Patent ID: 7273435

Claim:
An electrically variable transmission comprising: an input member to receive power from an engine; an output member; first and second motor/generators; first and second differential gear sets each having first, second and third members; said input member not being continuously connected with any member of said gear sets, and said output member being continuously connected with a member of said gear sets; an interconnecting member continuously connecting said first member of said first gear set with said first member of said second gear set or with a stationary member; said first motor/generator being continuously connected with a member of said first or second gear set; said second motor/generator being alternately connected with two of said members of said first or second gear set; a first torque transfer device selectively connecting a member of said first or second gear set with said input member; a second torque transfer device selectively connecting a member of said first or second gear set with said input member, this member being different from the one connected by the first torque transmitting device; a third torque transfer device selectively connecting a member of said first gear set with a member of said second gear set; a fourth torque transfer device connected in parallel with one of said first and second motor/generators for selectively preventing rotation thereof; a fifth torque transfer device connected in parallel with the other of said motor/generators for selectively preventing rotation thereof; wherein said first, second, third, fourth and fifth torque transfer devices are engageable to provide an electrically variable transmission with a continuously variable range of speed ratios and up to four fixed forward speed ratios.