Patent ID: 8313409

Claim:
A gear train of an automatic transmission for vehicles comprising first and second planetary gear sets being respectively a simple planetary gear set having three rotational elements and a third planetary gear set being a compound planetary gear set having four rotational elements, wherein the first planetary gear set comprises a first rotational element directly connected to an input shaft and always operated as an input element, a second rotational element selectively connected to one rotational element of the second planetary gear set, and a third rotational element directly connected to another rotational element of the second planetary gear set, wherein the second planetary gear set comprises a fourth rotational element directly connected to the third rotational element, a fifth rotational element selectively connected to the second rotational element, a transmission housing, and the input shaft, and a sixth rotational element directly connected to an output gear so as to be always operated as an output element, and wherein the third planetary gear set comprises a seventh rotational element directly connected to the input shaft, an eighth rotational element directly connected to the fourth rotational element and selectively connected to the transmission housing, and ninth and tenth rotational elements selectively connected to the transmission housing respectively.