Abstract: A device for joining the frames of structural units which are structural units having undercut grooves. The device is provided engages itself in these grooves, and is preferably in the form of a spindle consisting of two parts which rotate with respect to each other on a common threaded shaft or axis. By rotating the defice each of the two parts anchors itself firmly into the undercut grooves in the frames which may be metal sections thus holding the frames together.

Abstract: The device described enables hollow, basically rectangular sections to be joined together either orthogonally or end-to-end and also to be joined to floors, ceilings, beams and the like. The device is a piece of extrusion basically U-shaped in cross-section which fits neatly into extrusions and by means of flanges with threaded grooves can either be connected directly to the extrusion or by drawing a bracing web into the grooves. The connecting piece is then joined to the other component or floor etc either by means of tightening the bracing web screw or by means of a flat metal plate which fits neatly into a groove in the main web of the connecting piece being secured there by screws and then screwing this plate, which projects out of the connecting piece, to the floor, ceiling etc. Provision is also made for a sealing agent which accommodates dimensional differences due to tolerances or dilation and also prevents transmission of sound.