| 摘要 |
<p>A breathing gas supply controller, comprises a housing which has a gas inlet leading to an internal gas passage which opens at the opposite end in a gas supply opening for supplying gas to a place of use, such as to aid in a person's respiration. The interior gas passage has a widened portion with an elastic valve tube in the passage which defines an annular pressure chamber around the tube which is separated from the passage. A valve member extends through the passage and it includes an intermediate annular widened portion which is engaged against the interior of the valve tube in a closed position to close off the gas passage. A control chamber, which is defined in the housing, has a first control passage communicating with the pressure chamber and a second control passage communicating with the gas passage on the downstream or gas supply end thereof. The one-way flow connection to atmosphere permits the intake of air into the gas passage for mixing with the other gas such as oxygen for flow to the person for respiration. The air flow is aspirated into the passage, preferably by a nozzle formation downstream of the elastic valve tube, or which is formed as a downstream portion of the valve tube. The control chamber includes a diaphragm actuated valve member so that when the pressure in the gas passage drops beyond a predetermined amount, the valve is opened to the first control passage in order to vent the space around the valve tube. The valve member positioned in the valve passage has an annular surface which engages against the interior wall of the valve tube when the pressure is maintained in the annular chamber around the valve tube. When the control valve opens the annular passage around the valve tube, the valve tube flexes outwardly and permits the flow of gas therethrough.</p> |
