Anesthetist{3 s ventilator

Claim 1

An anaesthetist''s lung ventilator communicating with anesthetic equipment for connecting the respiratory system of a patient alternately to a source of gas under pressure for inspiration and to atmosphere for expiration and comprising: a valve body having a central bore communicating at one end with a gas inlet connecting to the anesthetic equipment for supplying the gas and at the opposite end with an outlet connecting to atmosphere and intermediate the gas inlet and outlet with a breathing inlet-outlet connecting to the patient; an outlet seat telescopically and slidably mounted within the outlet and having an inner end facing the central bore and defining an outlet valve seat; outlet seat adjustment means for selectively varying the extent of projection of the outlet seat into the central bore; an adjustable apertured guide plug having an inclined surface and being slidably mounted within the gas inlet; a guide plug adjustment means extending through the gas inlet and engageable with the guide plug for displacing the guide plug toward and away from the central bore; a tubular valve housing fixed within the central bore and defining a gas inlet valve seat adjacent the gas inlet; a spool valve reciprocable within the valve housing; valve biasing means for biasing the spool valve to rest position and including a first magnet adjustably disposed in the gas inlet and a second magnet carried by the spool valve and disposed for being attracted by the first magnet; and all adapted and arranged upon the continuous supply of gas to the gas inlet for the successive and alternate shifting of the spool valve between non rest position adjacent the outlet valve seat for outlet closure assumed upon the buildup of pressure at the gas inlet and against the action of the valve biasing means for the patient''s inspiration through the gas inlet and breathing inlet-outlet and rest position adjacent the gas inlet valve seat for gas inlet closure assumed upon the consequential lowering of pressure at the gas inlet anD increase of pressure at the breathing inlet-outlet for the patient''s unrestrained expiration through the breathing inlet-outlet through the outlet to atmosphere.