Patent ID: 6766675
Filing Date: 2004-07-27
Classification: B21D

Abstract:
A spindle mechanism comprising:a spindle having a distal end; a drawing tool-mounting member for having drawing tools supported thereon for sliding movement in a radial direction, provided at said distal end of said spindle; a cam shaft rotatably provided at said spindle in a coaxial relation thereto; a cam plate that is provided at a distal end of said cam shaft and that rotates to cause said drawing tools to move in the radial direction, as a result of a relative rotation difference produced between said spindle and said cam shaft; speed-change means for producing the relative rotation difference between said spindle and said cam shaft by adjusting a condition of engagement of said spindle with said cam shaft, both of said spindle and said cam shaft themselves constituting a part of said speed-change means.