Transmission for agricultural tractors
AssigneeNew Holland North America, Inc.
InventorGalli Maurizio
Life of this patent
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Abstract
A vehicle transmission presents a main stage and a range reducer cascade connected to each other. The main stage includes an input shaft, two drive shafts coaxial with each other and selectively connected to the input shaft by respective hydraulic clutches, a countershaft, and a driven shaft connectable to the countershaft according to a number of gear ratios. The countershaft is selectively connectable to one of the drive shafts directly or via an inverting train by means of a first synchronized clutch, and is selectively connectable to the other drive shaft according to a step-down ratio and a step-up ratio by means of a second synchronized clutch. The hydraulic clutches and first and second synchronized clutches are controlled by an electronic control unit in response to manual operation and in predetermined sequences.
Claims12
In a tractor transmission having a number of gears;
- an input shaft for receiving motion from the vehicle engine;
- first and second drive shafts coaxial with each other;
- first and second hydraulic clutches for selectively connecting said input shaft to said first drive shaft and to said second drive shaft, respectively;
- at least one driven shaft;
- and transmission means interposed between said first and second drive shafts and said driven shaft, and defining respective numbers of gear ratios, the improvement comprising:
- at least one countershaft drivingly engageable with said driven shaft according to a first number of gear ratios;
- first synchronized clutch means for selectively connecting a first countershaft to said first drive shaft according to a first and second gear ratio;
- and
- second synchronized clutch means for selectively connecting said first countershaft to said second drive shaft according to a third and fourth gear ratio respectively lower and higher than said first gear ratio.
Dependencies are inferred from the claim text.