Image Number 8 for United States Patent #7789101.
A Regulator-Oxygen (ROX) Unit for regulating oxygen flow in an emergency oxygen distribution system in passenger aircraft initially allows unregulated surge of oxygen to purge ambient air from the system. After sufficient pressure is achieved in the system, the ROX unit regulates oxygen flow mechanically with a diaphragm engaging a regulator valve that responds to the pressure of the oxygen under the diaphragm to reduce the flow of oxygen through the ROX unit, which accounts for altitude changes by communicating the inlet pressure to the chamber above the diaphragm. A bleed exit allows the oxygen to escape to the ambient air. One or more aneroid valves serve to adjust the amount of oxygen allowed to exit through the bleed exit, allowing less oxygen to escape with increasing altitude. An increase in pressure above the diaphragm allows more oxygen to flow through the regulator valve.