Patent ID: 7473202

Claim:
A dual mode continuously variable transmission for use with motor vehicles comprising: a transmission input shaft; a transmission output shaft; a variator disposed between the transmission input shaft and the transmission output shaft and the variator having a variator input shaft and a variator output shaft and configured to continuously vary a ratio of input torque to output torque between the variator shafts responsive to commands from an electronic control unit, the variator input shaft drivingly connected to the transmission input shaft and the variator output shaft drivingly connected to the transmission output shaft; a planetary mixer gear set operably disposed between the transmission input shaft and the variator output shaft including a ring gear rotatable about a first axis, a sun gear rotatable about the first axis and drivingly connected to the variator output shaft, and a carrier drivingly connected to the transmission output shaft and rotatable about the first axis with a plurality of planet gears in mesh with both the sun gear and the ring gear; a grounded element rotatively fixed relative to a transmission housing; a first clutching device operably disposed between the transmission input shaft and the ring gear and configured to selectively connect the input shaft with the ring gear to achieve a power splitting mode of operation; a second clutching device operably disposed between the ring gear and the grounded element and configured to selectively connect the ring gear and the grounded element to achieve a variator-only mode of operation; and the electronic control unit operably connected to the variator and operably connected to the clutching elements and configured to include logic rules for controlling the transmission, the logic rules including rules by which the clutching element maintains the transmission in the variator-only mode of operation in a first vehicle speed range and maintains the transmission in the power splitting mode of operation in a second vehicle speed range greater than the first vehicle speed range.