Printer system ribbon drive having constant ribbon speed and tension
US4177731A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1978 |
| Grant date | Dec 11, 1979 |
| Priority date | — |
| Expiry date | Mar 23, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J33/34
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An impact printer ribbon drive of the reel-to-reel type, in which a length of ink ribbon extending between and wound around opposite reels is disposed between a reciprocating hammer bank and print paper on a platen, drives the ribbon at substantially constant speed and tension independent of varying ribbon pack diameter on the two reels. Each one of the reels is driven by a different one of a pair of DC permanent magnet motors. The motors are energized by a circuit which maintains the sum of the currents through the two motors substantially constant and which also maintains the voltage at the leading or take-up motor substantially constant. The sum of the currents and the voltage are maintained substantially constant by a pair of servo circuits associated with different ones of the motors and coupled to be alternately actuated in response to external direction commands. Also included is circuitry responsive to voltages in different parts of the circuit for signalling unwanted conditions such as a run-away ribbon, a jammed ribbon or a loose hub at one of the reels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.