GB1363666A - Means and method for producing expanded metal - Google Patents

Abstract

1363666 Expanded metal JURY & SPIERS PTY Ltd 13 July 1971 [16 July 1970] 32845/71 Heading E1K [Also in Division B3] A method of making expanded metal comprises at least partly perforating a ductile metal member 21 to form a plurality of rows 23 of identical slots 20 having curved ends, which are staggered with respect to the slots of adjacent rows, to form a series of stretchable portions between the rows, securing the member in jaws 28, 30 and forcing the jaws away from each other to strain the stretchable portions beyond their yield point and to indine them to the longitudinal axes of the rows of slots, Fig. 4 (not shown). The member 21, which may be of aluminium, is fed between rolls (11), (12), Fig. 1 (not shown) respectively provided with projections (13) and grooves (17) which co-operate to shear slugs 20 either partially or fully from the member 21. The partially sheared slugs are ejected as the metal is expanded. The rounded ends of the slots reduce stress concentrations during expansion and tearing of the metal is prevented if the end radius is not less than half the metal thickness. In an alternative embodiment, Fig. 6, an aluminium member 47 is formed with spaced longitudinally extending flanges 48 and projections 13 on rolls 41 completely shear the slugs 20. During expansion the members may tend to contract inwardly and this is prevented by inserting pins through some, at least, of the end slots, the pins engaging against restraining members in the stretching machine.