| 摘要 |
<p>1528832 Respiratory apparatus demand regulator R A CHRISTIANSON 6 Feb 1976 [30 June 1975] 04782/76 Heading AST A second stage demand regulator for breathing apparatus consists of a control valve 19, between inlet and outlet passages 14 and 19 which is actuated by a diaphragm 26 in response to inhalation, a frusto-conical surface 35 being gradually contacted by the diaphragm on an increasing demand to reduce its effective area. The diaphragm is mounted on a floating block 27 linked by rods 28, 41 to the valve and has a peripheral bead 26d locatable with respect to the surface 35, a disc 31 on block 27, co-operating with an edge 30 to locate the diaphragm. On exhalation the bead leaves the surface edge 38 to provide an exhaust valve. The regulator may be purged by inward movement of a knob 70, to provide actuation of control valve 19, the knob 70 being outwardly biased by a coil spring 71. The valve 19 consists of a poppet 44 biased closed by a spring 55, opening of the valve causing an O-ring 52 to leave seat 51 and provide communication between the inlet and outlet passages via an aspirator opening 57. In a modification the aspirator opening is formed in a separate cylindrical part of the valve housing 20 which is rotatable from outside the regulator housing 17.</p> |
