Flow-controlled calibration syringe
US5827941A · kind A · utility
15Cited by
7References
39Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1997 |
| Grant date | Oct 27, 1998 |
| Priority date | — |
| Expiry date | Nov 6, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B53/1057
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A calibration syringe is constructed like a single stage manual pump having a plunger. The input manifold has a duckbill valve that functions to maintain a fixed air flow rate through the syringe even with variable forces acting on the plunger. The duckbill valve has a pair of flexible lips which face upstream against the air flow. As a vacuum is formed inside the pump's input chamber, ambient air pressure closes the flexible lips. Thus, variable plunger forces creates a variable orifice inversely proportional to the plunger force. The result is a constant flow rate syringe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.