Balance with inertia adjustment for timepieces, including a hub defining the pivot axis of the balance, a rim, a web extending between a lower plane and an upper plane on either side of a median plane, the web including at least one arm connecting the rim to the hub, the arm including a housing configured to receive and hold in place at least one inertia block. According to the invention, the inertia block has a front face and a rear face and is integrated in the balance arm, so that the front face and rear face are substantially in the upper plane and the lower plane.

Disclosed is an adjustment method for a timepiece oscillator including a balance, a support and a flexure pivot connecting the balance to the support and guiding the balance in rotation as to the support about a virtual axis of rotation, the flexure pivot having, in orthogonal projection in a plane perpendicular to the virtual axis of rotation, an axis of symmetry which is also an axis of symmetry for the points where the flexure pivot joins the balance. In the method, the unbalance of the balance is adjusted so, in orthogonal projection in the plane, the center of mass of the balance is substantially on the axis of symmetry and at a position distinct from that of the virtual axis of rotation and chosen to reduce, and preferably render minimal, the dependency of the oscillation frequency with respect to the orientation of gravity for a predetermined amplitude of oscillation.

A stud-holder (1) for a regulating member (10) of a horological movement, the regulating member (10) including an inertial mass, for example a balance (23), a balance spring (25) including a strip (2) wound about itself in several turns, and a balance cock (22), the stud-holder (1) including a main body (31) intended to be mounted on the balance cock (42), and a stud (34) mounted on the main body (31) in a first direction, wherein the stud-holder (1) includes an arm (5) extending from the stud (34), the arm (5) being directed in a second direction under the main body (31), the second direction forming a non-zero angle with the first direction, so as to pass at least in part beneath a balance spring (25) held by the stud (34), when the stud-holder (1) is mounted on the regulating member (10).

The guide element (1) for guiding the pivoting, about an axis (A), of a balance (91) of a timepiece (200), includes a first guide bearing (2) not fitted with a damper, and a first blank (3), in particular a first balance bridge or cock, the first blank (3) including at least a first fixing portion (31) for fixing to another blank (4), a first receiving portion (32) for receiving the first guide bearing (2), and at least a first flexible arm (33) mechanically connecting the first fixing portion (31) to the first receiving portion (32).

A piezoelectric balance spring (3) for a circuit (10) for self-regulating an oscillation frequency of an oscillating mechanical system (2, 3), or an energy recovery circuit or a motor circuit for actuating the movement or for the automatic maintenance thereof. The piezoelectric balance spring (3) includes at least one piezoelectric layer (7, 7, 17, 17, 27, 27) provided on a top face (20) or bottom face of a certain number of coils of the spring in a plane, and at least two pairs of electrodes (8a, 8b, 8c, 8d), whereby the electrodes of each pair are provided on two opposing faces of the same piezoelectric layer or respectively two piezoelectric layers so as to apply a reverse bias voltage on each pair of electrodes.

A horological assembly for a horological regulating member, including a balance spring (25) having a coiled flexible strip (2); a device for adjusting its rigidity which includes a flexible element (5) arranged in series with the strip and connecting one end (4) of said strip to a rigid support (17), the flexible element having a rigidity greater than that of the strip. The adjustment device includes a pre-stressing device (6) for applying a variable force or torque to the flexible element to vary the rigidity of the flexible element. A stud-holder (1) is configured to suspend the balance spring and includes a main body (30) connected to the flexible element, and a secondary body (33) connected to the pre-stressing device, the secondary body (33) being movable relative to the main body (30) and being connected to the main body by a flexure bearing (20).

A balance spring, in particular for a horological regulating member, the balance spring (100) including a flexible strip (2) wound about itself in several turns, the strip (2) having a predefined stiffness, the balance spring (100) having a stiffener for adjusting its stiffness, the balance spring (1) also including an actuator (10) for actuating the adjustment means, depending on the ambient temperature. Also, a horological regulating member including such a balance spring.

The invention relates to a device with a regulating member for a timepiece comprising a frame (2) and a regulating member (3). The regulating member (3) comprises a balance (8) fixedly attached to a staff (9) and first and second balance springs (10, 11). Each of the first and second balance springs (10, 11) has an inner end fixedly attached to one of the staff (9) and frame (2) and an outer end fixedly attached to the other of the staff (9) and frame (2). The staff (9) comprises pivots (14, 15) arranged to rotate in bearings (16, 17) of the frame (2). The first and second balance springs (10, 11) are preloaded so as to exert on the staff (9), parallel to the staff (9), two forces of opposite directions.

A horological movement including a plate (33) extending substantially in a first plane and being configured to support the other parts of the movement, such as a member extending at least in part along a second plane. The horological movement includes variable adjustment means (30, 40, 130) for variably adjusting the inclination of the member (1, 10, 100) relative to the plate (33). The variable adjustment means includes an inclining bridge (7, 57, 107) on which the member (1, 10, 100) is mounted, the inclining bridge (7, 57, 107) being inclining relative to the plate (33), such that the second plane forms an angle of variable value with the first plane of the plate (33).

A balance includes a balance staff rotatably supported by a main plate, a collet fixed to the balance staff, and a hairspring fixed to the collet, the hairspring including a Grossmann curve disposed at a side of the collet and an Archimedes curve coupled to the Grossmann curve, and an impact-resistant member configured to suppress displacement of a shape of the Grossmann curve at least at the side of the collet.