Abstract: A shutter blade device comprises a plurality of shutter blades which are pivotable each about its own tangentially extending pivot axis. Each shutter blade is provided with an elongated extension by means of which it passes through a slot into the interior of the apparatus body where the extension with its terminal portion meshes with an axially movable driver means. The driver means can be actuated electromagnetically or manually. The device is particularly suited for ventilators.

Abstract: A centrifugal governor comprises a bar member pivotally mounted on a rotatable bearing member. The bar member is provided with an inclined ramp against which a follower bears which is connected to a device which is to be regulated. First and second resilient forces, which may be overcome by the centrifugal force generated by rotation of the bar member, urge the bar member into its rest position and the follower member into contact with the bar member. The governor is generally applicable, one of the preferred fields of application being the control of the flow through a channel associated with a ventilator.