Apparatus and method for removing a wall portion from a wall of a tubular member

摘要

Apparatus and method for removing a wall portion from a wall of a tubular member. The wall portion has a distal end portion and a proximal end portion. The wall portion is connected to the wall of the tubular member by a pair of ligatures, which remain after use of a suitable cutting tool. The ligatures are aligned and disposed on either side of the wall portion to define a pivot axis. The apparatus has a probe body insertable into the tubular member, which probe body includes an expandable bladder for pushing the distal end portion of the wall portion in order to pivot the wall portion about the ligatures (i.e., about the pivot axis) as the bladder expands. As the wall portion pivots, the distal end portion of the wall portion rotates outwardly from the wall of the tubular member as the proximal end portion of the wall portion rotates inwardly into the tubular member. After the wall portion pivots, a cup-shaped retainer is moved upwardly to surround the proximal end portion of the wall portion. A movable elongate mandrel engages the proximal end portion of the wall portion. A hydraulic or pneumatic cylinder downwardly moves the mandrel in order to intimately engage the mandrel with the proximal end portion of the wall portion and downwardly displace the wall portion, such that the ligatures are severed. As the wall portion is downwardly displaced, it is drawn into the retainer. As the wall portion is drawn into the retainer, it is gripped between the retainer and the mandrel. The probe body is then removed from the tubular member for removing the severed wall portion from the tubular member. The apparatus may further include an eddy current sensor for locating the wall portion to be removed.