Patent ID: 7404246

Claim:
An improved manufacturing method for the hole-punching assembly of a hole-punching unit with a plurality of punching pieces, comprising the following steps: (1) forming a plurality of aluminum balancing pieces with a rectangular shape by extrusion, and forming an indentation area on one side of each balancing piece; (2) forming an elongated slot by stamping on the indentation area of each balancing piece; (3) obtaining a plurality of rectangular pieces, the number of which equals that of the balancing pieces, wherein the width of the rectangular pieces equals the width of the indentation area of the balancing pieces, and forming a row of holes by a single application of stamping on each rectangular piece so as to allow the punching pieces of the hole-punching unit to go through; and (4) fitting each of the rectangular pieces onto the indentation area of a respective one of the balancing pieces so that they are joined together, stacking up the balancing pieces, each fitted with one of the rectangular pieces, such that the two balancing pieces near a proximal end have their rectangular pieces facing each other so as to provide a gap for the insertion of a stack of paper, and then connecting the balancing pieces together by screws or bolts.