System for determining pumping mechanism position while limiting volume of fluid pumped
US5534691A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1994 |
| Grant date | Jul 9, 1996 |
| Priority date | — |
| Expiry date | Sep 12, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/347
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A drive member of a peristaltic pumping mechanism includes a disk that rotates with the drive member and has two transparent sectors and two opaque sectors alternating with the transparent sectors. As a stepper motor rotates the drive member to pump fluid, a single optical sensor senses the disk and provides signals indicative of whether a transparent sector or opaque sector is being detected. A processor counts the number of motor steps in the detected transparent or opaque sector and based on the number of counted steps in a type of sector detected or the number of steps counted when a state change to the other type of sector occurs, determines the motor position. In another aspect, the position disk is integrally formed as a single piece with the cams and cam shaft of a pumping mechanism.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.