SE315981B - - Google Patents

Abstract

1,175,714. Respiratory apparatus. O. H. DRAGER [trading as DRAGERWERK, HEINR & BERNH. DRAGER]. 24 July, 1967 [22 July, 1966], No. 33979/67. Heading A5T. Respiratory apparatus of the kind including a breathing bag 4 in a closed chamber 5 in which positive and negative pressures are alternately produced, for inducing inhalation and exhalation respectively, of the patient, comprises an adjustable control device 7 including a valve 8 which shuts off the flow of gas from the chamber 5 when the negative pressure therein reaches a predetermined value which is adjusted by adjustment of the control device. The breathing bag is connected to a respiratory circuit 2 which includes a carbon dioxide absorber 2c inhalation and exhalation valves 2a, 2b and an anaesthetic supply conduit 1. When a changeover valve 17 actuated by a diaphragm 14 in response to pressure in a chamber 13 of the control device closes a vent 10a, gas is supplied by an injector 10 to the chamber 5 for the inhalation phase via a conduit 6 and the valve 8 comprising a cup 21 and an adjustably spring loaded diaphragm 18 which is exposed on one side to atmosphere and on the other to the pressure in the chamber 5. Simultaneously pressure builds up in the chamber 13. At a predetermined positive pressure in the chambers 5, 13, the valve 17 opens the vent 10a so that gas from the injector 10 passes to atmosphere and entrains gas from the chambers 5, 13 for the exhalation phase. At a pressure in the chamber 5 determined by the spring-loading of the diaphragm 18, the valve 8 closes shutting off the chamber 5 from the control device so that there is no further drop in pressure in the chamber 5. Further pressure reduction in the chamber 13 operates the valve 17 to close the vent 10a so that gas is again supplied to the chamber 5 for the next inhalation phase.