method and system to operate the change of gear in a transmission - and power - shift, particularly for agricultural trattatrici.

摘要

The gearbox (1) incorporates a main friction clutch (2) operated by pedal, a pref. three-speed ratio selection assembly (3), a speed change mechanism (4) and a forward/reverse selector (5). It is controlled on load by an electronic unit (6) linked to a manual ratio selector (9) and an electronic monitor (10) of engine speed which responds to the accelerator pedal position (12) and governs the fuel injectors (13).A supplementary programme (15) can be invoked to select either an economical or a high-performance mode characterised by lower and higher engine speed thresholds respectively.