Patent ID: 7134304

Claim:
A micro-roll forming device for providing a cylindrical blank metal article with a minute convexoconcave bearing surface, comprising: a powered article holding structure that, when energized, rotates the cylindrical blank metal article about its axis; a forming tool that includes a form roller with a corrugated circular ridge; a tool holding structure that holds the forming tool in such a manner that the corrugated circular ridge of the form roller is directed toward and in contact with an outer surface of the cylindrical blank metal article rotatably held by the article holding structure; a biasing member that is incorporated with the tool holding structure to press the form roller against the outer surface of the cylindrical blank metal article with a given pressing force; a powered tool head that, when energized, moves the tool holding structure in both a first direction perpendicular to the axis of the cylindrical blank metal article and a second direction parallel with the axis of the cylindrical blank metal article; a control unit that controls the powered tool head in such a manner that the form roller of the forming tool moves in the second direction while contacting the outer surface of the cylindrical blank metal article at the corrugated circular ridge thereof with a given pressing force; and a pressure load detecting device that detects a pressure load applied to the form roller by the biasing member and feeds a corresponding information signal to the control unit to control the given pressing force.