GB515416A - Improvements relating to armoured electric cables - Google Patents

Abstract

515,416. Armouring electric cables. BARR, I. D. (Wessel, O. P.). Oct. 17, 1938, No. 25253/37. [Classes 83 (ii) and 83 (iv)] Angular bending; welding.-An apparatus for seam welding the upstanding longitudinal flanges of a ribbon such as of steel, iron, brass or aluminium in armouring on electric cable, comprises a pair of roller electrodes bearing on the flanges from opposite sides, the electrodes being supported on a base so that their axes are together free to move laterally. The ribbon 12, which may be from 0.8 mm. down to 0.6 mm. thick, is drawn by a drum 21 rotated through reduction gear from an electric motor first through rolls 11 which bend it to the section shown in Fig: 3a then through rolls 14, which shape it into flanged U-form, whereupon the cable 15 is introduced and the tube bent to the form shown in Fig. 3c by two pairs of rolls 16, 17. The rolls are laterally and also vertically adjustable. The flanges are then welded by a pair of bronze or other electrode rolls 18 and the armoured cable then passes through guiding and straightening rolls 19, 20 and is wound on a drum 26 driven by a belt from the drum 21. The forming rolls may reduce the thickness of the marginal portions of the ribbon. The roll electrodes are mounted on hollow vertical shafts 30 rotatable in vertically adjustable ball bearings 32 in bearings 31 carried by slides 34, which are freely movable laterally on guides 35 so that they can float and thus avoid bending of the seam laterally. The electrode pressure may be adjusted by a screw 36 and springs 37, the screw being threaded through a bridge plate 39 and the springs engaging bridge plate 40a. The plates 39, 40a are connected together by rods 41a slidable in openings 42a with machine base. The electrode pressure may alternatively be effected pneumatically or magnetically. The roll electrodes may be driven from the mill units and in order to counteract any tendency of the peripheral speed of the electrodes to exceed the linear speed of the flanges the electrodes are driven from the mill units by a transmission which can slip i.e. a friction transmission in which the friction is less than that between the electrodes and the flanges. This may oe effected by connecting the mill units by belts to pulleys 41, 42 on shafts 43 which are provided with slidable spiral gears 45 meshing with spiral wheels 46 carried by the shafts 30. The shafts 30 may alternatively be driven by flexible shafts from the pulleys 41, 42. Current is supplied to the electrodes by starting contacts 49 from a transformer and cooling water passes through a duct 51 and over a baffle plate 52 and shaft 30 to a drain 53.. The armoured cable is guided through the electrodes by a grooved idler 55 carried by a screw adjusted bridge 54.