US Patent 7182508 Linking device between a rim and a case of watch

This device comprises a first axial retention shoulder secured to the case, adjacent to a cylindrical seat, a second, opposite axial retention shoulder formed by one face of an annular groove secured to the rim, an annular retention element made of polymer bearing against each of said shoulders, said first shoulder being adjacent to the base of a conical surface, secured to the case, for the axial introduction of said annular retention element engaged with said annular groove. Said annular retention element forms an endless ring whose section is divided in the radial direction into two portions of which one is, perpendicularly to the plane of said endless ring, substantially thinner than the other, these two portions being intended to interact respectively with said first shoulder and second shoulder.