Flexible guide and set of superimposed flexible guides for rotary resonator mechanism, in particular of a horological movement

A flexible guide for a rotary resonator mechanism of a horological movement, the guide comprising:

• a first support,
• an element movable relative to the first support,
• a second support,
• a first pair of flexible strips connecting the first support to the movable element, so that the movable element can displace relative to the first support by bending the strips in a circular movement about a center of rotation, the flexible guide being arranged substantially in a plane,
• a second pair of flexible strips connecting the second support to the movable element, the second support and the second pair of strips being arranged by symmetry of the first support and the first pair of flexible strips relative to the movable element, the first and second pairs of flexible strips connecting on either side the first and the second support to the movable element at its center of rotation, and
• prestressing means, the prestressing means being configured to apply a force on the first and second supports to buckle the first pair of flexible strips and the second pair of flexible strips, so that the flexible guide comprises two stable angular positions of the movable element relative to the first support for which a return moment is zero, the two stable angular positions having a predetermined angle of rotation therebetween,
• wherein the return moment of the flexible guide has a substantially sinusoidal shape between the two stable angular positions.