Pumping system
US4964533A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1985 |
| Grant date | Oct 23, 1990 |
| Priority date | — |
| Expiry date | Mar 18, 2005 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B7/06
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
To control with precision and repeatability the amount of fluid dispensed or aspirated by a pumping system, a volume disk rotates with the output shaft of a DC motor that drives a reciprocating dispensing pump. A sensor detects indicia on the disk and provides periodic signals spaced-apart in time by an amount: (1) an amount proportional to the volume of fluid pumped; (2) proportional to the angle between indicia; (3) less than one-third of the length of the total stroke of the piston as the piston moves linearly in its working portion of a cycle; (4) necessary for the piston to sweep out a volume of less than five milliliters. The speed of the pump is controlled by a second disk having equally spaced indicia that are sensed to provide signals proportional to the motor speed. During dispensing or aspirating large volumes, the motor speed is increased to a high speed, run at the high speed and then decreased before stopping and during dispensing smaller volumes, it is maintained at a constant lower speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.