Patent ID: 7217213

Claim:
A transmission system for combining rotational velocities from a first and a second rotating shaft and transmitting a combined sum of the rotational velocities to an output shaft, said first shaft being driven at a rotational velocity V, a gear system interconnecting said first and second rotating shafts and for driving the second rotating shaft at a rotational velocity which is approximately 0.5V, a clutch associated with each of said rotating shafts, each of said clutches having a first state in which rotary motion is transmitted as an output, and a second state in which no rotary motion is transmitted, a first differential gear box receiving the rotary motion outputted by one or more of said clutches, and transmitting rotary motion to said output shaft, said output shaft being driven by said differential gear box at a rotational speed which is approximately equal to: 0, if the clutches associated with said first and second rotating shafts are in said second state: V, if the clutch associated with said first rotating shaft is in said first state and the clutch associated with said second rotating shaft is in said second state: 0.5V, if the clutch associated with said first rotating shaft is in said second state and the clutch associated with said second rotating shaft is in said first state; or 1.5V, if the clutches associated with said first and second rotating shafts are in said first state, including a third rotating shaft, said gear system interconnecting said first, second and third rotating shafts for driving the third rotating shaft at a rotational velocity which is approximately 0.25V, a clutch associated with said third rotating shaft and a second differential gear box, said first differential gear box receiving an output from the clutches associated with the first and second rotating shafts, and the second differential gear box receiving an output from the clutch associated with said third rotating shaft and an output from said first differential gear box, said output shaft being driven by said second differential gear box within a rotational speed range of approximately 0 to 1.75V, depending on the state of said clutches.