Abstract An automatic packaging machine makes hermetically sealed packages from which air has been exhausted by laminating two continuous sheets of packaging material. A roll of film on one end of the machine supplies a continuous support sheet to a chain belt conveyor which grips the opposite edges of the support sheet leaving the web unsupported, and transports this sheet the length of the machine. A vacuum forming die makes a plurality of receptacles in the support sheet in aligned longitudinal and transverse rows with transverse and longitudinal margins about the periphery of the receptacles. Another roll of film supplies a continuous cover sheet which is applied over the support sheet, the cover sheet being expediently severed longitudinally by a cutting blade in alignment with the inner longitudinal margins between the receptacles prior to application over the support sheet. The sheets are then heat sealed along the transverse margins. Subsequently, an evacuation unit heat seals the sheets along the outer longitudinal edge margins and an evacuation head exhausts the air from the receptacles through the evacuation opening advantageously provided by the severed cover sheet. A sealing bar in the evacuation head then closes the opening and the cover sheet is finally heat sealed to the support sheet in the areas adjacent the opening.
Packaging appaRatus for transporting continuous sheets of film with an unsupported web along the length of a packaging machine including; a pair of endless chain belts supported on the packaging machine by pairs of sprockets mounted in aligned, spaced relationship; said chain belts having a plurality of periodically spaced inwardly disposed clamps mounted along the opposing inner sides thereof; each of said clamps being mounted on said belts by a flange fastened to said chain belt on one end and having a lower jaw portion on the other end thereof; a generally C-shaped clip moveably mounted on said flange having an upper jaw portion cooperating with the lower jaw portion of said flange for engaging the sheet of packaging material therebetween; said generally C-shaped clip being obliquely mounted on said flange by an obliquely extending pin attached to the back of the C-shaped clip and slidably guided in a sleeve formed in said flange and said generally C-shaped clip being biased downwardly so that said upper jaw is normally held in engagement with said lower jaw; said generally C-shaped clip having an oblique contact surface engagable with a mating cam surface on the hub of said sprockets, engagement of said can surface with said clip contact surface causes the generally C-shaped clip to be moved upwardly on said flange in an inclined direction away from said lower jaw to allow the support sheet to be clamped without crimping.
Claim 2
Dependent Claim
238 words
Packaging appaRatus for transporting continuous sheets of film with an unsupported web along the length of a packaging machine including; a pair of endless chain belts supported on the packaging machine by pairs of sprockets mounted in aligned, spaced relationship; said chain belts having a plurality of periodically spaced inwardly disposed clamps mounted along the opposing inner sides thereof; each of said clamps being mounted on said belts by a flange fastened to said chain belt on one end and having a lower jaw portion on the other end thereof; a generally C-shaped clip moveably mounted on said flange having an upper jaw portion cooperating with the lower jaw portion of said flange for engaging the sheet of packaging material therebetween; said generally C-shaped clip being obliquely mounted on said flange by an obliquely extending pin attached to the back of the C-shaped clip and slidably guided in a sleeve formed in said flange and said generally C-shaped clip being biased downwardly so that said upper jaw is normally held in engagement with said lower jaw; said generally C-shaped clip having an oblique contact surface engagable with a mating cam surface on the hub of said sprockets, engagement of said can surface with said clip contact surface causes the generally C-shaped clip to be moved upwardly on said flange in an inclined direction away from said lower jaw to allow the support sheet to be clamped without crimping.