Caster with a structural improvement

Abstract

A caster with a structural improvement includes a wheel holder, a spindle seat, a spindle and two wheels. A through hole of the spindle seat is covered on a spindle housing of the wheel holder with a ring groove of the spindle seat engaged by an annular flange of the spindle housing, further the spindle is inserted into the spindle housing with at least one ring groove of the spindle engaged by at least one circumferential ridge of the spindle housing, and finally axle housings of the wheels are inserted by a wheel axle of the wheel holder with a ring groove of the wheel axle engaged by a circumferential ridge of the axle housings, whereby the wheels can swivel and move. Moreover, the spindle seat can be assembled with wheel holders and wheels of various sizes, thereby reducing the costs of new molds for spindle seats of different sizes.

What is claimed is:  
     
         1 . A caster with a structural improvement comprising: 
 a wheel holder having a wheel axle secured in a proper place thereof and a spindle housing upwards protruded thereon, said wheel axle provided with two ring grooves respectively disposed at both ends thereof, said spindle housing provided with at least one circumferential ridge disposed in an inner wall thereof and an annular flange formed on an outer wall of a top thereof;    a spindle seat capable of being covered on said spindle housing of said wheel holder and having a channel and a through hole, said through hole formed in a center of said spindle seat and provided with a ring groove disposed in an inner wall thereof;    a spindle capable of being inserted into said spindle housing of said wheel holder and having at least one ring groove; and,    two wheels capable of being respectively combined with both ends of said wheel axle of said wheel holder and each having an axle housing disposed in a proper place thereof, each of said axle housings provided with a circumferential ridge disposed in an inner wall thereof.    
     
     
         2 . The caster with a structural improvement as claimed in  claim 1 , wherein said wheel holder is formed in a shape approximated to a semi-circle for being combined with said two wheels.  
     
     
         3 . The caster with a structural improvement as claimed in  claim 1 , wherein said channel of said spindle seat is formed in a shape of an oblique curved surface whose lower portion is narrowed down for being engaged by said wheel holder.  
     
     
         4 . The caster with a structural improvement as claimed in  claim 1 , wherein said wheel holder and said two wheels are respectively provided with a plurality of reinforced ribs disposed in proper places thereof for providing the combination of said wheel holder and said two wheels with stability and firmness.