Multistage mixing valve for a medical respirator
US4072148A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1977 |
| Grant date | Feb 7, 1978 |
| Priority date | — |
| Expiry date | Jan 3, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/87692
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A valve assembly for mixing air and oxygen in a medical respirator over a wide range of volumetric flow rates, without sacrificing relative mixing accuracy at the lower flow rates. The assembly is divided into a plurality of mixing valve modules characterized respectively by progressively increasing volumetric flow capacities and progressively decreasing absolute mixing accuracies. The higher flow capacity modules are sequentially brought into operation as the overall valve flow increases and then interrupted when the flow decreases below a threshold level associated with each module. The valve assembly accordingly has a large range of flow capacities without degrading absolute mixing accuracy during low flow rate conditions by the effect of the higher capacity modules.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.