Packaging machine and method of forming packages

Claim 1

An apparatus for evacuating a sealed package formed of two opposite sheets of flexible material capable of being heat sealed and for sealing said package, comprising: a frame, a heat-sealing device carried by said frame and having two sections disposed opposite each other and movable toward each other, one of said sections constituting a suction head, the other of said sections having a pair of wells for holding one sheet of said flexible material with a load of product in each well and a partition extending between said wells against which a portion of the lastmentioned sheet engages, a knife means disposed in and immovable relative to said suction head and overlying said partition at a distance therefrom and adapted to pierce the other of said sheets upon subjecting said other sheet to movement toward the knife means by a suction effect from said suction head, vacuum means connected with said suction head to apply suction thereto to cause the other sheet to move toward said knife means to form a pierced opening in said other sheet and to exhaust air from between said sheets, vacuum means connected to the other of said sections to hold said one sheet against the partition and prevent movement and piercing thereof, and a heat-sealing mEmber disposed in and reciprocable in said suction head and overlying said partition for movement between a retracted position and an extended sealing position pressing both said sheets against said partition, said heat-sealing member being adapted to heat seal said sheets in an area surrounding said pierced opening when in said sealing position.

Claim 2

An apparatus for evacuating a sealed package formed of two opposite sheets of flexible material capable of being heat sealed and for sealing said package, comprising: a frame, a heat-sealing device carried by said frame and having two sections disposed opposite each other and movable toward each other, one of said sections constituting a suction head, the other of said sections having a pair of wells for holding one sheet of said flexible material with a load of product in each well and a partition extending between said wells against which a portion of the lastmentioned sheet engages, a knife means disposed in and immovable relative to said suction head and overlying said partition at a distance therefrom and adapted to pierce the other of said sheets upon subjecting said other sheet to movement toward the knife means by a suction effect from said suction head, vacuum means connected with said suction head to apply suction thereto to cause the other sheet to move toward said knife means to form a pierced opening in said other sheet and to exhaust air from between said sheets, vacuum means connected to the other of said sections to hold said one sheet against the partition and prevent movement and piercing thereof, and a heat-sealing mEmber disposed in and reciprocable in said suction head and overlying said partition for movement between a retracted position and an extended sealing position pressing both said sheets against said partition, said heat-sealing member being adapted to heat seal said sheets in an area surrounding said pierced opening when in said sealing position.

Claim 8

An apparatus for sealing and evacuating a package formed from two opposite sheets of heat sealable flexible material comprising, a pair of relatively movable parts having means at their perimeter for engaging and sealing the sheets together to form a perimeter seal for the package, one of said parts constituting a sealing head and the other part constituting a package-holding head, said package-holding head having a support member against which a portion of one sheet of said material engages, vacuum means connected to said package-holding head for holding said package against movement and said sheet portion against the support member during evacuation of the package, said suction head having a slitting knife overlying and spaced from said support member, vacuum means connected to said suction head to draw a part of the other sheet of material away from said one sheet and form an evacuation opening therein and then evacuate the package through said opening, and heat sealing means movable past the knife and toward the support member to return said other sheet into engagement with said one sheet and heat seal the sheets together by pressure against said support member.

Claim 9

An apparatus for sealing and evacuating a package formed from two opposite sheets of heat sealable flexible material comprising, a pair of relatively movable parts having means at their perimeter for engaging and sealing the sheets together to form a perimeter seal for the package, one of said parts constituting a sealing head and the other part constituting a package-holding head, said package-holding head having a support member against which a portion of one sheet of said material engages, vacuum means connected to said package-holding head for holding said package against movement and said sheet portion against the support member during evacuation of the package, said suction head having a slitting knife overlying and spaced from said support member, vacuum means connected to said suction head to draw a part of the other sheet of material away from said one sheet and form an evacuation opening therein and then evacuate the package through said opening, and heat sealing means movable past the knife and toward the support member to return said other sheet into engagement with said one sheet and heat seal the sheets together by pressure against said support member.