Patent ID: 6425450
Filing Date: 2002-07-30
Classification: B62D

Abstract:
A vehicle comprising:a frame assembly; an engine assembly carried by said frame assembly constructed and arranged to generate power; a track assembly on said frame assembly, a series of rollers including a drive roller, and an endless track trained about said rollers so as to provide an operative ground engaging flight extending longitudinally with respect to said frame assembly; a power operated track mover operatively connected to said drive roller to move said operative flight in ground engaging relation; a pair of left and right driving and steering wheels disposed on opposite sides of said track assembly in flanking relation thereto; each of said wheels having (1) mounting structure supporting the wheel for rotational movement about a rotational axis mounted on said frame assembly for vertical movements between extended and retracted positions with respect thereto; (2) a power operated wheel rotator connected thereto to rotate the associated wheel about its rotational axis and (3) a power operated vertical mover constructed and arranged to move said mounting structure with respect to said frame assembly between extended and retracted positions; the arrangement of the wheel mounting structures and vertical movers with respect to said frame assembly and track frame structure being such that movement by said movers of said wheel mounting structures with respect to said frame assembly between said retracted and extended positions creates a shift of load between said wheels and said track assembly progressively between a maximum traction condition wherein the load is shared relatively less by the wheels and the entire operative flight of the track and a maximum turning tricycle condition wherein the load is shared relatively more by said wheels and by only a portion of the operative flight of the track with the remainder of the operative flight of the track tilted out of ground contact; an electronic controller operable to control (a) an amount of power supplied from said engine assembly to said power operated track mover (b) an amount of power supplied from said engine assembly to a left one of said wheel rotators (c) an amount of power supplied from said engine assembly to a right one of said wheel rotators (d) an amount of power supplied from said engine assembly to a left one of said vertical movers and (e) an amount of power supplied from said engine assembly to a right one of said vertical movers; a speed input system communicated to said controller, said speed input system being operable to transmit a speed signal to said controller indicative of a selected speed at which said vehicle is to be moved; said controller being operable to receive said speed signal and responsively control the amount of power supplied from said engine assembly to said track mover and said wheel rotators so as to move said vehicle at said selected speed; a steering input device communicated with said controller, said steering input device being operable to transmit straight and turning signals to said controller indicative of a selected straight vehicle movement and of a selected angle at which the vehicle is to be turned; said controller being operable to process the steering signals transmitted thereto and responsively control (a) the respective amounts of power supplied from said engine assembly to said track mover, said wheel rotators and said vertical movers such that (1) when a straight signal is processed, both wheels rotate at the same speed in uncoordinated relation with the track speed and said wheel mounting structures are in relative retracted positions with respect to said frame assembly presenting a traction condition wherein the load is shared between the wheels and the entire operative flight of the track, and (2) when a turning signal is processed, an outer wheel with respect to the angle of turn rotates at a greater speed than an inner wheel with respect to the angle of turn to thereby effect the turn and said wheel mounting structures are in relative extended positions relative to said frame assembly presenting a turning tricycle condition wherein the load is shared between said wheels and only a portion of the operative flight of said track; a lateral tilt input system connected with said controller, said lateral tilt input system being operable to generate a lateral tilt signal indicative of a sustained movement of the vehicle along a slope in a direction wherein a downhill wheel is lower than an uphill wheel and said frame assembly has at least a predetermined lateral tilt; said controller being operable to process said lateral tilt signal and responsively control the respective amounts of power from said engine assembly to one or more of said vertical movers to move said frame assembly from said lateral tilted condition into a generally horizontally level condition.