain tension while the ribbon is stationary in a dual motor bidirectional ink ribbon drive for an impact printer. Maintaining ribbon tension when the ribbon is not moving during paper advance is important so that folds in the paper do not catch a slack ribbon and cause smudging.

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This is the abbreviated version, containing approximately 52% of the total text.

Ribbon Detent And Static Tension Control With One Motor Driver

      This article describes a means of using just one motor
driver to simultaneously power two stepper motors by selectively
placing the motors in parallel.  The intended application is to
maintain tension while the ribbon is stationary in a dual motor
bidirectional ink ribbon drive for an impact printer.  Maintaining
ribbon tension when the ribbon is not moving during paper advance is
important so that folds in the paper do not catch a slack ribbon and
cause smudging.

      A preferred embodiment is shown in the figure.  The key to this
disclosure is the 4PDT Relays 1 and 2 connected as shown and the
enabling of both Relay Control Lines 3 and 4 concurrently.  Relays 1
and 2 are then in a state where both Motors 5 and 6 are electrically
connected in parallel to the one Motor Driver 7.  When this is done,
the detenting and tensioning of the ribbon may be implemented as
described below.

      In this application, it is desired that both motors be
identical and that the connectors on the ends of the motor leads be
interchangeable between the two mating connectors on the circuit
card.  Because of this, it is required for tensioning that the two PM
stepper motors be oriented such that each motor shaft turns in the
same direction to wind the ribbon onto itself.  This is because the
driver will be giving the same drive voltages to both motors at once
and both motors will turn in the same direction.

      When...