AUTOMATIC TRANSMISSION

PROBLEM TO BE SOLVED: To simplify a device and operate engine brake at a time of reverse drive in an automatic transmission composed of a planetary gear mechanism and a parallel shaft type gear mechanism. SOLUTION: In an automatic transmission composed of a main transmission part and an auxiliary transmission part, having the main transmission composed of the planetary gear mechanism having a sun gear connected to, having a ring gear of a first planetary gear train connected to a start clutch, having a planetary carrier of the first planetary gear train and a ring gear of a second planetary gear train connected to an output shaft, having a planetary carrier of the secondary planetary gear train connected to a transmission case via a one-way clutch, provided with a direct clutch connecting a band brake and the ring gear of the first planetary gear train regulating rotation of the sun gear on the sun gear, and having the auxiliary transmission part composed of the parallel shaft type gear mechanism capable of speed change and changing over forward and backward travel, one of the band brake and the direct clutch is operated when the parallel shaft type gear mechanism shifted to backward travel. COPYRIGHT: (C)2006,JPO&NCIPI