Patent ID: 6874286
Filing Date: 2005-04-05
Classification: E06B

Abstract:
1. A window frame construction system for resisting blast forces comprising; a) an inner frame; b) an outer frame; and c) a plurality of aligning connector units for attaching said inner frame inside said outer frame, each of said connector units comprising; i) a hollow body attachable to said inner frame, said hollow body having a first extremity and an opposite, second extremity, at least a portion of the outer surface of said hollow body, including said first extremity, being externally screw-threaded; ii) a nut plate engageable with said inner frame and having an internal screw thread matching said externally screw-threaded portion of said hollow body, whereby said second extremity of said hollow body may be inserted into said nut plate and into an aperture in said inner frame and adjusted to project a desired distance outwards from said inner frame towards the outer frame to which said inner frame is to be attached; and iii) a first internal rotatable member, insertable in a hollow of said hollow body at said second extremity and projecting therefrom, provided with engagement means for a tool insertable through said first extremity of said hollow body, whereby a torque may be applied to turn said internal rotatable member relative to said hollow body, and wherein said first internal rotatable member is provided with a projection, an end portion of which faces outwards towards said outer frame for effecting engagement and alignment between said inner and outer frames, and whereby said projection of said internal rotatable member may thereby be brought into contact with said at least one abutment surface of said outer frame, and wherein and plurality of said abutment surfaces are positioned to be engagable by the projections of a plurality of said connector units; characterized in that said outer frame is provided with at least one channel bounded by at least one abutment surface extending substantially at right angles from said outer frame towards said inner frame for engagement with said first internal rotatable member for alignment between said inner and outer frames and wherein each of said connector units is further provided with a second internal rotatable member, insertable in said hollow of said hollow body at said second extremity and projecting therefrom adjacent said first internal rotatable member, said second internal rotatable member being provided with a rod-like projection, positioned to enter an adjacent channel bounded by said abutment surface for effecting secure engagement between said inner and outer frames, the cross-sectional area of said rod being less than the cross-sectional area of the base of the conical extremity of said first rotatable member.