Patent ID: 8479902

Claim:
A hydrokinetic coupling device ( 10 ), in particular for a motor vehicle, of longitudinal axis of rotation (B), having a lock-up clutch ( 14 ) comprising: at least one coaxial friction disc ( 50 A, 50 B) rotating as one with a first rotary shaft and mounted such that it can slide axially with respect to the first rotary shaft; first and second coaxial backing discs ( 58 A, 58 B, 58 C) rotating as one with a second rotary shaft and mounted such that the first and second backing discs being axially slideable with respect to the second rotary shaft, the friction disc ( 50 A, 50 B) being interposed axially between the first and second backing discs; at least one axial abutment element ( 75 , 94 ) rotating as one with each of the first and second backing discs ( 58 A, 58 B, 58 C) for enabling a reaction to be created for clamping the friction disc ( 50 , 50 A, 50 B); a coaxial support ring ( 66 ) of each of the first and second backing discs ( 58 A, 58 B, 58 C) rotating as one with the second rotary shaft and comprising at least one axial guide groove ( 62 B) circumferentially delineated by an upstream face ( 68 ) and by a downstream face ( 70 ), an associated radial guide tooth ( 60 B) of each of the first and second backing discs ( 58 A, 58 B, 58 C) being housed such that the first and second backing discs being axially slideable with circumferential play in the guide groove ( 62 B); a rear piston ( 38 ) moveable between a disengaged rear position in which the backing disc ( 58 , 58 A, 58 B, 58 C) are axially separated, and an engaged front position in which each backing disc ( 58 , 58 A, 58 B, 58 C) is pushed forward axially against the axial abutment element ( 94 ) clamping the intercalated friction disc ( 50 , 50 A, 50 B) so as to rotationally couple the first rotary shaft with the second rotary shaft; and elastic preload means ( 82 ) exerting a preload torque to clamp the guide tooth ( 60 B) of at least one of the first and second backing discs ( 58 A, 58 B) circumferentially against one of either the upstream ( 68 ) or downstream ( 70 ) faces of the guide groove ( 62 B); the elastic preload means comprising an elastically circumferentially deformable element interposed axially between the guide tooth of the first backing disc and the guide tooth of the second backing disc; the elastically circumferentially deformable element ( 82 ) mounted circumferentially loaded so as to exert a circumferential force so as to produce the preload torque to separate the guide teeth ( 60 B) of the consecutive first and second backing discs ( 58 A, 58 B) circumferentially against each of the upstream ( 68 ) and downstream ( 70 ) faces of the guide groove ( 62 B).