Patent ID: 6863276

Claim:
A device to reduce a hole having a wall of surrounding material, a central axis, and a predetermined inside diameter, the device comprising a first frustaconical surface of generally uniform thickness, having a base and a top, with a radially outer planar rim forming the base with a smaller diameter than the hole and a central opening at the top, the rim being of greater diameter than, and concentric with, the central opening, and a second frustaconical surface the same shape as the first surface with a central opening the same diameter as the first surface opening and a base forming a radially outer planar rim the same diameter as the first surface rim, the second surface being inverted with respect to the first surface such that the first and second surfaces are joined proximate to the central opening of each surface and the rims of each surface are axially separated, the outer rims being engageable with the wall of the hole such that when the device is positioned in the hole with the planes of the rims normal to the axis of the hole and one rim is supported in a first axial direction, upon application of axial force applied in a second opposing axial direction to the other rim, the axial separation of the rims is reduced and the rims are expanded radially outward to engage the hole wall.