Patent ID: 8075440

Claim:
A power train of an automatic transmission, comprising: a first planetary gear set including a first operating member connected to a transmission case, a second operating member, and a third operating member connected to an input shaft, wherein the second operating member outputs a reduced rotation speed; a second planetary gear set including a fourth operating member connected to the second operating member, a fifth operating member selectively connected to the input shaft, and a sixth operating member; a third planetary gear set including a seventh operating member selectively connected to the third or fourth operating members and selectively connected to the transmission case, an eighth operating member connected to the sixth operating member and selectively connected to the transmission case, and a ninth operating member selectively connected to the fifth operating member and connected to an output shaft; and a plurality of friction members selectively connecting the operating members of the first, second, and third planetary gear sets to the input shaft, other operating members, or the transmission case.