Patent ID: 7892135

Claim:
A power train of an automatic transmission for vehicles, comprising: a first, double pinion, planetary gear set, comprising: a first sun gear connected to a transmission housing so as to be operated as a fixed member; a first ring gear forming a first intermediate output pathway where a reduced rotational speed is always output; and a first planet carrier connected to an input shaft so as to form an input pathway and forming a second intermediate output pathway where an input rotational speed is directly output; a second planetary gear set comprising: a simple single pinion planetary gear set, comprising a second sun gear, a second planet carrier, and a second ring gear; and a double pinion planetary gear set comprising a third sun gear, a third planet carrier, and a third ring gear; wherein the third sun gear is directly connected to the first ring gear so as to form a first intermediate input pathway, the second ring gear is connected to an output shaft so as to form a final output pathway, the second planet carrier and the third ring gear are selectively connected to the input shaft so as to form a variable input pathway and also selectively connected to the transmission housing so as to be operated as a variable fixed member, and the second sun gear and the third planet carrier are selectively connected respectively to the first ring gear and the first planet carrier so as to form a second intermediate input pathway and also selectively connected to the transmission housing so as to be operated as a variable fixed member; and a plurality of frictional members for selectively connecting the gears and planet carriers with each other or with the transmission housing.