Hydrokinetic coupling apparatus, in particular for motor vehicle

Hydrokinetic coupling apparatus (10), comprising:

• a casing (12) provided with a wall (24), of transverse orientation overall, able to be connected with respect to rotation to a driving shaft;
• a turbine wheel (30) fixed with respect to rotation to a hub (34) able to be connected with respect to rotation to a driven shaft;
• a lock-up clutch (16), acting between the turbine wheel (30) and the transverse wall (24), which has, arranged axially from front to rear between the turbine wheel (30) and the transverse wall (24);
• a piston (50) in the form of an annulus, of transverse orientation overall, movable axially and connected with respect to rotation to the casing (12);
• and a set (56) of flat annular parallel friction discs (120, 124, 122) of roughly transverse orientation, which is adapted to be clamped axially by the piston (50) between a piston face (128) and an opposite internal face (130) of the transverse wall (24) of the casing (12) and which has on the one hand two radially external front (120) and rear (122) discs which are connected with respect to rotation to the turbine wheel (30) and on the other hand a radially internal intermediate disc (124) which is disposed axially between the front (120) and rear (122) discs and which is connected with respect to rotation to the two elements consisting of the piston (50) and the transverse wall (24) of the casing (12), annular friction linings (126) being interposed between the friction discs (120, 122, 124), the piston (50) and the internal face of the transverse wall (24);
• wherein the piston (50) and the transverse wall (24) of the casing (12) define two element that are connected with respect to rotation by tongues (104) substantially elongated tangentially to a circumference of the assembly and the opposite ends of tongues (104) are coupled to the two elements, and wherein the intermediate friction disc (124) is drivingly connected to at least one member coupling the ends of the tongues (104) to one of the two elements (50-24).