| 摘要 |
Apparatus for expanding metallic strip inwardly from its edges to leave an unexpanded selvedge at each edge e.g. in the manufacture of a battery plate, includes a lower fixed expander block whose edges converge in the direction of movement of the strip. An upper reciprocable expander block carries two lines of expander punches whose cutting edges cooperate with the edges of the fixed block to cut and expand those portions of the strip which extend over the edges of the fixed block. Feed means incrementally advances the strip through the apparatus. The cutting edge and underside surface of the upstream punch 20', and preferably the adjacent punch also has a rounded portion 18'. This reduces the distortion to which the selvedges are subjected thus facilitating their bending and reducing the incidence of broken mesh strands. <IMAGE> |
