Patent ID: 6865966

Claim:
An automatic transmission for a vehicle having an input shaft, a main clutch connecting the input shaft to an engine for driving the input shaft, an output shaft in connection with a vehicle drive wheel, a plurality of gear trains to transmit driving force from said input shaft to said output shaft at different ratios, and a gear-shift mechanism to shift the gear trains and to be automatically controlled during gear shift, comprising: a drive wheel spin detector to detect whether said drive wheel is spinning, a sub-clutch positioned downstream of said main clutch to engage one of said gear trains other than first-speed and reverse gear trains to effect transmission of driving force through said one gear train from said input shaft to said output shaft, and a controller to engage said sub-clutch when (1) said first-speed gear train or said reverse gear train is in driving engagement between said input and output shafts and (2) said drive wheel spin detector detects that said drive wheel is spinning.