Automatic machine for providing corrugated sheet-like elements

1. An automatic machine for providing corrugated sheet-like elements, comprising means for the continuous corrugation of a ribbon in motion in a longitudinal direction, said corrugation means comprising an upper conveyor and a lower conveyor, said upper conveyor comprising a plurality of upper abutment elements that are extended substantially transversely to said longitudinal direction of motion of said ribbon, said lower conveyor comprising a plurality of lower abutment elements that are extended substantially transversely to said longitudinal direction of motion of said ribbon, said upper abutment elements being intercalated between said lower abutment elements in a work area, wherein said upper abutment elements each comprise a flap, which has, in the end adapted to make contact with said ribbon, at least one portion comprising grip means, said upper conveyor and said lower conveyor each comprising respectively an upper chain and a lower chain, which unwind continuously, said upper abutment elements and said lower abutment elements being associated respectively with the links of said upper chain and of said lower chain, in said work area, said lower chain defining a lower movement direction of said lower abutment elements that is inclined with respect to the upper movement direction of said upper abutment elements defined by said upper chain, said upper conveyor comprising at least two upper sprockets, with which said upper chain is associated, said lower conveyor comprising at least two lower sprockets with which said lower chain is associated, at least one upper sprocket of said upper sprockets being connected kinematically to at least one lower sprocket of said lower sprockets, so that the rotation of said at least one upper sprocket causes the rotation of said at least one lower sprocket or vice versa, said at least one upper sprocket and said at least one lower sprocket being connected kinematically by a transmission chain, and further comprising means for offsetting the rotation of said upper sprocket about its own rotation axis with respect to the rotation of said lower sprocket relative to its own rotation axis in order to ensure that said upper abutment elements are intercalated between said lower abutment elements.

2. The automatic machine according to claim 1 , wherein said offsetting means comprise a guiding fork that comprises two arms with which two guiding sprockets are associated respectively to guide said transmission chain, said guiding fork being rotatable with respect to a rotation axis, the rotation of said guiding fork varying the length of the segment of said transmission chain comprised between said upper sprocket and said lower sprocket in order to offset the rotation of said upper sprocket with respect to the rotation of said lower sprocket.

3. The automatic machine according to claim 1 , further comprising, downstream of said work area, means for fixing a flat ribbon to said ribbon in its corrugated configuration obtained in passing through said work area.

4. The automatic machine according to claim 1 , wherein said fixing means comprise a hot air blower or a glue applicator to join said flat ribbon to said ribbon in its corrugated configuration.