Spiral spring for a horological resonator mechanism provided with means for adjusting the stiffness
A spiral spring for a horological resonator mechanism, including a flexible strip ( 2 ) coiled on itself into several turns The spring ( 1 ) including an element for adjusting its stiffness, which includes a first elongate flexible element ( 5 ), and a second elongate flexible element ( 15 ) arranged in series with the strip ( 2 ), each elongate flexible element ( 5 ) connecting the same end ( 4 ) of the strip ( 2 ) to a fixed support ( 11 ), so as to add an additional stiffness to the strip ( 2 ), each elongate flexible element ( 5 ) preferably having a stiffness higher than that of the strip ( 2 ). A prestressing element ( 6 ) applies at least two different adjustable efforts, the two efforts being applied on the first elongate flexible element ( 5 ) so as to make the stiffness of the first elongate flexible element ( 5 ) vary according to the prestress level.
1 . A spiral spring for a horological resonator mechanism, the spiral spring ( 1 , 10 ) comprising a flexible strip ( 2 ) coiled on itself into several turns, the strip ( 2 ) having a predefined stiffness, the spiral spring ( 1 , 10 ) including means for adjusting tensile/compressive forces acting on the spiral spring, wherein the adjustment means include a first elongate flexible element ( 5 ), and a second elongate flexible element ( 15 ) arranged in series with the strip ( 2 ), each elongate flexible element ( 5 , 15 ) connecting the same end ( 4 , 9 ) of said strip ( 2 ) to a fixed support ( 11 , 14 ), so as to add an additional stiffness to the spiral spring, each elongate flexible element ( 5 ) having a stiffness higher than that of the strip ( 2 ), the adjustment means including prestressing means ( 6 ) for applying at least two different adjustable forces, the two different adjustable forces being of the tensile/compressive forces acting on the spiral spring and applied on the first elongate flexible element ( 5 ) so as to make the stiffness of the first elongate flexible element ( 5 ) vary according to the prestress level.
2 . The spiral spring according to claim 1 , wherein a first of the two different adjustable forces is imparted by, of the tensile/compressive forces, a first tensile/compressive force directed in the longitudinal direction F L of the first elongate flexible element ( 5 ).
3 . The spiral spring according to claim 1 , wherein a first of the two different adjustable forces further is exerted and directed in a direction orthogonal to the longitudinal direction of the second elongate flexible element ( 15 ).
4 . The spiral spring according to claim 1 , wherein a second of the two different adjustable forces is imparted and directed in a direction orthogonal F T to the longitudinal direction of the first elongate flexible element ( 5 ).
5 . The spiral spring according to claim 4 , wherein the second of the two different adjustable forces is, as a second tensile/compressive force of the tensile/compressive forces, directed in the longitudinal direction of the second elongate flexible element ( 15 ).
6 . The spiral spring according to claim 1 , wherein each of the first ( 5 ) and second ( 15 ) elongate flexible elements includes a unique flexible blade ( 13 , 18 ).
7 . The spiral spring according to claim 1 , wherein each of the first ( 5 ) and second ( 15 ) elongate flexible elements includes a pair of main flexible blades ( 23 , 25 ).
8 . The spiral spring according to claim 1 , wherein the first ( 5 ) and second ( 15 ) elongate flexible elements are perpendicular to one another.
9 . The spiral spring according to claim 1 , wherein the first flexible element ( 5 ) is arranged in a radial direction of the spiral spring ( 1 , 10 ).
10 . The spiral spring according to claim 1 , wherein the second flexible element ( 15 ) is arranged in a direction tangential to the spiral spring ( 1 , 10 ).
11 . The spiral spring according to claim 1 , wherein the prestressing means ( 6 ) comprise two secondary flexible blades ( 12 , 13 ) connected at an end ( 4 ), each secondary flexible blade ( 12 , 13 ) being arranged in line with one of the elongate flexible elements ( 5 , 15 ).
12 . The spiral spring according to claim 11 , wherein the prestressing means ( 6 ) include two rigid bodies ( 14 , 16 ) each arranged at the end of each secondary flexible blade ( 12 , 13 ).
13 . The spiral spring according to claim 12 , wherein the prestressing means ( 6 ) include variable support means on each rigid body ( 14 , 16 ).
14 . The spiral spring according to claim 1 , wherein the two different adjustable forces are continuously adjustable by the prestressing means ( 6 ).
15 . The spiral spring according to claim 1 , wherein the first ( 5 ) and second ( 15 ) flexible elements are arranged at an outer end ( 4 ) of the strip ( 2 ).
16 . The spiral spring according to claim 1 , wherein the prestressing means ( 6 ) are configured to enable an adjustment of the two different adjustable forces at different intensities.
17 . A rotary resonator mechanism, in particular for a horological movement, including an oscillating mass and comprising a spiral spring ( 1 , 10 ) according to claim 1 .
18 . The spiral spring according to claim 1 , wherein a longitudinal axis of the first elongate flexible element ( 5 ) is arranged orthogonal to a longitudinal axis of the second elongate flexible element ( 15 ).
19 . The spiral spring according to claim 18 , wherein the prestressing means comprises screws ( 24 ), and the screws ( 24 ) comprise a first screw and a second screw, a longitudinal axis of the first screw is arranged orthogonal to the longitudinal axis of the second elongate flexible element ( 15 ), and a longitudinal axis of the second screw is arranged orthogonal to the longitudinal axis of the first elongate flexible element ( 5 ).