An attachment part for attaching a free end of an outer last coil of a balance spring of a horological movement, this balance spring taking the form of a ribbon wound in coils and being delimited by first and second faces which extend parallel to and at a distance from one another, the attachment part including elastically deformable clamping means which are arranged to be brought into contact with the free end of the outer last coil of the balance spring in order to exert a resilient clamping force on this free end so as to guarantee the immobilisation thereof, this resilient clamping force being exerted along at least a first line of contact (A; B) on the first face of the balance spring and along a contact surface (S) on the second face.

A balance-spring, in particular for a horological resonator mechanism, the balance-spring including a flexible strip coiled on itself into several coils, the strip having a predefined flexibility, the balance-spring including a device for adjusting its flexibility, the adjustment device including an elastic element in direct contact with the strip, the elastic element preferably having a flexibility less than that of the strip, the adjustment device including a prestressing device to apply a variable force or torque to the elastic element, so as to vary the flexibility of the elastic element, the elastic element and the strip being separate and assembled with each other. An horological resonator mechanism including such a balance-spring is also disclosed.

A method for maintaining and regulating frequency of a timepiece resonator mechanism around its natural frequency, the method including: at least one regulator device acting on the resonator mechanism with a periodic motion, to impose a periodic modulation of resonant frequency or quality factor or a position of a point of rest of the resonator mechanism, with a regulation frequency between 0.9 times and 1.1 times the value of an integer multiple of the natural frequency, the integer being greater than or equal to 2 and less than or equal to 10, and the periodic motion imposes a periodic modulation of the quality factor of the resonator mechanism, by acting on losses and/or damping and/or friction of the resonator mechanism.

The hairspring (1; 1) has a spring blade (11; 11) and a connecting member (12; 12) for fastening the hairspring (1; 1) to a frame (5, 6, 8), the connecting member including first (13a; 13a) and second (13b; 13b) fastening element, a first arm (121; 121) connecting the first fastening element (13a; 13a) to the second fastening element (13b; 13b), and a second arm (122; 122) connecting the first arm (121; 121) to the spring blade (11; 11), the second arm (122; 122) being connected to the spring blade (11; 11) in a first joining zone (122a; 122a), the hairspring (1; 1) being configured or arranged so that a first displacement of a first amplitude of the first fastening element (13a; 13a) relative to the second fastening element (13b; 13b) does not cause any displacement of the second arm (122; 122), particularly of the first joining zone (122a; 122a), or causes a second displacement of a second amplitude of the second arm (122; 122), particularly of the first joining zone (122a; 122a), relative to the second fastening element (13b; 13b), the second amplitude being less than 0.15 times or 0.1 times or 0.05 times the first amplitude.

An assembly (300) includes (i) a hairspring (2) made of a paramagnetic alloy including at least one of the following elements: Nb, V, Ta, Ti, Zr and Hf, notably an alloy including the elements Nb and Zr with between 5% and 25% by mass of Zr and an interstitial doping agent including oxygen, and least one fastening part (1; 1), notably two parts (1; 1), in particular a stud (1) or a collet (1), for an end (2a; 2b) of the hairspring (2), the at least one part (1; 1) having a first portion (10; 10) that is designed to come into contact with the hairspring (2) and that is made of titanium or titanium alloy or of tantalum or tantalum alloy, notably grade 2 titanium or grade 5 titanium.

An assembly for holding or supporting a timepiece balance spring, including a balance spring stud and a stud-holder, wherein the stud-holder includes a base having at least one circular portion, the base including, on the circular portion, a first lug and a second lug each extending radially; one of the two lugs including an elastic arm extending from the lug, in a direction parallel to that of the base, towards the other lug, the elastic arm forming with the base a housing for housing the balance spring stud therein and in that the first and second lugs are able to cooperate with a tool to allow the balance spring stud to exert a stress on the elastic arm to deform the latter and permit the assembly or disassembly of the stud.

The invention relates to a balance-spring stud-holder for a mechanical timepiece movement, which comprises a pair of tabs, namely a front tab and a rear tab, jointly defining a notch, the tabs being arranged in such a way that a balance-spring stud can be held in the notch, wherein the rear tab of the balance-spring stud-holder comprises an extension which defines, beyond the notch, a bend forming a retaining abutment for the balance-spring stud after said balance-spring stud has been extracted from the notch.

A device for assembling and adjusting a balance spring, including a base joined to a balance bridge with an adjustable angular orientation, and having a bearing surface and a bearing plate adjacent to the bearing surface, both defining a service position of the end turn of the balance spring. A first arm extends from the base and bears a locking member for the end turn, the locking member being designed to keep the terminal coil in abutment against the bearing surface. A second arm of the device extends from the base and bears a shoe that is able to be arranged at a predefined distance from the bearing surface so as to cooperate with the end turn. A movable control member is able to act on the second arm in order to deform it elastically and move the shoe with respect to the base in order to free the end turn.

The present invention concerns an assembly for holding or supporting a timepiece balance spring, comprising a balance spring stud and a balance cock on which is fixed a balance spring stud-holder, wherein said stud-holder comprises a holding means provided with a housing for housing the balance spring stud therein and a gripping means, at least said gripping means being movable with respect to the holding means in order to lock the balance spring stud inside its housing.

A device (6) for autonomously adjusting the active length of a balance spring (5), for an oscillator (4, 5) of the sprung balance type, including a cock (12) mounted on a plate (13) of a horological movement (2) and in which cock a balance staff pivots, the balance spring (5) including an inner end integral with the balance staff and an outer end integral with a stud (8) fastened to a stud-holder (10), the stud-holder (10) being pivotally mounted on the cock (12) concentrically with the balance staff, and means for modifying the active length of the balance spring (5).