1. Field of the Invention
This invention relates to apparatus for filling sacks comprising clamping means for engaging the initially collapsed sacks adjacent to the side portions of their opening-defining edges, suction devices, which engage mutually opposite side walls of the sacks adjacent to their opening-defining edges and pull said side walls apart, and a filling pipe.
2. Description of the Prior Art
In the operation of such apparatuses, which are known e.g., from U.S. Pat. No. 4,537,013 (corresponding to Published European Patent Application 82 955), U.S. Pat. No. 3,830,266 and British Patent Specification No.691,916, it has been observed that dustlike content of the sack will adhere to the inside surfaces of the sack walls which are made of thermoplastic material, specifically in those regions in which the suction devices engages the side walls on the outside. This is due to the fact that when the suction devices pull the sack walls apart the suction devices move relative to said sack walls so that electrostatic charges are produced on the sack walls consisting of thermoplastic material and said charges subsequently attract dustlike contents of the sack. Because the sealing seam welds are usually formed specifically in the regions in which the suction devices have previously been applied to pull open the sacks for the insertion of the filling pipe, the adherent dustlike contents of the sack may adversely affect the quality or tightness of the sealing seam welds.
USPTO Backgrounds
USPTO Backgrounds