Endless Belt Drive for a Vehicle

Abstract

An endless belt system for a vehicle having a negative trail steering geometry is provided. The endless belt system replaces the wheels that steer a vehicle, particularly an all-terrain vehicle, to provide increased steerability and floatation over soft terrain.

1 .- 12 . (canceled) 
     
     
         13 . A drive system suitable for use on a vehicle having:
 a frame having a front portion, a rear portion and a longitudinal axis;   an engine supported by the frame;   a seat supported by the frame to accommodate a rider; and   a manually-operable steering device connected to the frame to accept steering input from the rider;   
       the drive system comprising:
 a drive-system frame operatively connectable to the frame of the vehicle
 so as to be capable of pivotal movement with respect to the frame of the vehicle relative to the longitudinal axis of the vehicle such that the drive system may be pivoted to steer the vehicle, and 
 so as to be incapable of pivotal movement with respect to the frame of the vehicle in a plane parallel to the longitudinal axis and normal to the ground when the vehicle is on flat level terrain and steered straight; 
 
 a rail pivotally mounted to the drive-system frame; 
 a ground-engaging endless belt in sliding engagement with the rail such that a ground contact area of the belt is below the rail when the vehicle is on flat level terrain, the belt being operatively connectable to the engine to propel the vehicle; and 
 the drive system being operatively connectable to the steering device of the vehicle. 
 
     
     
         14 . The drive system of  claim 13 , further comprising a plurality of wheels about which the belt is disposed, the wheels being associated with the rail so as to pivotally move in unison therewith with respect to the drive-system frame. 
     
     
         15 . The drive system of  claim 14 , further comprising a stopper for limiting pivotal movement of the rail. 
     
     
         16 . The drive system of  claim 13 , further comprising a belt tensioner associated with the endless belt for maintaining a tension of the belt constant notwithstanding pivotal movement of the rail. 
     
     
         17 . The drive system of  claim 14 , wherein the rail is pivotally mounted to the drive system frame about a pivot axis, and wherein a load axis, being defined by the resultant load statically equivalent to the distribution of loads across the ground contact area of the belt with the ground, intersects the pivot axis. 
     
     
         18 . An all-terrain vehicle, comprising:
 a frame having a front portion, a rear portion and a longitudinal axis;   an engine supported by the frame;   a straddle seat supported by the frame to accommodate a rider;   a handlebar connected to the frame to accept steering input from the rider;   a first drive system as recited in  claim 14  at a front left side of the vehicle; and   a second drive system as recited in  claim 14  at a front right side of the vehicle.   
     
     
         19 . The all-terrain vehicle of  claim 18 , further comprising a steering angle stopper limiting a steering angle of at least one of the drive systems, the steering angle stopper disposed on the vehicle such that a steering linkage of the vehicle does not bear a force created when the stopper is engaged. 
     
     
         20 . A vehicle comprising:
 a frame having a front portion, a rear portion and a longitudinal axis;   an engine supported by the frame;   a seat supported by the frame to accommodate a rider;   a manually-operable steering device connected to the frame to accept steering input from the rider;   a suspension system movably connected to the frame, the suspension system including a shock absorbing element;   a drive system connected to the suspension system and capable of pivotal movement with respect to the longitudinal axis of the frame to steer the vehicle, the drive system operatively connected to the steering device, the drive system having:
 a plurality of wheels; 
 ground-engaging endless belt rotatable about the plurality of wheels; 
   a steering angle stopper limiting a steering angle of the drive system, the steering angle stopper disposed on the vehicle such that a steering linkage of the vehicle does not bear a force created when the stopper is engaged.   
     
     
         21 . The vehicle of  claim 20 , wherein the drive system further comprises a rail with which the belt is in sliding engagement. 
     
     
         22 . The vehicle of  claim 20 , wherein the stopper is mounted on the frame. 
     
     
         23 . The vehicle of  claim 20 , wherein the stopper is mounted on the drive system. 
     
     
         24 . The vehicle of  claim 20 , wherein the stopper is mounted on the suspension system. 
     
     
         25 . The vehicle of  claim 20 , wherein the vehicle is an all-terrain vehicle, the seat is a straddle seat, and the steering device is a handlebar. 
     
     
         26 . The vehicle of  claim 21 , wherein the stopper is mounted on the frame. 
     
     
         27 . The vehicle of  claim 21 , wherein the stopper is mounted on the drive system. 
     
     
         28 . The vehicle of  claim 21 , wherein the stopper is mounted on the suspension system. 
     
     
         29 . The vehicle of  claim 21 , wherein the vehicle is an all-terrain vehicle, the seat is a straddle seat, and the steering device is a handlebar.