US Patent 7381144 Gearbox assembly with gearbox means for speed overlap

A gearbox assembly, in particular for a wheel drive of a vehicle with a hydrostatic gearbox having, according to a first driving mode, the sun gear of the single planetary stage in effective interaction with a ring gear of the planetary stage via a first coupling, so that the output speed of the planetary stage is a linear function of the output speed of the hydrostatic gearbox and that, according to a second driving mode, the ring gear is in effective interaction with the hydrostatic gearbox, wherein, at the same time, the sun gear is in effective interaction with a gearbox input shaft via a second coupling so that as a consequence of power distribution, the speeds of the ring gear and the sun gear overlap.