Patent ID: 7887453
Filing Date: 2011-02-15
Classification: F16H

Abstract:
1. A multi-speed transmission comprising: an input member; an output member; first, second, third and fourth planetary gear sets each having first, second and third members; wherein said input member is continuously interconnected with said first member of said first planetary gear set; wherein said output member is continuously interconnected with said third member of said third planetary gear set; a first interconnecting member continuously connecting said second member of said first planetary gear set with a stationary member; a second interconnecting member continuously connecting said third member of said first planetary gear set with said first member of said second planetary gear set; a third interconnecting member continuously connecting said third member of said second planetary gear set with said first member of said third planetary gear set; a fourth interconnecting member continuously connecting said second member of said third planetary gear set with said third member of said fourth planetary gear set; a fifth interconnecting member continuously connecting said third member of said third planetary gear set with said second member of said fourth planetary gear set; six torque-transmitting devices each of which selectively interconnects a respective one of said members of said planetary gear sets with one of said stationary member, said input member, and another respective one of said members of said planetary gear sets, said six torque-transmitting devices being engaged in combinations of two to establish at least nine forward speed ratios and at least one reverse speed ratio between said input member and said output member; and wherein said six torque-transmitting devices include only two brakes.