Vehicle for running on rail

Abstract

A vehicle for running on rail is provided, which has the capability of achieving smooth running, while moderately gripping the rail. This vehicle has a base, a pair of first and second wheels held by the base to be rotatable on an upper surface of the rail and spaced from each other in an extending direction of the rail, a third wheel held by the base to be rotatable on a lower surface of the rail, and a motor for rotating the first wheel. The first wheel is positioned between the second and third wheels in the extending direction of the rail, and the second wheel is held by the base through a cushioning member. When the vehicle is tilted due to an elastic deformation of the cushioning member for the second wheel, gripping forces of the first and third wheels on the rail increase.

1 . A vehicle for running on a rail comprising: 
 a base;    a pair of first and second wheels held by said base to be rotatable on an upper surface of said rail and spaced from each other in an extending direction of said rail;    a third wheel held by said base to be rotatable on a lower surface of said rail;    a motor for driving at least one of the first and second wheels; 
 wherein the first wheel is positioned between the second wheel and the third wheel in the extending direction of said rail, and the second wheel is held by said base through a cushioning member.  
   
   
   
       2 . The vehicle as set forth in  claim 1 , wherein the third wheel comprises at least two wheels spaced from each other in the extending direction of said rail.  
   
   
       3 . The vehicle as set forth in  claim 1 , wherein the first wheel comprises a tire made of an elastic material.  
   
   
       4 . The vehicle as set forth in  claim 1 , comprising an auxiliary wheel held by said base to be rotatable on a side surface of said rail under at least one of the first and second wheels.  
   
   
       5 . The vehicle as set forth in  claim 1 , wherein a distance between the first wheel and a center of gravity of the vehicle in a running state is greater than the distance between the second wheel and the center of gravity, and shorter than the distance between the third wheel and the center of gravity.