Patent ID: 6871733

Claim:
A torque converter, comprising: a) an impeller and a cover, fixed to one another and configured for attachment to a drive member; the cover having a plurality of lugs on a surface thereof facing the impeller; b) a turbine, rotationally mounted between the impeller and the cover and configured for attachment to a driven member; and c) a lockup clutch, comprising: i) a piston, splined to and rotating with the turbine between the turbine and the cover; and ii) a clutch-pack comprising a first ring that is splined to and rotates with the piston, and a second ring that is positioned between the first ring and the piston; the second ring comprising a plurality of outwardly facing tabs splined to the plurality of lugs on the cover; at least some of the outwardly facing tabs and their corresponding lugs comprising flanks; with an orientation between radial and parallel, wherein the piston, rings and cover frictionally engage one another as a fluid pressure between the turbine and the piston increases above a torque converter lockup pressure.