CA1095459A

CA1095459A - Patch-top containing a closure

Info

Publication number: CA1095459A
Application number: CA260,382A
Authority: CA
Inventors: Donald H. Ellerbrock
Original assignee: Boise Cascade Corp
Current assignee: Officemax Inc
Priority date: 1976-06-07
Filing date: 1976-09-02
Publication date: 1981-02-10
Also published as: MX144577A; DK474776A; GB1571938A; JPS52150183A; FR2353456A1; AU511659B2; DE2647775C3; IT1065375B; DE2647775A1; SE7610553L; BR7606652A; AU1801676A; NL7610080A; FR2353456B1; LU77044A1; DE2647775B2; BE852916A

Abstract

ABSTRACT OF THE DISCLOSURE

Closure means are disclosed for closing the reversely curled end of a composite container, including a synthetic plastic overcap member which is bonded in hermetically sealed relation with the container end, and is also removably connected with the container, whereby upon removal of the overcap member, the hermetic seal is automatically broken, the overcap member being adapted to be reapplied to the container to reclose the end thereof. In a first embodiment, the overcap member is directly bonded to the curled end of the container. In a second embodi-ment, a patch top member is arranged between the container and the overcap member, the patch top member being bonded to the container by a weaker first adhesive material to define an hermetic seal, and to the overcap member by a stronger second adhesive, whereby upon removal of the overcap member, the bond of the first material is broken and the patch top member is moved simultaneously with the overcap member. Anti-tampering means, such as a shrink-fit tape, may be provided with either embodiment to reduce the possibility of inadvertent removal of the overcap member.

Description

SPECIFICATION

Brief Description of the Prior Art . Patch top container and methods of making the same are . well known in the patented prior art, as evidenced, for example, by the patents to Asmus et al Nos. 3,501,045 and 3,734,044, and ~7 . ' ~ ~

- 2 --- --~
- -j 10954~3~

Johnson et al l~o. 3,892,351, and the ~3estphal et al Patent No.

3,961,566 (which is assigned to the same assignee as the instant invention).
In these prior patents, the end of a container (which is normally of the composite type including layers of paperboard, rOil, synthetic plastic material or the like) is closed by a relatively thin patch top member (normally formed from aluminum foil or the like). T~e patch top member is bonded to the con-tainer end ~for e~ample, by a heat sealable membrane, a hot melt adhesive, an ethylene vinyl acetate adhesive, or the like) to afford an hermetically sealed container. A reusable synthetic plastic overcap is then provided for protecting and maintaining in place the patch top member. As is conventional in the art, pull tab means are provided on the patch top members so that ~hen the plastic overcap is removed to expose the patch top, the pull tab portion of the patch top member may be manually grasped by the user to remove the patch top from, and thereby open, the container. The patch top member is then discarded, and the packaged contents may be removed from the container. If desired, the container may be reclosed by the reapplication of the plastic overcap to the container.

SVI~MARY OF THE INYENTION
_ .
In general terms, the present invention provides composite container closure means that are initially in a bonded condition to afford an hermetically sealed closure for the container, and which~are subsequently operable to afford means for reclosing the container. In one embodiment, the synthetic 1()95459 ;~ stic overcap member is dilectly bonded to tihe container end, an~ is also removably connected with the container for the reapplication thereto. In a second embodiJnent, a patch top member is bonded to the plastic overcap for simultaneous removal therewith. In this manner, the possibility of undesirab]e litter normally produced by the removal of the patch top member is eliminated, and since the patch top member is always protected and/or supported by the overcap member, it may be formed of a thinner gauge aluminum foil, ~hereby the cost Or the resulting O container is reduced. Furthermore, the necessity of providing pull tab me2ns on the patch top member and the manufacturing and assemb]ing considerations resulting therefrom are eliminated.
In a primary aspect of the present invention a ~-`
method and closure means for a container is provided, including .5 a synthetic plastic overcap member extending transversely across the reversely curled open end Or a composite container, means bonding the overcap member in hermetically sealed relation to the curled end, and means releasably connecting the overcap member with the body member, whereby when the overcap member is .0 rernoved from the body member end, the hermetically sealed bond is automatically broken and access ~s afforded to the interior of the container, whereupon the overcap member may be reapplied to close the container end. In a first embodiment, the synthetic plastic overcap member is directly bonded to the curled container ?5 end, said overcap member being provided with means for removably connecting the overcap with the container. In a second embodi-ment, the overcap is bonded to the container end by means of a patch top member which is bonded between the overcap and the container, respectivelY, said patch top being connected wi~th the overcap member for the simultaneous removal from the con-tainer therewith.

