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Publication numberUS3923237 A
Publication typeGrant
Publication dateDec 2, 1975
Filing dateAug 6, 1974
Priority dateAug 6, 1974
Publication numberUS 3923237 A, US 3923237A, US-A-3923237, US3923237 A, US3923237A
InventorsDonald J Bostrom, Stanley Moorad
Original AssigneeEkco Prod Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Package and method of forming same
US 3923237 A
Abstract
A package wherein a plastic dome cover is releasably secured to a container by distorting a depending skirt of the cover so that it curls around and interlocks with a flange on the container. The cover being a material with known shrink characteristics, distortion of the skirt is achieved by the application of heat thereto, and the skirt is segmented to provide selective distortion. The amount of distortion as well as the location of the distortion are factors which cooperate to produce a predetermined interlock between the cover skirt and the container flange.
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Description  (OCR text may contain errors)

United States Patent [1 1 Bostrom et al.

[ Dec. 2,1975

[ PACKAGE AND METHOD OF FORMING SAME [75] Inventors: Donald J. Bostrom, Northbrook;

Stanley Moorad, Niles, both of Ill.

[73] Assignee: Ekco Products, Inc., Wheeling, Ill.

{22] Filed: Aug. 6, 1974 [2]] Appl. No.: 495,197

[52] US. Cl. 229/43; 206/497; 215/246; 220/359 [5 ll Int. Cl. B65D 5/64; B65D 43/08 [58] Field of Search..... 53/30, 42; 229/43, DIG. 12; 206/497, 508; 2l5/246; 220/359, 67

[56] References Cited UNITED STATES PATENTS 2,975,931 3/l96l Harrison 220/359 3,298,505 1/1967 Stephenson 229/43 3,344,912 l0/l967 Stcrnau 229/43 3,402,874 9/1968 Sternau 229/43 3,615,707 10/1971 Filz v 229/43 3,799,389 3/l974 Bloeck 220/359 Primary E.\'aminerGeorgc E. Lowrance Assistant Examiner-Bruce H. Bernstein [57] ABSTRACT 3 Claims, 8 Drawing Figures lllllll PACKAGE AND METHOD OF FORMING SAME BACKGROUND OF THE INVENTION This invention relates to packaging and more particularly to the securing of a plastic dome cover to a container or like receptacle, such as an aluminum foil pan, and the package formed thereby. The resulting package is particularly useful for holding pies and the like which are decorated or covered with fruit, whipped cream or other culinary items.

Heretofore the application and securing of plastic domes to pans of this type has been accomplished by various types of snap-on features, by applying a plastic shrink tape around the perimeter of the pan and dome, or by heat shrinking a plastic overwrap or bag around entire package to hold the dome securely to the pan. Each of these methods and its resulting package has one or more of several disadvantages. The closure may be ineffective; the package may be difficult to open and difficult or impossible to effectively be reclosed; or the additional materials and extra steps necessitated in the application of the domes may make the package more expensive to produce or difficult if not impossible to produce on high speed production lines.

SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of the prior art and obtains the desired characteristics of a package of this type by providing a method whereby a preformed domed cover of biaxially oriented thermoplastic material is placed on the pan filled with its intended contents and heat is selectively applied to the cover to shrink selective portions of the cover and thereby secure the cover to the pan. The cover has a peripheral skirt which depends downwardly beyond a corresponding outwardly extending flange on the pan. When heat is applied to the flange area, the skirt shrinks and is tucked beneath the flange of the pan to effect the closure. The skirt is preferable segmented to permit easy removal from the pan and easy reclosure of the cover on the pan after part of its contents is removed. More particularly, the skirt has short portions which, when heat is applied thereto, curl just slightly around the outermost edge of the flange, and long portions which curl beneath the flange of the pan for a substantial portion of the lateral dimension thereof.

BRIEF DESCRIPTION OF THE DRAWING -tion of the cover skirt upon application of heat thereto.

