Patent ID: 8007399

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 and constantly locked; a second planetary gear set including a second sun gear connected with the first carrier to define a second rotating member, 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; a third planetary gear set including a third sun gear connected with the first sun gear to define a first rotating member, a third pinion engaged with the third sun gear, a third carrier supporting the third pinion, and a third ring gear engaged with the third pinion; an input shaft constantly connected with the first rotating member; an output shaft constantly connected with the third carrier; and five friction elements including a first friction element adapted to selectively connect the second ring gear with the third ring gear, a second friction element adapted to stop a rotation of the second carrier, a third friction element adapted to selectively connect the second carrier with the third ring gear, a fourth friction element adapted to selectively connect the second ring gear with the third carrier, and a fifth friction element adapted to selectively connect the first rotating member with the second carrier, wherein the automatic transmission is adapted to achieve at least seven forward speed-ratios and one reverse speed-ratio, wherein the seven forward speed-ratios and one reverse speed-ratio are achieved by eight different patterns of engaged states of two friction elements selected from the five friction elements.