Patent ID: 7559723

Claim:
A hull-to-caisson interface connection assembly for connecting a platform hull and a caisson extending downwardly from an upper portion coupled to the bottom of the hull, the caisson defining vertical axis and having a top end located within the hull, the assembly comprising: a shoulder fixed to and extending radially from the top end of the caisson; and a bearing assembly disposed coaxially around the upper portion of the caisson below the shoulder, the bearing assembly comprising: a steel top bearing ring forming the uppermost part of the bearing assembly, against which the shoulder is seated, the top bearing ring having a bottom surface with a defined axis of curvature; a steel bottom support ring forming the lowermost part of the bearing assembly, the bottom support ring having a top surface with the defined axis of curvature; and a laminated structure of alternating steel and elastomeric flex rings, disposed between the top bearing ring and the bottom support ring, the steel and elastomeric flex rings being configured with the defined axis of curvature, each successive flex ring having an inside diameter slightly greater than the inside diameter of the flex ring immediately above it, thereby defining a central passage of the bearing assembly having a diameter that increases from the top bearing ring to the bottom bearing ring so as to permit the caisson to pivot relative to the vertical axis in response to an angular flexing load applied to the caisson, the flex rings being bonded to each other to flex together as a unit substantially without sliding between adjacent flex rings in response to loads applied to the top bearing ring by the shoulder when the caisson pivots relative to the vertical axis.