Medical pin removal tool

An apparatus for gripping a cylindrical shaft, comprising:

• a housing having an axis and an inner surface with multiple asymmetric cam surfaces, and a distal end having an opening configured to receive the cylindrical shaft,
• a first rotatable frame, wherein the first rotatable frame is biased into a first position within the housing;
• at least two first cylindrically symmetric gripping members held by the first rotatable frame, the at least two first cylindrical gripping members being configured to grip the cylindrical shaft,
• wherein each of the at least two first cylindrically symmetric gripping members contacts a first end of a corresponding asymmetric cam surface when the first rotatable frame is in the first position;
• a second rotatable frame axially spaced from the first rotatable frame;
• and
• at least two second cylindrically symmetric gripping members held by the second rotatable frame, the at least two second cylindrical gripping members being configured to grip the cylindrical shaft,
• wherein each of the at least two second cylindrically symmetric gripping members contacts a second end of the corresponding asymmetric cam surface,
• wherein:
• the first and second rotatable frames are configured to rotate relative to the housing upon insertion of the cylindrical shaft into a space defined by the at least two first cylindrically symmetric gripping members and the at least two second cylindrically symmetric gripping members so that the at least two first cylindrically symmetric gripping members and the at least two second cylindrically symmetric gripping members rotate in opposite directions along the corresponding asymmetric cam surface;
• and
• after insertion of the cylindrical shaft, the housing is configured to:
• rotate in a first direction so as to cause the at least two first cylindrically symmetric gripping members to move toward the second end of the corresponding asymmetric cam surface, gripping the cylindrical shaft and rotating the cylindrical shaft in the first direction;
• or
• rotate in a second direction so as to cause the at least two second cylindrically symmetric gripping members to move toward the first end of the corresponding asymmetric cam surface, gripping the cylindrical shaft and rotating the cylindrical shaft in the second direction.