Patent ID: RE42176

Claim:
Machine for manufacturing mesh bags ( 2 ) from a continuous roll of tubular mesh ( 3 ), preferably obtained from a reel, and for filling and closing said mesh bags, which comprises a first bag-shaping station ( 4 ), provided with: tubular mesh continuous feed devices and first and second laminates ( 5 ) of thermally weldable material; a perimetric expansion device ( 6 ) of the tubular mesh provided with a core expander ( 7 ) with an essentially oblong and flattened configuration, to be inserted, floating and vertically, inside the tubular mesh ( 3 ), determining in said mesh as it passes through the core expander, two frontal faces ( 8 ) and two lateral faces ( 9 ), and the first and the second laminates ( 5 ) of thermally weldable material face and superimpose said frontal faces of the tubular mesh; welding devices ( 10 ) arranged on both sides of the tubular mesh ( 3 ) for the welding of each of the laminates ( 5 ) of thermally weldable material to the face adjacent to the tubular mesh; and a bag-shaping device ( 11 ), equipped with a cross-sectional welding device ( 12 ) to configure a bag bottom and a cross-sectional cutting mechanism ( 14 ) arranged next to the cross-sectional welding mechanism, characterised in that the core expander ( 7 ) of the perimetric expansion device ( 6 ) is equipped with a vertical aperture ( 15 ) which, as if it were a slot, traverses the core expander and connects the two frontal faces thereof and extends from its base to an intermediate point, for which the core expander adopts an inverted “U” shape, the machine being fitted with preventive welding means ( 16 ), situated on a level with the core expander, adapted for partially welding the two frontal faces ( 8 ) of the tubular mesh ( 3 ) and the adjoining laminates ( 5 ) of thermally weldable material through the said aperture ( 5 ) ( 15 ) of the core expander ( 7 ); and in that the first station ( 4 ) comprises a traction device ( 17 ) which stretches the mesh downwards, so the thermally welded zone ( 18 ) of the two frontal faces of the mesh moves along the core expander ( 7 ) aperture ( 15 ), dragging a section of the tubular mesh provided with a bottom ( 13 ) so that the tubular mesh and laminates of thermally weldable material adjoining are cut by the cutting mechanism ( 14 ), turning out an unclosed mesh bag ( 2 ) which is delivered to the a first conveyor means ( 20 ) which convey it towards a second filling station ( 21 ), wherefrom the a second conveyor means ( 22 ) subsequently convey it to a third closing station ( 23 ), both being arranged linearly.