Patent ID: 7833124

Claim:
A power train of an automatic transmission for a vehicle, the power train comprising: an input shaft connected to a torque converter; an output gear; a transmission case; a first planetary gear set that includes a first operating member fixedly connected to the input shaft, a second operating member fixedly connected to the transmission case, and a third operating member outputting a reduced speed by an operation of the first operating member and the second operating member; a second planetary gear set that includes a fourth operating member selectively connected to the third operating member, a fifth operating member selectively connected to the input shaft and selectively connected to the second operating member or selectively connected to the third operating member, a sixth operating member selectively connected to the input shaft or selectively connected to the transmission case, a seventh operating member selectively connected to the transmission case, and an eighth operating member always acting as an output element, wherein the second planetary gear set outputs ten forward speeds and two reverse speeds to the output gear; and a plurality of friction members selectively connecting the operating members, the input shaft, or the transmission case, wherein the plurality of friction members comprise: a first clutch selectively connecting the fourth operating member and the third operating member; a second clutch selectively connecting the fifth operating member and the third operating member; a third clutch selectively connecting the fifth operating member and the input shaft; a fourth clutch selectively connecting the sixth operating member and the input shaft; a fifth clutch selectively connecting the fifth operating member and the second operating member; a first brake selectively connecting the sixth operating member and the transmission case; and a second brake selectively connecting the seventh operating member and the transmission case.