| 摘要 |
<p>A window assembly comprises a frame (10) and two movable panels (12, 14) mounted in the frame, at least one of the movable panels (12) being transparent, and drive means, such as a worm drive (16) for moving the panels into and out of operative positions. The weight of one movable panel acts on the drive means in a direction opposite to that of the other movable panel. The weight of one panel serves, at least in part, to counter-balance the weight of the other. The movable transparent panel (12) comprises a sub-frame (22), and one or more minor frames (24) hingedly mounted in the sub-frame and each carrying a sheet (26) of transparent material. The sub-frames (22) can be hinged from an operative position to a maintenance position, allowing access to both sides of the transparent material for cleaning purposes. <IMAGE></p> |
