| 摘要 |
<p>1,076,246. Breathing apparatus demand valve. MINE SAFETY APPLIANCES CO. Feb. 11, 1966 [April 9, 1965], No. 6171/66. Heading A5T. A breathing apparatus demand valve, as illustrated with reference to Figure 2, comprises a housing having a back wall provided with an outlet port 4, a flexible diaphragm 7 in the housing, the diaphragm having a stiff central portion 9, 10 movable backward during inhalation, the side of the housing being provided with an inlet passage 14 encircled by a valve seat 15, a tiltable valve head 16 for said seat, a spring 18 normally holding the head on the seat, a stem 19 fastened to the centre of the valve head and extending through the inlet passage to a point behind said stiff central portion of the diaphragm, a head 22 on the inner end of the stem for engagement by the rearwardly moving diaphragm to tilt the stem and valve head, and a stop 25 rigidly mounted between the stem and diaphragm in the path of said stiff diaphragm portion near said inlet passage, whereby when the diaphragm is drawn backward during inhalation said stiff portion engages said stop and tilts the diaphragm towards the back wall of the housing. Diaphragm flutter is thus avoided.</p> |
