GB1431457A - Expanded mesh - Google Patents

Abstract

1431457 Forming expanded mesh COMALCO (J & S) FTY Ltd 21 Aug 1973 [23 Aug 1972] 39672/73 Heading B5A [Also in Divisions B3 and E1] A method of forming expanded mesh comprises extruding extrusile material to form an extrusion of constant cross-sectional shape including ribs 21 and webs 22, forming a row of slots 24 in each web which are staggered with respect to the slots in an adjacent row, increasing the width of each slot in the two outermost rows of slots by bending at least one of the ribs flanking the respective slot, engaging hooks of two rows of hooks of an expanding machine in respective widened slots of the outermost rows of slots, separating the rows of hooks from one another so as to bend the ribs and expand the slotted extrusion and simultaneously moving the hooks in each row towards one another, and removing the expanded mesh from the hooks. Slotting of the extrusion 20 is performed by slotting rollers 29 keyed to a roller shaft 36. A spreader head 40 carries a pair of adjustable bearings which journal a spreader finger shaft 42. The relative heights of the shafts 36, 42 can therefore be adjusted to account for varying height of ribs 21 in different extrusions. A driving chain 46 extends between the shafts to drive the latter at identical speeds. The number of spreader fingers 47 is identical with the number of radially outstanding projections 31 when the shafts are driven at the same speed. After the extrusion has been slotted and the outermost rows of slots widened, the extrusion is driven by dogs 28 of a chain 27 to a discharge support 56. The expanding machine is provided with side rails 60 carrying a track 61 engaged by rollers 62 on carriage blocks 63. A workpiece engaging hook 65 is secured to each block 63 and the blocks are interconnected by a flexible line 66. A swinging gauge member 67 has hookengaging cut-outs 68 for accurately locating the hooks 65 when the member is swung downwardly. In the expansion of the workpiece the carriage blocks move towards each other until they abut one another. A slight degree of stretching can then be performed to remove any irregularities in the workpiece.