초록 ▼

A modular reciprocating heat seal jaw assembly is disclosed for sealing reclosable fastener strips to a web of thermoplastic film and for sealing the web of thermoplastic film into a series of reclosable bags. The jaw assembly includes first and second sealing jaws and means for slidably mounting th

A modular reciprocating heat seal jaw assembly is disclosed for sealing reclosable fastener strips to a web of thermoplastic film and for sealing the web of thermoplastic film into a series of reclosable bags. The jaw assembly includes first and second sealing jaws and means for slidably mounting the first and second sealing jaws on a first pair of parallel shafts near the lateral ends of the first and second sealing jaws in a horizontal configuration. A mechanical system is providing for selectively effecting reciprocal movement of the first and second sealing jaws together and apart as required. A modular frame is provided for supporting the first and second sealing jaws and the first and second pairs of parallel shafts and for maintaining the lateral and vertical position of the first and second sealing jaws as they are moved toward or away from each other. The modular frame and heat seal jaw assembly may be inserted into existing form-fill-seal machine to make them more efficient and accurate. An additional feature of the invention is the use of third and fourth sealing jaws constructed and arranged for sealing the reclosable fastener strips to the back wall of a web of thermoplastic film. A second mechanism is provided for selectively effecting reciprocal movement of the third and fourth sealing jaws together and apart as required to seal the fastener strips to the web of thermoplastic film. A pair of air cylinders is provided having drive shafts extending therefrom for providing mechanical force to move the first and second sealing jaws and the third and fourth sealing jaws as required. A unique mechanical drive system simultaneously advances the first and second sealing jaws together or apart in opposite movement to the third and fourth sealing jaw members, so as to either cross seal the web of thermoplastic film into a series of reclosable bags or to seal the reclosable fastener strips to the thermoplastic film as required. A method of performing the sealing of the reclosable fastener strips and web thermoplastic film into a series of reclosable bags is also disclosed.

대표청구항 ▼

The invention claimed is: 1. A modular reciprocating heat seal jaw assembly for sealing a series of reclosable fastener strips to a web of thermoplastic film and for sealing said web of thermoplastic film into a series of reclosable bags, said jaw assembly comprising: a first sealing jaw having a f

The invention claimed is: 1. A modular reciprocating heat seal jaw assembly for sealing a series of reclosable fastener strips to a web of thermoplastic film and for sealing said web of thermoplastic film into a series of reclosable bags, said jaw assembly comprising: a first sealing jaw having a first and second lateral end; a second sealing jaw having a first and second lateral end; means for slidably mounting said first sealing jaw on a first pair of parallel shaft members, proximate to and perpendicular to said first and second lateral ends of said first sealing jaw, said shaft members being disposed in a substantially horizontal plane; means for slidably mounting said second sealing jaw on said first pair of parallel shaft members proximate to and perpendicular to said first and second lateral ends of said second sealing jaw; means for selectively effecting reciprocal movement of said first and second sealing jaws together and apart, as required; and modular frame means for supporting said first and second sealing jaws and said first pair of parallel shaft members, and for maintaining a lateral and vertical position of said first and second sealing jaws; and wherein said means for selectively effecting reciprocal movement of said first and second sealing jaws together and apart comprises a reciprocal drive mechanism; and a first drive shaft extending laterally from said reciprocal drive mechanism, said first drive shaft having a first end and a second end; and wherein said reciprocal drive mechanism comprises: a first right rotating drive arm having a midpoint, a first distal end and a second distal end, wherein said first end of said first drive shaft is fixedly attached proximate said midpoint of said first right rotating drive arm so as to allow selective rotation of said first right rotating drive arm; a first left rotating drive arm having a midpoint, a first distal end and a second distal end, wherein said second end of said first drive shaft is fixedly attached proximate said midpoint of said first left rotating drive arm so as to allow selective rotation of said first left rotating drive arm; a first right outer linear drive arm having a proximal end and a distal end, wherein said first right outer linear drive arm is pivotally connected proximate said proximal end to said first right rotating drive arm proximate said first distal end thereof, and pivotally connected proximate said distal end to said first sealing jaw proximate said first lateral end thereof; and a first left outer linear drive arm having a proximal end and a distal end wherein said first left outer linear drive arm is pivotally connected proximate said proximal end to said first left rotating drive arm proximate said first distal end thereof, and pivotally connected proximate said distal end to said first sealing jaw proximate said second lateral end thereof; whereby rotation of said first drive shaft causes said first right and left outer linear drive arms to be selectively moved in the direction of said first sealing jaw, or pulled in the direction away from said first sealing jaw, causing said first sealing jaw to slide either towards or away from said second sealing jaw on said first pair of parallel shaft members. 