VALVES

摘要

A gas-powered resuscitator includes an oscillatory timing valve (14) having an outlet (23) connected via a manually-operable valve assembly (16, 25) to a patient valve (41). The timing valve (14) has a sealing rod (145) movable along a bore (141) between a forward position in which it blocks flow throug h the valve and a rear position in which it enables flow through the valve. Th e rear end (151) of the rod (145) is mounted in a piston (146) and is urged rearwardly to an open position by a spring (148). A flexible diaphragm (149) is joined around its edge (158) to the housing (140) of the valve, separatin g the rear end (159) of the valve from the forward end (160) and extending ove r the rear end (146) of the piston (146). The control inlet (34) of the valve (14) opens into its rear part (159) so that gas pressure applied to the inle t acts on one side of the diaphragm (149) to urge the piston (146) and rod (14 5) forwardly to the closed position against the action of the spring (148).