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US 3,988,970 AGranted
Apparatus for forming flat bottom plastic bags
AssigneeViolet M. Hanson
InventorsViolet M. Hanson, John E. Finn
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AssigneeViolet M. Hanson
InventorsViolet M. Hanson, John E. Finn
Estimating the term…
Flat bottom bags are formed from a supply of substantially endless plastic tubing, gusseted along two sides to form a flat reel. A sleeve of predetermined length is withdrawn from the reel and allowed to hang along a vertical plane between two foraminous plenum chambers which are then moved toward each other to squeeze the length therebetween. Simultaneously a sealing and shearing mechanism forms a transverse seal and cuts the sleeve length from the reel, the gussets being at the same time sealed in the seam. The plenum chambers are then subject to vacuum and are moved apart, causing the sides of the now formed bag to separate opening the same. Upon opening of the bag, a forming mandrel is inserted therein and moved through the length of the bag until it reaches the sealed end. Simultaneously a presser member is moved across the outside surface of the bag folding over the seam, and pressing the gusset portions into flat flaps and in addition forming simultaneously the flat bottom to the bag. The mandrel or the presser plate is provided with heat sealing means sealing the flaps to the sleeve sides.
Apparatus for forming reinforced flat bottom bags from a tubular sleeve having opposed faces and gusseted sides, comprising means for supporting said sleeve, a plurality of foraminous plenum chambers, one of said chambers located adjacent each of the faces of said sleeve, means for moving said plenum chambers toward and away from each other to engage the respective faces of said sleeve and thereafter movable outwardly, means for seaming closed one end of said sleeve to seal said opposed faces together with the gusseted sides therebetween, means for applying a vacuum through said plenum chambers on the outward movement thereof to cause the faces of said sleeve to adhere thereto and to open said sleeve, means for cutting said sleeve into individual bag sleeves before said bag sleeves are opened, a mandrel movable into the other end of each said bag sleeve to press against the seamed end flattening the gusseted sides and forming flaps having folds with the opposed faces in overlying relationship, and means for securing selected portions of said flaps and said overlying sides and faces to form a reinforced bottom.
In an apparatus for forming a reinforced flat bottom plastic bag from a roll of plastic tubing having opposed faces and gussetted sides, means on said apparatus to support the roll of plastic tubing and means to dispense the same from said support means, means operable on said apparatus to engage the faces of the plastic tubing to seal the same together with the gussetted sides therebetween and to form the bag bottom at one end thereof and to sever a length of the sealed tubing from the roll thereof to form the bag length, means adjacent the length of the bag to cause the faces thereof to separate and to open the length of the bag after the bag length is severed, a mandrel movable into the open severed end of the bag and engaging the gussetted sides to press and flatten the same against the bag bottom thereby forming reinforcing flaps relative to the bag bottom and opposed faces sealed together.
Dependencies are inferred from the claim text.