FIG. 6 is a fragmentary cross-sectional view taken along lines 66 of FIG. 3.

FIG. 7 is a view similar to FIG. 6 but showing distortion of the cover skirt.

FIG. 8 is a bottom view of pan having a cover secured thereto in accordance with the teachings of the invention herein disclosed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawing, a domed cover generally designated by the numeral 10 is provided, the cover having a top wall 12, a side wall 14 depending down- -wardly from the top, a peripheral shoulder 16 extending outwardly from the side wall 14, and a peripheral skirt 18 which initially depends downwardly from the shoulder 16. As noted above, the skirt 18 is preferable segmented to permit easy removal thereof from the pan 20 and easy reclosure of the cover 10 on the pan 20. The skirt 18 has short portions 18a which are dimensioned so that when heat is applied thereto, curl just slightly around the outermost edge of the flange 26 of the pan 20, and long portions 18b and which curl beneath the flange 26 for a substantial portion of the lateral dimension thereof. The shape of the skirt 18 prior to shrinking is best shown in FIGS. 4 and 6, wherein there is illustrated the long and short portions, respectively. Preferably long portion 18b extends for a relatively short distance along the periphery of the cover 10 in an opening area 19, and for a greater distance therealong, as indicated by 180, opposite the opening area 19. The short portions 18a extend between the long portions 18b and 180. This particular configuration of the skirt 1% and the reason therefor will be discussed more fully hereinbelow.

While the top wall 12 is shown to be planar and the side wall 14 is shown to be fluted and to extend generally downwardly and outwardly in a straight line, obviously any suitable shape of side wall and top wall could be employed.

The cover is formed from sheet stock of biaxially oriented thermoplastic and is preferably clear to provide for visibility of the contents in the completed package. Many plastics of this character are available, it being sufficient for purposes of the subject invention that the selected plastic have suitable shrink characteristics.

The pan 20 is preferably formed from aluminum foil and has a bottom wall 22, a side wall 24 extending upwardly and outwardly from the bottom wall 22 and a peripheral flange 26 extending outwardly from the upper end of the side wall 24.

To secure the cover 10 to the pan 20, the cover 10 is placed on the pan 20 so that the shoulder 16 of the cover 10 rests on the flange 26 of the pan and the skirt 18 of the cover It) depends downwardly over the outside of the flange 26 as shown in FIGS. 4 and 6. Hot air is then applied upwardly from the bottom of the pan and because the side wall 24 of the pan 20 slopes upwardly and outwardly, the only portion of the cover 10 that is exposed to the direct blast of hot air is the skirt 18. Thus, this area shrinks around the flange 26 of the pan 20, thereby securing the cover 10 to the pan as shown in FIGS. 5 and 7.

With the description of the cover 10 given above, in its secured position on the pan 20, the long skirt 18b in opening area 19 and skirt 18c opposite opening area 19 will curl under the flange 20 for a substantial portion of the width of the flange 20 as shown in FIG. 5. The short skirts 18a curl just slightly under the flange 20 as shown in FIG. 7. With this construction it is possible for the consumer to open the package by lifting the skirt 18b in the opening area 19 and lifting the cover 10 from the pan 20. It is also possible to replace the cover on the pan by reversing this procedure after part of the contents have been removed.

It should be noted that of the entire circumferential length of securement of the cover to the pan, approximately one-half of the securement is by the short skirts 18a, while approximately one-half of the securement is by the long skirts 18b and 18c. As shown by reference to FIG. 8, long skirt 18c secures considerably less than one-half the total circumferential length of securement, and is effective in conjunction with skirt 18b to provide positive and substantial interlocking of the cover skirt with the pan flange. Obviously, lifting or distorting skirt 18b away from securement to the pan flange 26 also moves skirt 18a out of securement with the pan flange and permits sliding disengagement of skirt 18c from the pan flange.

