摘要 |
<p>The framework for a door or window is made up of two hollow metal members (21, 22) interconnected by two spaced apart heat insulating members (3). The hollow chamber (8) enclosed by these members can then be filled with further insulating material. Each insulating member has a cross section in the form of a shallow channel, and its two flanges (33), 34) are locked inside hollow grooves (14) in the lower side of the upper metal member (22) and in the upper side of the lower metal member (21). A special locking system is used, giving a rigid structure, in which a forming tool is drawn through the hollow chamber.</p> |