Patent ID: 7950119

Claim:
A method of producing a grid for a battery electrode plate, comprising the steps of: providing a sheet to become the grid for the battery electrode plate; providing a rotary expander, and forming the grid from the sheet by the rotary expander, wherein said rotary expander comprises a disk cutter cluster comprising: a first disk cutter roll having a first middle disk cutter; a second disk cutter roll having a second middle disk cutter, the first disk cutter roll and the second disk cutter roll being a pair; an edge disk cutter at an outermost end of said disk cutter cluster; wherein the edge disk cutter comprises; a first face facing the second middle disk cutter; a second face opposite to the first face; ridges disposed at a periphery of said edge disk cutter, wherein a notch is interposed between the ridges, wherein the notch is provided at the periphery of said edge disk cutter by penetrating said edge disk cutter in the thickness direction of said edge disk cutter; and an inclined surface provided on the ridges such that the ridges have a tip having an acute angle, wherein the acute angle is formed between the first face and the inclined surface, wherein said notch is provided to serve as an edge node forming part.