Patent ID: 7988589

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 that is connected to a transmission housing and operated as a fixed element, a second rotational element that forms an intermediate output path outputting a reduced rotational speed of an input shaft, and a third rotational element that is directly connected with the input shaft and forms an input path; a second planetary gear set that is formed by combining first and second simple planetary gear sets, has four rotational elements, and comprises: a fourth rotational element that is one of the rotational elements of the first and second simple planetary gear sets, is directly connected to the second rotational element, and forms a first intermediate input path; a fifth rotational element that is one of the rotational elements of the first and second simple planetary gear sets, is connected to an output shaft, and is operated as an output element; a sixth rotational element that includes two rotational elements, which are directly connected each other, of the first and second simple planetary gear sets, is variably connected with the input shaft to form a variable input path, and is variably connected to the transmission housing to be operated as a fixed element; and a seventh rotational element that includes two rotational elements, which are variably connected or separated to/from each other, of the first and second simple planetary gear sets, is variably connected with the second rotational element to form a second intermediate input path, and is variably connected to the transmission housing to be operated as a fixed element; and a plurality of friction members including clutches and brakes that selectively connect the rotational elements of the first and second planetary gear sets to each other or to the transmission housing; wherein the first planetary gear set is a single pinion planetary gear set, the first rotational element is a first sun gear, the second rotational element is a first planet carrier, and the third rotational element is a first ring gear; the first simple planetary gear set of the second planetary gear set is a single pinion planetary gear set comprising a second sun gear, a second planetary carrier, and a second ring gear, and the second simple planetary gear set of the second planetary gear set is a double pinion planetary gear set comprising a third sun gear, a third planetary carrier, and a third ring gear; and the fourth rotational element is the third sun gear, the fifth rotational element is the second ring gear, the sixth rotational element is the second planet carrier and the third ring gear, and the seventh rotational element is the second sun gear and the third planet carrier.