Wheel structure

Abstract

A wheel which comprises a hub having an axle receiving aperture, a first portion extending circumferentially about the hub, a second portion extending circumferentially about the first portion, the second portion having a hardness less than the hardness of the first portion, and the second portion forming at least a major percentage of the surface contacting area. The wheel is suitable for use on trolleys and the like wherein it is desirable to have a relatively soft portion when the trolley is stationary to thereby provide stability while, at the same time, providing an easy rolling capability.

1 . A wheel comprising: 
 a hub having an axle receiving aperture;    a first portion extending circumferentially about said hub, said first portion having a first hardness;    a second portion extending circumferentially about said first portion, said second portion having a second hardness, said second portion forming at least a major percentage of a surface contacting area; and    the arrangement being such that said second hardness is less than said first hardness.    
   
   
       2 . The wheel of  claim 1  wherein said first portion has a hardness of at least 70 D.  
   
   
       3 . The wheel of  claim 2  wherein said second portion has a hardness of between 80 A and 87 A.  
   
   
       4 . The wheel of  claim 3  wherein said hub is formed of a metallic material.  
   
   
       5 . The wheel of  claim 4  wherein said metallic material is aluminum.  
   
   
       6 . The wheel of  claim 4  wherein said first portion is formed of a plastic material.  
   
   
       7 . The wheel of  claim 6  wherein said second portion is formed of a polyurethane material.  
   
   
       8 . In a vehicle having wheels thereon, the improvement wherein at least one of said wheels comprises: 
 a hub having an axle receiving aperture;    a first portion extending circumferentially about said hub, said first portion having a first hardness;    a second portion extending circumferentially about said first portion, said second portion having a second hardness, said second portion forming at least a major percentage of a surface contacting area; and    the arrangement being such that said second hardness is less than said first hardness.