Patent ID: 7252611

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; said first motor/generator being continuously connected with a member of said first or second gear set; said second motor/generator being continuously connected with a member of said second gear set which is different from said member connected with said first motor/generator; a first torque transfer device selectively connecting said input member with a member of said first or second gear set or with said interconnecting member; a second torque transfer device selectively connecting said input member with a member of said first or second gear set, or with said interconnecting member, such that the pair of members connected by the second torque transfer device is different than the pair of members connected by the first torque transfer 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 said first motor/generator for braking rotation thereof; a fifth torque transfer device connected in parallel with said second motor/generator for braking rotation thereof; and wherein said first, second, third, fourth and fifth torque transfer devices are engageable in combinations of two or three to provide an electrically variable transmission with a continuously variable range of speed ratios and four fixed forward speed ratios.