Adjustable structure for the footrest ring of a chair

Abstract

An adjustable structure for the footrest ring of a chair includes a footrest ring, a sleeve, a nut, an adjusting rod and two retaining rings. The sleeve is received in a through hole of a fixed base of the footrest ring, having a wall cut with an oblique groove. The nut is secured in an insert hole of the fixed base of the footrest ring. The adjusting rod has one end screwed in the nut and another end extending out of the fixed base. The two retaining rings are respectively engaged in the engage groove at an upper and a lower outer wall of the sleeve. Thus, the footrest ring can conveniently be adjusted in height and stably positioned on the support tube of a chair.

What is claimed is: 
     
         1 . An adjustably structure for the footrest ring of a chair comprising:
 a footrest ring provided with a fixed base, said fixed base bored with a through hole in the interior, said through hole having an inner wall disposed with a notch, said fixed base having a wall bored with an insert hole, said insert hole communicating with said notch;   a sleeve received in said through hole of said fixed base of said footrest ring, said sleeve having an upper and a lower outer wall respectively formed with an engage groove, said sleeve further having a wall cut with an oblique groove;   a nut secured in said insert hole of said fixed base of said footrest ring, said nut having one end provided with a stop edge, said stop edge fixed in said notch of said fixed base, said nut bored with an insert hole in the interior, said insert hole formed with female threads on the inner wall;   an adjusting rod having one end threadably fixed in the interior of said nut and another end extending out of said fixed base of said footrest ring, said adjusting rod having one end formed with male threads; and   two retaining rings respectively engaged in said engage groove at the upper and the lower outer wall of said sleeve.   
     
     
         2 . The adjustable structure for the footrest ring of a chair as claimed in  claim 1 , wherein said through hole of said fixed base of said footrest ring is formed with a recessed face at the topside for receiving one of said two retaining rings. 
     
     
         3 . The adjustable structure for the footrest ring of a chair as claimed in  claim 1 , wherein said fixed base of said footrest ring has outer wall set with a plurality of connecting ribs spaced apart equidistantly.