Constrictor ring joint

Claim 1

A connector comprising: a. an inner tube having an external cylindrical portion; b. an outer tube having outer cylindrical surfaces and an internal cylindrical portion telescopingly received over the external cylindrical portion of the inner tube; c. the outer tube having axially inward of its extremity, a first zone of greater wall thickness and external cylindrical diameter, and having at its extremity, a second zone of lesser wall thickness and external cylindrical dimension; d. a first constrictor ring surrounding said first zone and having a tapered bore forming an abrupt shoulder at its smaller end, the first constrictor ring being of an inner diameter freely movable axially over the second zone and being internally dimensioned in the region of its shoulder to directly effect progressive localized constriction of both of the inner and outer tubes as the first constrictor ring is moved axially along the first zone thereby to form a first mechanical bond and seal between the tubes within the first zone; e. a second separate constrictor ring surrounding said second zone and having a tapered bore and abrupt shoulder at its smaller end, the second constrictor ring being internally dimensioned in the region of its shoulder to directly effect progressive localized constriction of both the outer tube and inner tube as the second constrictor ring is moved axially along the second zone thereby to form a second mechanical bond and seal between the tubes within the second zone; f. one of the tubes including between the first and second constrictor rings a set of corrugations to permit relative axial expansion and contraction of the tubes while maintaining intact the bonds and seals between the tubes.