Patent ID: 7371203

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 being continuously connected with at least one member of said gear sets, and said output member being continuously connected with another 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 grounding one of said members of said first gear set; said first motor/generator being selectively alternately connectable with members of said second gear set; said second motor/generator being continuously connected with a member of said third gear set; and first, second, third, fourth, fifth, and sixth torque-transfer devices for selectively interconnecting said members of said first, second, or third gear sets with a stationary member, one of said first and second motor/generators, or with other members of said planetary gear sets, said first, second, third, fourth, fifth, and sixth torque-transfer devices being engageable to provide said electrically variable transmission with a continuously variable range of speed ratios and four fixed forward speed ratios between said input member and said output member.