Traction drive system

Abstract

A traction drive system includes an endless member having a coupling couplable to a vehicle. A pair of rotating wheels support the endless member for rotation in a closed path. A drive assembly includes at least a pair of counter-rotating drive wheels wherein the drive wheels of the pair of counter-rotating drive wheels are disposed on opposite portions of the endless member to apply a driving force thereto. Each drive wheel is operably coupled to a drive motor.

What is claimed is:  
     
         1 . A traction drive system comprising: 
 an endless member having a coupling couplable to a vehicle;    a pair of rotating wheels supporting the endless member for rotation in a closed path; and    a drive assembly comprising at least a pair of counter-rotating drive wheels wherein the drive wheels of the pair of counter-rotating drive wheels are disposed on opposite portions of the endless member to apply a driving force thereto, and wherein each drive wheel is operably coupled to a drive motor.    
     
     
         2 . The traction drive system of    claim 1    wherein the endless member comprises a belt having a width dimension substantially greater than a thickness dimension, and wherein the drive wheels of the pair of counter-rotating drive wheels are disposed on opposite facing sides of the belt having the width dimension.  
     
     
         3 . The traction drive system of    claim 2    and further comprising: 
 a second endless belt coupled to the first-mentioned endless belt, wherein the second endless belt has a width dimension substantially greater than a thickness dimension, and wherein a coupled portion of the first-mentioned endless belt and the second endless belt travel along a longitudinal extent to drive a vehicle; and  
 a second pair of rotating wheels supporting the second endless belt for rotation in a second closed path, the second closed path encircling the first closed path.  
 
     
     
         4 . The traction drive system of    claim 3    and wherein the drive assembly is disposed away from the longitudinal extent to drive the vehicle.  
     
     
         5 . The traction drive system of    claim 4    and further comprising: 
 a third endless belt coupled to at least one of the first-mentioned endless belt and the second endless belt, wherein having a width dimension substantially greater than a thickness dimension; and  
 a third pair of rotating wheels supporting the third endless belt for rotation in a third closed path.  
 
     
     
         6 . The traction drive system of    claim 5    and further comprising: 
 a fourth endless belt coupled to at least one of the first-mentioned endless belt, the second endless belt and the third endless belt, having a width dimension substantially greater than a thickness dimension; and  
 a fourth pair of rotating wheels supporting the fourth endless belt for rotation in a fourth closed path, the fourth closed path encircling the third closed path.  
 
     
     
         7 . The traction drive system of    claim 6    and further comprising: 
 a second drive assembly comprising at least a pair of counter-rotating drive wheels wherein the drive wheels of the pair of the second counter-rotating drive wheels are disposed on opposite facing sides of the third endless belt to apply a driving force thereto.  
 
     
     
         8 . A traction drive system comprising: 
 a first endless member;    a first pair of rotating wheels supporting the first endless member for rotation in a first closed path;    a second endless member; and    a second pair of rotating wheels supporting the second endless member for rotation in a second closed path, the second closed path having a longitudinal extent being parallel and adjacent to the first closed path, the longitudinal extent being a path for driving a vehicle couplable to at least the first endless member.    
     
     
         9 . The traction drive system of    claim 8    and further comprising: 
 a third endless member;  
 a third pair of rotating wheels supporting the third endless member for rotation in a third closed path, the third closed path having longitudinal segments being parallel and adjacent to longitudinal segments of the first closed path;  
 a fourth endless member; and  
 a fourth pair of rotating wheels supporting the fourth endless member for rotation in a fourth closed path, the fourth closed path having longitudinal segments being parallel and adjacent to longitudinal segments of the second closed path.  
 
     
     
         10 . The traction drive system of    claim 9    wherein the first closed path encircles the third closed path and wherein the second closed path encircles the fourth closed path.  
     
     
         11 . The traction drive system of    claim 8    and further comprising: 
 a drive assembly engaging at least one of the first and second endless members.  
 
     
     
         12 . The traction drive system of    claim 11    wherein the drive assembly comprises a pair of counter-rotating drive wheels engaging said at least one of the first and second endless members.  
     
