Mechanism, comprising: - a support including a base, a pendulum suspended on the base, and connecting suspension rods articulated on the base and on the pendulum; - a first cog wheel mobile in rotation in relation to the support around a first axis; - a second mobile cog wheel in rotation in relation to the support around a second axis; - a first eccentric element integral with the first cog wheel in rotation and generating a first moment of gravity force around the first axis; - a second eccentric element integral with the second cog wheel in rotation and generating a second moment of gravity force around the second axis; and - a connecting rod (60; 160) comprising a rotary head mounted as a pivot link on a first shaft and an eccentric head mounted as an eccentric pivot link on a second shaft; wherein: - the axis (A1; A2) are parallel within a horizontal or vertical reference plane; and - the pendulum supports the axis (A1; A2) of the cog wheels (12; 22) and of the eccentric elements (14; 24); - the connecting suspension rods are slanting in accordance with an angle comprised between 45 degrees and 80 degrees in relation to a vertical plane; - for the connecting link rod (60; 160), the first shaft is either a shaft (11; 21) supporting one of the cog wheels (12; 22), or a shaft fixed on the base, whereas the second shaft is the other shaft among the shaft (11; 21) supporting one of the cog wheels (12; 22) and the shaft fixed on the base; - the cog wheels (12; 22) engage one with the other using a unitary transmission ratio and are mobile in rotation (R1; R2) in opposing directions; - when the mechanism is in operation, the eccentric elements (14; 24) follow an elliptical movement, whereas the pendulum follows a travel movement having a vertical component and a horizontal component; - the moments (M1; M2) of gravity force (P1; P2) of the eccentric elements (14; 24) have a same value and a same direction, both being variable depending on their angular position around the axis (A1; A2); - for each angular position of the cog wheels (12; 22) and of the eccentric elements (14; 24) around the axis (A1; A2), the mechanism presents an equilibrium configuration at rest. - a support including a base, a pendulum suspended on the base, and connecting suspension rods articulated on the base and on the pendulum; - a first cog wheel mobile in rotation in relation to the support around a first axis; - a second mobile cog wheel in rotation in relation to the support around a second axis; - a first eccentric element integral with the first cog wheel in rotation and generating a first moment of gravity force around the first axis; - a second eccentric element integral with the second cog wheel in rotation and generating a second moment of gravity force around the second axis; and - a connecting rod (60; 160) comprising a rotary head mounted as a pivot link on a first shaft and an eccentric head mounted as an eccentric pivot link on a second shaft; - the axis (A1; A2) are parallel within a horizontal or vertical reference plane; and - the pendulum supports the axis (A1; A2) of the cog wheels (12; 22) and of the eccentric elements (14; 24); - the connecting suspension rods are slanting in accordance with an angle comprised between 45 degrees and 80 degrees in relation to a vertical plane; - for the connecting link rod (60; 160), the first shaft is either a shaft (11; 21) supporting one of the cog wheels (12; 22), or a shaft fixed on the base, whereas the second shaft is the other shaft among the shaft (11; 21) supporting one of the cog wheels (12; 22) and the shaft fixed on the base; - the cog wheels (12; 22) engage one with the other using a unitary transmission ratio and are mobile in rotation (R1; R2) in opposing directions; - when the mechanism is in operation, the eccentric elements (14; 24) follow an elliptical movement, whereas the pendulum follows a travel movement having a vertical component and a horizontal component; - the moments (M1; M2) of gravity force (P1; P2) of the eccentric elements (14; 24) have a same value and a same direction, both being variable depending on their angular position around the axis (A1; A2); - for each angular position of the cog wheels (12; 22) and of the eccentric elements (14; 24) around the axis (A1; A2), the mechanism presents an equilibrium configuration at rest.