System for steering and driving a full-track vehicle

Abstract

A full-track vehicle has an engine connected via a pair of differentials to a pair of tracks. A steering shaft extending between the differentials is rotatable in one sense for deflection of the vehicle to one side during forward advance and in the other direction for deflection toward the other side. This steering shaft is connected to the planet carrier of a primary planet gear assembly and to the ring gear of an intermediate planetary gear assembly. The sun gears of both of these assemblies are connected to the output side of a reversible variable-speed transmission whose input side is connected directly to the engine. The ring gear of the primary planetary gear assembly is connectable to a brake which may arrest its rotation and the planet carrier of the intermediate planetary gear assembly is connected to the planet carrier of a left-turn planetary gear assembly and the ring gear of a right-turn planetary gear assembly. The ring gear of the left-turn assembly is provided with a brake as is the planet carrier of the right-turn assembly, and the sun gears of both of these assemblies are directly connected to the engine. For minor deflections the primary brake is closed and the transmission alone directly rotates the sun gear of the primary gear assembly and thereby rotates the steering shaft in the necessary direction. For greater deflection the left- or right-turn brakes are closed and the output rotation of the variable-speed reversible transmission is subtracted from the rotation speed of the sun gears of the turn gear assemblies, and for greatest possible deflection the output rotation of the transmission is added to the rotation of the sun gears. A Z-shaped cam is provided to effect this increasing, decreasing, and reversing operation of the transmission.

Dependencies are inferred from the claim text.