Patent attributes
A planetary gear train may include input and output shafts, first to fourth planetary gear sets respectively having first to third, fourth to sixth, seventh to tenth, and eleventh to thirteenth elements, a first shaft connected to the second element and the input shaft, a second shaft connected to the twelfth element and the output shaft, a third shaft connected to the first and seventh elements, a fourth shaft connected to the eighth element, a fifth shaft connected to the ninth and eleventh element, a sixth shaft connected to the fifth and thirteenth elements, and a plurality of shafts each selectively connecting a corresponding element to a transmission housing, the corresponding element being an element of the first, second and third planetary gear sets which is not interconnected.
