Clamp device

Claim 1

A clamp device comprising: an outer tubular member having a bore lying on a longitudinal axis and first and second oppositely disposed ends; an inner tubular member within the bore of and pliable relative to the outer member, the inner member having portions adjacent the ends of said outer tubular member at first and second regions; said outer tubular member having an inner bore and a pair of outer circular cylindrical bores aligned on said axis, one outer bore at each end of the outer tubular member at said first and second regions, the inner bore having a smaller diameter than the outer bores and positioned next to and between the outer bores, the transition region between said outer and inner bores being inclined relative to said axis to form a frustro-conical surface of a given extent parallel to said axis, each of said outer bores extending parallel to said axis a distance substantially greater than said given extent; said given extent having a magnitude just sufficiently great to provide said frustro-conical surface; a pair of clamping rings, a different one in each of said outer bores, each ring having a circular cylindrical portion extending along said axis and dimensioned to closely fit within the bore of the inner tubular member at a corresponding one of said outer bores, an end of each of said rings having a frustro-conical surface corresponding to and adapted to face a different transition region to compressively clamp that inner tubular member substantially in that transition region in response to a tensile force induced in the inner member; and inlet means coupled to the outer member adapted to couple a source of pressurized fluid to the chamber defined by said inner and outer tubular members between said clamped end regions to induce said tensile force in said inner member.