US 4,162,599 AGranted

Vacuum packaging

AssigneeC. A. Pemberton & Co. Limited

InventorRhoden R. Kyle

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Abstract

In a vacuum packaging machine there is provided the combination of a sealing unit and vacuum unit. The sealing unit comprises first and second sealing dies and the vacuum unit comprises a primary spacer located adjacent the input end of the sealing dies. The primary spacer is spaced from the first die to form a first web feeding passage therebetween and is spaced from the second die to form a second web feeding passage therebetween. The vacuum unit also includes a secondary spacer located adjacent the input end of the dies and mounted for movement between a retracted position permitting closure of the dies to effect sealing and an extended position maintaining at least a portion of the webs which passed through the first and second web feeding passages, in a spaced relationship to permit evacuation of the container space formed between the webs. A drive mechanism is provided for driving the secondary spacer to and fro between the retracted and extended positions and vacuum passages are provided in the vacuum drawing unit opening towards the sealing dies for communicating with the interior of a packaging space when the secondary spacers are in the extended position to maintain the webs in a spaced relationship whereby atmosphere from the container space may be withdrawn through the vacuum passage means prior to sealing of the webs.

In combination, a sealing unit and a vacuum unit for use in a vacuum packaging machine in which a container spaced formed between oppositely disposed sealing faces have a pair of sealable webs is to be evacuated before the webs are sealed together about the periphery of the container space, said sealing unit comprising;

(a) first and second sealing dies mounted one on either side of a sealing plane for movement relative to one another between an open position to permit movement of a package forming web assembly therebetween and a closed position for engaging and sealing said web assembly, said sealing unit having an input end for receiving web to be sealed between said dies and an output end through which sealed packages are discharged;
said vacuum unit comprising;
(b) primary spacer means located adjacent said input end of said sealing dies, said primary spacer means being spaced from said first die to form a first web feeding passage therebetween and spaced from said second die to form a second web feeding passage therebetween whereby said primary spacer means is located between oppositely disposed sealing faces of webs being fed into said dies through said first and second web feeding passages,
(c) secondary spacer means located adjacent said input end of said dies and mounted for movement between a retracted position permitting closure of the dies to effect sealing and an extended position maintaining at least a portion of the webs in a spaced relationship to permit evacuation of the container space formed therebetween,
(d) means for driving said secondary spacer means to and fro between said retracted and extended positions,
(e) vacuum passage means in said vacuum drawing unit opening towards said sealing dies for communicating with the interior of a packaging space when said secondary spacer means is in said extended position to maintain said webs in a spaced relationship whereby atmosphere from the container space may be withdrawn through said vacuum passage means prior to sealing of the webs.

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Abstract

Claims8