     
         13 . The traction drive system of    claim 8    and further comprising: 
 a first drive assembly engaging the first endless member along a portion of the first endless member not adjacent to the second endless member; and  
 a second drive assembly engaging the second endless member along a portion of the second endless member not adjacent to the first endless member.  
 
     
     
         14 . The traction drive system of    claim 13    wherein the first drive assembly comprises a pair of counter-rotating drive wheels engaging the first endless member.  
     
     
         15 . The traction drive system of    claim 14    wherein the second drive assembly comprises a pair of counter-rotating drive wheels engaging the second endless member.  
     
     
         16 . The traction drive system of    claim 9    and further comprising: 
 a first drive assembly engaging at least one of the first and third endless members along a portion thereof not adjacent to the second endless member; and  
 a second drive assembly engaging at least one of the second and fourth endless members along a portion thereof not adjacent to the first endless member.  
 
     
     
         17 . The traction drive system of    claim 16    wherein the first and second drive assemblies each comprises a pair of counter-rotating drive wheels engaging the corresponding endless member.  
     
     
         18 . The traction drive system of    claim 8    wherein the first and second endless members each comprise a belt having a width greater than a thickness, and wherein surfaces of width of each endless members are placed adjacent to each other.  
     
     
         19 . The traction drive system of    claim 9    wherein the first, second, third and fourth endless members each comprise a belt having a width greater than a thickness, and wherein surfaces of width of adjacent endless members are placed adjacent to each other.  
     
     
         20 . The traction drive system of    claim 8    and further comprising a shuttle coupling the first and second endless members along the path for driving the vehicle.  
     
     
         21 . The traction drive system of    claim 9    and further comprising a shuttle coupling the first, second, third and fourth endless members along the path for driving the vehicle.  
     
     
         22 . A traction drive system comprising: 
 a first endless belt;    a first pair of rotating wheels supporting the first endless belt for rotation in a first closed path;    a second endless belt secured to the first endless belt;    a second pair of rotating wheels supporting the second endless belt for rotation in a second closed path, the second closed path having a longitudinal extent being parallel and adjacent to the first closed path; and    wherein the first and second endless belts are secured together for travel along only the longitudinal extent to drive a vehicle.    
     
     
         23 . The traction drive system of    claim 22    and further comprising: 
 a third endless member;  
 a third pair of rotating wheels supporting the third endless member for rotation in a third closed path, the third closed path being encircled by the first closed path, the third closed path having longitudinal segments being parallel and adjacent to longitudinal segments of the first closed path;  
 a fourth endless member; and  
 a fourth pair of rotating wheels supporting the fourth endless member for rotation in a fourth closed path, the fourth closed path being encircled by the second closed path, the fourth closed path having longitudinal segments being parallel and adjacent to longitudinal segments of the second closed path; and  
 wherein the first, second, third and fourth endless belts are secured together for travel along only the longitudinal extent to drive the vehicle.  
 
     
     
         24 . A traction drive system comprising: 
 an endless member having a coupling couplable to a vehicle;    a pair of rotating wheels supporting the endless member for rotation in a closed path; and    a drive assembly comprising a plurality of pairs of counter-rotating drive wheels wherein the drive wheels of each pair of counter-rotating drive wheels are disposed on opposite portions of the endless member to apply a driving force thereto.    
     
     
         25 . The traction drive system of    claim 24    wherein the drive assembly includes a drive motor operably coupled to each drive wheel.  
     
     
         26 . The traction drive system of    claim 24    wherein the endless member comprises a belt having a width dimension substantially greater than a thickness dimension, and wherein the drive wheels of the pair of counter-rotating drive wheels are disposed on opposite facing sides of the belt having the width dimension.  
     
     
         27 . The traction drive system of    claim 26    wherein the plurality of drive wheels comprise groups of drive wheels, each group having drive wheels engaging the endless member along the width dimension of the endless member, and wherein each group of drive wheels is driven by a drive motor.