Plastic strapping machine

Claim 2

Plastic strapping apparatus comprising: base means including work platform means for supporting articles to be strapped and defining a joint-forming station; supply means for strapping material; first and second joint-forming heads mounted for convergible movement toward said station, said first head including strap-gripping means and said second head including guide means for controllably feeding strapping material from said supply means generally toward said station, one of said heads including nozzle means for directing a joint-forming agent against regions of the strapping material selected to form a joint; and passageway means mounted for connection with said nozzle means for transferring quantities of said joint-forming agent to said nozzle means.

Claim 3

Plastic strapping apparatus according to claim 1 wherein said passageway means and said nozzle means have complemental portions engageable upon convergence of said heads to form a continuous duct.

Claim 4

Plastic strapping apparatus according to claim 1 wherein said strapping is a thermoplastic material, said agent is a heated fluid and said passageway means and said nozzle means are of refractory material.

Claim 5

Plastic strapping apparatus according to claim 3 wherein said apparatus further includes heating element means in said passageway means.

Claim 6

Plastic strapping apparatus according to claim 1 wherein one of said heads includes pressure foot means and the other of said heads includes a backup member cooperatively opposing said pressure foot means to form a joint-forming assembly for compressibly confining therebetween regions of strapping material treated with said agent.

Claim 7

Plastic strapping apparatus according to claim 1 wherein said nozzle means includes a relatively large orifice preferentially exhausting said joint-forming agent for use in forming joints in said strapping material, a relatively small orifice and a conduit connecting said orifices; and wherein the other of said heads includes valve member means selectively positionable with respect to said relatively large orifice for closing the same and directing said agent to said relatively small orifice for use in severing said strapping material.

Claim 8

Plastic strapping apparatus according to claim 1 wherein said supply means includes a source of strapping material and strap-feeding means mounted in said base means for controllably advancing strapping material from said source toward said joint-forming station, said strap-feediNg means including selectively operable means having spaced drive elements for engaging said strapping material at the lateral edges thereof.

Claim 9

Plastic strapping apparatus comprising: base means including work platform means for supporting articles to be strapped and defining a joint-forming station; strap supply means including a source of strapping material and strap-feeding means mounted in said base means for controllably advancing strapping material from said source toward said joint-forming station, said strap-feeding means including selectively operable feeding means having spaced drive elements for engaging said strapping material at the lateral edges thereof; first and second joint-forming heads mounted for convergible movement toward said station, said first head including strap-gripping means and said second head including guide means for controllably feeding strapping material from said strap supply means toward said joint-forming station; and joint-forming means including a first member mounted in said base means and a second member mounted on one of said heads to cooperate with said first member in forming strapping joints.

Claim 10

Plastic strapping apparatus comprising: base means including work platform means for supporting articles to be strapped and defining a joint-forming station; strap supply means including a source of strapping material and strap-feeding means mounted in said base means for controllably advancing strapping material from said source toward said joint-forming station, said strap-feeding means including selectively operable feeding means having spaced drive elements for engaging said strapping material at the lateral edges thereof; first and second joint-forming heads mounted for convergible movement toward said station, said first head including strap-gripping means and said second head including guide means for controllably feeding strapping material from said strap supply means toward said joint-forming station; and joint-forming means including a first member mounted in said base means and a second member mounted on one of said heads to cooperate with said first member in forming strapping joints.

Claim 11

Plastic strapping apparatus according to claim 8 wherein said selectively operable feeding means comprises an endless member defining said drive elements and wherein said strap-feeding means further includes a selectively energizable clutch drivingly coupled to said endless member.

Claim 12

Plastic strapping apparatus according to claim 8 wherein said guide means includes spaced opposed spring blades grippingly engageable with said strapping material at the lateral edges thereof.

Claim 13

Plastic strapping apparatus according to claim 8 wherein said base means further includes spaced-apart package-elevating members mounted on said work platform means to define therebetween a channel for receiving strapping material draped about an item to be strapped whereby to relieve said strapping material of the weight of said item.