Patent ID: 6257357
Filing Date: 2001-07-10
Classification: B62D

Abstract:
A mechanism for steering a vehicle, comprising:a vehicle power source,first and second ground engaging drive wheels positioned near the rear of the vehicle,at lease one pivotable ground engaging wheel positioned near the front of the vehicle,a transmission carried by the vehicle and including a driving portion and a steering portion, whereinthe driving portion includes a power input from the vehicle power source, the driving portion being operative to transmit rotational motion from the vehicle power source to output shafts operatively coupled with the respective first and second drive wheels for propelling the vehicle across the ground surface, and the driving portion further includes a driving control input which controls the amount of rotational motion transmitted from the vehicle power source to the vehicle drive wheels, the driving control input being operatively engagable by an operator for altering the vehicle velocity and the forward or reverse direction of the vehicle, andsaid steering portion operatively engages the driving portion for affecting the amount of rotational motion transmitted to each drive wheel for executing vehicle turns, said steering portion includes a power input which receives power from the vehicle power source, and the steering portion includes a steering control input which controls the steering portion of the transmission, said steering portion being engaged with the driving portion for increasing the rotational speed of one drive wheel as the operator engages the steering control input, and the steering portion decreases the rotational speed of the other drive wheel for execution of a turn,a steering wheel operatively coupled with the steering control input and being pivotable by an operator to cause the steering portion to change the relative speeds of the first and second wheels, said steering wheel having a neutral position corresponding to straight vehicle travel, and said steering wheel is pivotable a maximum of between ninety and two-hundred-seventy degrees in either direction from said neutral position,a linkage operatively extending between the steering wheel and the steering portion of the transmission, said linkage comprising:a steering shaft operatively coupled with the steering wheel,a first lever operatively coupled with the steering shaft for pivoting in response to pivotal motion of the steering shaft,a link pivotally coupled with the first lever,a steering input control shaft coupled with the steering portion of the transmission and pivotable to control said steering portion, the steering input control shaft having a pivotal range of motion in both directions from a neutral position,a second lever fixed with the steering input control shaft and pivotally coupled with the link.