Patent ID: 8029403

Claim:
A multi-speed transmission for a vehicle comprising: an input member; an output member; a stationary member; a first, a second, a third, and a fourth planetary gear set, each planetary gear set having a first, a second, and a third member; wherein the input member is connected for common rotation with one of the members of the planetary gear sets and the output member is connected for common rotation with another of the members of the planetary gear sets; a first interconnecting member connecting the first member of the first planetary gear set for common rotation with the first member of the second planetary gear set; a second interconnecting member connecting the second member of the first planetary gear set for common rotation with the first member of the fourth planetary gear set; a third interconnecting member connecting the second member of the second planetary gear set for common rotation with the first member of the third planetary gear set; a fourth interconnecting member connecting the second member of the third planetary gear set for common rotation with the second member of the fourth planetary gear set; a first brake selectively engagable to ground the first member of the first planetary gear set to the stationary member; a first, a second, and a third rotating clutch each selectively engagable to connect a different respective pair of the members of the planetary gear sets for common rotation; a selectable one-way braking clutch configured to brake in one rotational direction and to be selectively reversible to brake in an opposite rotational direction; wherein the first brake, the first rotating clutch, the second rotating clutch, the third rotating clutch and the selectable one-way braking clutch are engaged in combinations of three to establish the reverse speed ratio and eight forward speed ratios between the input member and the output member; wherein the selectable one-way braking clutch is configured to be selectively operable in a first mode in the reverse speed ratio and in three of said forward speed ratios; wherein the selectable one-way braking clutch locks in one direction of rotation and freewheels in an opposing direction of rotation in the first mode, and thereby brakes rotation of the third member of the first planetary gear set when the transmission is in the reverse speed ratio and allows rotation of the third member of the first planetary gear set in said three of said forward speed ratios; wherein the selectable one-way braking clutch is switchable to a second mode in the other five of said eight forward speed ratios; and wherein the selectable one-way braking clutch brakes rotation of the third member of the first planetary gear set in both directions of rotation in the second mode.