Abstract: A hydrokinetic torque converter includes an impeller cover and bypass clutch located within the impeller housing. The impeller cover has welded to it a clutch plate, which carries friction material adjacent the clutch piston. The piston has legs that extend axially into engagement with helical springs carried in a damper assembly arranged in series with the damper between the impeller cover and the input shaft of the transmission. The springs are located in a retainer that accommodates two, three or four springs, as required by the torque requirements of the clutch and damper. The spring constant of the damper can be linear or piecewise linear over the full displacement range of the damper springs.

Abstract: A lockup clutch for a torque converter (10) has a piston (63) with a tapered face (67) that engages a grooved friction material (61). The edge (71) of the piston face (67) extends outward away from the center portion (69) of the piston face (67) toward the friction material (61). The friction material (61) is arranged in a pattern of concentric lands (80, 82, 84) defining annular grooves (86) between adjacent lands with an innermost land (82) being free of radial grooves (92) and all other lands being connected by radial grooves (92) in communication with the interior of the torque converter housing (12, 14) through the torus circuit cavity. The innermost land (82) blocks fluid flow from the torus flow circuit cavity when the piston (63) engages the disk (61) in a hard lockup condition but permits fluid flow during a soft lockup condition.