2. The modular reciprocating heat seal jaw assembly of claim 1, wherein said reciprocal drive mechanism further comprises: a first right inner linear drive arm having a proximal end and a distal end, wherein said first right inner linear drive arm is pivotally connected proximate said proximal end to said first right rotating drive arm proximate said second distal end thereof, and pivotally connected proximate said distal end to said second sealing jaw proximate said first lateral end thereof; and a first left inner linear drive arm having a proximal end and a distal end, wherein said first left inner linear drive arm is pivotally connected proximate said proximal end to said first left rotating drive arm proximate said second distal end thereof pivotally connected proximate said distal end to said second sealing jaw proximate said second lateral end thereof; whereby rotation of said first drive shaft causes said first right and left inner linear drive arms to be selectively moved in the direction of or in the direction away from said second sealing jaw along said first pair of parallel shaft members simultaneously with and opposite to said movement of said first right and left outer linear drive arms, thereby selectively bringing said first and second sealing jaws together and apart, as required. 3. The modular reciprocating heat seal jaw assembly of claim 2, wherein said reciprocal drive mechanism comprises a first air cylinder having a plurality of air lines extending therefrom and connected thereto at a first and second connector and a source of pressurized air connected to said plurality of air lines; said first air cylinder being constructed and arranged to rotate said first drive shaft in a first desired direction for a selected degree of rotation when said source of pressurized air is introduced into said first connector and for rotating said first drive shaft in the opposite direction and to an opposite degree of rotation when said source of pressurized air is introduced into said second connector, thereby causing said first right and left outer and inner linear drive arms to effect horizontal movement of said first and second sealing jaws so as to bring said first and second sealing jaws together and apart, as required. 4. The modular reciprocating heat seal jaw assembly of claim 1 and further comprising: a second pair of parallel shaft members disposed in a substantially horizontal plane parallel to said first pair of parallel shaft members; a third sealing jaw having a first and second lateral end; a fourth sealing jaw having a first and second lateral end; means for selectively effecting reciprocal movement of said third and fourth sealing jaws together and apart, as required; said second pair of parallel shaft members being attached to said third and fourth sealing jaws proximate said first and second lateral ends thereof whereby greater stability is provided during movement of said third and fourth sealing jaws and greater precision is provided in positioning of said third and fourth sealing jaws during sealing of said series of reclosable fastener strips to said web of thermoplastic film. 5. The modular reciprocating heat seal jaw assembly of claim 4, wherein said means for selectively effecting reciprocal movement of said third and fourth sealing jaws comprises: a second air cylinder having a plurality of air lines extending therefrom and connected thereto at a third and fourth connector, and a source of pressurized air connected to said plurality of air lines; a second drive shaft extending laterally from said second air cylinder, said second drive shaft having a first end and a second end; a second right rotating drive arm having a midpoint a first distal end and a second distal end, wherein said first end of said second drive shaft is fixedly attached proximate said midpoint of said second right rotating drive arm so as to allow selective rotation of said second right rotating drive arm; a second left rotating drive arm having a midpoint, a first distal end and a second distal end, wherein said second end of said second drive shaft is fixedly attached proximate said midpoint of said second left rotating drive arm so as to allow selective rotation of said second left rotating drive arm; a second right outer linear drive arm having a proximal end and a distal end, wherein said second right outer linear drive arm is pivotally connected proximate said proximal end to said second right rotating drive arm proximate said first distal end thereof, and pivotally connected proximate said distal end to said third sealing jaw proximate