Easy-open Thermoplastic Container Package

Abstract

A thermoplastic container package wherein both the container and its lid have horizontal rims and descending flanges. The lid rim has a peripheral score line along its undersurface and the flanges are sealed along their length except adjacent a lid tab utilizable for lifting and thereby severing the score line and removing the lid from the container. A tight fitting reclosure of the lid is obtained by the coaction of an outwardly protruding lid closure bead adjacent the junction of the lid central panel and its peripheral substantially vertical wall, and of a juxtaposing groove surrounding the inside of the container.

Description

BACKGROUND OF THE INVENTION

In the manufacture of containers for the storage and transportation of foods or liquids, it is advantageous that such containers be substantially fully sealed after being filled. Sealing prevents product deterioration by exposure to the atmosphere and prevents people from unnoticeably tampering with and peeking at and/or sampling the contents at the market place. When such a sealed container reaches the ultimate consumer, it is advantageous that he be able to open the container quickly and easily without having to read elaborate instructions, without having to apply any specific tools such as knives or can openers, and without having to exercise any particular skill to remove the lid without destroying the package or spilling its contents. It is also advantageous that the container be reusable and include a secure lid reclosure feature and that the container be a low cost item that is chemically inert in relation to the contents stored therein.

It is still further advantageous that the container package be easy to manufacture without having the heretofore problem of registering the tab of a lid with the tab of a container prior to sealing the lid to the container. This problem is eliminated because only the lid has a tab and the lid can be randomly placed on a container and sealed without worrying about what direction the tab is facing.

In view of these advantageous objectives, it is an object of the present invention to provide a thermoplastic container package having a full easy-open lid sealed thereto and removable therefrom without need of special tools or skills.

It is another object of the present invention to provide a thermoplastic container package having a full easy-open lid sealed thereto and severably removable therefrom along a continuous score line along most of the periphery of the underside of the lid rim.

It is another object of the present invention to provide a thermoplastic container package having a full easy-open lid, the container and lid having flanges sealed together and remaining together on the container when the score line is severed and the lid is removed from the container.

It is another object of the present invention to provide a tab on the lid by which the latter may be removed from the container and subsequently replaced, if desired.

It is further object of the present invention to provide a container package that has a secure lid reclosure feature and is reusable.

It is a still further object of the present invention to provide a container package that is easy to manufacture because it provides a tab only on the lid portion of the package which enables the placing and sealing of lids on containers in random rather than in registered fashion.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

SUMMARY OF THE INVENTION

The thermoplastic container package of this invention comprises in combination an open-ended container having a closed base, sides integral with the base, a container rim integral with an extending substantially horizontally from the sides, and a container flange integral with and descending the rim. The container package also comprises a lid having a central panel, an integral substantially horizontally extending lid rim peripheral to the central panel and a flange integral with and descending from the lid rim. The lid has a substantially continuous score line along its undersurface and substantially peripheral to its central panel. The lid also has an unscored tab portion integral with and descending from the rim for removing the lid and replacing it on the container. The container and lid flanges are sealed to each other except adjacent the lid tab portion such that they remain sealed to each other and on the container when the tab is lifted, the score line is severed and the lid interior of the score is removed from the container.

The lid can include a generally vertical wall peripheral to the central panel and integral with and adjoining the central panel and the rim. The lid can also include an outwardly protruding peripheral lid closure bead adjacent the junction of the wall and the central panel for coacting with a juxtaposingly abutting circumferential groove in the interior surface of the container sides. The bead can be continuous around the panel and the groove can be continuous around the interior surface of the container sides. Preferably, the bead tapers off to non-existence adjacent and below the tab. Coaction of the bead in the groove provides for a tight lid closure on the container. Both the container sides and the generally vertical wall of the lid extend substantially vertically downward from their respective rims and extend inwardly toward the center of the central panel to form a substantially horizontal step and then extend downwardly and outwardly from the central panel to where they adjoin their respective groove and bead. The lid tab can be abhered to an underlying portion of the container flange. The lid and container flanges and the tab can descend substantially vertically from their respective rims at an angle of from about 70.degree. to 90.degree. from the substantially horizontal plane of the lid rim, and the container sides can be tapered.

The lid wall portion extending downwardly and outwardly from the substantially horizontal step can include a plurality of still slightly further inwardly protruding stacking lugs for supporting the central panel of an overlying nested lid and preventing the central panel of the overlying lid from lodging within an area defined by the horizontal step and the stacking lugs of the supporting lid. The continuity of the outwardly protruding lid closure bead can be broken by a plurality of vertical vents or channels carved therein and running from the bottom surface of the central panel to the top of the closure bead. The vents allow air to escape from the container when lid reclosure is effected on the container. The vents can vertically feed into and allow air to escape into, i.e., behind, a plurality of the stacking lugs. The continuity of the score line along each side of the lid tab and adjacent the junction of the lid rim and lid flange can be broken by a window to provide a skip in the score line which increases the force exerted therethrough and facilitates severing the score line around the rest of the container lid rim.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a thermoplastic container package.

