Patent ID: 8197381

Claim:
An automatic transmission comprising: a first planetary gear set including: a first sun gear, a first pinion engaged with the first sun gear, a first carrier supporting the first pinion, and a first ring gear engaged with the first pinion; a second planetary gear set including: a second sun gear, a second pinion engaged with the second sun gear, a second carrier supporting the second pinion, and a second ring gear engaged with the second pinion and constantly locked; a third planetary gear set including: a third sun gear connected with the second sun gear to define a second rotating member, a third pinion engaged with the third sun gear, a third carrier supporting the third pinion, and being connected with the first carrier to define a first rotating member, and a third ring gear engaged with the third pinion; an input shaft directly connected with the first sun gear; an output shaft directly connected with first rotating member; and five friction elements including: a first friction element adapted to selectively connect the first ring gear with the second carrier, a second friction element adapted to selectively connect the first ring gear with the second rotating member, a third friction element adapted to selectively connect the second carrier with the third ring gear, a fourth friction element adapted to selectively stop a rotation of the third ring gear, and a fifth friction element adapted to selectively connect the first sun gear with the second carrier, the automatic transmission being adapted to achieve at least seven forward speed-ratios and one reverse speed-ratio, each of the at least seven forward speed-ratios and one reverse speed-ratio being achieved by an engaged state of only two friction elements selected from the five friction elements.