| 摘要 |
1,157,365. Assisting respiration. AIR REDUCTION CO. Inc. 16 May, 1967 [23 May. 1966], No. 22700/67. Heading A5T. A device for assisting respiration comprises a housing 10 having at one end a peripherally grooved flange supporting a normally expanded compressible breathing bag 16 and a branch tube 12 supporting breathing mask 14. A gas delivery passage 22 in the housing and the branch tube 12 communicate with a chamber 25 in which a spring-urged valve 26 is slidably supported by a stem 36 fixed to a removable bushing 30. The bushing has exhaust openings 32. For resuscitation, the breathing bag is alternately compressed, to drive gas to the mask and relaxed so that it is expanded by entry of air through passages 48' and a check valve formed by a rubber ring 46. As the bag is compressed, the valve 26 is moved away from one valve seat 24 against a spring 38 to abut a second valve seat 42 provided by the bushing so that the exhaust openings 32 are occluded. As the bag expands, the valve 26 abuts the first valve seat 24 to close the delivery passage and permit exhaled gas to pass from the mask through the exhaust apertures to atmosphere. The bag is made of thin flexible natural or synthetic rubber which is resistant to deformation and has spaced internal longitudinal radially projecting ribs 62 which urge the bag into expanded condition. The bag is sufficiently thin for the determination of the pressure of gas within it by feel. A passage 50 in a boss 52 on the housing communicates with one of the gas inlet passages 48' for supplying oxygen to the bag. A pressure relief valve 72 is disposed in a venting passage 76 in a boss 52' on the housing. The valve comprises a magnetisable ball 72 normally held against a seat 74 to close the venting passage by an adjustable magnetic rod 80. A pin 88 projecting into the venting passage holds the ball within the magnetic field on the rod 80 when the valve is opened against its closing magnetic force by excess pressure in the delivery passage. |
