Patent · US Expired

Method and apparatus for normalizing the speed of an element positionable by a servomechanism

US4517503A · kind A · utility

12Cited by
5References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 27, 1983
Grant dateMay 14, 1985
Priority date
Expiry dateSep 27, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05B2219/45187
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

A speed normalization circuit for eliminating the need to fine tune a servomechanism, such as a daisy wheel printer, after manufacture, for example, in order to compensate for speed variations caused by tolerance variations throughout the manufacturing process and evidenced by variations in the actual print wheel speed and the actual carriage speed, is disclosed. In operation, when a restore sequence is called for (power up, remote restore, cover open/resume, check/resume), the carriage is restored to the leftmost home position and is then stepped three times by an identical amount (twelve increments, 1/120 of an inch per increment). The average value of the actual carriage speed for these three movements is determined and a compensation value is selected. If the carriage speed is too slow, the nominal speed value stored in a read only memory look-up table is incremented by a fixed value (i.e., plus one, two, or three units); if the speed is too fast, the nominal speed value is decremented by a fixed value (i.e., minus one, two, or three units). The compensation value is added to the nominal speed value during subsequent actual operation of the servomechanism. For the print wheel, …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.