Claims
- 1. The method of serially forming sealed containers comprising the steps of: intermittently advancing a series of open topped containers along a horizontal processing path; positioning a closure means in sealing engagement with the open top of each container, so that a seam is provided at a level between each closure means and its container; providing a supply of heat shrinkable thermoplastic tape having a tacky side and a non-tacky side; intermittently feeding along a tape path predetermined lengths of tape from said supply each length having a dimension greater than the peripheral dimension of said container at the level of said seam; said feeding operation includes the steps of applying a transverse force to each tape length by drawing a portion of each tape by suction adjacent one end thereof during dwell periods of tape advancement to deflect a portion of said tape length out of said tape path and place adjacent portions of the tacky side of the tape in face-to-face relationship with respect to one another in a tab formation chamber located in back the non-tacky side of said tape along said tape path; compressing the facing adjacent portions of each tape segment toward and into surface-to-surface adherent engagement with one another in said tab formation chamber during said dwell periods to form a tab; feeding each length of tape with said tab between a feed roll and a tape wrapping head with the tacky side thereof facing said feed roll; and severing each tape length from the supply of tape outwardly of said tab to provide a tape segment having a free tape end beyond said tab; elevating said container to position its seam in a tangential relationship with respect to said tape wrapping head and wrapping each tape segment after the feeding operation about a container at the level of its seam, with the tacky side of said tape facing said container during a dwell period of container advancement by rotating the container about its own axis, whereby said tape segment is positioned in adhesive engagement with a container and its closure means, and said free end is positioned in overlapping adhesive engagement with an opposite end of the tape segment, said folded portions defining an integral gripping tab to facilitate removal of said tape segment from said container and said free end preventing premature removal of said tape segment and applying heat to said tape during the rotation of the container to shrink the same into tight engagement with said container and closure means.
- 2. The method according to claim 1, wherein the heating step includes: providing a source of heated air; directing said heated air towards the tape on said container; and rotating said container so that the heated air is evenly applied to said tape on said container.
- 3. The method according to claim 1, wherein the step of feeding tape segments is performed by feeding said segments in interconnected end-to-end relationship, and further including: providing a cutter blade in said tape head; projecting said cutter blade outwardly from said tape head to sever a tape segment from said supply of tape.
- 4. The method according to claim 1 wherein said step of directing heated air is performed by discharging heated air along an arcuate path generally concentric with said container.
- 5. Apparatus for providing a secondary closure for open-top lidded containers comprising: intermittently driven conveyor means for moving filled open-topped containers along a horizontal path; means along said path for placing a lid in the open top of each of said filled containers to thereby form a primary closure, said lids having a downwardly extending peripheral skirt embracing the upper end of a container sidewall, thereby forming a seam between the lower end of the skirt and a container sidewall; a supply of heat-shrinkable thermoplastic tape having adhesive on only one side thereof; means for intermittently feeding tape from said supply along a tape feed path; a vacuum chamber adjacent said tape feed path, said vacuum chamber having an open side facing the non-adhesive side of said tape, a source of vacuum connected to said chamber for causing a U-shaped length of tape to be drawin into said chamber during dwell periods of tape advancement; plunger means mounted for movement in said chamber to press said U-shaped length of tape together causing the adhesive surface thereof to adhere to one another to form a tab; means for reciprocating said plunger means during dwell periods of tape advancement; means operable during dwell periods of container advancement for wrapping said tape around container such that a first portion of the tape is adhesively secured to the said downwardly extending peripheral skirt and a second portion of said tape is adhesively secured to the sidewall of the container; means for severing said tape from said supply at a location spaced from said tab and at a length sufficient to allow the tape to be wrapped around the containers and slightly overlap, such that the outer overlapping end is adhesively secured to an underlying portion of the tape; said wrapping means including a rotatable wrapping head; means at a fixed location for elevating a container to position its seam in tangential contact with said rotatable wrapping head; means for rotating said container about its own axis at said fixed location; said means for severing said tape is mounted within said rotatable wrapping head; and means for heat-shrinking the tape wrapped on the container into compressive engagement with said skirt and sidewall, whereby said heat-shrunken length of adhesively secured tape provides a secondary closure.
- 6. Apparatus according to claim 5, wherein said wrapping means includes feed roll means in contact with the adhesive side of said tape for guiding the non-adhesive side of said tape into engagement with the external cylindrical surface of said tape head, said tape head having a plurality of passageways therein extending radially outward and opening on said external cylindrical surface; a source of vacuum connected to said tape head; and means for intermittently rotating said tape head to establish communication between said vacuum source and said passageways, whereby said tape is removably attached to said tape head with the adhesive side of the tape facing outwardly for transfer of the tape onto a container.
- 7. Apparatus according to claim 6, wherein said severing means in said wrapping head further includes a cutter blade assembly pivotally mounted to said head; cam means fixedly positioned on said head; and cam follower means on said cutter blade assembly for causing the cutter blade assembly to sever the tape in response to the rotation of the head.
- 8. Apparatus according to claim 7, wherein said cam means is a cam member having an internal cam track, and said cam follower means is a roller projecting from said cutter blade assembly and into said track.
- 9. Apparatus according to claim 7, in which said cutter blade assembly includes a pivotally mounted arm having a cutter blade fixed thereon, said blade being movable along an arc having at least one of said passages on each side thereof, whereby the vacuum at the passages of each side of the cutter blade serve to positively hold the tape on opposite sides of the line of severance.
- 10. Apparatus according to claim 6, wherein said vacuum source is present over a substantial portion of the arc between the locations where the tape first engages the tape head and the container, a plurality of adjacent radial passageways being in communication with said vacuum source as said tape head moves along said arc.
- 11. Apparatus according to claim 10, wherein said wrapping means includes further passage means vented to atmosphere beyond the arc of said vacuum source to facilitate transfer of said tape from said tape head to a container.
- 12. Apparatus according to claim 10 wherein said feed roll is located adjacent said wrapping head in a position spaced circumferentially from a container, the external surface of said feed roll having means providing limited surface engagement with the adhesive side of said tape for feeding the non-adhesive side of said tape against the outer cylindrical surface of said wrapping head where the tape is held against a portion of the surface of said tape head by the suction force of the vacuum in said passageways.
- 13. Apparatus according to claim 6, further including a continuously revolving container rotating assembly.
- 14. Apparatus according to claim 13, wherein said means for intermittently rotating said tape head includes a single revolution clutch means connected to said tape head, and means for actuating the clutch means in response to movement of said container into engagement with said container rotating assembly.
- 15. Apparatus according to claim 14, wherein said single revolution clutch means includes a cam member having a stop surface thereon and a pivotally mounted cam follower having a detent thereon engageable with said stop surface for disengaging said clutch means, and said clutch actuating means includes means for pivoting said cam follower in response to movement of said container into engagement with said container rotating assembly.
- 16. Apparatus according to claim 5, wherein said heat-shrinking means includes a heating block located adjacent to the seam of a container when the container is positioned adjacent the tape wrapping means, said heating block having a plurality of air ports directed towards the tape on said container; means establishing communication between said air ports and a source of air; and said heating block including means for heating air flowing through said air ports.
Parent Case Info
This is a Continuation of application Ser. No. 575,537 filed May 8, 1975, now abandoned.
US Referenced Citations (11)
Continuations (1)
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Number |
Date |
Country |
Parent |
575537 |
May 1975 |
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