As shown, the opening area 19 is located centrally between the short skirts 18a and opposite long skirt 18c. It is clear that the integrity of the package is maintained until and unless skirt 18b is lifted or otherwise distorted so as to move from securement with the pan flange 26.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

What is claimed is:

1. A reclosable package comprising a circular pan having a bottom wall, a side wall extending upwardly and outwardly from said bottom wall, and a peripheral flange extending outwardly from the upper end of said side wall; a product in said pan; and a preformed circular dome cover of biaxially oriented thermoplastic material, said cover comprising a top wall, a side wall depending downwardly from said top wall, a peripheral shoulder extending outwardly from said side wall and a peripheral skirt depending downwardly from said shoulder, said shoulder overlying said pan flange, said skirt extending below said pan flange and having the periphery thereof curled beneath said flange, said skirt comprising long portions and short portions whereby said long portions curl under said flange a substantial portion of the lateral dimension of the flange and said short portions curl just slightly under the flange, said short portions comprising less than one-half the total circumferential length of said skirt, and at least one long portion being liftable from securement with the pan flange.

2. The reclosable package of claim 1 wherein the skirt comprises two short portions which are disposed on either side of the liftable one long portion, and an other long portion disposed opposite said one long portron.

3. The reclosable package of claim 2 wherein the other long portion of the skirt comprises less than onehalf the total circumferential length of said skirt.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2975931 *Jun 4, 1959Mar 21, 1961Grace W R & CoContainer
US3298505 *Feb 12, 1965Jan 17, 1967Brown CoLaminated closure for food trays and trays closed with same
US3344912 *Jul 1, 1964Oct 3, 1967Grace W R & CoClosures
US3402874 *May 12, 1964Sep 24, 1968Grace W R & CoContainer closure
US3615707 *Mar 18, 1970Oct 26, 1971North Pacific Canners & PackerHermetically sealed container with readily detachable protective cover
US3799389 *Nov 14, 1972Mar 26, 1974AlusuissePackaging container with tear-open thread
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3575110 *Sep 4, 1962Apr 13, 1971Conroy Kenneth EdwinNonmetallic antipersonnel mine
US4772112 *Jun 19, 1986Sep 20, 1988Cvi/Beta Ventures, Inc.Eyeglass frame including shape-memory elements
US4815603 *Aug 16, 1988Mar 28, 1989Harris Charles CShrink wrap package with venting openings
US4895438 *Jun 1, 1988Jan 23, 1990Cvi/Beta Ventures, Inc.Eyeglass frame including shape-memory elements
US4896955 *Dec 5, 1988Jan 30, 1990Cvi/Beta Ventures, Inc.Eyeglass frame including shape-memory elements
US6789393Dec 6, 2002Sep 14, 2004S.C. Johnson Home Storage, Inc.Container with pressure relief and lid and method of manufacture therefor
US6805659 *Sep 18, 2003Oct 19, 2004Ivex Packaging CorporationMethod of making one-piece lidded container and containers made by the same
US7318534Jun 10, 2004Jan 15, 2008S.C. Johnson Home Storage, Inc.Disposable container cover with elastic replacement
EP1938951A2 *Dec 6, 2007Jul 2, 2008D2 Food Systems LimitedFood container
WO2005095224A1 *Mar 31, 2005Oct 13, 2005Plus Pack AsA package
WO2007016030A1 *Jul 24, 2006Feb 8, 2007Pactiv CorpContainer assemblies with releasable locking feature
Classifications
U.S. Classification220/305, 229/125.36, 215/246, 220/359.4, 206/497
International ClassificationB65D43/02
Cooperative ClassificationB29K2995/0053, B65D2543/00351, B29K2101/12, B65D2543/00574, B65D2543/00296, B29C65/64, B65D2543/00527, B29C66/54, B29K2305/02, B29C65/10, B65D43/0233, B65D2543/00537, B29K2995/0049, B65D2543/00092, B29C65/66
European ClassificationB29C65/10, B29C65/64, B29C65/66, B29C66/54, B65D43/02S9