Abstract: A dry powder inhaler comprises a body 1 defining a storage chamber for a powder and further defining an inhalation passage 2 through which air is drawn via a mouthpiece 3. A flow duct passing through the mouthpiece includes a circulatory section 25 in which the flow duct is in the form of one or more passageways. The flow duct further includes a cyclone chamber 35 between the circulatory section and the outlet of the mouthpiece.

Abstract: A thermally sensitive actuator for opening and closing a louvre window of the type in which the louvre blades are mounted fast with bell-cranks having their free ends pivotally connected to an operating member which has a pivotal link coupled thereto. The thermally sensitive actuator comprises a housing for mounting on the frame of the window and containing a channel of uniform cross-section having a block slideably mounted therein, and a piston and cylinder assembly, the cylinder of which contains a thermally expansible flowable material and is mounted on the housing with the piston in engagement with the slideable block so that expansion of the flowable material causes displacement of the block. The side walls of the housing contain elongate slots through which projects a pivot pin which is movable in an oblique slot in said block and has connecting means on its projecting end for attachment to the pivotal link of the louvre window.