FIG. 2 is a top plan view of the container lid of FIG. 1.

FIG. 3 is an enlarged detailed cross section taken through the tab portion and the stacking lug of the container package along line 3--3 of FIG. 2.

FIG. 4 is an enlarged detailed cross section taken along line 4--4 of FIG. 2.

FIG. 5 is the enlarged detailed cross section of FIG. 4 shown with the lid removed.

FIG. 6 is an enlarged detailed cross section taken through a stacking lug along line 6--6 of FIG. 2.

FIG. 7 is an enlarged detailed top cross section taken through a vent along line 7--7 of FIG. 6.

FIG. 8 is a perspective view of another embodiment of the container package of this invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings in detail, FIG. 1 is a perspective view of a thermoplastic container package 10 comprised of an open-ended container 12 having a closed base 14, sides 16 integral with the base and in turn having a continuous circumferential groove 18 (FIGS. 3-5) surrounding the inside of sides 16 of container 12. The grooves can, but need not, result in or impress a corresponding protruding bead 19 (same figures) on the outside of container sides 16. Sides 16 terminate in an integral substantially horizontal rim 20 (same figures) and an integral descending flange 22 (same figures). Also shown as part of the container package of FIG. 1, is lid 24 having a central panel 26, a generally vertical wall, generally designated W (FIG. 3) peripheral to panel 26 and an integral substantially horizontal rim 30 which terminates in a descending flange 32 having an integral tab 34. Central panel 26 can include a continuous upwardly protruding reinforcing bead (not shown) extending around the central panel equidistant from and proximate to the junction of the lid wall and central panel.

FIG. 1 shows lid 24 having a substantially continuous score line 46 in the undersurface of lid rim 30 and substantially diagonally to where it adjoins the edges of tab 34 where the tab adjoins lid flange 32. Tab 34 is not sealed to underlying container flange 22 (see FIG. 3), but lid flange 32 to either side of tab 34 is sealed to flange 22 (FIGS. 3-6).

FIG. 1 also shows wall W of lid 24 having a substantially vertical wall portion 28 and a substantially horizontal step 36 (better shown in FIGS. 2 and 3) extending inward from generally vertical wall portion 28 and toward the center of central panel 26. The lower wall portion 38 of wall W below the substantially horizontal plane of step 36 extending downwardly from the direction of central panel 26, has a plurality of stacking lugs 38' which protrude slightly further inwardly from the edge of step 36 and from the downwardly and outwardly extending lower portions 38 of wall W.

Lid 24 also includes an outwardly protruding lid closure bead 40 peripheral to central panel 26 and adjoining panel 26 and the aforementioned lower portion of wall W. The bead can be continuous around panel 26 but preferably it tapers off to non-existence adjacent and below the tab. This tapering facilitates removal and closure of lid 26 on container 10. The continuity of bead 40 can be broken by a plurality of vents or channels 42 carved therein, which run substantially vertically from the bottom surface of central panel 26 to the top of bead 40 and which can be aligned with and feed into a plurality of stacking lugs 38' of wall W. Vents 42 allow air to escape from the interior of container 12 and exit into, i.e., behind stacking lugs 38' when lid 24 is securely placed on container 12. Lid 26 can also include a continuous upwardly protruding circular reinforcing bead (not shown) having a radius of curvature shorter than that of lid closure bead 40.

FIG. 2 is a top plan view of the container lid of FIG. 1 and shows a plurality of stacking lugs 38' protruding slightly more inwardly than inwardly extending substantially horizontal step 36 of wall W whose generally vertical portion 28 adjoins outwardly extending lid rim 30, a portion of which in turn adjoins tab 34.

FIG. 3 is an enlarged detailed cross section taken through the tab portion along line 3--3 of FIG. 2 and shows the juxtaposingly abutting relationship of lid 24 and container 12. More particularly, FIG. 3 shows the coaction of lid closure bead 40 with juxtaposingly abutting groove 18 in one of the container sides 16, the coaction providing a tight reclosure fit of the lid on the container. Stacking lug 38' juts further inwardly than also inwardly extending adjacent lower angular portions 38 of wall W. (See 38 of FIG. 4). FIG. 3 also shows lid rim 30 and adjoining tab 34 juxtaposingly abutting respective underlying adjoining container rim and container flange 22.

