Abstract: A seat (1) comprises a seating surface (2) suitable to receive a user and a backrest (3) adaptable according to the user's needs. The seat further comprises a support structure (4) configured to connect the seat to the backrest. The backrest comprises an upper shoulder portion (6) and a lower lumbar portion (7) and the lumbar portion is movable along the support structure while the shoulder portion remains at a fixed height with respect to the support structure (4).

Abstract: A seat (1) comprises a seating surface (2) suitable to receive a user and a backrest (3) adaptable according to the user's needs. The seat further comprises a support structure (4) configured to connect the seat to the backrest. The backrest comprises an upper shoulder portion (6) and a lower lumbar portion (7) and the lumbar portion is movable along the support structure while the shoulder portion remains at a fixed height with respect to the support structure (4).

Abstract: Hybrid propulsion system comprising an internal-combustion engine (1) rotatably connected to a reversible electrical machine (2), a rechargeable battery (3), an electric driving motor (7), control apparatus (8) commanding first switching device (4, 5) for selectively connecting the battery (3) to the electric driving motor (7) and/or the reversible electrical machine (2). When the electric driving motor (7) is supplied with the current flowing in from the battery (3), said control apparatus (8) monitor the voltage at the poles (3P, 3N) of the battery (3). When the motor (7) is at least partially supplied with the current generated by the reversible electrical machine (2), owing to the latter being driven rotatably by the internal-combustion engine (1), the same control apparatus (8) monitor the voltage at the poles (2P, 2N) of the reversible electrical machine (2).