Locking system for threaded fasteners

A locking system for connecting at least one threaded fastener to an anchor for preventing loosening of the fastener, each of the anchor and the fastener having a body and a lock wire aperture therethrough of a size sufficient to closely receive a locking wire, the system comprising.:.

• a flexible multi-strand locking wire having first and second ends, the first end of the wire having a restraining head of a dimension sufficient to interfere with the lock wire apertures, the wire being threaded through each of the lock wire apertures in a predetermined direction, and
• a ferrule having a stop end, a barrel end and an axial aperture between said ends, the ferrule being of malleable metal having a cross sectional wall thickness which is substantially uniform from end to end, the stop end having a dimension sufficient to interfere with the lock wire apertures, the barrel end having a dimension substantially smaller than the stop end so as to reduce the force required to crimp the barrel end, the second end of the locking wire being threaded through the ferrule with the stop end facing the lock wire aperture closest to the second end of the wire, the locking wire being tensioned between the restraining head on the first end and the ferrule on the second end, the tension in the locking wire being maintained by said crimped deformations on the barrel end engaging the strands of the locking wire, the barrel end of the ferrule and the axial aperture of the ferrule defining a thin wall section adapted for a crimped connection of the ferrule to the locking wire.

A locking method for connecting at least one threaded fastener to an anchor for preventing loosening of the fastener, each of the anchor and the fastener having a body and a lock wire aperture therethrough of a size sufficient to closely receive a locking wire, the method comprising the steps of:

• providing a flexible multi-strand locking wire having a first end with a restraining head and a free second end,
• threading the second end through each of the lock wire apertures of the anchor and the fastener in a predetermined direction,
• threading the second end of the wire through an axial aperture in a ferrule, the ferrule having a stop end and a barrel end, the stop end having a dimension sufficient to interfere with the lock wire apertures, the barrel end having a thin wall section adapted for a crimped connection of the ferrule to the locking wire.., orienting the ferrule so that the wire enters the ferrule at the stop end,
• tensioning the locking wire by pulling the second end while forcing the stop end of the ferrule against the body closest to the second end of the wire, so that the restraining head on the first end of the locking wire is pulled against the body closest to the first end,
• while holding the tension in the wire, crimping the barrel end of the ferrule to impress crimped deformations on the outside of the barrel end which form pinch points on the inside of the barrel end to grip the locking wire and maintain the tension therein, the barrel end having a dimension substantially smaller than the stop end to correspondingly reduce the force necessary to perform the crimping step.