A hybrid vehicle is driven by either an engine or a motor by tightening or releasing a clutch interposed between an engine and a transmission. A generator is connected to the engine, and the engine torque is absorbed by the generator when the power source is changed over from the motor to the engine....http://www.google.fr/patents/US6175785?utm_source=gb-gplus-shareBrevet US6175785 - Hybrid vehicle
