Nonvented needle-free injection valve
US6482188B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2001 |
| Grant date | Nov 19, 2002 |
| Priority date | — |
| Expiry date | Dec 17, 2021 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2039/266
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An injection valve includes a housing having an inlet, an outlet, and a fluid channel extending between the inlet and the outlet. A piston is slidable within a bore of the housing between a first position wherein the piston is relatively far from the closed end and a second position wherein the piston is relatively near to the closed end. A biasing spring biases the piston toward the first position. The piston closes and seals the inlet when the piston is in the first position and allows fluid to pass from the inlet to the fluid channel to the outlet when the piston is in the second position. A piston seal is formed between the piston and a wall of the bore, dividing the bore into a unsealed chamber and a sealed chamber adjacent to the closed end. There is no vent between the sealed chamber and an exterior of the housing. Pressure differences between the unsealed chamber and the sealed chamber that adversely affect performance may be minimized by providing a deformable membrane or a gas accumulator communicating with the sealed chamber, or providing an initial pressure differential wherein a gas pressure within the sealed chamber is less than a gas pressure within the unsealed cham…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.