GB341887A - Improvements relating to the manufacture of hlongated metal bodies comprising a core and smooth shell - Google Patents

Abstract

341,887. Sheathing wires, rods, or tubes with metal. METALLGES. .AKT.-GES., 45, Bockenheimer Anlage, Frankfort-on-Main, Germany. Oct. 19, 1929, No. 31854. Addition to 304,736, [Class 83 (iv), Metals, Working]. [Classes 83 (ii) and 83 (iv).] Wire; welding ; drawing.-In making elongated metal bodies consisting of a core and metal sheath having one or more longitudinally welded joints, by pressing one or more strips over the core, as described in the parent Specification with reference to sheathed wire cores, the strips are narrower than the periphery of the core so as to leave one or more gaps between adjacent edges, the gap being closed by flow of metal in the direction of the joint during welding. The strip may be thickened locally at one or more points 5, Fig. 2. Sheathed wires, cables, rods or tubes may thus be made. An aluminium strip 2 may be drawn from a furnace 20 heated to welding temperature through a die 4 to bend it over an iron core 1 into the form shown in Fig. 3. Welding may then be performed by rolls 6 with circular grooves which cause the metal to flow towards the joint to effect the weld. The burr may then be removed by rolls 7 and the sheath finally smoothed by a die 9. Guide rolls may be provided on both sides of the die 4. In another form, the sheath may be bent and then welded on a hollow mandrel through which the core is passed, the sheath being subsequently pressed on the core and the joint smoothed by rolling or drawing, after first cooling if necessary. Welding may be effected also by drawing or hammering. For electrical purposes the sheath may consist of aluminium, copper, iron, lead or other metal or alloy. For overhead conductors the core may consist of iron wire or of a cable of steel or other metals or alloys of high mechanical strength such as normalizable aluminium alloys and the sheath of aluminium. A conductor with a sheath of a normalizable aluminium alloy may be subjected to a subsequent heat treatment to effect the normalizing. If the core is of such an alloy this may be normalized during welding. High tension cables may consist of a core of copper wires or cables and a sheath of aluminium. Bands may also be made by deforming the composite wire.