Two-wheeled vehicle and chassis braking system

Abstract

A two-wheeled vehicle able to assist wheels and keep a chassis in a stable posture at the time of abnormal operation without detracting from mobility at the time of normal operation, wherein, when some sort of abnormality is detected in the two-wheeled vehicle, an auxiliary wheel actuator disengages a projection and recess, whereby a first auxiliary wheel springs out toward a road surface together with a shank due to a biasing force of a coil spring. At the time of normal operation, the first auxiliary wheel is recessed in a step board.

What is claimed is:  
     
         1 . A two-wheeled vehicle comprising: 
 a first wheel and a second wheel rotating about shafts perpendicular to a running direction and arranged at a chassis along said perpendicular direction,    a third wheel having a first state assisting said first wheel and said second wheel and a second state up to shifting to said first state, and    a control means for shifting said third wheel from said second state to said first state when detecting an abnormality in running of said chassis.    
     
     
         2 . A two-wheeled vehicle as set forth in  claim 1 , further comprising drive means for driving said first wheel and said second wheel.  
     
     
         3 . A two-wheeled vehicle as set forth in  claim 1 , comprising a plurality of said third wheels arranged between said first wheel and said second wheel at a plurality of different positions in said running direction.  
     
     
         4 . A two-wheeled vehicle as set forth in  claim 1 , wherein 
 said third wheel is biased in a direction for shifting to said first state in said second state and movement in said biased direction is locked, and    said control means releases said lock when detecting an abnormality in running of said chassis.    
     
     
         5 . A two-wheeled vehicle as set forth in  claim 4 , wherein said third wheel shifts from said second state to said first state by linear motion.  
     
     
         6 . A two-wheeled vehicle as set forth in  claim 4 , further comprising 
 a lock means for said locking and    an operation means coupled with said lock means,    said third wheel moving together with said lock means in said locked state and shifting from said second state to said first state linked with movement of said operation means.    
     
     
         7 . A two-wheeled vehicle as set forth in  claim 4 , wherein said third wheel shifts from said second state to said first state by rotational motion about a predetermined axis.  
     
     
         8 . A chassis braking system for braking a chassis, comprising 
 a braking means comprising a braking surface biased toward a road surface on which said chassis runs and having a first state where movement of said braking surface toward said road surface is locked and a second state where said braking surface abuts against said road surface and    a control means for releasing said lock of said braking means and shifting said braking means from said first state to said second state when predetermined conditions are met.    
     
     
         9 . A chassis braking system as set forth in  claim 8 , wherein 
 said braking means comprises    a first moving body and a second moving body biased in directions approaching each other and    a movement mechanism for making said braking surface move toward said road surface as said first moving body and said second moving body approach each other,    movement of said first moving body and said second moving body to approach each other being locked in said first state.    
     
     
         10 . A two-wheeled vehicle comprising 
 a first wheel and a second wheel rotating about shafts perpendicular to a running direction and arranged at a chassis along said perpendicular direction,    a braking means comprising a braking surface biased toward a road surface on which said first wheel and said second wheel run and comprising a first state where movement of said braking surface toward said road surface is locked and a second state where said braking surface abuts against said road surface, and    a control means for releasing said lock of said braking means and shifting said braking means from said first state to said second state when predetermined conditions are met.