Sheet feed shaft

1. A method for manufacturing a sheet feed shaft comprising:

providing a metallic rod with a circumferential surface having a defined length;

supporting said metallic rod at each end;

providing a pair of punch units, each punch unit having a pair of perforating members, one punch unit being located on one side of said metallic rod, another punch unit being located on another side of said metallic rod such that said another punch unit is disposed 180° opposite said one punch unit, each perforating member having perforated edges arranged in an axial direction with respect to said metallic rod;

controlling a rotational angle of said metallic rod;

simultaneously reciprocating each punch unit such that said one punch unit approaches said metallic rod from a first direction and said another punch unit approaches said metallic rod from a direction opposite said first direction, whereby said perforated edges are forced into said circumferential surface from both sides of said metallic rod to form a plurality ofspike-shape portions whose bristled directions are opposite to each other, said metallic rod being rotated step by step in a successive manner, said plurality of spike-shape portions extending along entire length of said circumferential surface of said metallic rod.

2. A method for manufacturing a sheet feed shaft comprising:

providing a metallic rod with a circumferential surface having a defined length;

supporting said metallic rod at each end;

providing a pair of movable punch units, each punch unit having a set of perforating elements, one punch unit being located one side of said metallic rod, another punch unit being located on another side of said metallic rod such that said one punch unit is opposite said another punch unit, each perforating element having perforated edges arranged in an axial direction with respect to said metallic rod;

controlling a rotational angle of a metallic rod to form a plurality of spike-shape portions whose bristled directions are opposite to each other while supporting the metallic rod at both ends thereof;

reciprocating said pair of punch units simultaneously from both sides of the metallic rod such that said one punch unit engages said metallic rod from a first direction and said another punch unit engages said metallic rod in a direction opposite said first direction, whereby the perforating edges of one punch unit is circumferentially coincident with the perforating edges of the other punch unit, said perforating edges perforating the whole circumference of said metallic rod, whereby said metallic rod rotates a half turn in a successive manner, said plurality of spike-shape portions extending along entire length of said circumferential surface of said metallic rod.

3. A method for manufacturing a sheet feed shaft comprising:

providing a metallic rod with a circumferential surface having a defined length;

supporting said metallic rod at each end thereof and without a support contacting a location intermediate of said each end;

providing a first punch unit having a first pair of perforating members, said first punch unit being movable along length of said metallic rod, said first punch unit being located on one side of said metallic rod, each first perforating member having first perforated edges arranged in an axial direction with respect to said metallic rod;

providing a second punch unit having a second pair perforating members, said second punch unit being movable along length of said metallic rod, said second punch unit being located on another side of said metallic rod such that said second punch unit is opposite said first punch unit, each second perforating member having second perforated edges arranged in an axial direction with respect to said metallic rod;

controlling a rotational angle of said metallic rod;

simultaneously reciprocating said first punch unit and said second punch unit such that said first perforated edges and said second perforated edges are forced into said circumferential surface of said metallic rod, whereby a first plurality of spike-shape portions and a second plurality of spike-portions are formed on said circumferential surface of said metallic rod, said first plurality of spike-shape portions extending in one circumferential direction, said second plurality of spike-shape portions extending in another circumferential direction, said one circumferential direction being opposite said another circumferential direction, said metallic rod being rotated step by step in a successive manner, said plurality of spike-shape portions extending along entire length of said circumferential surface of said metallic rod, said first plurality of spike-shape portions being adjacent said second plurality of spike-shape portions.

4. A method in accordance with claim 3 , wherein said first punch unit and said second punch unit are disposed in a direction transverse of said metallic rod such that said first punch unit moves in a direction opposite said second punch unit.

5. A method in accordance with claim 3 , wherein said first punch unit is circumferentially coincident with said second punch unit when said first punch unit and said second punch unit are reciprocated.

6. A method in accordance with claim 3 , wherein said first plurality of spike-shape portions is adjacent said second plurality of spike-shape portions.