# US 2025/0164932 A1 · Timepiece regulating member comprising an actuation system provided with an eccentric > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0164932 A1 - Document ID: US20250164932A1 - Status: Published application - Kind: A1 - Application number: 18/923,996 - Filed: 2024-10-23 - Published: 2025-05-22 - Earliest claimed: 2023-11-16 - Assignees: ETA SA Manufacture Horlogere Suisse - Applicants: Eta SA Manufacture Horlogere Suisse - Inventors: Ivan Villar; Pascal Winkler - Web page: https://patentgrep.com/patent/US20250164932A1 ## CPC - G04B 17/325: {for fastening the hairspring in a fixed position, e.g. using a block} - G04B 18/06: by setting the collet or the stud of a hairspring - G04B 17/06: Oscillators with hairsprings, e.g. balance {(electrically driven balances G04C3/04; contacts actuated by a balance G04C13/065)} - G04B 18/023: {with means for fine adjustment of the indexing device} - 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) ## Abstract A regulating member (1) for a horological movement including an inertial mass, for example a balance (23), a balance spring (25), a balance cock (22), and an actuation system (20) for adjusting the rate of the balance spring (25), the balance spring (25) including a coiled ribbon (2) and device (30) for adjusting the stiffness of the balance spring, which device is provided with a resilient element (5) arranged in series with the coiled ribbon (2), the adjustment device (30) including a pre-stress device (6) for applying a variable force or torque to the flexible element (5), the actuation system (20) including an eccentric actuating the pre-stress device (6) of the adjustment device (30). ## Claims ### Claim 1 A regulating member (1) for a horological movement comprising a balance, a balance spring (25), a balance cock (22), and an actuation system (20) for adjusting the rate of the balance spring (25), the balance spring (25) comprising a coiled ribbon (2) and means (30) for adjusting the stiffness of the balance spring, which means are provided with a resilient element (5) arranged in series with the coiled ribbon (2), the adjustment means (30) comprising prestressing means (6) for applying a variable force or torque to the flexible element (5), wherein the actuation system (20) comprises an eccentric (10) actuating the prestressing means (6) of the adjustment means (30). ### Claim 2 (depends on 1) The regulating member according to claim 1, wherein the eccentric (10) is rotatably mounted through the balance cock (22). ### Claim 3 (depends on 1) The regulating member according to claim 1, wherein the eccentric (10) comprises a head (21) and a main body (11) extending from the head (21). ### Claim 4 (depends on 3) The regulating member according to claim 3, wherein the eccentric (10) further comprises a finger (12) extending from the main body (11), the finger (12) being off-centred relative to the main axis of the main body (11) of the eccentric (10). ### Claim 5 (depends on 3) The regulating member according to claim 3, wherein the head (21) comprises a recess (18) intended to receive the tip of a tool for actuating the eccentric (10). ### Claim 6 (depends on 1) The regulating member according to claim 1, wherein the prestressing means (6) comprise a movable first lever (14) connected to the flexible element (5), with the eccentric (10) being in direct or indirect contact with the lever (14) in order to be able to actuate it. ### Claim 7 (depends on 6) The regulating member according to claim 6, wherein the prestressing means (6) comprise a second movable lever connected to the flexible element (5), with the eccentric (10) being in direct or indirect contact with the second lever (26) in order to be able to actuate it. ### Claim 8 (depends on 6) The regulating member according to claim 6, wherein the prestressing means (6) comprise a movable body (19) connected to the first lever (14) and/or to the second lever (26), with the finger (12) being in contact with the movable body (19). ### Claim 9 (depends on 8) The regulating member according to claim 8, wherein the finger (12) comprises a peripheral groove (33) cooperating with the movable body (19). ### Claim 10 (depends on 1) The regulating member according to claim 1, wherein the actuation system (20) comprises a stud-holder (31) comprising a stud (34) on which the balance spring (25) is mounted, the stud (34) being mechanically linked to the resilient element (5) of the balance spring (25). ### Claim 11 (depends on 1) The regulating member according to claim 1, wherein the stud-holder (31) is arranged on the balance cock (22) around a bearing (28) on the balance staff (24). ### Claim 12 (depends on 1) A horological movement, comprising the regulating member (1) according to claim 1. ### Claim 13 (depends on 12) A timepiece comprising the horological movement according to claim 12.