Castor axle having noise suppression function

Abstract

A chair includes a leg having a mounting hole, a castor having an end portion provided with an axle mounted in the mounting hole of the leg, and a substantially S-shaped snap ring mounted in the annular groove of the axle and rested on a peripheral wall of the mounting hole of the leg. Thus, the S-shaped snap ring is enclosed around the peripheral wall of the annular groove of the axle and rested between the upper wall and the lower wall of the annular groove, so that the S-shaped snap ring will not slip in the annular groove of the axle to prevent from producing noise due to friction between the axle of the castor and the leg during movement of the castor.

1 . A chair, comprising:
 a leg having an inside formed with a mounting hole;   a castor pivotally mounted on the leg and having an end portion provided with an axle mounted in the mounting hole of the leg, the axle of the castor having an upper end formed with an annular groove;   a substantially S-shaped snap ring mounted in the annular groove of the axle and rested on a peripheral wall of the mounting hole of the leg.   
   
   
       2 . The chair in accordance with  claim 1 , wherein the annular groove of the axle has an upper wall and a lower wall, and the S-shaped snap ring has two end portions rested on the upper wall and the lower wall of the annular groove of the axle respectively. 
   
   
       3 . The chair in accordance with  claim 2 , wherein each of the two end portions of the S-shaped snap ring has a curved bending shape. 
   
   
       4 . The chair in accordance with  claim 1 , wherein the S-shaped snap ring has a curved bending shape. 
   
   
       5 . The chair in accordance with  claim 1 , wherein the S-shaped snap ring is snapped into the annular groove of the axle. 
   
   
       6 . The chair in accordance with  claim 1 , wherein the S-shaped snap ring has an outer periphery rested on the peripheral wall of the mounting hole of the leg elastically. 
   
   
       7 . The chair in accordance with  claim 1 , wherein the S-shaped snap ring is enclosed around a peripheral wall of the annular groove of the axle and rested between the upper wall and the lower wall of the annular groove, so that the S-shaped snap ring will not slip in the annular groove of the axle. 
   
   
       8 . The chair in accordance with  claim 1 , wherein the S-shaped snap ring is compressible elastically upward and downward.