Abstract: Improvement in shielding windows having at least two panes, which form an enclosed space by means of a frame, in which space a shield is arranged to adjustably shield the window opening completely or partly. The shield is extendable and retractable out of and in to a storing position in the space, one end of said shield being fixed to a storing device and either the other end or said storing device being fixed to a piston disposed between the panes. The piston is displacable along the panes and corresponds to the cross-section of the space. Either the storing device or the other end is fixed to the frame so that displacement of the piston will cause a relative displacement of the two ends of the shield (extension or retraction). A pressurized air conduit opens into the space on one side of the piston and a second conduit opens into the space on the other side of the piston.

Abstract: Window including a rectangular frame, which supports and encloses at least two panes separated at a certain distance, a slab being placed between said two panes, said slab having a width corresponding to the width of the panes but having a height which is smaller than the height of the panes, said slab being displaceable up and down by a current of air which is introduced in the frame under the slab and is let out above the slab or vice versa.