Improvements relating to the covering of the external surfaces of iron and steel pipes and tubes with bituminous material

摘要

300,933. Stewarts & Lloyds, Ltd., and Mitchell, J. Aug. 17, 1927. Moulding pipes; extrusion machines.-The exterior surfaces of pipes are covered with bituminous material in the form of a ribbon, preferably while the latter is still plastic after delivery by an extrusion machine. In the illustrated form the pipe 13 is set up in a screw-cutting lathe and the extrusion apparatus is carried on the travelling slide-rest. The plunder 5 is driven through gearing 21 to expel the ribbon 16 from the steamjacketed cylinder 1 at the same rate as it is taken up by the revolving pipe. The shutting or overlapping surfaces of adjacent convolutions may be formed as shown in Fig. 5 or 6. A hot roller may be run over the joints and the surface then wrapped with hessian soaked in bituminous material. In a modified construction the gearing 21 is replaced by a second cylinder and plunger for hydraulic operation. In some cases the extruded ribbon may be wound and stored before being used for coating. The composition described in Specification 224,365, [Class 99 (ii), Pipes, tubes, &c.], may be used. Reference has been directed by the Comptroller to Specification 276,047.