Patent ID: 7854678

Claim:
A gear train of an automatic transmission for a vehicle, comprising: a first planetary gear set that is a simple planetary gear set, and comprises a first rotational element operating as a fixed element, a second rotational element outputting a reduced rotational speed, and a third rotational element directly connected with an input shaft and operating as an input element; a second planetary gear set that is a simple planetary gear set and comprises a fourth rotational element directly connected with the second rotational element, a fifth rotational element selectively connected with a transmission housing by interposing a first brake therebetween, and a sixth rotational element selectively connected with the transmission housing by interposing a second brake therebetween, wherein a first clutch selectively connects at least two rotational elements of the fourth, fifth, and sixth rotational elements; and a third planetary gear set that is a compound planetary gear set combined by a single pinion planetary gear set and a double pinion planetary gear set, and comprises a seventh rotational element directly connected with the sixth rotational element, an eighth rotational element selectively connected with the input shaft by interposing a second clutch therebetween and selectively connected with the transmission housing by interposing a third brake therebetween, a ninth rotational element connected with an output shaft, and a tenth rotational element connected with the fourth rotational element by interposing a third clutch therebetween, wherein a fourth clutch is disposed between the seventh rotational element and the eighth rotational element.