The watch movement includes a mechanical resonator with a balance and a spring, a device for setting the oscillation frequency of the mechanical resonator and a device for setting the guide mark on the mechanical resonator. A moving part of the setting device includes a fastener for attaching an outer end part of the spring and a device for defining the active length of the spring. A mechanism for varying the active length of the spring includes a first toothed wheel, carried by the moving part, and a first toothing, arranged along the outer end part of the spring, with which the first toothed wheel meshes. The fastener holds the outer end part by friction such that the first toothed wheel can drive this outer end part via the first toothing and thus vary the active length of the spring.

The watch movement includes a mechanical resonator with a balance and a spring, a device for setting the oscillation frequency of the mechanical resonator and a device for setting the guide mark on the mechanical resonator. A moving part of the setting device includes a fastener for attaching an outer end part of the spring and a device for defining the active length of the spring. A mechanism for varying the active length of the spring includes a first toothed wheel, carried by the moving part, and a first toothing, arranged along the outer end part of the spring, with which the first toothed wheel meshes. The fastener holds the outer end part by friction such that the first toothed wheel can drive this outer end part via the first toothing and thus vary the active length of the spring.

A horology component based on a fragile material, wherein said component comprises at least one surface part of fragile material covered with a coating (10) comprising at least two layers CE of elastic material (11) separated by a layer CR of a material (12) stronger than the elastic material (11).

A thermally-actuated micromechanical device (1), in particular for a horology movement, the micromechanical device (1) including a first mechanically-actuatable mobile (3) and a second mechanically-actuatable mobile (4), the second mobile (4) being translationally mobile relative to the first mobile (3) between a coupled position, in which the first mobile (3) mechanically engages with the second mobile (4) to actuate it, and a locked position, in which the second mobile (4) cannot engage mechanically with the first mobile (3), the micromechanical device (1) including a support (5) on which the second mobile (4) is mounted, wherein the support (5) is thermally distortable to move the second mobile (4) from the locked position to the coupled position and/or inversely.

A thermally-actuated micromechanical device (1), in particular for a horology movement, the micromechanical device (1) including a first mechanically-actuatable mobile (3) and a second mechanically-actuatable mobile (4), the second mobile (4) being translationally mobile relative to the first mobile (3) between a coupled position, in which the first mobile (3) mechanically engages with the second mobile (4) to actuate it, and a locked position, in which the second mobile (4) cannot engage mechanically with the first mobile (3), the micromechanical device (1) including a support (5) on which the second mobile (4) is mounted, wherein the support (5) is thermally distortable to move the second mobile (4) from the locked position to the coupled position and/or inversely.