Externally threaded bodies for use as taps or screws
Patent 5643269 Issued on July 1, 1997. Estimated Expiration Date: 
September 16, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
September 16, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 177731 1693768 2479730 Tapping tool for making vibration resistant prevailing torque fastener Patent #: 4181457 InventorApplicationNo. 308119 filed on 09/16/1994US Classes:606/79, Orthopedic cutting instrument606/72, Orthopedic fastener606/73Threaded fastener elementExaminersPrimary: Brown, Michael A.International ClassA61B 017/00Foreign Application Priority Data1993-08-24 DEAbstractThere is provided set of at least two externally threaded bodies each of which has a cylindrical external surface provided with a screw thread. The screw threads have identical pitches, and the crest diameter or diameters of one or more helices of one of the screw threads is or are larger than the crest diameters of helices of the other screw thread. The externally threaded bodies can constitute screws or taps for use in osteosynthesis. If a screw becomes loose, it is removed and the hole for such screw is tapped with a larger tap prior to insertion of a screw having helices with crest diameters larger than the crest diameters of helices of the removed screw. The core diameters of the screw threads of a set of externally threaded bodies need not be the same. | |
