US Patent 7614975 Gear train of an automatic transmission for a vehicle

A gear train of an automatic transmission for a vehicle includes first and second shifting sections and a plurality of friction members, wherein: the first shifting section includes first and second simple planetary gear sets forming a first input path for directly receiving an input shaft rotation speed and an intermediate output path for outputting a reduced speed of the first shifting section; and the second shifting section includes third and fourth simple planetary gear sets forming a first intermediate input path for variably receiving an input shaft rotation speed, a second intermediate input path for receiving the reduced speed of the first shifting section through the intermediate output path and also for variably receiving an input shaft rotation speed, and a final output path for outputting a modified speed of the second shifting section.