Clamp tension compensating, self-sustaining cuff apparatus and method

A coupling apparatus for coupling a free end of each one of a pair of tubular ducts in flow communication with one another, the apparatus comprising:

• a tubular sleeve including:
• a first stretchable ply of material having a first surface and a second surface, said first surface being adapted to be placed against an exterior surface of each said free end of said pair of ducts, and said first stretchable ply including a first seam disposed at a first peripheral location;
• a non-stretchable ply having first and second surfaces, and having said first surface disposed against said second surface of said first stretchable ply, and said non-stretchable ply further having a second seam arranged such that it is circumferentially offset from said first seam;
• said non-stretchable ply further having an axial length less than that of said first stretchable ply and being positioned such that opposite ends of said first stretchable ply extend past said opposing edges of said non-stretchable ply;
• and
• a second stretchable ply having a first surface, a second surface and a third seam, said first surface being positioned against said second surface of said non-stretchable ply, and said third seam being circumferentially offset from said second seam.

A coupling apparatus for coupling over free ends of a pair of tubular ducts in flow communication with one another, the free ends of the ducts being separated by an axial gap and the ducts being operable to pass a fluid therethrough, the apparatus comprising:

• a sleeve having an axial length sufficient to span said gap and to overlap portions of said free ends of said ducts when said sleeve is secured to said free ends of said ducts, said sleeve including:
• a first stretchable ply of material, a generally non-expandable helical coil, and a second stretchable ply of material sandwiched together, with the helical coil disposed between the first and second stretchable plies of material, to form a unitary assembly, said helical coil having an axial length limited to a length that is approximately equal to a length of said axial gap to overlay said axial gap;
• said helical coil having a cross-sectional shape providing at least one flat surface, with said flat surface being positioned against one of said first and second stretchable plies of material to enhance a bond between said helical coil and said one stretchable ply;
• and
• said first and second stretchable plies of said sleeve each having a length longer than the generally non-expandable helical coil, with one of the first and second stretchable plies having an inner diameter that is approximately equal to an outer diameter of the free ends of the pair of ducts generally constant outer diameter over the axial length thereof.