Miniature manipulator for servicing the interior of nuclear steam generator tubes

A manipulator for servicing tubes extending through a tube sheet, comprising:

• (a) a base member having a holder for holding tooling or an inspection device, the base member also having at least one gripper for releaseably gripping a tube extending through the tube sheet;
• (b) a block member directly, rotatably connected to the base member so that the base member can rotate in a plane relative to the block member when a position of the block member is fixed and a position of the base member is not fixed and the block member can rotate relative to the base member when the position of the base member is fixed and the position of the block member is not fixed, at least a portion of the block member moveable, relative to the base member, in a linear direction in a straight line in a plane perpendicular to the plane the base member rotates in;
• (c) a foot member directly connected to the block member for linear movement relative thereto, the foot member having at least one gripper for releaseably gripping a tube extending through the tube sheet;
• (d) wherein the block member moves in two directions of linear travel in a straight line in the horizontal and vertical directions between the foot member and the base member, while maintaining the foot member and the base member in parallel planes;
• and
• (e) wherein at least one of the grippers on each of the base member and the foot member includes a gripper mechanism for forcing a gripping arm against an inside wall of the tube extending through the tube sheet when the gripper mechanism is actuated and a withdrawal mechanism that when actuated exerts a force in a direction to pull at least one of either the base member or the foot member associated with the at least the one of the grippers, toward the tube sheet when engaged to the tube extending through the tube sheet, to positively bias the one of the base member or the foot member against the tube sheet, the withdrawal mechanism and the gripper mechanism being separately actuated.