Patent ID: 7115060

Claim:
An automatic transmission multi-step reduction gear of a planetary design for a motor vehicle, the multi-step reduction gear comprising one drive shaft and one driven shaft situated in a housing, three planetary spider sets (P 1 , P 2 , P 3 ), a first planetary spider set (P 1 ) defining a fixed input ratio for a second planetary set (P 2 ), at least six rotatable shafts ( 0 , 1 , 2 , 3 , 4 , 5 , 6 ) and at least five shift elements ( 00 , 03 , 04 , 13 , 16 , 45 ) comprising one or more of brakes and clutches and whose selective engagement in pairs produces different reduction ratios between the drive shaft and the driven shaft so that at least six forward gears and one reverse gear are implemented, wherein said drive shaft ( 1 ) is directly connected with a sun gear of said first planetary set (P 1 ), a spider of said first planetary set (P 1 ) is non-rotatably connected with the housing, an output is formed via a connection of the driven shaft ( 2 ) with a ring gear of the second planetary set (P 2 ) and a spider of a third planetary set (P 3 ), a third shaft ( 3 ) is permanently connected with a spider of the second planetary set (P 2 ) and a ring gear of the third planetary set (P 3 ), a fourth shaft ( 4 ) is permanently connected with a sun gear of the second planetary set (P 2 ), a fifth shaft ( 5 ) is permanently connected with a ring gear of the first planetary set (P 1 ) and a sixth shaft ( 6 ) is permanently connected with a sun gear of the third planetary set (P 3 ), a first brake ( 03 ) releasably couples the third shaft ( 3 ) with the housing, the fourth shaft ( 4 ) is releasably coupled by a second brake ( 04 ) with the housing, a first clutch ( 13 ) detachably connects the drive shaft ( 1 ) with the third shaft ( 3 ), a second clutch ( 16 ) detachably connects the drive shaft ( 1 ) with the sixth shaft ( 6 ) and a third clutch ( 45 ) detachably connects the fourth shaft ( 4 ) with the fifth shaft ( 5 ).