Patent ID: 6907801

Claim:
An automatic transmission for a vehicle, the transmission including a main clutch connected and disconnected by a clutch actuator, an input shaft to receive driving force through said main clutch from an engine mounted on the vehicle, an output shaft in parallel with said input shaft for outputting the shifted driving force to drive wheels of the vehicle, a plurality of gear trains, to transmit the driving force of said input shaft at different ratios to said output shaft, a shift mechanism including a shift sleeve which shifts said gear trains, a shift actuator to operate said shift sleeve to shift said gear trains according to a driving state of the vehicle, and a sub clutch disposed on a driving force transmitting path between said input and output shafts to variably control the torque transmitted therethrough, said sub clutch transmitting the driving force from said input shaft to said output shaft during gearshift in which said shift sleeve is operated for shifting, comprising the improvement wherein said driving force transmitting path in which said sub clutch is disposed forms a third speed gear train that is the third gear ratio counted from a first speed gear train having a maximum speed ratio, and said sub clutch functions as a third speed shift mechanism for said third speed gear train.