Fastener with lubricating ring for interference fitting, and assembly method using such a fastener

A fastener for assembling at least two structural elements, the fastener comprising an enlarged head and a cylindrical or tapering smooth shank exhibiting, prior to fitting, an outside diameter (D1) greater than an inside diameter (DS) of a destination aperture, a locking portion comprising a screw thread or annular grooves exhibiting an outside diameter always smaller than the inside diameter (DS) of the destination aperture, and a transition portion between a distal end, with respect to the enlarged head, of said smooth shank and a proximal end, with respect to the enlarged head, of said locking portion, wherein said fastener comprises at least one sacrificial ring containing a lubricant, arranged on an exterior surface of the fastener, positioned on an exterior surface of the smooth shank and or of the locking portion and or of the transition portion, said sacrificial ring exhibiting, prior to the fitting of the fastener into the structure, an outside diameter greater than a maximum outside diameter of the locking portion and greater than a smallest diameter of the aperture with which the smooth shank will interfere after the fastener has been fitted, and wherein the sacrificial ring exhibits, prior to the fitting of the fastener into the structure, a toroidal shape.

A method of assembly for assembling at least two structural elements comprising a aperture exhibiting, before fitting, an inside diameter (DS), the method comprising the steps of

• supplying a fastener according to claim 1,
• forcibly fitting the fastener into the aperture or into the sleeve placed in the aperture, during which step the lubricating sacrificial ring is worn through interference with an interior wall of the aperture or of the sleeve, so as to release a lubricating substance between a distal end of the smooth shank and a proximal end of said smooth shank.