US Patent 10281012 Planetary gear train of automatic transmission for vehicles

A planetary gear train of an automatic transmission for a vehicle provides at least ten forward speeds and one reverse speed by combination of: first to fourth planetary gear sets respectively having first to third rotational elements, fourth to sixth rotational elements, seventh to ninth rotational elements, or tenth to twelfth rotational elements; first to ninth shafts; and multiple control elements including four clutches and three brakes. In particular, each of the tenth, eleventh, twelfth rotational elements is fixedly connected with a different shaft selected from the first, sixth, seventh and ninth shafts, and one clutch is fixedly connected with the ninth shaft.