Abstract: The invention concerns a rotational movement transmission device comprising a flexible shaft and a casing inside which the shaft is housed, said casing being formed from a hollow body of plastic material whose internal diameter is arranged to allow the rotation of said shaft inside said casing, the wall of the body having a variable thickness so that at least part of the casing has an internal surface comprising corrugations extending longitudinally. The invention also concerns an adjustment system for a motor vehicle seat comprising such a transmission device.

Abstract: A device for the transmission of a rotation motion (1) comprising a flexible shaft and a sheath (3), said sheath (3) comprising a core (4), the core (4) comprising at least one shoulder-forming area (6), said area (6) comprising at least three portions, two external portions (7, 8) and a central portion (9), said portions having axes substantially parallel to that of the core (4) and having diameters substantially equal to that of the core (4), the external portions (7, 8) being substantially coaxial and having their axes shifted with respect to the axis of the central portion (9) and of the core (4), said device comprises an inner tube (2) positioned inside the core (4) the tube (2) being deformed in a similar way as the core (4) in the shoulder-forming area (6).

Abstract: The invention concerns a device for transmitting a rotational movement comprising a flexible shaft and a sheath inside which the flexible shaft is housed, said sheath being arranged in order to allow the rotation of said shaft inside said sheath. The outer surface of the flexible shaft is machined so as to have a substantially smooth surface finish. The invention also concerns an adjustment system for a motor vehicle seat comprising such a device.

Abstract: A flexible shaft designed to rotate inside a sheath for transmitting rotary motion can include at least one core wire and winding wired wound around the core wire. The core wire has an elasticity and resilience that are lower than the elasticity and resilience of the winding wires. According to some examples, the core wire can be formed of annealed copper or annealed brass. The winding wires can be formed of steel.

Abstract: The invention relates to a rotation transmission device and a motor vehicle seat adjustment system comprising one such device. The inventive transmission device comprises a flexible shaft and a casing which houses the shaft therein. The aforementioned casing comprises a core consisting of a hollow cylinder having an inner diameter which is dimensioned such as to enable the rotation of the shaft inside said core. The core of the device comprises at least one bearing-forming zone which is obtained by means of plastic deformation, said zone comprising at least three parts, namely: two outer parts and one central part. The axes of the above-mentioned parts are essentially parallel to that of the core while the diameter of said parts is essentially equal to that of the core. Moreover, the outer parts are substantially coaxial and comprise an axis which is offset in relation to the axes of the central part and the core.