Low speed servo control
US4146824A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1977 |
| Grant date | Mar 27, 1979 |
| Priority date | — |
| Expiry date | Sep 26, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K17/0019
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A control system is described for use in a web transport in which a web is advanced from a supply spool to a take-up spool by a pair of drive motors, the latter of which are actuated by a servo control. The system includes a variable gain network which enhances the gain of the servo system at very low speeds without sacrificing system stability at higher speeds, and a circuit for adding a hold-back torque to the motor driving the take-up spool to smooth its rotation under low torque conditions. In addition, the system includes a device for inhibiting the rotation of the spools when an operator has removed the web from the spools, thereby preventing the servo control from rotating the spools in an uncontrolled manner in response to inadvertent operator movement of one of the spools.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.