Abstract: A hydrodynamic torque converter mechanism having a bladed impeller, a bladed turbine and a bladed stator arranged in a toroidal fluid flow circuit enclosed within a common impeller housing, a friction clutch in the housing including a clutch disc with a friction surface thereon situated adjacent a cooperating friction surface formed on the housing, a stator sleeve shaft supporting the stator, an impeller sleeve hub journalled on the housing, a turbine shaft connected to the turbine and extending through the stator sleeve shaft, and a double circuit flow path for fluid circulating through the torus circuit, one circuit being defined in part by the annular space between the impeller hub and the stator sleeve shaft and the other circuit being defined by the annular space between said turbine shaft and said stator sleeve shaft and by the annular flow space between said friction surfaces.

Abstract: A multiple ratio power transmission mechanism having planetary gear elements controlled by friction clutches and brakes and having two torque input gear elements, a hydrokinetic torque converter disposed in the torque delivery path for each input gear element and a torque splitting gear unit disposed between the torque input side of the hydrokinetic converter and the other of said torque input gear elements, wherein provision is made for selecting alternately one of the two torque input gear elements whereby the torque delivery path during operation in the higher speed ratios is partly mechanical and partly hydrokinetic and wherein the torque delivery path during operation in the lowest speed ratio is fully hydrokinetic.