Abstract: To render more economical the manufacture of galvanized bar segments 10 illustratively used for three-dimensional frameworks, the components of the bar segments 10, namely the hollow bar 11 and the end pieces 12, are galvanized before being assembled. The ring welds between the galvanized components 11, 12 are implemented by laser welding. Because of the high energy density of the laser welding beam and on account of the narrow ring-weld seams 18 so formed, a zinc coating 24 supplied from the zinc coats 22 of the adjacent components 11, 12 is created during welding and covers each surface 25 of the ring-weld seams, as a result of which, following welding, the bar segment 10 also is provided with a zinc coating 24 covering the surfaces 25 of the ring-weld seams protecting them against corrosion.

Abstract: Tubular bars are connected to form room or open space framing by screw bolts with heads at their ends to connect the bars with intersecting members. Screw bolts with heads are supported in the end areas of the bars to be rotatable and axially movable. Their outward axial movement in each case is limited by a limiting boss in the end area of each bar. The limiting boss for the screw bolts with heads is formed by shaping of the end segments of the tubular bars in their hollow space. In tubular bars with tapered, truncated conical end segments, the head of the screw bolts can be welded against the inside wall of these end segments, when it is of correspondingly fitted truncated conical shape.

Abstract: Screwing-in apparatus for set screws which can be operated by a wrench, for the connection of hollow rod elements with junction members of a framework, in which the junction members have threaded bores to receive the set screws and the rod elements have end members with middle bores for the passage of the shanks of the set screws. The heads of the set screws can be applied on inside shoulders of the end members for positioning. Other tubular elements are provided which extend inwardly from an opening in the wall of the rod element and open axially parallel to the middle bore in the end member and against it, in order to guide the drive elements of the screwing-in apparatus. A tubular, curved element forms a guide member for the screwing-in apparatus, in the rod element, in which a drive member or members are rotatable and axially immovable. The end of the tubular element which is turned away from the wrench is configured as a plug holder for the set screw.

Abstract: A joint connection for space frameworks made of rods and joint members wherein the joint members have concentric threaded bores for receiving threaded bolts for the connection of the rods with the joint members. The required torque is applied by means of screwing tools through non-rotatable but axially slidable drive sleeves on the threaded bolts. The drive sleeves inserted between the rod ends and joint members are also used to bias the threaded bolts so strongly that the bias force is greater than the charges from the outside which have a dynamic effect, in order to avoid the danger of fatigue fractures. For this purpose, each drive sleeve may be formed of three parts which, on the basis of cooperating helical surfaces with suitable relative rotation of the middle part relative to both outside parts, are axially adjustable in opposite directions to axially bias the threaded bolt to lengthen it and therewith to axially bias it.

Abstract: A flange-screw connection between a rod and a junction means having corresponding support surfaces, characterized in that a flange is secured to a connecting part provided at the end of the rod, the connecting part being of such cross section as to have the same (area) moment of inertia as the rod. The flange comprises bores adapted to receive fastening screws therethrough, the bores being disposed near the outer periphery of the flange and each terminating in an insertion cavity for receiving the fastening screws.