Patent ID: 7003201

Claim:
Flexible factory joint for metallic tubes, which enclose loosely inside them optical fibers, comprising: first and second metallic tubes ( 3 , 10 ) having internal and external diameter, which enclose loosely inside them optical fibers, said optical fibers surrounded by a suitable filling material, separated in one or more bundles ( 1 , 2 ) and spliced together at their ends, and a connecting metallic tube ( 6 ) having an internal and external diameter, said internal diameter being slightly larger than the external diameter of each of the first and second metallic tubes ( 3 , 10 ), placed in a way such that it encloses the spliced optical fibers and externally overlaps an end section of each of the above first and second metallic tubes ( 3 , 10 ), and is characterized in that the connecting tube ( 6 ) is firmly connected to the first and second metallic tubes ( 3 , 10 ) at the sections at which it overlaps them, through the creation by plastic deformation of more than one grooved rings ( 11 ) which have a diameter smaller than the external diameter of the connecting tube ( 6 ).