INTERNAL BACKUP RING SYSTEM

摘要

An actuation system preferably for mounting between front and rear clamping mechanisms in a pipe clamping apparatus as part of an internal back up ring system. The system includes a guide, a cam plate positioned adjacent to the guide and rotatable relative thereto, a drive mechanism coupling the guide a nd the cam plate such that actuation of the drive mechanism causes the cam plate to rotate relative to the guide about an axis of rotation, and a power source for driving the drive mechanism. A backup ring assembly, having a plurality of backup shoe units, may be associated with the cam plate such that rotation of the cam plate relative to the guide plate causes the backup ring assembly to move radially relative to the axis of rotation of the cam plate in order to engage or disengage the inner wall of a pipe. The system may also include auxiliary means for dislodging the backup ri ng assembly when at least one of the backup shoe units is stuck to the inner wa ll of the pipe.