Torsional damper having variable bypass clutch with centrifugal release mechanism

A torsional damper (10) rotatably supported for translating torque between a prime mover and the input of a transmission, said torsional damper (10) comprising:

• a torque input member (12) operatively connected for rotation with the power take off of a prime mover, an output member (14) operatively connected for rotation with the input to a transmission and a plurality of damping elements (16) interposed between said input member (12) and said output member (14), said damping members (16) acting to translate torque between said input and said output members and to dampen torsional forces generated between the prime mover and the transmission;
• a bypass clutch (40) including an annular friction plate (44) disposed generally spaced from said torque input member (12) and in frictional contact with said output member (14), said annular friction plate (44) including a plurality of fingers (46) annularly disposed in spaced relationship relative to one another about the rotational axis (A) of the torsional damper, said plurality of fingers (46) extending toward and being carried by said input member (12), a biasing member (50) acting on said plurality of fingers (46) to constantly bias said friction plate (44) into engagement with said output member (14), said output member (14) including an annular friction surface (56) disposed opposite to and corresponding to said friction plate (44) of said bypass clutch (40), said annular friction surface (56) and said friction plate (44) adapted for continuously slipping engagement to translate torque directly between said input and output members thereby providing a path for partial torque translation bypassing said damping elements at low rotational speeds of said input and output members;
• and
• a clutch release mechanism (42) operatively supported by said input member (12) and responsive to centrifugal forces acting on said torsional damper to disengage said bypass clutch (40) to reduce the torque translated directly between said input and output members at high rotational speeds.