The Dotcom Survival Guide

A machine for forming between-conductor insulation in a coaxial electric conductor pair usable as a transmission line for very high frequency signals. The insulation is of the so-called "balloon" type, that is it consists of a thin thermoplastic tube constricted onto the central conductor at regularly spaced points by means of endless chains of small dies progressing at the same speed as the conductor and part of which press the tube against said conductor at said points. To prevent the possible appearance of periodic defects in the insulation, a small number of dies succeeding each other in the chain are exchanged at random time intervals for an equal number of similar dies taken from a reserve magazine, this being done without having to stop the operation of the machine. The dies of a chain are not mechanically interconnected and simply push each other in endless slides. A mechanism effecting substitution of a group of dies taken from the magazine for an equal number of dies taken in the chain during progression of the latter is described.