l~9~;~S9 According to anotheraspect ol the invention, a~ improved patch top container is provided including a patch top member seated across the open end of a container, a plastic overcap mounted on the contalner end in protective relationship above the patch top member, first adhesive means bonding the patch top member in hermetically sealed relation to the container end, and second adhesive means bonding ~he patch top member to the overcap member, the second adhesive means having a greater bonding strength than the first adhesive means, whereby the patch ) top member will be automatically removed from the container simultaneously with the plastic overcap member.
In accordance with a more specificfeature of the invention, the plastic overcap of either embodiment includes a central por-tion which extends slightly into the container end, and an intermediate portion containing an annular groove or recess which has a configuration which conforms generally to the inner circumferential surface of the container end. In the patch top embodiment, the patch top me~nber has a transverse central portion which is axially displaced from the extremity Or the container end, and an annular peripheral portion which is pressed in con-forming relation against the inner circumferential surface of the reversely curled portion of the container end.
In accordance with a further feature of the invention, the container is Or the composite container type including a fibrous body wall layer and at least one impervious liner layer, the end of the container being reversely outwardly curled to define a curled end portion. The plastic overcap member fur~her includes an annular flange portion that extends concentrically about the container end portion, said flange portion carrying on its inner O surface locking means which engage the container curled portion to retain the o~ercap on the container, and also to ~ias the overcap intermediate portion in a direction causing conforming en~agement of the patch top peripheral annular portio~ with the inner end surface of the container.
_ A further object of the invention is to provide a patch top container assembly of the type described above including tfimper-proof means for resisting the removal of the plastic overcap member ~rom the container; more particularly, a con-ventional s~rink tape member is shrunk-fit about the outer .
circumference of the end portion of the container across the juncture between the free end of the flange portion of the plasti overcap and the adjacent outer surface of the container.
Accor~ing to another f~ef the invention, a metho~ for forming a patch top container is provided which includes the steps of removably connecting an overcap member to the reversely curled end of a composite container, and bonding the overcap member to the container end to define an hermetic seal, whereby upon removal of the overcap, the seal is automatically broken, and the overcap may then be reapplied to the container. Accord-ing to an embodiment of the ~nvention, a patch top member is arranged between the container and overcap member, the patch top member being bonded to the container by a first adhesive material affording a relatively weak bond, and to the overcap member by a second adhesive material affording a relatively strong bond, whereby ~hen the overcap member is removed, the bond afforded by the first adhesive material is broken, and the patch top member is removed from the container simultaneously wit the overcap member. In either embod~iment, a synthetic plastic tape may be shrunk-fit about the ~unction between the f~ange portion of the overcap member and the outer surface o~ the ~X - 6 i~)954~5~

container, thereby to resist unintentional removal of the overcap member.

BRIE~ DE-SCRIPTION OF ~HE F~GURES

Other objects and advantages of the invention will become apparent from a study of the following specification when viewed ; in the light of the accompanying drawing, in which:

Fig. 1 is a detailed side elevational view of a composite container provided with the patch top closure means of the present invention;

Figs. 2 and 3 are side elevational and top plan views of the synthetic plastic overcap member of the embodi-; ment of Fig. l;

Fig.-4 is a detailed sectional view taken along line '

4-4 of Fig. 2;

Fig. 5 is a detailed sectional view of a modification of the invention of Fig. l;

Fig. 6 is a detailed sectional view of a second modi-fication Or the invention of Fig. 1;

Fig. 7 is a detailed sectional view of a second embodi-ment of the invention; and Fig. 8 is a detailed sectional view of a modification of the invention of Fig. 7.

