APPARATUS FOR CUTTING-THROUGH OF THREADED RODS, AND CONTRACTOR Russian patent published in 2005 - IPC

FIELD: traumatology and orthopedics.

SUBSTANCE: apparatus for cutting-through of nut-shaped threaded rods with hexagonal base is made paired and comprises inserts and screws. Insert receptacle is provided in base and is open toward one of nut ribs. Insert receptacle is equipped with slot open toward the same side. Threaded-through openings for receiving of headless screws are extending perpendicular to slot axis in nut wall. Headless screws have sharpened ends and are provided with grooves. Inserts are formed as bars of rectangular section. Outer base of each bar is chamfered. Inner base is rounded to conform to shape of receptacle. Semi-cylindrical slots provided in the vicinity of rounded bases are arranged concentrically with respect to said bases. Concentric slots are provided with thread and upon joining of inserts, their inner long faces define threaded opening for receiving of threaded rod after cutting-through of threaded rod. Conical depressions are formed on outer faces of inserts for receiving sharpened ends of headless screws. Contractor is made in the form of pair of pivotally connected intersecting branches with working parts and tie rod. Working parts are arranged at different levels and formed as nut holders made as hollow semi-cylinders generatrix edges of which are formed as straight plates extending beyond diameters of semi-cylinder. Straight plates are contacting with one another with their sliding ends. Inner diameter of semi-cylinders corresponds to space between opposite nut faces. Semi-cylinder bottoms are arranged at opposite sides and provided with slots whose openings face one another. Axes of outer semi-circular slot ends are eccentrically extending to the outside of axes of semi-cylinders. Tie rod is positioned on inoperative ends of branches. Tie rod screw head is pivotally mounted on one of branches. End of said screw extends through recess at end of other branch and is equipped with wing nut. Upon joining of branches, ends of straight plates are brought into contact with and overlap one another.

EFFECT: reduced traumatism during cutting-trough of excessively extending ends of threaded rods of bone retainers, including portions between supports of compression-distraction apparatus.

3 cl, 7 dwg