Patent ID: 7591750

Claim:
An electrically variable transmission comprising: an input member to receive power from an engine; an output member; first and second motor/generators; first, second and third 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 at least one member of said gear sets; a first interconnecting member continuously connecting said first member of said first gear set with said first member of said second gear set and with said first member of said third gear set; a second interconnecting member continuously connecting said second member of said first gear set with a stationary member; said first motor/generator being continuously connected with a member of said second gear set; said second motor/generator being continuously connected with a member of said third gear set; a first torque transfer device selectively connecting a member of said first gear set with said input member; a second torque transfer device selectively connecting another member of said first gear set with said input member; a third torque transfer device selectively grounding 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 first and second motor/generators for selectively preventing rotation thereof; and wherein said first, second, third, fourth and fifth torque transfer devices are selectively engagable alone or in combinations of two or three to provide an electrically variable transmission with a continuously variable range of speed ratios and two fixed forward speed ratios.