Patent ID: 8388255

Claim:
A drilling riser tensioner ring assembly, comprising: an annular tensioner ring body having a central opening for receiving a tubular riser component and an outer surface having an outer cylindrical portion concentric with the central ring; a plurality of bores integrally formed in the tensioner ring body, each of the bores extending radially through the tensioner ring body from the central opening to the outer surface relative to an axis of the central opening; a plurality of hydraulic passages within the tensioner ring body, each of the hydraulic passages extending to one of the bores for delivering hydraulic fluid pressure to the bore; a plurality of actuators, each of the actuators having a piston with a seal mounted thereto and carried within a respective one of the bores, the pistons being movable in response to fluid pressure applied to the bores via the hydraulic passages between an outer disengaged position and an inner engaged position in engagement with the riser component; a plurality of lockdown supports, each of the lockdown supports being mounted in a fixed position to the outer surface of the tensioner ring body radially outward from a respective one of the pistons, relative to the axis; and a plurality of lockdown members, each mounted to a respective one of the lockdown supports radially outward from a respective one of the pistons, each of the lockdown members being movable between retracted and extended positions relative to a respective one of the lockdown supports, such that movement of each of the lockdown members to the extended position while a respective one of the pistons is in the engaged position causes the lockdown member to abut an outer end of the piston and prevent the piston from moving to the disengaged member to abut an outer end of the piston and prevent the piston from moving to the disengaged position, wherein the piston is movable between the engaged and disengaged positions while the lockdown member is in the retracted position.