Abstract: A tractor transmission includes first and second hydraulically actuated disc clutches adapted to drivably connect an input shaft, which is clutched by a friction clutch to an engine, to a first and second sleeve shafts. The countershaft and the sleeve shafts support gear-pinion pairs that produce four speed ratios. The range box includes gearing mounted on an output shaft, a countershaft, and the input shaft to drive the output shaft at a slower speed than that of the countershaft when the low range is selected, to drive the output shaft in the opposite direction to its forward drive direction when reverse operation is selected, and to directly connect the countershaft to the output shaft when the high speed range is selected.

Abstract: A transmission mechanism adapted especially for agricultural and industrial tractors and for heavy construction vehicles comprising a pair of hydrostatic pump-and-motor units arranged in a closed hydrostatic fluid flow circuit, a planetary gear unit and geared connections between separate elements of the gear unit and the rotor for each hydrostatic unit, each geared connection having its characteristic speed ratio thereby defining multiple speed ranges within which an infinite torque ratio variation is achieved.