Abstract: An attachment device and assembly for effecting connection and disconnection between component parts in a simple but reliable manner. A first structure includes first and second substantially parallel spaced apart plates, a conically-shaped, conically threaded member having a given cone angle attaching the first structure to a second structure which operatively abuts the first structure. Each plate has an aperture formed in it, the apertures being larger than the cross-sectional area of the threaded member portions being received thereby, and the second structure having a surface portion operatively abutted by the threaded member so that forces are applied tending to push the surface portion and aperture edges apart. The angle formed between a line tangent to the aperture edges and a line in the plane of the surface portion is equal to the cone angle of the threaded member.

Abstract: A connecting clamp is described which is adapted for easily releasable attachment to a bar or tube having a multi-cornered cross-section. The clamp consists of a yoke having fixed jaws at its ends. One jaw fits closely to one corner of the bar or tube, and the other jaw extends past an opposite corner of the bar or tube and at an obtuse angle, so that a tapering interspace is formed. A wedge for securing the clamp is pressed into said space by a bolt attached to the midpoint of the wedge and extending through the yoke. A recess in the obtuse-angled jaws allows the bolt to swing aside when the wedge has been retracted past the tip of the jaw, thus clearing the tapering space and enabling the removal of the clamp.