# US 2018/0024500 A1 · Component for a timepiece movement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0024500 A1 - Document ID: US20180024500A1 - Status: Published application - Kind: A1 - Application number: 15/651,318 - Filed: 2017-07-17 - Published: 2018-01-25 - Earliest claimed: 2016-07-19 - Assignees: Nivarox-FAR S.A. - Applicants: Nivarox-FAR S.A. - Inventors: Christian CHARBON; Alexandre Fussinger; Marco Verardo - Web page: https://patentgrep.com/patent/US20180024500A1 ## CPC - G04B 1/16: Barrels; Arbors; Barrel axles (arrangements facilitating the removal of the mainspring G04B33/14) - G04B 13/02: Wheels; Pinions; Spindles; Pivots (bearings G04B31/00 {; chain wheels, spindles for chain wheels, also chains and driving weights G04B1/08}) - G04B 15/14: Component parts or constructional details, e.g. construction of the lever or the escape wheel {(assembly and manufacture of the spring G04B1/145; assembly and manufacture of components, e.g. pinions, spindles G04B13/02; lubrication of clockwork bearings G04B31/008; oils for clockwork bearings in general G04B31/08)} - G04B 17/32: Component parts or constructional details, e.g. collet, stud {, virole or piton} - G04B 43/007: {Antimagnetic alloys (antimagnetic alloys with temperature compensation G04B17/227; apparatus for antimagnetising G04D9/00; alloys in general C22C)} - G04D 3/0069: {for working with non-mechanical means, e.g. chemical, electrochemical, metallising, vapourising; with electron beams, laser beams} - G04B: MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS (spring- or weight-driven mechanisms in general F03G; electromechanical clocks or watches G04C; electromechanical clocks with attached or built-in means operating any device at pre-selected times or after predetermined time intervals G04C23/00; clocks or watches with stop devices G04F7/08) - G04D: APPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES ## Abstract The invention relates to a pivot arbor comprising a metal pivot (3) at each of its ends. The metal is a non-magnetic copper alloy in order to limit its sensitivity to magnetic fields, and at least the outer surface (5) of one of the two pivots (3) is deep-hardened to a predetermined depth with respect to the rest of the arbor to harden the pivot or pivots (3). The invention concerns the field of timepiece movements. ## Claims ### Claim 1 A pivot arbor for a timepiece movement comprising at least one metal pivot at at least one of the ends thereof, wherein the metal is a non-magnetic copper alloy so as to limit the sensitivity of the pivot to magnetic fields, and wherein at least the outer surface of said pivot is deep-hardened to a predetermined depth relative to the core of the pivot arbor. ### Claim 2 (depends on 1) The pivot arbor according to claim 1, wherein the predetermined depth represents between 5% and 40% of the total diameter (d) of the pivot ### Claim 3 (depends on 1) The pivot arbor according to claim 1, wherein the deep-hardened outer surface comprises diffused atoms of at least one chemical element. ### Claim 4 (depends on 1) The pivot arbor according to claim 1, wherein the deep-hardened outer surface has a hardness of more than 600 HV. ### Claim 5 (depends on 1) The pivot arbor according to claim 1, wherein the non-magnetic copper alloy is chosen from the group consisting of a copper and zinc based brass, a copper-beryllium, a nickel silver, a bronze, an aluminium bronze, a copper-aluminium, a copper-nickel, a copper-nickel-tin, a copper-nickel-silicon, a copper-nickel-phosphorus, a copper-titanium, an alloy having a mass percent composition of between 14.5% and 15.5% Ni, between 7.5% and 8.5% Sn, at most 0.02% Pb and the remainder copper. ### Claim 6 (depends on 1) The pivot arbor according to claim 1, wherein said outer surface of said pivot has no hardening layer directly deposited on said outer surface. ### Claim 7 (depends on 1) The pivot arbor according to claim 1, wherein at least the outer surface of said pivot is rolled. ### Claim 8 (depends on 1) The pivot arbor according to claim 1, wherein the pivot arbor has two pivots. ### Claim 9 A movement for a timepiece comprising a pivot arbor, wherein said pivot arbor comprises at least one metal pivot at at least one of the ends thereof, the metal being a non-magnetic copper alloy so as to limit the sensitivity of the pivot to magnetic fields, and wherein at least the outer surface of said pivot is deep-hardened to a predetermined depth relative to the core of the pivot arbor. ### Claim 10 A movement for a timepiece wherein the movement comprises a balance staff, a pallet staff and/or an escape pinion comprising a pivot arbor comprising at least one metal pivot at at least one of the ends thereof, the metal being a non-magnetic copper alloy so as to limit the sensitivity of the pivot to magnetic fields, and wherein at least the outer surface of said pivot is deep-hardened to a predetermined depth relative to the core of the pivot arbor. ### Claim 11 A method for fabricating a pivot arbor for a timepiece movement comprising the following steps: a) forming a pivot arbor comprising at least one metal pivot at one of the ends thereof, said metal being a non-magnetic copper alloy, to limit the sensitivity thereof to magnetic fields; b) diffusing atoms to a predetermined depth in at least the outer surface of said pivot in order to deep-harden the pivot arbor in the main areas of stress while maintaining a high tenacity. ### Claim 12 (depends on 11) The method according to claim 11, wherein the predetermined depth represents between 5% and 40% of the total diameter (d) of the pivot. ### Claim 13 (depends on 11) The method according to claim 11, wherein the diffusion step comprises the diffusion of atoms of at least one chemical element. ### Claim 14 (depends on 11) The method according to claim 11, wherein step b) consists of a thermochemical diffusion treatment. ### Claim 15 (depends on 11) The method according to claim 11, wherein step b) consists of an ionic implantation process which may or may not be followed by a diffusion treatment. ### Claim 16 (depends on 11) The method according to claim 11, wherein the method does not comprise any step of depositing a hardening layer directly on the outer surface of the pivot. ### Claim 17 (depends on 11) The method according to claim 11, wherein the pivot is subjected to a rolling/polishing step after step b).