Hydrokinetic coupling apparatus, in particular for motor vehicle, comprising improved means linking the piston with the cover

Hydrokinetic coupling apparatus, for a motor vehicle, including a generally transversely oriented wall (36) adapted to be coupled in rotation to a driving shaft, a central sleeve (52), and a piston (50) mounted for sealed sliding movement along a cylindrical surface (58) of the central sleeve (52) and defining, with the sleeve (52) and the transverse wall (36), a variable volume control chamber (38) which is bounded radially on the outside by at least one annular ring (40) which is adapted to be gripped between the piston (50) and the internal rear face of the transverse wall (36), and comprising an annular coupling disc (92) for coupling the piston (50) in rotation with the sleeve (52), which is disposed axially between the transverse wall and the piston (50) and which includes a central portion (96) extending radially inwards in facing relationship with an annular internal surface portion (98) of the transverse wall (36), against which it is in axial engagement and to which it is directly or indirectly fixed,

• wherein the sleeve (52) is attached axially to said central portion (96) of the annular coupling disc (92), with respect to which the sleeve (52) is radially centred.