Top cap of bicycle handlebar stem tube and method for manufacturing same

Abstract

A top cap is provided for a bicycle handlebar stem. The top cap includes a cap body, which has a lower portion forming a fitting cylinder of a reduced diameter and a radially expanding circumferential shoulder atop the fitting cylinder. A barrel extends from a bottom of the fitting cylinder. The barrel forms a downward-facing hollow blind hole. The cap body forms a bolt head hole extending therethrough and coaxial with and communicating the blind hole. The barrel forms slits, which define a tightening section.

I claim: 
     
         1 . A top cap for a bicycle handlebar stem, comprising:
 a cap body, which has a lower portion forming a fitting cylinder of a reduced diameter and a radially expanding circumferential shoulder atop the fitting cylinder, the cap body forming a bolt head hole extending through a central portion of the cap body in a vertical direction; and   a barrel, which extends downward from a bottom of the fitting cylinder in a coaxial manner, the barrel forming a blind hole that faces downward and has an inside diameter greater than the bolt head hole, a lower end portion of the barrel forming a plurality of slits extending in a vertical direction, the slits communicating between inside and outside of the blind hole, whereby the lower end of the blind hole forms a tightening section for receiving a nut to be fit therein.   
     
     
         2 . The top cap according to  claim 1 , wherein the bolt head hole has an upper section in the form of a cone of which diameter is increased in an upward direction.