said first lateral end thereof; a second left outer linear drive arm having a proximal end and a distal end, wherein said second left outer linear drive arm is pivotally connected proximate said proximal end to said second left rotating drive arm proximate said first distal end thereof, and pivotally connected proximate said distal end to said third sealing jaw proximate said second lateral end thereof; a second right inner linear drive arm having a proximal end and a distal end, wherein said second right inner linear drive arm is pivotally connected proximate said proximal end to said second right rotating drive arm proximate a second distal end thereof, and pivotally connected proximate said distal end to said fourth sealing jaw proximate said first lateral end thereof; and a second left inner linear drive arm having a proximal end and a distal end, wherein said second left inner linear drive arm is pivotally connected proximate said proximal end to said second left rotating drive arm proximate said second distal end thereof, and pivotally connected proximate said distal end to said fourth sealing jaw proximate said second lateral end thereof; said second air cylinder being constructed and arranged to rotate said second drive shaft in a first desired direction for a selected degree of rotation when said source of pressurized air is introduced into said third connector and for rotating said second drive shaft in the opposite direction and to an opposite degree of rotation when said source of pressurized air is introduced into said fourth connector, thereby causing said second right and left outer linear drive arms to effect horizontal movement of said third sealing jaw and said second right and left inner linear drive arms to effect horizontal movement of said fourth sealing jaw so as to bring said third and fourth sealing jaws together and apart, as required. 6. The modular reciprocating heat seal jaw assembly of claim 5, wherein said pivotal connections of said third sealing jaw to said second right and left outer linear drive arms comprises: a third and fourth ball joint respectively mounted proximate said first and second lateral ends of said third sealing jaw, said second right outer linear drive arm being pivotally connected to said third ball joint proximate said distal end of said second right outer linear drive arm, and said second left outer linear drive arm being pivotally connected to said fourth ball joint proximate said distal end of said second left outer linear drive arm. 7. The modular reciprocating heat seal jaw assembly of claim 6 further comprising: a third spring member extending axially from said third ball joint; a fourth spring member extending axially from said fourth ball joint; whereby said second right outer linear drive arm extends through said third ball joint and through said third spring member; whereby said second left outer linear drive arm extends through said fourth ball joint and through said fourth spring member; and a lock nut threadably attached to each of said second right and left outer linear drive arms proximate said distal end, thereof whereby said second right and left outer linear drive arms are fixedly connected respectively to said third and fourth ball joints, but are vertically and horizontally pivotable therein. 8. The modular reciprocating heat seal jaw assembly of claim 7, wherein each of said third and fourth ball joints further comprises shock absorber means for substantially affixing the axial position of said second right and left outer linear drive arms while allowing pivotal movement thereof and absorption of shock during reciprocal movement of said third and fourth sealing jaws. 9. The modular reciprocating heat seal jaw assembly of claim 4, wherein said third and fourth sealing jaws are sized, constructed and arranged for sealing said series of said reclosable fastener strips to a side of said web of thermoplastic film. 10. The modular reciprocating heat seal jaw assembly of claim 4 further comprising a vertical form-fill-seal machine for forming said web of thermoplastic film into said series of reclosable bags, each reclosable bag of said series of reclosable bags having a reclosable fastener strip of said series of reclosable fastener strips contained therein and heat sealed thereto. 11. The modular reciprocating heat seal jaw assembly of claim 10, wherein said web of thermoplastic film has a first side wherein said series of reclosable fastener strips are sequentially sealed thereon in bag-length intervals; said vertical form-fill-seal machine comprising means for forming said web of thermoplastic film into a tube, said tube having an inside surface and another inside surface, said tube further having said series of reclosable fastener strips sealed to said inside surface of said tube; and said third and fourth sealing jaws are sized, constructed and arranged to seal an unsealed side of said reclosable fastener strip of said series of reclosable fastener strips to said another inside surface of said tube. 12. The modular reciprocating heat seal jaw assembly of claim 11, wherein each of said third and fourth sealing jaws comprises: a pair of rectangularly shaped, vertical side seal surfaces, each side surface being sized, disposed and separated