Patent ID: 7387585

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 connecting said second member of said first gear set with said second member of said second gear set; a third interconnecting member continuously connecting a member of said first, second or third gear set with a stationary member; said first motor/generator being continuously connected, or selectively connected via a dog clutch, with a member of said first, second or third gear set; said second motor/generator being continuously connected with a member of said first, second or third gear set; a first torque transmitting device selectively connecting a member of said first or second gear set with another member of said first or third gear set; a second torque transmitting device selectively connecting a member of said third gear set with another member of said first, second or third gear set; a third torque transmitting device selectively connecting a member of said first, second or third gear set with said stationary member; a fourth torque transmitting device connected in parallel with one of said first and second motor/generators for selectively preventing rotation thereof; and wherein said first, second, third and fourth torque transmitting devices are engagable to provide an electrically variable transmission with a continuously variable range of speed ratios and up to four fixed forward speed ratios.