Abstract: A driveline for an engined vehicle, comprises a continuously-variable ratio transmission (1) having an input, adapted to be driven by the engine, and an output (3) and first and second epicyclic gears (4, 10) for providing a high and low regime. The planet carrier (6) of the first epicyclic gear and the sun gear (12) of the second epicyclic gear are directly driven by the said output of the continuously-variable ratio transmission, and the sun gear (5) of the first epicyclic gear and the annulus (11) of the second epicyclic gear are directly driven by the engine, the annulus (7) of the first epicyclic gear providing an output in low regime, and the planet carrier (13) of the second epicyclic gear providing an output in high regime.

Abstract: A tank engine drive shaft (1) drives respective tank track drive shaft (20, 30) by way of a continuously-variable ratio transmission variator (200), a transfer system (12, 13, 15) including coupling means (C1, C2, 16, 17), a cross shaft (18, 19) and respective summing epicyclic gears (7, 6). Steering of the tank is achieved by a steer variator (100) also driven (2, 3) by the engine, which outputs differential rotations as further inputs (82, 55) to the summing epicyclic gears (7, 6). The drive line operates in four distinct regimes: reverse, low I, low II and high, by means of an epicyclic gear brake (B), and clutches (H, C1 and C2). The two parts (16, 17) of the coupling means are made to rotate in opposite directions by the annulus (15) of the epicyclics.As the tank accelerates from rest in low I regime, with brake B applied and clutch C1 applied but clutch H disengaged, the cross shaft (18, 19) decelerates.