Flexible elbow joint for pipes

Claim 1

A flexible elbow joint for pipes comprising: a 90* elbow subtended by identical flexure units, each unit comprising: an annular housing with a central cavity and a centrally perforated end flange; a nipple partially submerged in said cavity; a spherically flared end on the submerged portion of the nipple; a first annular, elastomeric seal assembly being disposed in said cavity and extending between the nipple end and the housing end flange and closing said cavity; said first seal assembly being comprised of a first reinforced elastomeric element bonded to the exterior surface of the nipple end, a second reinforced elastomeric element bonded to the interior surface of the end flange, and an annular, rigid transition element between said first and sscond elastomeric elements, said transition element being bonded to said elastomeric elements; a second annular, elastomeric seal assembly being disposed interiorly of said nipple end and bridging said nipple and said housing to provide a constant inside diameter for said flexure unit; said second seal assembly being comprised of a first ring member resting against the housing, a ball member having a spherical surface complementary to the interior surface of the nipple end, a first elastomeric element bonded to said surfaces of the nipple and said ball member, and a second elastomeric element bonded to the ball member and the ring member; said ball member having an opening to provide for fluid communication between the joint interior and the closed portion of the housing cavity; said first elastomeric elements of the first and second seal assemblies having a common center of rotation in the central axis of the joint to provide omnidirectional flexure movement of said nipple with respect to said housing; and said second elastomeric elements of the first and second seal assemblies being configured to provide for lateral movement of the nipple with respect to said housing.