Packaging method and machine

Claim 2

A packaging machine for loosely packaging a manufactured article in an envelope composed of thermoplastic material, said packaging machine wherein the improvement comprises: a framework defining a sealing station; said framework having means for supplying sheets of thermoplastic material, said sheets being joined at the extremities thereof by heat responsive fusion; first conveying means being supported by said framework and being operative to convey an article to be packaged into engagement with said sheets of thermoplastic material and to further convey said article until said sheets are positioned above and below said article; opposed backing and sealing means carried by said framework adjacent said sealing station and being movable one relative to the other into compressive engagement with said sheets of thermoplastic material about an article positioned at said sealing station; said heat sealing means being heated by electrical resistance; means for injecting a coolant fluid into said heat sealing means for selectively cooling the same; means for injecting a gas into said heat sealing means for selectively ejecting said coolant fluid from said heat sealing means prior to each heating cycle of said sealing means; and second conveying means being supported by said framework and being operative to eject a completed package from said packaging machine.

Claim 3

A packaging machine as recited in claim 1, wherein: said means for supplying spaced sheets of thermoplastic material being rolls of continuous webs of thermoplastic material being rotatably supported by said framework; said sheets of thermoplastic material being withdrawn from said rolls by an article being conveyed to said heat sealing station; and means for severing a sealed package from said continuous webs of thermoplastic material simultaneously with seaing of said package.

Claim 4

A packaging machine as recited in claim 2, wherein: said means for severing a sealed package from said continuous webs of thermoplastic material comprises an element heated by electrical resistance; and said heated element being moved into cutting engagement with said webs of thermoplastic material on the upstream side of said package substantially simultaneously with sealing of said package.

Claim 5

A packaging machine as recited in claim 2: said sealing means having a generally ''''U''''-shaped tubular electrical resistance energized heating element for sealing two sides and the upstream end of a package disposed at said sealing station; said sealing means having a generally transverse tubular electrical resistance heating element for sealing the downstream end of a succeeding package substantially simultaneously with sealing the sides and upstream end of said package; and said means for severing being an electrical resistance heated element moving into severing engagement with said webs of thermoplastic material between the upstream end of a package at said sealing station and the downstream end of a succeeding package.

Claim 6

A packaging machine as recited in claim 1: said backing means comprisinG a backing frame having backing surface means disposed for engagement with said sheets of thermoplastic material; means supporting said backing frame and being operative to move said backing surface means into engagement with said sheets of thermoplastic material; said sealing means comprising a sealing frame; and electrical resistance heating element means carried by said sealing frame and disposed for compressive engagement of said sheets of thermoplastic material against said backing surface means.

Claim 7

A packaging machine as recited in claim 5, wherein said sealing element means comprises: a tubular electrical resistance energized heating element of generally ''''U''''-shaped configuration for sealing two sides and the upstream end of a package disposed at said sealing station; a transverse tubular electrical resistance energized heating element for sealing the downstream end of a succeeding package substantially with sealing the sides and upstream end of said package; and an electrical resistance energized heating element carried by said sealing frame and being moved into severing engagement with said sheets of thermoplastic material between the upstream end of said package and the downstream end of a succeeding package simultaneously with sealing of said package.

Claim 8

A packaging machine as recited in claim 2: brake means being carried by said framework and being operative to allow free rotation of said rolls during part of the packaging cycle and to retard rotation of said rolls during the remaining portion of said packaging cycle, said brake means comprising a brake disc being provided for each of said rolls, fluid motor means being disposed adjacent said discs and having brake shoes disposed in juxtaposed relation with said discs, and compressed gas means for energizing said fluid motor means and causing said brake shoes to retard rotation of said discs.

Claim 9

A packaging machine as recited in claim 2: means supplying a jet of compressed gas and directing the same to impinge upon said sheets of thermoplastic material and causing movement of said sheets toward said sealing station.

Claim 10

A packaging machine for loosely packaging a manufactured article in an envelope composed of thermoplastic material, said packaging machine comprising: a framework defining a sealing station; at least two rolls of thermoplastic sheet material being rotatably supported by said framework, said sheet material being at least in part withdrawn from said rolls by an article being conveyed to said sealing station and being joined by heat induced fusion; first conveyor means being supported by said framework and being operative to convey a bale of tacky polymer into engagement with said sheets of thermoplastic material; a backing frame being carried by said framework and having backing surface means defined thereon being disposed for support of said sheets of thermoplastic material; a sealing frame being supported by said framework and having a generally transverse tubular electrical resistance energized heat sealing element for sealing the downstream end of a succeeding package substantially with sealing the sides and upstream end of said package; means for injecting a coolant fluid into said heat sealing element for selectively cooling the same; means for injecting a gas into said heat sealing element for selectively ejecting said coolant fluid therefrom; and second conveying means being supported by said framework and being operative to eject a completed package from said packaging machine immediately following said sealing and severing operation.

Claim 11

A packaging machine for loosely packaging a manufactured article in an envelope composed of thermoplastic material, said packaging machine comprising: a framework defining a sealing station; at least two rolls of thermoplastic sheet material being rotatably supported by said framework, said sheet material being at least in part withdrawn from said rolls by an article being conveyed to said sealing station and being joined by heat induced fusion; first conveyor means being supported by said framework and being operative to convey a bale of tacky polymer into engagement with said sheets of thermoplastic material; a backing frame being carried by said framework and having backing surface means defined thereon being disposed for support of said sheets of thermoplastic material; a sealing frame being supported by said framework and having a generally transverse tubular electrical resistance energized heat sealing element for sealing the downstream end of a succeeding package substantially with sealing the sides and upstream end of said package; means for injecting a coolant fluid into said heat sealing element for selectively cooling the same; means for injecting a gas into said heat sealing element for selectively ejecting said coolant fluid therefrom; and second conveying means being supported by said framework and being operative to eject a completed package from said packaging machine immediately following said sealing and severing operation.

Claim 12

A packaging machine as recited in claim 9, wherein said sealing element means comprises: a tubular electrical resistance energized heating element of generally ''''U''''-shaped configuration for sealing two sides and the upstream end of a package disposed at said sealing station; a transverse tubular electrical resistance energized heatiNg element for sealing the downstream end of a succeeding package substantially simultaneously with sealing the sides and upstream end of said package; and an electrical resistance energized heating element carried by said sealing frame and being moved into severing engagement with said sheets of thermoplastic material between the upstream end of said package and the downstream end of a succeeding package.

Claim 15

A method according to claim 11 and including the method step of: severing said sheets of thermoplastic material to complete said package substantially simultaneously with energizing said heat sealing element.

Claim 16

A method according to claim 11 and including the method step of: severing said sheets of thermoplastic material subsequent to energizing said heat sealing element.