Hydrokinetic torque converter with lockup clutch

A torque transmitting apparatus comprising a hydrokinetic torque converter having a fluid-containing chamber and including a pump rotatable about a predetermined axis at a variable RPM by a rotary output element of a prime mover, and a turbine disposed in said chamber and including an output member rotatable about said axis;

• a lockup clutch engageable to transmit torque of variable magnitude from said output element to said output member and disengageable to interrupt the transmission of torque from said output element to said output member, said clutch including a piston rotatable at a plurality of speeds and movable in the direction of said axis and dividing said chamber into first and second compartments respectively containing bodies of a fluid at first and second pressures, the differential between said pressures determining the magnitude of torque being transmitted by said clutch;
• and at least one valve which is adjustable to establish at least one path for the flow of fluid between said compartments at a rate which varies as a function of variations of the RPM of the piston to thus influence the pressure differential and hence the magnitude of torque being transmitted by said clutch, said at least one valve being operative to permit the flow of fluid between said compartments in response to a reduction of said RPM of said piston to below a predetermined RPM and to at least reduce the rate of fluid flow between said compartments in response to a rise of the RPM of said piston above said predetermined RPM, said at least one valve comprising at least one valving element which is acted upon and is movable by centrifugal force in response to rotation of said piston to thereby reduce the rate of fluid flow between said compartments, said at least one valve further comprising means for yieldably urging said at least one valving element in a direction to increase the rate of fluid flow between said compartments.