Patent ID: 8469029

Claim:
A breathing device comprising: an air inlet; an air outlet through which a user can breathe; a conduit connecting the air inlet and outlet; a rotary valve positioned in the conduit so that air entering through the air inlet and inhaled by the user can be interrupted by the rotary valve; means to rotate the rotary valve; and means to vary the speed of rotation of the rotary valve to vary the frequency of interruption of the flow of air through the conduit whilst the device is in use; wherein the rotary valve comprises: a housing containing a fluid flow path with a central axis; a plug having a sealing face cooperating with a valve seat in said housing in the closed position to block the fluid flow path; and a support shaft arranged to carry said plug and being rotatable on an axis which is normal to and spaced from the central axis of the fluid flow path so that rotation of the said shaft moves said plug relative to said housing.