Connecting cord junction

A power cable joint device, comprising:

• at least one tubular rigid support element;
• a cold-shrinkable, pre-expanded sleeve;
• and
• a releasable means for immobilizing the at least one support element with respect to the pre-expanded sleeve,
• wherein most of an exterior surface of the at least one support element is lubricated by a grease that does not flow under action of a pressure exerted by the pre-expanded sleeve,
• wherein the pre-expanded sleeve grips the at least one support element over most of a length of the at least one support element,
• wherein the pre-expanded sleeve grips the at least one support element at internal ends of the at least one support element, and
• wherein the grease is based on a silicone or on a polyalkylene glycol and comprises:
• a filler in proportions ranging from 15%-by-weight to 45%-by-weight, or
• a pressure-withstanding additive in proportions ranging from 2%-by-weight to 10%-by-weight, or
• a filler in proportions ranging from 15%-by-weight to 45%-by-weight and a pressure-withstanding additive in proportions ranging from 2%-by-weight to 10%-by-weight.