Patent ID: 6848550

Claim:
A power transmission device comprising: a rotary input member adapted to receive drive torque from a source of torque; a rotary output member adapted to provide drive torque to an output device; and a torque transfer mechanism operable for transferring drive torque from said input member to said output member, said torque transfer mechanism including a first torque amplifier and a second torque amplifier operably disposed between said input member and said output member, said first torque amplifier including a first ball ramp actuator and a first friction clutch, said second torque amplifier including a second ball ramp actuator and a second friction clutch, wherein said torque transfer mechanism further includes an operator for selectively providing an input torque to said first torque amplifier and wherein said first torque amplifier is coupled to said second torque amplifier such that an amplified torque is supplied from said first torque amplifier to said second torque amplifier, wherein said first ball ramp actuator includes a plurality of balls positioned in driving engagement with a first cam and a second cam, wherein said second cam provides an input force to said first friction clutch, said second cam being splined to a clutch drum of said first friction clutch.