Patent ID: 7892136

Claim:
A gear train of an automatic transmission for a vehicle comprising: a first planetary gear set being a double pinion planetary gear set and having a first sun gear which always operates as a fixed element, a first ring gear which forms a first intermediate output pathway always outputting a reduced rotation speed, and a first planet carrier which forms an input pathway connected to an input shaft and forms a second intermediate output pathway outputting a rotation speed of the input shaft; a second planetary gear set being a single pinion planetary gear set and having a second sun gear which is selectively connected to the first intermediate output pathway and forms a first variable input pathway, a second planet carrier which forms a third intermediate output pathway and is selectively operated as the fixed element, and a second ring gear which is selectively connected to the second intermediate output pathway and forms a second variable input pathway, wherein a friction element for selectively connecting two rotation elements of the three rotation elements in the second planetary gear set in order to make the second planetary gear set be a direct-coupling state is provided; a third planetary gear set being a Ravigneaux planetary gear set which is formed by combining a single pinion planetary gear set and a double pinion planetary gear set and sharing a ring gear and a planet carrier, and having a third sun gear which is engaged with a long pinion and forms an intermediate input pathway directly connected to the third intermediate output pathway, a fourth sun gear which is engaged with a short pinion and forms a third variable input pathway selectively connected to the first intermediate output pathway, a third planet carrier which forms a fourth variable input pathway by being selectively connected to the input shaft and is selectively operated as a fixed element, and a third ring gear which is connected to an output shaft and forms a final output pathway; and a friction member comprising the friction element, wherein the friction member includes a plurality of clutches disposed on the first, second, third, and fourth variable input pathways and the second planetary gear set, and a plurality of brakes disposed between the rotation element operated as the fixed element and a transmission housing.