Patent ID: 7044881

Claim:
An automatic transmission, comprising: an input member; an output member; a first transmitting portion including a first planetary gear set having three rotating elements, one of the three rotating elements being coupled to the input member, another of the three rotating elements being fixed and inhibited from rotating, a remaining one of the three rotating elements serving as an intermediate output member and rotating at a reduced speed as compared with that of the input member to output power; and a second transmitting portion including a second planetary gear set and a third planetary gear set each of which includes a sun gear, a carrier and a ring gear, at least one of the sun gear, the carrier and the ring gear of the second planetary gear set being coupled to at least one of the sun gear, the carrier and the ring gear of the third planetary gear set to provide a first rotating element, a second rotating element, a third rotating element and a fourth rotating element, the second transmitting portion further including a first brake that selectively stops rotation of the first rotating element, a second brake that selectively stops rotation of the second rotating element, a first clutch that selectively couples the fourth rotating element to the intermediate output member, a second clutch that selectively couples the first rotating element to the intermediate output member, a third clutch that selectively couples the second rotating element to the input member, and a fourth clutch that selectively couples two of the first, second, third and fourth rotating elements to each other, the third rotating element being coupled to the output member to output rotary power, wherein a first-speed gear stage having the largest gear ratio is established when the first clutch and the second brake are engaged, a second-speed gear stage having a smaller gear ratio than that of the first-speed gear stage is established when the first clutch and the first brake are engaged, a third-speed gear stage having a smaller gear ratio than that of the second-speed gear stage is established when the first clutch and the second clutch or the first clutch and the fourth clutch are engaged, a fourth-speed gear stage having a smaller gear ratio than that of the third-speed gear stage is established when the first clutch and the third clutch are engaged, a fifth-speed gear stage having a smaller gear ratio than that of the fourth-speed gear stage is established when the third clutch and the fourth clutch are engaged, a sixth-speed gear stage having a smaller gear ratio than that of the fifth-speed gear stage is established when the second clutch and the third clutch are engaged, and a seventh-speed gear stage having a smaller gear ratio than that of the sixth-speed gear stage is established when the third clutch and the first brake are engaged.