Valve for use in a breathing apparatus

A valve comprising:

• a housing having an inlet and an outlet adapted for a fluid flow;
• a valve seat disposed in said housing in a path of said fluid flow;
• a valve body having a central rigid portion and a circumferential, wrinkled and flexible portion mounting said valve body in said housing so as to be freely movable relative to said valve seat and allowing friction-free movement of said rigid central portion, said valve body being disposed for interaction with said fluid flow and being movable between a closed position wherein said valve body completely covers said valve seat and an open position wherein said valve body is spaced from said valve seat;
• and
• an actuator for applying and controlling a force acting on said valve body in response to a control signal, opposed to a force acting on said valve body by interaction with said fluid flow, said actuator having an actuator body, a shaft having an end contactable with said valve body, and an electromagnetic displacement coil disposed in said actuator body for displacing said shaft, in response to said control signal, toward and away from said valve body.