Constant-force device
AssigneeRichemont International SA
InventorJean-Francois Mojon
Life of this patent
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Abstract
The present invention relates to a constant-force device for precise regulation of mechanical watch movements by means of a uniform transmission of force from the escape wheel to the regulating organ of the watch, this device being adapted to be integrated into a Tourbillon mechanism.
Claims8
Constant-force device comprising a stop wheel (12) attached to a stop wheel pinion (12a), an escape wheel (6) attached to an escape wheel shaft (9), a tension ring (7) attached to a tension ring pinion (8), and a cam (5) attached to the escape wheel shaft (9) where the movement of the escape wheel (6) is blocked or released by two anchor pallets of a first anchor (4) and where the movement of the stop wheel (12) is blocked or released by two anchor pallets (11a, 11b) of a second anchor (11) that is controlled by a fork-shaped part of this anchor (11) engaged with the cam (5), characterized in that it comprises a force balance mechanism securing transmission of a constant torque to the regulating organ of a watch by compensating the loss of tension of a spring (10) that provides the driving energy.
Constant-force device acording to one of the preceding claims, characterized in that the stop wheel (12) is not concentric with the wheel (6) transmitting the constant torque.
Constant-force device according to one of the preceding claims, characterized in that the device is integrated into a Tourbillon mechanism comprising a Tourbillon cage (1), a balance wheel (2), and a fixed wheel of seconds (14).
Constant-force device according to the preceding claim, characterized in that the escape wheel (6) is rotatably attached to the border of the Tourbillon cage (1) and the tension ring pinion (8) is engaged with the fixed wheel of seconds (14), in that the stop wheel (12) is attached to the border of the Tourbillon cage (1), rotatably but nonconcentrically to the escape wheel (6), and that the stop wheel pinion (12a) is engaged with the fixed wheel of seconds (14) or with a second fixed wheel of seconds attached concentrically to said wheel, and in that the balance wheel (2) controls the movements of the first anchor (4) of the constant-force device.
Dependencies are inferred from the claim text.