| 摘要 |
<p>A valve, notably for use as a demand valve in breathing apparatus, has a pressure-responsive diaphragm coupled to a separate control member which lies in the path of a jet of gas which vents from a control chamber through an orifice, gas being continuously supplied to the control chamber. Deflection of the diaphragm in response to pressure changes in a second chamber caused by inhalation and exhalation of the user of the apparatus pivots the control member towards or away from the jet orifice to control the rate of venting from the control chamber and thereby vary the pressure within the control chamber. Flow of gas through the valve to the user of the apparatus is controlled by a flexible disc which in turn responds to the pressure in the control chamber. By employing a separate diaphragm and control member the former can be optimized for pressure-response while the latter can be optimized for valve-regulation by interaction with the gas jet from the control chamber.</p> |
