Apparatus for molding insulating disks on coaxial-cable wire

An apparatus for molding a succession of discrete insulating spacers on an elongated flexible conductor, particularly such which is to be used as an inner conductor of a coaxial cable, comprising a support;

• a plurality of molds together forming an array which is mounted on said support for displacement in a closed path and has an exposed surface that extends in and along a closed trajectory, each of said molds including a pair of mold members mounted for relative movement toward and away from one another between an open and a closed position and together bounding a cavity in said closed position, and an inlet which extends between said cavity and said exposed surface;
• means for displacing said array in said path relative to said support so that said exposed surface travels in said trajectory;
• means for moving said mold members of each respective mold between said positions thereof and for maintaining the same in said open position in a first, and in said closed position in a second, consecutive portion of said path;
• means for introducing the conductor between said mold members of the respective mold at said first portion of said path for the conductor to extend across the respective cavity in said second portion of said path;
• means for supplying plastified hardenable material under pressure into said inlet of the respective mold at a predetermined location of said second portion of said path for the material to fill the respective cavity around the conductor, to harden thereabout and thus to form a spacer in said cavity and a sprue in said inlet, in said second portion of said path downstream of said location as considered in the direction of displacement of said array, including a nozzle having an end face which faces said exposed surface of said array at said location and a nozzle end which opens onto said end face;
• means for withdrawing the conductor together with the spacer from between said mold members at a withdrawing location situated in said first portion of said path;
• means for reducing wear of said exposed surface of said array and of said end face of said nozzle, including means for mounting at least said nozzle on said support for movement toward and away from said trajectory at said location, means for urging said nozzle toward said trajectory with a variable force, and control means controlling said means for urging so that said force is overcome by a reaction force with which the material emerging from said nozzle end acts on said end face away from said trajectory, forming a gap therebetween containing a film of the material on said exposed surface which film is integral with the sprue, extends at least between said location and said withdrawing location, separates said end face of said nozzle from said exposed surface of said array, and is in a sliding contact with said end face;
• and means for severing the sprue from the spacer at said withdrawing location to thereby detach the sprue and the film from the spacer.