| 摘要 |
<p>1344101 Breathing valves AGA AB 19 April 1971 [5 March 1970] 21823/71 Heading AST A breathing valve comprises a housing 10 with a breathing opening 9, an inhalation valve 17, a lever 4 and a control diaphragm 6 arranged to control the valve 17 by the lever, the breathing valve having means to provide an overpressure region 8 delimited by the control diaphragm 6 and a second diaphragm 3, and first and second exhalation valves 7, 18 respectively leading into and out of the region and operable to allow exhalation through the region by way of the exhalation valves, there being an overpressure in the breathing opening during inhalation and exhalation. An overpressure is produced in the breathing valve when lid 13 is adjusted to a position in which springs 1, 2 are compressed against diaphragm 3. A control spring 1 loads lever 4 via a central stud 5 and diaphragm 6 causing inhalation valve 17 to be opened for an inflow of gas. Some of the gas flows into region 8 via valve 7 to equalise the pressures in the inlet chamber 15 and region 8. The pressure increases until a balance is obtained between the forces on diaphragm 3 and spring 1. The inhalation valve 17 then closes when balance has been achieved and a sealing spring 2 loads the circumference of the diaphragm 3 so that the overpressure is maintained. Thus, upon inhalation the pressure in the inlet chamber 15 decreases and diaphragm 6 exerts a force on lever 4 which causes valve 17 to open and gas to flow into chamber 15. During exhalation the exhaled gas is expelled through valve 7 into the region 8. The increase in pressure causes diaphragm 3 to open allowing the exhaled gas to pass through holes 14 in the adjustable lid 13.</p> |
