Microstructure gas valve control
US5323999A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1992 |
| Grant date | Jun 28, 1994 |
| Priority date | — |
| Expiry date | Dec 1, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16K2099/0074
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A flow control device includes a housing with separate main flow and flow control (servo) passages between an inlet port and an exit port. A control chamber in the housing is in fluid communication with the servo passage. A flexible membrane forms a partition between the main flow passage and the control chamber. The servo passage includes a variable servo orifice upstream of the control chamber and a fixed orifice downstream of the chamber. When the servo valve is open to permit passage of fluid into the control chamber, the resultant pressure on the membrane maintains the main valve closed. The main valve opens in response to closing the servo valve. The fixed orifice has a profile sufficiently small to provide for an acceptable leak or continuous fluid flow through the device when the servo valve is open, and further provides for a soft start when the servo valve is closed to open the main valve. The fixed orifice, servo valve including a servo valve orifice and electrostatically controlled closure tabs, and a microbridge flow sensing device, are advantageously formed on a monolithic semiconductor chip mounted inside the housing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.