Device for guiding pivotally and horological resonator mechanism for a pivoting mass

A device for guiding a pivoting mass about an axis. A first support is fixed and a second support forms or supports the pivoting mass. The device is includes a first and second flexible leaf oriented in the same direction when the device is at rest, and an intermediate leaf having a rigidity notably greater than the flexible leaves and connecting the first flexible leaf to the second, the device including a first fixed link formed by the first support and a first end of the first leaf, a second fixed link formed by a second end of the first leaf and by a first end of the intermediate leaf, a third fixed link formed by a second end of the intermediate leaf and by a first end of the second leaf and a fourth fixed link formed by at least one second end of the second leaf, wherein the first and/or the fourth link is arranged substantially between the second and the third link in the direction when the device is at rest.