GB1326053A - Cable jacket extrusion apparatus and die with wire positioning means - Google Patents

Abstract

1326053 Extrusion coated cables ANACONDA WIRE & CABLE CO 18 Aug 1970 39661/70 Heading B5A [Also in Division H1] In a process wherein a jacket 24, e.g. of polyvinylchloride rendered semi-conducting by the inclusion of carbon black, is extruded around an electric cable core 16 guided through an extrusion head by a member 12, drain wires 14 of undulatory configuration which are incorporated into the jacket 24 are fed, through circumferentially distributed passages 13 of the memder 12, into the jacketing material wherein their depth is determined by radially adjustable shoes 29 which press against them. The shoes 29 are formed at the ends of pins 28, the radial adjustment whereof is effected by the engagement, within slots thereof, of circular cams 33 formed eccentrically at the ends of members 34 which are threaded into the die 11 from the face of which they may be rotated by slots 39. The shoes 29 engage the wires 14 upstream of the land which should be at least of a length "l" equal to the die radius. The undulations of the wires 14 may extend circumferentially as in Fig. 1, or radially as in Fig. 4 when the shoe length exceeds that of an undulation cycle.