by a sufficient distance to seal lateral flanges of said at least said unsealed side of said reclosable fastener strip of said series of fastener strips to said another inside surface of said tube without interfering with interlocking and disengaging of closure members of said reclosable fastener strip of said reclosable fastener strips; and a pair of rectangularly shaped, horizontal seal surfaces, each horizontal seal surface being sized, disposed and separated at a sufficient distance to seal longitudinal flanges of said at least said unsealed sides of said reclosable fastener strip of said series of reclosable fastener strips to said another inside surface of said tube without interfering with interlocking and disengaging of said closure members; whereby, when said third and fourth sealing jaws are brought together by said means for selectively effecting reciprocal movement of said third and fourth sealing jaws and said third and fourth sealing jaws are heated, at least said unsealed side of said reclosable fastener strip of said series of fastener strips are sealed to said another inside surface of said tube. 13. The modular reciprocating heat seal jaw assembly of claim 12, wherein said third and fourth sealing jaws are moved by said means for selectively effecting reciprocal movement of said third and fourth sealing jaws to a position in contact with each other, and to exert a force of 150 pounds, plus or minus 50 pounds, of pressure against each other. 14. The modular reciprocating heat seal jaw assembly of claim 4 and further comprising means for forming said web of thermoplastic film into a reclosable bag of said series of reclosable bags. 15. The modular reciprocating heat seal jaw assembly of claim 4 and further comprising: a perforation knife fixedly attached to at least one of said third and fourth sealing jaws for perforating said web of thermoplastic film, so as to allow access to a reclosable fastener strip of said series of reclosable fastener strips within a reclosable bag of said series of reclosable bags, thereby allowing separation of closure elements of said reclosable fastener strip and access to an interior of said reclosable bag. 16. The modular reciprocating heat seal jaw assembly of claim 4, wherein said means for selectively effecting reciprocal movement of said third and fourth sealing jaws comprises: a second drive shaft, said second drive shaft having a first end and a second end; a second right rotating drive arm having a midpoint, a first distal end and a second distal end, wherein said first end of said second drive shaft is fixedly attached proximate said midpoint of said second right rotating arm so as to allow selective rotation of said second right rotating drive arm; a second left rotating drive arm having a midpoint, a first distal end and a second distal end, wherein said first end of said second drive shaft is fixedly attached proximate said midpoint of said second left rotating drive arm so as to allow selective rotation of said second left rotating drive arm; a second right outer linear drive arm having a proximal end and a distal end, wherein said second right outer linear drive arm is pivotally connected proximate said proximal end to said second right rotating drive arm proximate said first distal end thereof and proximate said distal end to said third sealing jaw proximate said first lateral end thereof; a second left outer linear drive arm having a proximal end and a distal end, wherein said second left outer linear drive arm is pivotally connected proximate said proximal end to said second left rotating drive arm proximate said first distal end thereof, and pivotally connected proximate said distal end to said third sealing jaw proximate said second lateral end thereof; a second right inner linear drive arm having a proximal end and a distal end, wherein said second right inner linear drive arm is pivotally connected proximate said proximal end to said second right rotating drive arm proximate a second distal end thereof, and pivotally connected proximate said distal end to said fourth sealing jaw proximate said first lateral end thereof; and a second left inner linear drive arm having a proximal end and a distal end, wherein said second left inner linear drive arm is pivotally connected proximate said proximal end to said second left rotating drive arm proximate said second distal end thereof, and pivotally connected proximate said distal end to said fourth sealing jaw proximate said second lateral end thereof; said means for selectively effecting reciprocal movement being constructed and arranged to rotate said second drive shaft in a first desired direction for a selected degree of rotation, and for rotating said second drive shaft in the opposite direction and to an opposite degree of rotation as required, thereby causing said second right and left outer linear drive arms to effect horizontal movement of said third sealing jaw and said second right and left inner linear drive arms to effect horizontal movement of said fourth sealing jaw so as to bring said third and fourth sealing jaws together and apart, as required. 