FIG. 4 is an enlarged detailed cross section taken along line 4--4 of FIG. 2 through a section of lid wall W that does not have a stacking lug and shows that the lower angular portion 38 of wall W does not extend as far inward toward the direction of central panel 26 as does protruding stacking lug 38' of FIG. 3. FIG. 4 also shows that lid rim 30 is not sealed to underlying container rim 20, has a score line 46 thereunder and adjoins lid flange 32 sealed to underlying container flange 22.

FIG. 5 is an enlarged detailed cross section showing the detailed cross section of FIG. 4 when lid 24 is removed therefrom.

FIG. 6 is an enlarged detailed cross section taken along line 6--6 of FIG. 2 through stacking lug 38' and through vent 42, carved into lid closure bead 40. Vent 42 runs from the bottom surface of central panel 26 to the top of lid closure bead 40 and, as previously stated, allows air to escape from the container when lid 24 is closed on the container 12.

FIG. 6 taken with the previous figures also indicates that score line 46 runs continuously around the undersurface of lid rim 30 and that lid and container flanges 32 and 22 respectively are sealed to each other all the way around the container up to where score lines 46 define tab 34.

FIG. 7 is an enlarged detailed top cross sectional view taken along line 7--7 of FIG. 6 and shows vent 42 carved into lid closure bead 40 juxtaposingly abutting and coacting with groove 18 in one of the sides 16 of container 12.

FIG. 8 shows another embodiment of the container package of this invention and shows lid 124 of container package 100 having portions of container rim 120 and container flange 122 showing through windows 226 in lid rim 130 and in lid flange 132 adjacent tab 134. Score line 146 adjoins the edge of window 226 that defines and adjoins the respective edges of tab 134.

In order to open either embodiment of the container package of this invention, tab 34 is lifted with a force sufficient to initiate and effect severance of score line 46 which occurs on either side of tab 34 and then occurs continuously along the arcs of score line 46 on opposing sides of lid rim 30. When an equal, balanced and steady force is applied, the last point to sever on the score line usually is within a lid rim area opposite of tab 34. When lid 24 interior of score line 46 is removed from container 12, lid flange 32 remains sealed to container flange 22. Except for the area that was under tab 34, a portion of lid rim 30 remains integral with lid flange 32, the width of this portion remaining depending upon where score line 46 is located on the lid rim in relation to the junction of it and lid flange 32.

When the lid of the container package of this invention includes windows therein such as are shown in FIG. 8, the windows provide a skip in score line 146 such that any force utilized to initiate severance of score lines 146 adjacent tab 134, will be increased through the window skips and this increased force renders it easier to sever score line 146 around the rest of container rim 130.

Score line 46 or 146 can be located anywhere along the width of the undersurface of lid rim 30 from its junction with lid flange 32 to its junction with wall W so long as the easy-opening feature of this invention is maintained. It has been found that satisfactory openings can be obtained when score line 46 in lid rim 30 is located as shown in the drawings.

The angle at which the lid and container flanges 32 and 22 respectively and at which tab 34 descend from their respective substantially horizontal rims can be from about 70.degree. to 90.degree. but preferably is about 78.degree., or, otherwise stated, about 12.degree. from a line drawn vertically from the junction of lid rim 30 and lid flange 32. Such an angle has been found advantageous because it facilitates the manufacture and sealing of the lid and container flanges.

A tight and secure reclosure of lid 24 on container 12 can be effected by setting the lid on the container and pushing downward until a tight-fit-implying "popping" sound is heard as lid closure bead 40 coacts with and seats itself within groove 18 of container 12. Reclosure and initial closure or capping is facilitated by vents 42 carved vertically in lid closure bead 40 which allow otherwise trapped and resisting air pressure to escape through the vents from the container.

Stacking lugs 38' in lid 24 allow many such lids to be nested on one another because they prevent the central panels of overlying lids from becoming blocked or lodged within the substantially vertical wall W or underlying lids. Lugs 38' can be of any practical number or size. Preferably, six to eight lugs are employed and preferably they are equidistant from each other. The lugs can protrude inward to any extent sufficient to prevent the aforementioned lodging.

An abhesive can be utilized to abhere the portion of lid rim 30 adjacent and extending into tab 34, to the underlying portion of container rim 22. The abhesive can be any suitable cured or non-cured release agent which could be made from parafinns, parafin oils, amides and silicones and commonly employed as an abhesive for thermoplastic materials. An example of an non-cured silicone release agent is that sold by Inmont Corporation as I.P.I. (International Printing Ink, Co.) No. F-60909.

