Improvements in or relating to cable manufacturing apparatus

850,792. Cables. PYROTENAX Ltd. Jan. 18, 1957 [March 5, 1956], No. 6841/56. Class 36 [Also in Group XXIII] In apparatus for the manufacture of powder-insulated cables comprising a sheath tube N with conductors N1 mounted in it (such apparatus being similar to that described in Specification 669,781), the hammer has a striker, receiving the blows of the hammer piston and transmitting them to the ram, an aperture in the striker assembly allowing the escape of air from the hammer and hence a cessation of, or reduction in the force of, the blows transmitted unless the ram is operative on the powder and hence urged against the striker. The powder is fed through a hole in the upper part of the ram into its interior and thence through valved ports in the ram (closed when it engages the powder column) into the tube N so that powder is admitted to the tube N when cylinder Q moves the ram upwardly, compacting of the powder by the pneumatic hammer taking place during the downward movement of Q. A friction grip between tube N and a fixed shroud tube P allows the cable to be fed downwardly into a well M when the powder is properly compacted, and the cable may then be drawn and annealed in one or more stages.