17. The modular reciprocating heat seal jaw assembly of claim 1, wherein said means for selectively effecting reciprocal movement of said first and second sealing jaws together and apart comprises reciprocating said first and second sealing jaws between a first abutting position in which said web of thermoplastic film is cross sealed and a second separated position which allows said web of thermoplastic film to be advanced between said first and second sealing jaws. 18. The modular reciprocating heat seal jaw assembly of claim 1, wherein said pivotal connections of said first sealing jaw to said first right and left outer linear drive arms comprise: a first and second ball joint respectively mounted proximate said first and second lateral ends of said first sealing jaw said first right outer linear drive arm being pivotally connected to said first ball joint proximate said distal end of said first right outer linear drive arm, and said first left outer linear drive arm being pivotally connected to said second ball joint proximate said distal end of said first left outer linear drive arm. 19. The modular reciprocating heat seal jaw assembly of claim 18 further comprising: a first spring member extending axially from said first ball joint; a second spring member extending axially from said second ball joint; whereby first right outer linear drive arm extends through said first ball joint and through said first spring member, whereby said first left outer linear drive arm extends through said second ball joint and through said second spring member; and a lock nut threadably attached to each of said first right and left outer linear drive arms proximate said distal ends thereof whereby said first right and left outer linear drive arms are fixedly connected respectively to said first and second ball joints, but are vertically and horizontally pivotable therein. 20. The modular reciprocating heat seal jaw assembly of claim 18, wherein each of said first and second ball joints further comprises shock absorber means for substantially affixing the axial position of said first right and left outer linear drive arms while allowing pivotal movement thereof and absorption of shock during reciprocal movement of said first and second sealing jaws. 21. The modular reciprocating heat seal jaw assembly of claim 1, wherein each of said first right and left outer linear drive arms comprises a first, rectangular section and a second, rod-shaped section extending axially away from said first, rectangular portion, each of said first right and left outer linear drive arms farther comprises a bore extending through a respective one of said first, rectangular sections and a fastening means extending through said bore for rotatably connecting said respective one of said first, rectangular sections to a respective one of said first right and left rotating drive arms proximate said first distal end of said respective one of said first right and left rotating drive arms. 22. The modular reciprocating heat seal jaw assembly of claim 21, wherein said fastener means comprises a bolt extending through said bore and through a corresponding bore in a side of said respective one of said first right and left rotating drive arms proximate said first distal end thereof, said bolt having a head thereon for retaining said bolt in said bore and a lock nut attached proximate a distal end of said bolt, said lock nut being disposed on an inner surface of said respective one of said first right and left rotating drive arms proximate said first distal end thereof for rotatably connecting by means of said lock nut and said bolt each of said first right and left outer linear drive arms to said respective one of said right and left rotatable drive arms. 23. The modular reciprocating heat seal jaw assembly of claim 1, wherein said means for slidably mounting said first and second sealing jaws on said first pair of parallel shaft members comprises: a plurality of sleeve bearings laterally disposed on said first and second sealing jaws, each of said sleeve bearings also being coaxially disposed about one shaft member of said first pair of parallel shaft members whereby said first and second sealing jaws are slidably supported and maintained in parallel to each other as they are advanced together and apart. 24. The modular reciprocating heat seal jaw assembly of claim 1 and further comprising: wire members connected to said first and second sealing jaws; an electric power source connected to said wire members for providing means to heat said first and second sealing jaws; and temperature control means connected to said electric power source and said wire members for measuring the temperature of said first and second sealing jaws, heating said first and second sealing jaws and maintaining said first and second sealing jaws at a desired temperature. 25. The modular reciprocating heat seal jaw assembly of claim 1 and further comprising a plurality of pillow block bearings on said modular frame means having said first drive shaft extending rotatably through one of the pillow block bearings for supporting said first drive shaft during rotation. 26. The modular reciprocating heat seal jaw assembly of claim 1, wherein said first and second sealing jaws are sized, constructed, and arranged for cross sealing said web of thermoplastic film so as to facilitate forming said series of reclosable bags therefrom.