US Patent 8715128 Multi-speed transmission

A transmission of the present invention has an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes a sun gear, a carrier member supporting a plurality of planet pinion gears and a ring gear member. The torque transmitting devices may include clutches and brakes. The torque transmitting devices are selectively engageable in combinations of at least three to establish a plurality forward speed ratios and at least one reverse speed ratio.