INTERFERENCE FIT SCREW DRIVER

摘要

An interference fit screw driver (10) has a polygonal driving surface (12) to impart torque to a corresponding surface in a screw (20). The end of the polygonal driving surface has a frusto-conical shaped gripping means (14) which fits into an aperture (24) in the screw to create a friction fit between the screw (20) and screw driver (10). This allows the screw to be attached to the screw driver to facilitate installation of the screw. The friction fit is tight enough to hold the screw (20) to the driver (10), yet allows the driver to be easily disengaged from the screw by pulling the driver away from the screw once the screw is lodged in place. The interference fit screw driver (10) is particularly useful in turning bone screws into the spine of a patient during orthopedic surgery.