A method for manufacturing a hole jewel, including forming a precursor from a mixture of at least one powder material with a binder; pressing the precursor, with upper lower dies, to form a green body of the future hole jewel including a blind cavity having a height between a height of the green body and a height of the future hole jewel, the cavity being provided with upper and lower portions respectively including blanks of a through hole and of a functional element of the future hole jewel; sintering the green body to form a body of the future hole jewel; machining the body, including a first sub-step of shaping a top of the body, during which a height of the upper portion is configured in readiness for an opening in the through hole blank for connecting the functional element to the upper surface, and a second sub-step of shaping a base of the body to form a lower surface of the hole jewel for connecting the functional element to to the lower surface.

A method for manufacturing a hole jewel, including forming a precursor from a mixture of at least one powder material with a binder; pressing the precursor, with upper lower dies, to form a green body of the future hole jewel including a blind cavity having a height between a height of the green body and a height of the future hole jewel, the cavity being provided with upper and lower portions respectively including blanks of a through hole and of a functional element of the future hole jewel; sintering the green body to form a body of the future hole jewel; machining the body, including a first sub-step of shaping a top of the body, during which a height of the upper portion is configured in readiness for an opening in the through hole blank for connecting the functional element to the upper surface, and a second sub-step of shaping a base of the body to form a lower surface of the hole jewel for connecting the functional element to to the lower surface.

A device (1) for guiding a rotary shaft (6) of a sprung balance. The device includes at least the rotary shaft and a guide bearing (2) for guiding an end of the rotary shaft of the sprung balance, the guide bearing including at least one blade (3) and a surface (5) for coming into contact with and holding the end of the rotary shaft of the sprung balance. At least one end part of the shaft and at least the blade and the contact surface of the guide bearing are made of a material with a Young's modulus of less than or equal to 100 GPa and to reduce the coefficient of friction of the contacting parts.

A device (1) for guiding a rotary shaft (6) of a sprung balance, including the rotary shaft and a guide bearing (2) for guiding an end of the rotary shaft. The guide bearing includes a blade (3) and a surface (5) for coming into contact with and holding the end of the rotary shaft of the sprung balance. The contacting parts are made of a material with a Young's modulus of less than or equal to 100 GPa and/or to reduce the coefficient of friction of the contacting parts. The device also includes a solid body (15) with a guide opening, such as a hole jewel (15), disposed along the axis of the rotary shaft (6) in a centred position. An end of the shaft passes through the opening without too much angular play caused by the effect of gravity.

A magnetic device for centring a shaft on a predetermined axis in a clockwork movement includes at least one first magnetic bearing provided with a magnet to exert an attractive force on a first ferromagnetic end pivot of the shaft. The first magnetic bearing includes a central part made of soft ferromagnetic material mounted between the magnet and the first end pivot of the shaft. The central part is positioned centrally in a washer made of non-magnetic material so as to centre the magnetic field flux generated by the permanent magnet through the central part in order to magnetically attract the first end pivot of the shaft on the predetermined axis. The diameter of the central part can be identical to, or 0 to 20% less than, or 0 to 20% greater than, the diameter of the first end pivot.

A magnetic device for centring a shaft on a predetermined axis in a clockwork movement includes at least one first magnetic bearing provided with a magnet to exert an attractive force on a first ferromagnetic end pivot of the shaft. The first magnetic bearing includes a central part made of soft ferromagnetic material mounted between the magnet and the first end pivot of the shaft. The central part is positioned centrally in a washer made of non-magnetic material so as to centre the magnetic field flux generated by the permanent magnet through the central part in order to magnetically attract the first end pivot of the shaft on the predetermined axis. The diameter of the central part can be identical to, or 0 to 20% less than, or 0 to 20% greater than, the diameter of the first end pivot.

An element for radial guiding of a pivot of a rod of a rotating wheel, for example a rod of a balance, for a bearing of an horological movement, in particular shock-absorbing, the guide element including a body configured to cooperate with a bearing unit in such a way as to be maintained in the unit, the body defining a space for radial retention of the pivot, to maintain the rod radially while allowing it to rotate. The radial guide element includes at least three localized radial-bearing parts distributed angularly, the three parts defining the radial retention space, each part having a face for contact with the pivot, each face locally having a cylindrical shape convex towards the inside of the radial retention space, the bearing parts having an elongated body.

A method and device for manufacturing a bevelled stone, particularly for a timepiece are disclosed. A precursor is produced from a mixture of at least one material in powder form with a binder. The method includes pressing the precursor so as to form a green body, using a top die and a bottom die comprising a protruding rib, sintering the green body so as to form a body of the future stone in at least one material, the body including a peripheral face and a bottom face provided with a groove, and machining the body including a substep of planning the peripheral face up to the groove, such that an inner wall of the groove forms at least a flared part of the peripheral face of the stone.

A timepiece component includes a first silicon-based or ceramic-based part, and a second metal-based part. One surface of the first part is directly welded using laser-type electromagnetic radiation onto a surface of the second part in order to secure the parts without addition of material. A method for fabrication of a timepiece component for a timepiece includes forming a first silicon-based or ceramic-based part and a second metal-based part, mounting a surface of the first part on a surface of the second part, and welding, using laser-type electromagnetic radiation, the surface of the first part mounted directly on the surface of the second part, in order to secure the parts to each other without addition of material.

A timepiece component includes a first silicon-based or ceramic-based part, and a second metal-based part. One surface of the first part is directly welded using laser-type electromagnetic radiation onto a surface of the second part in order to secure the parts without addition of material. A method for fabrication of a timepiece component for a timepiece includes forming a first silicon-based or ceramic-based part and a second metal-based part, mounting a surface of the first part on a surface of the second part, and welding, using laser-type electromagnetic radiation, the surface of the first part mounted directly on the surface of the second part, in order to secure the parts to each other without addition of material.