Transmission assembly for a self-propelled machine, and machine fitted with such a transmission

A transmission assembly for a self-propelled machine positioned between a primary motor shaft and wheels of said machine comprises:

• a transmission housing fitted with an input shaft and an output shaft that is a main shaft of the wheels of the machine, a drive shaft driven in rotation by the primary motor shaft and is linked to said input shaft forming a driven shaft driven by an endless belt drive, a clutch mechanism and, arranged between the input shaft and the output shaft for transmitting the movement from the input shaft to the output shaft, a transmission including a mechanism for reversing the direction of rotational drive of the output shaft, the clutch and direction-reversing mechanisms each having control assemblies, said clutch and direction reversing control assemblies being carried on said housing and being mounted respectively and movably, the direction reversing control assembly between at least three positions, i.e. a neutral position, a forward position and a reverse position, and the clutch control assembly between at least an engaged position and a disengaged position, wherein the direction reversing control assembly, when said direction reversing control assembly is in neutral position, blocks the clutch control assembly in disengaged position that prevents the clutch control assembly from shifting from the disengaged position to the engaged position, and the clutch control assembly, when the clutch control assembly is in engaged position, locks the direction reversing control assembly in the forward or reverse position, that prevents the direction reversing control assembly from shifting from the forward or reverse position into the neutral position.