ii~;459 DETAILED DESCRIPTION

Referring now more particularly to Fig. l, the container assembly includes a tubular composite body wall 2 having a fibrous body wall 2a to the inner and outer surfaces of which are bonded impervious inner and outer liner layers 2b and 2c, respectively, which are normally formed from relatively thin gauge aluminum foil. The open end of the container body wall is reversely curled to define the curled end portion 2d. Seated across the open end of the container body wall 2 is a patch top member 4 which is of a uniform disk-shaped configuration (i.e., without the pull-tab means normally provided on such patch top closure members) .
The patch top member normally includes a layer 4a of aluminum foil the inner and outer surfaces of which are coated with first and second layers of adhesive means 4b and 4c, respectively.
Mounted in protective relation upon the end of the con-tainer 2 above the patch top member 4 is an overcap member 6 which is preferably formed of a synthetic plastic material. The plastic overcap member 6 includes a central portion 6a which extends slightly within the container body wall 2, an intermediate portion 6b which contains a concave recess 8 for receiving the curled end portion 2d of the container, and a flange portion 6c that extends concentrically about the container end. As shown in Fig. l, the central portion 6a of the plastic overcap causes displacement of the central portion 4d of the patch top member axially within the container. The inner wall surface of the recess of the intermediate portion 6b of the plastic overcap con-forms generally with and is spaced from the configuration of the reversely curled end portion of the container body 2. Thus, the annular peripheral portion 4e of the patch top is caused to conform with the inner circumferential end portion of the container 2 by :10954~9 the curved wall portion of the recess 8 contained in the inter-mediate portion of the plastic overcap. Furthermore, in order to maintain the plastic overcap on the container, the flange portion 6c of the overcap member is provided on its inner surface with an annular locking rib 6d which extends in snap-fit relation beneath the lower extremity of the container curled end portion 2d.
Preferably the cavity or recess 8 is so dimensioned that the lock-ing of the rib 6d beneath the curled portion 2d causes the applica-tion of a biasing force in the direction indicated by the arrow F, which biasing force causes the peripheral annular portion 4e of the patch top member 4 to be maintained in conforming engagement with , the corresponding surface on the container end.
In accordance with the present invention, the second adhesive layer 4c for bonding the paich top 4 to the overcap 6 is stronger than the first adhesive layer 4b which adhesively bonds in an hermetically sealed manner the patch top member 4 to the container 2. Thus, the second adhesive layer 4c is selected which has a relatively high bonding strength, as for example, a heat-sealable layer of polyethylene, or the like. The first adhesive layer 4b is selected having a relatively low bonding strength, as, for example, a peelable hot melt adhesive, a layer of ethylene vinyl acetate, or a suitable pressure-sensitive adhesive layer. Although the first adhesive layer 4b has been illustrated as extending continuously across the inner surface of the patch top member, if desired it could be provided only adjacent the annular peripheral portion 4e of the patch top. In either case, the first adhesive layer provides an hermetiG seal for the container for the container contents.
In order to assist in ~e removal of the plastic overcap, there is provided a pull tab portion 6e which extends downwardly ~ 1095~59 ~ `

from the flange portion 6c longitudinally of the container, said pull tab portion containing an opening 6f. In order to resist removal of the plastic overcap from the container, tamper-proof means in the form of a shrink-fit tape 10 are provided, said tape being wound circumferentially about the container across the junction between the flange portion 6c of the overcap and the body wall 2 of the container, said shrink-fit tape including a pull tab portion 10a for the removal thereof from the container. The shrink-fit tape is conventional in the art (as evidenced, by the Minnesota Mining & Manufacturing shrink-fit tape No. Y6887).
Referring to Figs. 2-4, it will be seen that the synthetic plastic overcap member 6 -- which is preferably formed from low density polyethylene or the like -- is of flexible unitary molded con-struction. If desired, the upper surfacec~ the plastic overcap member may be provided with radially extending reinforcing ribs 6g.
It will be apparent from Fig. 4 that the recess 8 eontained in the intermediate portion 6b of the plastie overcap 6 has a configuratic n to conform with that of the curled end portion 2d of the container body 2.
l 1, OPERATION
In operation, to open the container package of Fig. 1, the pull tab portion 10a of the shrink-fit tape 10 is pulled to remove the tape from the eontainer package, whereupon the tab portion 6e of the plastie overcap is lifted to pull the overcap member 6 upwardly from the eontainer. During this removal of the plastie overcap member, the weaker adhesive bond 4b between the patch top 4 and the conforming portion of the inner circumferential surface of the eontainer end portion 2d is broken, so that the patch top 4 lQ~