Claims

We claim:

1. A thermoplastic container package comprising in combination:

an open-ended container having,

a closed base,

sides integral with said base,

a container rim integral with and extending substantially horizontally from said sides, and

a container flange integral with and descending from said rim; and

a lid for closing the open end of said container, said lid having

a central panel,

an integral substantially horizontally extending lid rim peripheral to said central panel, said lid rim having in its undersurface a substantially continuous score line substantially peripheral to said central panel,

an unscored tab integral with and descending from said lid rim, for severably removing said lid from and replacing said lid on said container,

a lid flange integral with and descending from said lid rim, said container flange and lid flange being sealed to each other such that they remain so sealed on said container when said lid tab is lifted said score line is severed and said lid interior of said score is removed from said container.

2. The container package of claim 1 wherein said lid includes a generally vertical wall peripheral to said central panel, said wall being integral with and adjoining said central panel and said rim, and being in juxtaposingly abutting relationship with adjacent container sides.

3. The container package of claim 2 wherein said lid includes an outwardly protruding peripheral lid closure bead adjacent the junction of said wall and said central panel, and wherein the interior surface of said container sides include a juxtaposingly abutting circumferential groove for receiving and coacting with said lid closure bead to provide a tight lid closure on said container.

4. The container package of claim 3 wherein said bead is continuous around said panel and said groove is continuous around said interior surface of said container sides.

5. The container package of claim 3 wherein said groove is continuous around said interior surface and said bead is continuous except that said bead tapers off to non-existence adjacent and below said tab.

6. The container package of claim 5 wherein said container and lid flanges and said lid tab descend at an angle of from about 70.degree. to 90.degree. from the substantially horizontal plane of said lid rim.

7. The container package of claim 6 wherein said container sides and said juxtaposingly abutting lid wall extend inwardly toward the center of said central panel to form a substantially horizontal step and extend downwardly and outwardly from the direction of said central panel to where they adjoin their respective groove and bead.

8. The container package of claim 7 wherein said inwardly extending substantially horizontal step and said lid wall extending downwardly and outwardly from said step include a plurality of slightly further inwardly protruding stacking lugs for supporting the central panel of an overlying nested lid and preventing the central panel of said overlying lid from lodging within an area defined by said horizontal step and stacking lugs of said supporting lid.

9. The container package of claim 8 wherein the continuity of said outwardly protruding lid closure bead is broken by a plurality of vertical vents carved therein and running from the bottom surface of said central panel to the top of said closure bead, said vents allowing air to escape from said container through said vents when lid reclosure is effected on said container.

10. The container package of claim 9 wherein said vents are aligned with and vertically feed and allow air to escape into a plurality of said stacking lugs.

11. The container package of claim 10 wherein said sides of said container are tapered.

12. The container of claim 11 wherein said tab is abhered to an underlying portion of said container flange.

13. The container package of claim 1 wherein said container sides are tapered and wherein said tab is abhered to an underlying portion of said container flange.

14. The container package of claim 3 wherein said container sides are tapered and wherein said tab is abhered to an underlying portion of said container flange.

15. The container package of claim 4 wherein said container sides and said juxtaposingly abutting lid wall extend inwardly toward the centre of said central panel to form a substantially horizontal step and extend downwardly and outwardly from the direction of said central panel to where they adjoin their respective groove and bead, and said container and lid flanges and said lid tab descend at an angle of from about 70.degree. to 90.degree. from the substantially horizontal plane of said lid rim.

16. The container package of claim 15 wherein said inwardly extending substantially horizontal step and said lid wall extending downwardly and outwardly from said step include a plurality of slightly further inwardly protruding stacking lugs for supporting the central panel of an overlying nested lid and preventing the central panel of said overlying lid from lodging within an area defined by said horizontal step and stacking lugs of said supporting lid.

17. The container package of claim 16 wherein the continuity of said outwardly protruding lid closure bead is broken by a plurality of vertical vents carved therein and running from the bottom surface of said central panel to the top of said closure bead, said vents allowing air to escape from said container through said vents when lid reclosure is effected on said container.

18. The container package of claim 17 wherein said vents are aligned with and vertically feed and allow air to escape into a plurality of said stacking lugs.

19. The container package of claim 18 wherein said sides are tapered.

20. The container package of claim 19 wherein said tab is abhered to an underlying portion of said container flange.

21. The container package of claim 12 wherein the continuity of said score line along each side of and defining said tab is broken adjacent the junctions of said lid rim and lid flange by a window which provides a skip in the score line for increasing any force exerted therethrough to facilitate severance of said score line around the rest of said container lid rim.

22. The container package of claim 20 wherein the continuity of said score line along each side of and defining said tab is broken adjacent the junctions of said lid rim and lid flange by a window which provides a skip in the score line for increasing any force exerted therethrough to facilitate severance of said score line around the rest of said container lid rim.