Patent ID: 8826751

Claim:
A circumferential sampling tool for obtaining a sample from an interior wall of a tube comprising: a cylindrical body having a central axis; an aperture in the cylindrical body; a shaft disposed in the cylindrical body along the central axis; a first cutter operatively connected to the shaft for rotation therewith, the first cutter being movable radially between a retracted position where the first cutter is disposed inside the cylindrical body at a first distance from the central axis and an extended position where the first cutter extends at least in part through the aperture at a second distance from the central axis, the second distance being greater than the first distance; a first actuator operatively connected to the first cutter for moving the first cutter between the retracted position and the extended position as the shaft rotates, the first actuator mechanically biasing the first cutter toward the retracted position; a second cutter operatively connected to the shaft for rotation therewith and being disposed at an angle to first cutter, the second cutter being movable radially between a retracted position where the second cutter is disposed inside the cylindrical body at a third distance from the central axis and an extended position where the second cutter extends at least in part through the aperture at a fourth distance from the central axis, the fourth distance being greater than the third distance, the fourth distance being greater than the second distance; and a second actuator operatively connected to the second cutter for moving the second cutter between the retracted position and the extended position as the shaft rotates, the second actuator mechanically biasing the second cutter toward the retracted position, the second cutter being in the retracted position when the first cutter is in the extended position, and the first cutter being in the retracted position when the second cutter is in the extended position; wherein rotating the shaft causes the first cutter to move to the extended position thereby cutting a portion of the interior wall of the tube and then causes the second cutter to move to the extended position thereby cutting the sample from the interior wall of the tube from a location in the tube revealed by cutting the portion of the interior wall of the tube.