Method of and apparatus for forming packages with tear tabs

Claim 2

In the production of filled packages by the form-fill-seal technique in which a web of heat-sealable material is formed into tubing and the tubing is intermittently advanced in package length increments with a dwell interval between successive feed cycles, and in which transverse seals constituting package end seals are formed across the tubing at package length intervals, the product with which the packages are to be filled being delivered endwise internally of the tubing, the steps of applying a length of tab material which is heat-sealable at least on one face thereof to the outside of each package length increment of the tubing with the heat-sealable face of the tab material facing the tubing, and heat-sealing the said length of tab material to the tubing over a portion only of the area of the said length of tab material, thereby to provide a tear tab on each package with the tab having a free portion adapted to be grasped and pulled to tear an opening in the package where the tab is sealed to the package, each said length of tab material being cut from a continuous length of tape, the tape being fed toward the tubing from a roll of the tape and forward in the direction of the length of The tubing, the end portion of the tape being cut off to form the said length of tab material, the said end portion of the tape being clamped against the tubing and heat-sealed thereto during the dwell interval of the tubing between successive feed cycles, the said end portion of the tape being cut off after it has been heat-sealed to the tubing, the cut-off being spaced from the seal, the feed of the tape being effected by enlarging a loop in the tape between the clamped lower end portion of the tape and the roll of tape.

Claim 3

In a form-fill-seal packaging machine in which a web of heat-sealable flexible sheet packaging material is formed into tubing and the tubing is intermittently advanced in package length increments with a dwell interval between successive feed cycles, transverse seals constituting package end seals being formed across the tubing at said package length increments, the product with which the packages formed by the machine are to be filled being delivered endwise internally of the tubing, means for applying a length of tab material which is heat-sealable on at least one face thereof to the outside of each package length increment of the tubing with the heat-sealable face of the tab material facing the tubing, and means for effecting heat-sealing of the said length of tab material to the tubing over a portion only of the area of the said length of tab material to provide a tear tab on each package having a free portion adapted to be grasped and pulled to tear an opening in the package where the tab is sealed to the package, said means for applying said length of tab material including means for cutting said length from a continuous length of tape, and further comprising means for feeding the tape toward the tubing from a roll of the tape and forward in the direction of the length of the tubing, said cutting means being operable to cut off the end portion of the tape to form the said length of tab material, said applying means further comprising means for clamping the said end portion of the tape against the tubing and heat-sealing said end portion of the tape to the tubing during the dwell interval of the tubing between successive feed cycles, the cutting means being located to cut the tape a sufficient distance from the seal to provide the said free portion of the tab adapted to be grasped and pulled, and being operable after the said end portion of the tape has been heat-sealed to the tubing, said feeding means comprising means for enlarging a loop in the tape between the clamped end portion of the tape and the roll of tape.

Claim 4

In a form-fill-seal packaging machine in which a web of heat-sealable flexible sheet packaging material is formed into tubing and the tubing is intermittently advanced in package length increments with a dwell interval between successive feed cycles, transverse seals constituting package end seals being formed across the tubing at said package length increments, the product with which the packages formed by the machine are to be filled being delivered endwise internally of the tubing, means for applying a length of tab material which is heat-sealable on at least one face thereof to the outside of each package length increment of the tubing with the heat-sealable face of the tab material facing the tubing, and means for effecting heat-sealing of the said length of tab material to the tubing over a portion only of the area of the said length of tab material to provide a tear tab on each package having a free portion adapted to be grasped and pulled to tear an opening in the package where the tab is sealed to the package, said means for applying said length of tab material including means for cutting said length from a continuous length of tape, and further comprising means for feeding the tape toward the tubing from a roll of the tape and forward in the direction of the length of the tubing, said cutting means being operable to cut off the end portion of the tape to form the said length of tab material, said applying means further comprising means for clamping the said end portion of the tape against the tubing and heat-sealing said end portion of the tape to the tubing during the dwell interval of the tubing between successive feed cycles, the cutting means being located to cut the tape a sufficient distance from the seal to provide the said free portion of the tab adapted to be grasped and pulled, and being operable after the said end portion of the tape has been heat-sealed to the tubing, said feeding means comprising means for enlarging a loop in the tape between the clamped end portion of the tape and the roll of tape.

Claim 5

In a form-fill-seal packaging machine having means around which a web of heat-sealable flexible sheet packaging material is formed into tubing and having vertically reciprocating end sealer bars for forming transverse seals constituting package end seals across the tubing at package length increments, said bars closing at the upper end of their stroke and pulling the tubing down one package length on each downstroke, and opening for their upstroke, the tubing dwelling during the upstroke, the product with which the packages formed by the machine are to be filled being delivered to the lower end of the tubing during intervals between the formation of successive end seals, means for applying tear tabs to the tubing at package length increments so that each package has a tear tab, said applying means comprising a lever pivoted intermediate its ends for rocking movement with one end of the lever constituting its inner end adjacent the tubing, means at the outer end of the lever for supporting a roll of tab-forming tape which is heat-sealable at least on one face thereof, means at the inner end of the lever for guiding the tape forward adjacent the tubing with an end portion of the tape extending beyond said guide means, means for rocking the lever between a first position wherein the guide means is advanced and a second position wherein the guide means is retracted, means for clamping said end portion of the tape against the tubinG and heat-sealing it to the tubing, and means for cutting off said end portion of the tape.

Claim 6

In a form-fill-seal packaging machine having means around which a web of heat-sealable flexible sheet packaging material is formed into tubing and having vertically reciprocating end sealer bars for forming transverse seals constituting package end seals across the tubing at package length increments, said bars closing at the upper end of their stroke and pulling the tubing down one package length on each downstroke, and opening for their upstroke, the tubing dwelling during the upstroke, the product with which the packages formed by the machine are to be filled being delivered to the lower end of the tubing during intervals between the formation of successive end seals, means for applying tear tabs to the tubing at package length increments so that each package has a tear tab, said applying means comprising a lever pivoted intermediate its ends for rocking movement with one end of the lever constituting its inner end adjacent the tubing, means at the outer end of the lever for supporting a roll of tab-forming tape which is heat-sealable at least on one face thereof, means at the inner end of the lever for guiding the tape forward adjacent the tubing with an end portion of the tape extending beyond said guide means, means for rocking the lever between a first position wherein the guide means is advanced and a second position wherein the guide means is retracted, means for clamping said end portion of the tape against the tubinG and heat-sealing it to the tubing, and means for cutting off said end portion of the tape.

Claim 7

In a form-fill-seal packaging machine as set forth in claim 3, said clamping and heat-sealing means comprising a carriage movable toward and away from the tubing, a clamp jaw for clamping said end portion of the tape against the tubing, said jaw being carried by the carriage for movement relative to the carriage toward and away from the carriage, means biasing the jaw to an extended position away from the carriage, said jaw having an opening therein and being yieldable back toward the carriage against the bias, and a heat-seal member carried by the carriage in line with said opening, the forward end of said member being engageable with the tubing via said opening on yielding back of said jaw relative to the carriage against the bias.

Claim 8

In a form-fill-seal packaging machine as set forth in claim 4, said cutting means comprising a fixed shear blade spaced from said jaw, and a movable cutter blade cooperable with said fixed blade to cut the tape spaced from said jaw.