The main element 2 is connected to the mechanism of the movement, having parts 4, 5, by an arbor about which it can turn. To this end, it comprises an attachment 6 for fixing to the movement, which is for example formed by a small ring arranged in the opening 9 of the ring of the main element 2. The attachment 6 is thus composed of the same material as the main element and is arranged in the same plane. By virtue of the attachment 6, the winding mass can make a circular movement about the arbor, when it oscillates.

An oscillating weight (I) with variable geometry for a timepiece mechanism has a first and a second part (10; 20), and an axis of rotation (40) shared by the first and the second part (10; 20). At least one part (10; 20) is arranged in order to oscillate about the axis of rotation. A differential mechanism (30) is connected to the first and to the second part (10; 20) so as to vary the position of one part relative to the other through a rotational movement of at least one of the parts about the axis of rotation (40). Owing to the presence of the differential mechanism (30), the user of the watch can vary the geometry of the oscillating weight (I) directly and therefore the position of its centre of gravity, and thus adapt it to their lifestyle (for example, sport mode, normal mode).

An oscillating winding weight for a timepiece movement including a heavy portion fixed to a connecting element intended to connect the heavy portion to an arbor integral with a movement, the oscillating winding weight being intended to be rotatably mounted on the arbor, the connecting element being made of a transparent or translucent material. According to the invention, the connecting element includes at least one coloured filter.

A method for making an oscillating weight for an automatic winding mechanism of a self-winding watch including a central part made from a first composite material and a heavy sector made from a second composite material charged with heavy metal particles, the method including: forming the central part with a lateral rib and a rebate by injecting the first composite material into a mold; overmolding the heavy sector onto the central part by injecting the second composite material into a mold containing the central part, so that the second composite material fills the rebate and a gap underneath the lateral rib, so that the lateral rib is embedded in the second composite material and the central part and the heavy sector are interlocked.

The oscillating weight includes a drive ring and a heavy sector. The drive ring includes an annular transmission portion which has a coaxial toothing and a second annular portion concentric to the annular transmission portion, the heavy sector being fixed to the second annular portion. The drive ring further includes a plurality of connecting elements which are elastically deformable and which connect the annular transmission portion to the second annular portion.

An oscillating mass (1) for a self-winding timepiece including a carrier bow (2) including a first transmission part (20) provided with coaxial toothing (21) to drive the winding of the timepiece and a second supporting part (22), and including a heavy sector (3) or attached to the second supporting part of the carrier bow (2). The heavy sector (3) is attached to the carrier bow at several points via blom studs (4) with an uneven surface to form a reservoir for holding glue.