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 balance spring (1) of a sprung balance assembly of a mechanical horological movement, formed by a succession of coils (S1, . . . , Sn) which extend between a first free end, referred to as inner first coil (2), and a second free end, referred to as outer last coil (6). The are arranged off-centre when the balance spring is in the free state, the outer last coil (6) terminating in a stop means for the attachment thereof to a stud (14). The balance spring (1) is centred and its spires concentric when the spring (1) is in the mounted state inside the sprung balance assembly, the coils being rearranged concentrically when the spring is in the mounted state. The attachment of the spring to the stud inducing, in the coils, a resilient stress as a result whereof the stop is attached in a captive manner to the stud (14).

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 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.

A balance-spring stud for fixing with a spot of glue a free end of a last turn on the outside of a spiral spring for a timepiece movement, this balance-spring stud includes a base within a plane, first and second arms extending from the plane and free at their end opposite the base, the first and second arms being separated from one another by a gap in which the free end of the last turn on the outside of the spiral spring that is trapped in the hardened spot of hardened glue is housed, at least one of the first and second arms being provided with a stop device arranged to prevent the spot of hardened glue in which the free end of the last turn on the outside of the spiral spring is trapped from being released from the gap in which the spot of hardened glue is housed when this spot of hardened glue no longer adheres to the balance-spring stud.

A resonator of the inertia/elasticity type includes a balance-spring coupled to an inertia flywheel and a system for adjusting the frequency of the resonator including an index-assembly arranged to cooperate with one coil of the balance-spring in order to selectively choose the active length of the balance-spring. The portion of the coil of the balance-spring cooperating with the index-assembly includes at least one area of larger cross-section than the other balance-spring coils for finer adjustment of the frequency of the resonator.

A spiral spring for a horological resonator mechanism, including a flexible strip (2) coiled on itself into several turns, the strip (2) having a predefined stiffness. The spring (1) include an element for adjusting its stiffness, including a unique elongate flexible element (5) arranged in series with the strip (2), and connecting one end (4) of said strip (2) to a fixed support (11), to add additional stiffness. The flexible element (5) has a stiffness higher than that of the strip (2). A prestressing element (6) applies two different efforts on the element (5), and includes a first lever (8) attached to the end (4) of the strip (2) to allow adjusting a first effort, and a second lever (8) also attached to the end (4) of the strip (2) to adjust a second effort independently of the first effort.

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 (ii) at 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 (1) for attaching a free end (8) of an outer last coil (10) of a balance spring (12) for a horological movement, this attachment assembly (1) including a stud (2) and a blocking element (14), the stud (2) being provided with a groove (6) in which the free end (8) of the outer last coil (10) of the balance spring (12) is engaged, the blocking element (14) also being engaged in the groove (6), in contact with the outer last coil (10) of the balance spring (12), the attachment assembly (1) further including a clamping member (16) which presses the blocking element (14) against the free end (8) of the outer last coil (10) of the balance spring (12), such that the free end (8) of the outer last coil (10) of the balance spring (12) is immobilised in the groove (6) of the stud (2).

A fastening stud (1) for one end of a hairspring, the stud having a first portion (10) designed to come into contact with the hairspring, the first portion being formed such as to have a first surface (10b) and a second bearing surface (10c) with the hairspring.

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.