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AssigneeRovema Verpackungsmaschinen GmbH
InventorsHans J. Plock, Manfred Schmachtel, Helmut Wosch, Walter Baur
Estimating the term…
A tube sack has a fill chamber and a flag at one end thereof, the flag having a sealing seam at the outer end thereof and a labyrinth seam which is adjacent the fill chamber and which is arranged to provide small passages through which air can flow from the fill chamber to a ventilation chamber located between the sealing and labyrinth seams. A vent opening is provided in the form of a perforation through a wall of the flag or an interruption in the seal seam, and is sealed by a bridging seam which surrounds it or by a seal piece which is glued over it. In a method and apparatus for making the sack, a tube is formed and sealed at one end, is then filled, and the flag, sealing seam and labyrinth seam are then made in the other end along with, where appropriate, a perforation for the vent opening. The sack is placed on a horizontal conveyor apparatus and passes through a mechanism which presses air out of the fill chamber through the vent opening, and the vent opening is then sealed by the bridging seam or by the seal piece.
A method for filling, removing air from, and closing a sack which is open at one end and is made of a material which prevents air from passing therethrough, comprising the steps of at least partially filling the sack with a fill material at a fill station, producing a sealing seam at the open end of the sack immediately after the filling step, producing a labyrinth seam at a location spaced from the sealing seam, said labyrinth seam hindering the movement of fill material out of said sack, providing a vent opening in the sack which communicates with the air external to the sack and with the region between said labyrinth seam and said sealing seam, thereafter moving the sack away from the fill station, thereafter removing air from the sack during further transport thereof through said vent opening, and thereafter sealing the vent opening in an air-tight manner.
The sack according to claim 11, wherein at least one wall of the sack has a vent opening therethrough which communicates with the ventilation chamber and can be sealed by adhesively securing a seal piece thereover.
A sack, comprising a fill chamber located within the sack, a flag at one end of the sack, and a sealing seam arranged near a free end of the flag of said sack, wherein at an edge of the sack flag adjacent the fill chamber there is provided a labyrinth seam which is generally parallel to the sealing seam, the sack having at least one passageway which extends past the labyrinth seam and provides communication between the fill chamber and a ventilation chamber located between the labyrinth seam and the sealing seam.
An apparatus for filling, removing air from, and closing a sack which is open at one end and is made of a material which prevents air from passing therethrough, comprising:
Dependencies are inferred from the claim text.