Patent ID: 9523412
Filing Date: 2016-12-20
CPC Classification: F16H

Claim Text:
1. A planetary gear train of an automatic transmission for a vehicle, comprising: an input shaft receiving torque of an engine; an output shaft outputting changed torque of the engine; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements; and seven friction elements disposed to selectively connect the rotation elements and selectively connect the rotation elements with a transmission housing, wherein the input shaft is continuously connected to the second rotation element, the output shaft is continuously connected to the eleventh rotation element, the first rotation element is continuously connected to the sixth rotation element, the first rotation element is continuously connected to the tenth rotation element, the second rotation element is continuously connected to the seventh rotation element, the fifth rotation element is continuously connected to the ninth rotation element, the output shaft is selectively connected to third rotation element, and three friction elements among seven friction elements are operated at each speed stage.