Patent ID: 7836993

Claim:
A device for selecting the overall cubic capacity of a hydraulic circuit comprising: a first motor set comprising at least one first hydraulic motor for driving first vehicle-moving means for moving a vehicle, and a second motor set comprising at least one second hydraulic motor for driving second vehicle-moving means for moving the vehicle, said first and second vehicle-moving means being situated one behind the other in a direction in which the vehicle moves, the circuit further comprising first and second main ducts for the first motor set, and third and fourth main ducts for the second motor set, the first and third main ducts and the second and fourth main ducts being suitable for being connected in respective pairs to respective ones of two orifices of a pump for feeding and discharging the motor sets in parallel, the device comprising a selector suitable for taking up a first stable position corresponding to a first configuration of the selector device, in which configuration the third and fourth main ducts are connected to respective ones of the orifices of the pump, and said third and fourth ducts are isolated from each other so that the second motor set is active, and for taking up a second stable position corresponding to a second configuration of the selector device, in which configuration one of the first and second main ducts is connected to the third and fourth main ducts, so that the second motor set is inactive, the selector being such that, while the selector is moving between said stable positions, a temporary situation exists in which the first, second, third, and fourth ducts are interconnected; said device further comprising means serving, at least while the selector is moving in a first direction between its first and second stable positions, to sustain said temporary situation for a period of time in an intermediate stage during which an interconnection between the third and fourth main ducts and an interconnection between at least one of the first and second main ducts and at least one of the third and fourth main ducts are constricted.