Planetary gear train of automatic transmission for vehicles

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;
• a first planetary gear set including a first sun gear, a first planet carrier, and a first ring gear;
• a second planetary gear set including a second sun gear, a second planet carrier, and a second ring gear;
• a third planetary gear set including a third sun gear, a third planet carrier, and a third ring gear;
• and
• a fourth planetary gear set including a fourth sun gear, a fourth planet carrier, and a fourth ring gear,
• wherein the input shaft is directly connected to the second planet carrier,
• the output shaft is directly connected to the third ring gear and the fourth planet carrier,
• the first sun gear is directly connected to the second sun gear,
• the first planet carrier is directly connected to the fourth ring gear,
• the second ring gear is directly connected to the third sun gear,
• the third ring gear is directly connected to the fourth planet carrier,
• the fourth sun gear is selectively connected to the input shaft,
• the first planet carrier and the fourth ring gear are selectively connected to the second ring gear and the third sun gear,
• the second ring gear and the third sun gear are selectively connected to the fourth sun gear,
• the third planet carrier is selectively connected to the fourth sun gear,
• the first sun gear and the second sun gear are selectively connected to a transmission housing, and
• the first ring gear is selectively connected to the transmission housing.