Patent ID: 7722615

Claim:
A reaming device comprising: a reamer head; a shaft having an upper end and a bottom end, wherein the reamer head is operatively connected to the shaft near said bottom end for rotating the reamer head on a reamer head axis; wherein the reamer head comprises a moveable plate-like first blade having a blade plane that, when said first blade is in a retracted position, is generally parallel to the reamer head axis, wherein the first blade has a sharpened outer perimeter edge that curves greater than 180 degrees; and wherein the entire first blade is moveable, in a direction generally perpendicular to said blade plane and away from said reamer head axis, to an expanded position wherein the effective cutting diameter of the rotating head is increased, and, wherein, when said first blade moves in said direction from said retracted position to said expanded position, said blade plane remains parallel to said reamer head axis; and wherein the reaming device further comprises a moveable plate-like second blade on a side of the reamer head opposite said first blade, the second blade having a second blade plane that, when the second blade is in a retracted position, is parallel to the reamer head axis, wherein the second blade further has a sharpened outer perimeter edge that curves greater than 180 degrees; wherein said second blade is moveable, in a direction generally perpendicular to said second blade plane and away from said reamer head axis and away from said first blade, to an expanded position, wherein said second blade plane remains parallel to said reamer head axis while the second blade is expanding, so that the effective cutting diameter of the rotating head is increased; and wherein the entire first blade moves upwards in a direction parallel to the reamer head axis at the same time the entire first blade moves outward away from said reamer head axis and remains parallel to said reamer axis.