Patent ID: 7607366

Claim:
A hydraulic control apparatus for an automatic transmission, comprising: a main shaft connected to an output shaft of an internal combustion engine via any one of a first clutch and a second clutch both actuated under hydraulic pressure; a gear train transmitting rotation of the main shaft to a transmission output shaft; and a hydraulic circuit adapted to transmit pressure of a working fluid to the first clutch and the second clutch is provided for each of the first and second clutches individually, the hydraulic circuit including: a first oil passage adapted to supply a working fluid to the first clutch; a second oil passage adapted to supply the working fluid to the second clutch; and a changeover valve adapted to connect the pressure of the working fluid to any one of the first oil passage and the second oil passage, wherein a speed ratio is determined by engagement and disengagement of the first and second clutches and engagement and disengagement of a dog clutch in the gear train.