is removed from the container 2 simultaneously with the removal of the plastic overcap member 6. The contents may then be removed from the container 2. In the event it should be desired to reclose the container, the plastic overcap member 6 -- with the patch top member 4 secured thereto -- is reapplied to the container 2 in the illustrated position with the locking rib 6b again extending in snap-fit relation beneath the curled container end portion 2d.
It is possible, of course, to further prevent litter by forming the removable shrink-fit tape lO from a suitable bio-degradable material, as is known in the art.
Referring now to the alternate embodiment of Fig. 5, it will be seen that the shrink-fit tape lO' may extend at its upper extremity lOa' upon the upper marginal portion of the plastic overcap member 6, thereby to more positively secure the overcap member to the composite body wall 2.
In accordance with the method of the present invention, the end portion of the composite containeris reversely outwardly curled in a conventional manner (for example, as illustrated in the Ellerbrock Patent No. 3,882,763). The patch top member 4 having the adhesive layers 4b and 4c thereon is preferably introduced into the plastic overcap (for example, during the punching operation by which the patch top member is formed from an aluminum foil sheet, as disclosed in the aforementioned Westphal et al Patent No. 3,961,566), and to ~e end of the container with the locking shoulder 6d extending in snap-fit relation beneath the lower extremity of the container reverse curl 2d. Thus, the central portion 4d of the patch top is dis-placed axially within the container and the peripheral annular portion 4e of the patch top is caused to conform with the inner 10954~9 circumferential surface of the curled end portion 2d of the container body member 2. The end of the container is then heated (for example, by conventional ultrasonic, induction or dielectric heating techni~ues) to effect bonding of the patch top member to the container and to the overcap member by the heat-responsive layers 4b and 4c, respectively. Thus, in the case where the second adhesive layer 4d comprises a layer of conventional hot melt material arranged at least on the peripheral annular portion of the patch top, the layer is softened by the application of heat to effect a bond between the patch top member and the container which is weaker than the bond between the patch top and the plastic overcap member. The shrink-fit tape 10 is then wound upon the container, and the container is passed through a separate oven to effect shrinking of the tape in tight engagement across the juncture between the lower edge of the flange portion 6c and the outer surface of the container body. The overcap member is thus connected against inadvertent displacement relative to the con-tainer.
Of course, various means may be provided for applying the first and second layers of adhesive. For example, the second layer of adhesive 4d could be coated on the inner circumferential surface of the reversely curled portion 2d prior to the mounting of the patch top 4 upon the open end of the container. Further-more, it might be desirable to bond the patch top member 4 to the plastic overcap member 6 prior to the assembly of the plastic overcap 6 upon the curled end portion 2d of the container 2.
Finally, as shown in Fig. 5, the central portions of the overcap and patch top members 6 and 4', respectively, may be flat and horizontal, the patch top member extending in contiguous engagement across the upper extremity of the reversely curled container end.

lO9S459 In the modification of Fig. 7, the patch top member is omitted, the synthetic plastic overcap member 106 (of low density polyethylene, for example) being bonded directly to the reversely curled end portion of the body member 102 (for example, by con-ventional ultrasonic or dielectric techniques). In this embodi-ment, the central portion 106a of the plastic overcap member extends axially slightly within the container end, and in the embodiment of Fig. 8, the inner surface of the plastic overcap member is flat and horizontal and extends in contiguous engagement across the upper extremity of the reversely curled container end.
In both embodiments, the snap-fit locking shoulders 106d and 106d' serve to bias theinner surface of the overcap member against the upper extremity of the container during the bonding operation.
In the embodiments of Figs. 7 and 8 (as in the embodiments f Figs 1-6), the hermetic seal is automatically broken during the removal o~ the plastic overcap, the overcap then being suitable for reapplication to the container.
Whlle in accordance with the provisions of the Patent Statutes, the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various improvements and modifications may be made in the described apparatus without deviating from the inventive concepts set forth above.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed axe defined as follows:

1. Closure means for closing the open end of a container, comprising:
(a) a vertically arranged tubular body member open at its upper end and comprising a composite body wall including a fibrous body wall layer and an impervious inner layer, said body member terminating at its upper end in a reversely curled annular end portion;
(b) an overcap member formed of a thermoplastic synthetic plastic material extending transversely across said body member open end, said overcap member including an annular flange portion extending concentrically about said body member curled end portion;
(c) means bonding said overcap member in hermetically sealed relation with said body member end and comprising:
(1) an impervious patch top member arranged between said overcap and body wall members, said patch top member extending across, and being in contiguous engagement with, the extremity of the reversely curled end portion of said body member;
(2) first adhesive means bonding said patch top member in hermetically sealed relation with the container open end; and (3) second adhesive means bonding said patch top member to said overcap member, said second adhesive means affording a stronger bond between said patch top and overcap members than that afforded by said first adhesive means between said patch top and body wall members, whereby upon removal of said overcap member from said body wall, the bond afforded by said first adhesive means is broken and the patch top member is simultaneously removed from the container with the overcap member, thereby to afford access to the interior of the container;
(d) connecting means releasably connecting said overcap member with said body member, whereby when said overcap member is removed from said body member end, the hermetically sealed bond is automatically broken and access is afforded to the interior of the container, whereupon the overcap may be reapplied to close the container end, said connecting means comprising an annular locking shoulder arranged on the inner circumference of the overcap flange portion and extending in snap-fit relation beneath said body member curled end portion.

2. Closure means as defined in Claim 1 wherein said patch top member is flexible.

3. Closure means as defined in Claim 2, wherein said patch top member consists of metal foil.

4. Closure means as defined in Claim 2, wherein said patch top member has the configuration of a disk having a circular circumference.

5. Closure means as defined in Claim 4, wherein said overcap member includes a flat horizontal inner surface opposite and extending transversely across the reversely curled body member end portion, said patch top member being generally planar and including an annular sealing portion opposite and hermetically bonded by said first adhesive means to the extremity of said body member curled end portion.

6. Closure means as defined in Claim 5, wherein said patch top member is bonded by said second adhesive means with the flat horizontal inner surface of said overcap member.

7. Closure means as defined in Claim 4, wherein said overcap member includes a central portion that projects axially partially within the curled end of said body member;
and further wherein said patch top member includes a first horizontal portion arranged within said body member curled end adjacent the lower extremity of said patch top central portion and an annular sealing portion opposite and hermetically bonded by said first adhesive means to said body member curled end portion.

8. Closure means as defined in Claim 7, wherein said overcap member contains in the junction between the center and flange portions thereof an annular recess which receives the reversely curled end of said body member, said annular sealing portion of said patch top member being maintained in conforming engagement with a curved surface portion of the curled end portion by a corresponding curved portion of the wall surface of the overcap recess.

9. Closure means as defined in Claim 8, wherein the cooperating curved surfaces of said body and overcap members are arranged generally diametrically opposite the surface of the curled end portion which is engaged by said annular locking shoulder, said locking shoulder being so arranged on the overcap flange portion that when it is in locking engagement with the body member curled end portion, the recess wall surface is biased in a direction to press the annular sealing portion of the patch top member into conforming engagement with the body member curled end portion.

10. Closure means as defined in Claim 1, and further including anti-tampering means connected between said overcap member and said body member for resisting the removal of said overcap member from the container.

11. Closure means as defined in Claim 10, wherein said anti-tampering means comprises a peelable strip of synthetic plastic material circumferentially arranged about and shrunk fit across the juncture between the extremity of the overcap flange portion and the body member.

12. Closure means as defined in Claim 11, wherein said peelable strip extends completely about the outer surface of said flange portion and the adjacent marginal portion of the end surface of said overcap member remote from the end of said body member.

13. Closure means for closing the open end of a container, comprising:
(a) an impervious patch top member extending transversely across and seated upon the container open end;
(b) an overcap member mounted upon said container end portion for maintaining said patch top member in seated engagement with the container open end;
(c) first adhesive means bonding said patch top member in hermetically sealed relation with the container open end; and (d) second adhesive means bonding said patch top member to said overcap member, said second adhesive means affording a stronger bond between said patch top and overcap members than that afforded by said first adhesive means, whereby upon removal of said overcap member from the container, the bond afforded by said first adhesive means is broken and the patch top member is simultaneously removed from the container with the overcap member, thereby to afford access to the interior of the container.