| 摘要 |
503,532. Powder cables. PYROTENAX, Ltd., and BECKETT, C. M. Oct. 7, 1937, No. 27268. [Class 36] A multi-core electric cable is made by grouping two or more separate cables, each cornprising one or more conducting cores separated from an enclosing metal sheath by powdered mineral insulation, within an outer sheath of ductile material and binding the sheath closely around the group of component cables by a drawing or other metallurgical treatment to form a compact body. Preferably filling. material, such as metal strips or insulating material such as powdered insulation, is inserted before the metallurgical treatment into the spaces between the component cables. The component cables may be inserted into a tube of copper or aluminium and the workpiece mechanically treated so as to increase its length. Alternatively, the 'outer sheath may be applied by wrapping strip metal around the grouped component cables and welding the edges, or by extrusion. To prevent cohesion of the metal fillings and cables during the mechanical treatment, they may be coated with lamp-black or acetylene-black. |
