Patent ID: 8591376

Claim:
A planetary gear train of an automatic transmission for a vehicle, comprising: an input shaft adapted to receive engine torque; an output shaft adapted to output changed torque; a first compound planetary gear set having five rotation elements by combining first and second planetary gear sets and adapted to change a rotation speed of the input shaft input through one input path and two variable input paths into six rotation speeds and to output the six rotation speeds; a second compound planetary gear set having four rotation elements including a rotation element directly connected to any one rotation element of the first compound planetary gear set by combining third and fourth planetary gear sets and adapted to change the rotation speeds input from the first compound planetary gear set and the rotation speed of the input shaft input through one variable input path into eleven forward speeds and one reverse speed and to finally output eleven forward speeds and one reverse speed; eight rotation paths having two rotation elements connected to each other or one rotation element among the rotation elements of the first and second compound planetary gear sets; and seven friction members including four clutches interposed between the rotation paths or between a selected rotation path and the input shaft, and three brakes variably connecting a selected rotation path to a transmission housing.