Abstract: A tractor electronic linkage control system comprises electronic draft force and linkage position sensors (30, 33) and manual draft force and linkage position controls (31, 32). An electronic control unit 17 derives draft and position error signals and continually compares them to determine whether the system is to operate in draft control mode, where the draft error signal governs linkage movement, or position control mode, where the position error signal governs linkage movement.

Abstract: A CVT having a variator unit, epicyclic unit for plural ratio combinations, plural regime engagin couplers, a clutch and an output shaft. The epicyclic unit includes a splitting epicyclic gear and two components of the splitter is connected to the oppsite ends of the variator. The epicyclic unit having plural connections to the drive output shaft through the regime engaging couplers. The epicyclic unit also includes a recirculating epicyclic which has two components commoned with two components of the splitter epicyclic. The recirculating epicyclic provides an additional output which is connectable to the output shaft to provide at least one creep regime. The clutch can either be locked when starting with the creep regime operative or slippingly engaged when starting with the creep regime non-operative.