Timepiece oscillator with flexure bearings having a long angular stroke

A mechanical timepiece oscillator comprising, between a first rigid support element and a second solid inertial element, a flexure bearing including more than two first flexible strip which support said second solid inertial element and are arranged to return said second solid inertial element to a rest position, wherein said second solid inertial element is arranged to oscillate angularly in an oscillation plane about said rest position, said two first flexible strips do not touch each other and their projections onto said oscillation plane cross, in the rest position, at a crossing point, in proximity to which or through which passes the axis of rotation of said second solid inertial element perpendicularly to said oscillation plane, and the embedding points of said first flexible strips in said first rigid support element and said second solid inertial element define two strip directions parallel to said oscillation plane, each said strip has an aspect ratio RA=H/E, where H is the height of said strip perpendicularly both to the oscillation plane and to the elongation of said strip along said length L, and wherein E is the thickness of said strip in the oscillation plane and perpendicularly to the elongation of said strip along said length L, wherein said aspect ratio RA=H/E is less than 10 for each said strip.