Device for controlling the working conditions of a self-propelled vehicle

A self-propelled tractor having ground-engaging wheels, said tractor comprising:

• power means including an internal combustion engine with a drive shaft and at least two electrical machines, each said engine and said electrical machines each having output power, said engine and said at least two electrical machines each being connected mechanically to a device operable to subdivide and to re-combine the output powers delivered by said engine and said electrical machines, said electrical machines being operable to deliver and to absorb output power, said power means drivingly connected to said wheels to supply motive power thereto to move said tractor at a selectively variable travel speed and provide rotational power from said drive shaft directly to a PTO shaft at selectively variable output speeds;
• a first device for controlling said travel speed of said tractor, said first device comprising a foot-operated throttle and a hand-operated throttle;
• a second hand-operated device for controlling said output speed of said drive shaft and thus said PTO shaft;
• said first and second devices being separate one from the other such that there is no direct relationship there between;
• said device for subdividing and re-combining the output powers comprises epi-cycloid gearing;
• said power means also including a clutch for said PTO;
• and wherein operation of said clutch disables said first device to selectively end control over the travel speed by said first device and enables said second device to control said travel speed and said output rotational speed of said drive shaft, and thus said PTO, at the same time.