Patent GB-550383-A (GB)
Title: Improvements in respiratory apparatus
IPC: A61M16/00
Filed: 1941-12-01
Abstract: 550,383. Valves. EMERSON, J. H. Dec. 1, 1941, No. 15468. [Class 135] [Also in Group VI] Respiratory apparatus for persons suffering from gas asphyxiation or otherwise unable to breathe normally is so arranged as to be used either as a resuscitator functioning alternately to deliver oxygen to the lungs and to remove exhaled gases therefrom or as an aspirator to remove mucus from the mouth and throat or as an inhalator in which oxygen does not come in contact with exhaled gases. Fig. 14 shows the complete apparatus. Oxygen is led from a highpressure supply O through a gauge G and a pressure regulator PR which reduces pressure to about 15 p.s.i. and thence to a control valve CV. The control valve has a cored-out plug which directs oxygen (1) via tube 26 to the resuscitator 17 or (2) via tube 27 to the aspirator 18 or (3) to a rubber inhalation bag 19 according to the position of the handle 21. The aspirator 18 is furnished with an internal jet 82, Fig. 16, which when receiving oxygen from the tube 27 greatly increases its velocity and so sucks air from the side tube 86. The negative pressure in the tube 86 is transmitted to a jar 87 and to tubes 88, 89. When the aspirator is to be used the face mask M is removed and the end of tube 89 inserted in the mouth of the person to be treated, where it functions to suck mucus &c. from the mouth and throat and deposit them in the jar 87. The resuscitator consists of an oxygen distributing chamber 92, Fig. 11, in which there is a vertically movable two-part valve 93, 94 part 93 being slidable on stem 95 while 94 is secured to it. When the valve stem is lowered, a tapered end 95a prevents oxygen from passing into a passage 100 while the member 93 permits oxygen to flow into passages 96, 97 and through tubes 98, 40 to the face mask M. When the valve stem is elevated, oxygen passes into a tube 101 with a restricted orifice 102 which has a sucking action on the air in chamber 106. The jet of combined oxygen and air emerging from the orifice 104 sucks still more air and creates suction in a tube 110, communicating by a port 111, chamber 112, tube 113 and the exhalation tube 41. The suction in the tube 110 thus removes exhaled gases and passes them to the atmosphere via port 107, the arrangement being such that the inhaled and exhaled gases do not pass over the same surfaces. A toggle and diaphragm device regulates the change over from suction in the tube 110 to positive pressure of oxygen in the tubes 96, 97. While the tube is in suction the chamber 112 continues to exhaust gas from the lungs and this goes on until the negative pressure in 112 is enough to elevate the diaphragm and trip the toggle. This shuts off valves 140 and 95a, opens valve 93 and starts the phase of positive pressure. When oxygen has filled the lungs to cause a normal inhalation positive pressure is built up in exhalation tube 41, tube 113 and chamber 112 and this eventually forces the diaphragm down and elevates valves 140, 93. The oxygen is then forced through passage 100 to create suction in the tube 110 again and induce the next exhalation.