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Publication numberUS3884383 A
Publication typeGrant
Publication dateMay 20, 1975
Filing dateJan 17, 1973
Priority dateSep 29, 1970
Publication numberUS 3884383 A, US 3884383A, US-A-3884383, US3884383 A, US3884383A
InventorsBurch Charles H, Medendorp Roger L
Original AssigneeKirkhof Manufacturing Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Nesting container
US 3884383 A
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Description  (OCR text may contain errors)

United States Patent 1191 Burch et al. 1 May 20, 1975 541 NESTING CONTAINER 2,752,970 7/1956 Tapper 150/5 2,814,427 11/1957 Emery 229/25 Inventory Charles Burch; 8" 3,055,540 9/1962 Ringlen 150/.5 Medendorp, bflth of Grand Rapldsi 3,080,997 3/1963 Brown 220/97 c Mich. 3,178,051 4/1965 Edwards 220/97 C 3,203,611 8 1965 Anderson 220/97 c [73] Asslgnee' Krkhof Mamfac'urmg 3,344,974 10 1967 BOSUOII 220 97 F Cmpwamn, Grand Rapldsi 3,426,939 2 1969 Young 1 1 220/66 3,520,441 7/1970 Fitzgerald 220/97 c [22] Filed 1973 3,539,552 11/1970 Mounts 220 97 0 211 App]. NO.Z 324,346

FOREIGN PATENTS OR APPLICATIONS Related Appl'cam Data 1,198,864 7/1970 United Kingdom 229/25 [63] Continuation of Ser. No. 76,395, Sept. 29, [970,

abandoned' Primary Examiner-George E. Lowrance 52 us. c1. 220/72; 150/5; 206/119; i Heneveld Hu'zenga 220/66; 220/74; 229/25 [51] Int. Cl B65d 1/46; 865d l/26 [58] Field of Search 220/66, 72, 74, 97 C, 97 F; [57] ABSTRACT B; 215/10; 206/65 K; ISO/'5 A plastic container that has a plurality of sides and a [56] References C ted bottom with a frustro-pyramidal portion projecting up- Sherman 229/25 wardly to a flat surface.

5 Claims, 4 Drawing Figures PATEMEUHAYZOBYS 3,884,383

SHEET 10F 2 INVENTORS CHARLES H. BuEcH ROGER L MEDEUDOEP BY %,W

ATTORNFYQ- WEM'EM 3884383 SHEET 2 OF 2 INVENTORS CHARLES H BURCH- EOGER L. MEDENDOEP BY 'g ATTORNEYS 1 NESTING CONTAINER This is a continuation of application Ser. No. 76,395 filed Sept. 29, 1970, now abandoned.

BACKGROUND This invention relates to plastic containers such as might be used, for example, as berry containers. Prior art plastic containers are subject to such defects as flimsiness and weak bottoms. Thus, the bottoms tend to oil can and the container generally tends to split readily. The oil canning caused when the container is filled tends to create splits in the bottom edges where the sides and bottoms join. The bottom corners are also particularly weak because an insufficient amount of plastic flows to those corners when the containers are molded. The top edge or top rim of such containers is another weak area at which splitting tends to occur. This is particularly true at the top corners which are subjected to forces of twisting when the container is used.

Further, because the containers are so flimsy, they are difficult to use. If one attempts to pick up a filled container with one hand, it tends to bend, twist and bow and the material of the container tends to split. Their flimsiness also makes them undesirable for merchandising berries since the berries become crushed when the flimsy containers are handled. This can be overcome by increasing the amount of plastic of which the container is made. However, this increases the expense of the container and makes it uneconomical for many applications.

In the present invention, the bottom of such a molded plastic container comprises a generally cone-shaped portion extending upwardly so as to resist oil canning. In order to resist bottom edge splitting, the juncture between the sides of the container and its bottom are beveled. Similarly, the corners formed by the sides and bottom of the container are beveled. Finally, top splitting is avoided by the provision of a rim including two generally vertical surfaces joined by a horizontal sur face.

Thus, this invention provides a plastic container which has far more utility than those which are currently available. Undesirable oil canning, split edges and ruptured corners are minimized. Increased strength is achieved without increasing the amount of plastic used in the container.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the invention will be seen by reference to the specification and appended drawings wherein:

FIG. 1 is a plan view of the plastic container;

FIG. 2 is a cross section taken along II-II of FIG. 1;

FIG. 3 is a cross section taken along IIIIII of FIG. 1; and

FIG. 4 is an enlarged view of a top corner of the con tainer.

PREFERRED EMBODIMENT The container 1 of this invention is preferably formed of biaxially oriented polystyrene, although other plastics could be acceptable. The bottom of the container comprises an upwardly extending cone-shaped portion 30 and a generally flat portion 20. Sides l and bottom are joined along beveled edges 60 (FIG. 2) and at beveled comers (FIG. 3). A step-shaped rim 40 (FIGS. 1, 2 and 3) is provided at the top edge of the container.

Cone-shaped portion 30 is preferably frustropyramidal in shape, comprising a plurality of flat segments 31 extending upwardly to a generally flat top 32. The segments 31 preferably extend upwardly in a linear fashion rather than extend upwardly along an arc of curvature. The fact that this protrusion is generally cone-shaped provides this construction with considerable resistance to oil canning since the cone tends to resist inversion. The provision of flat segments 31 lends further resistance to oil canning. Because segments 31 are flat, the lateral cross sections of the cone 30 are rectilinear in shape. Thus, an angle is formed between different segments 31 of the cone 30. In order to oil can the bottom, one would not only have to invert the angle of the cone, one would have to invert the angles between the flat sides 31. Finally, it is important that the cone-shaped portion 30 comes either to a point or to a generally flat upper surface 32. If upper surface 32 were radiused, it would tend itself to oil can and defeat the purpose of cone-shaped portion 30. Of course, if cone-shaped portion 30 were brought to a point, the point could have a slight radius thereon since this would not provide any substantial surface area which could oil can.

Cone 30 also resists oil canning because it is thicker generally than flat bottom 20. Additionally, cone 30 becomes progressively thicker as it proceeds upwardly, and its thickest portion is top 32. As an example, one of these containers was formed of a 30 mil sheet of plastic draw such that bottom portion 20 had a thickness of seven mils while top portion 32 had a thickness of 12 mils. The thickness of cone 30 approximately half-way up was about 8 mils. This added thickness in the center of the bottom of the container adds considerable strength thereto.

A step or shoulder portion 33 joins cone-shaped portion 30 to flat bottom portion 20 and further tends to minimize oil canning (FIGS. 2 and 3). Shoulder 33 extends upwardly from flat surface 20 and intersects cone 30 at an angle thereto. Preferably, it extends generally vertically upwardly from flat bottom 20. When a downwardly acting force is applied to cone 30, much of it is transmitted to the point of intersection between cone 30 and flat bottom 20. This acts to force cone-shaped portion 30 down through the bottom of the container which the presence of shoulder 33 tends to resist.

Top rim 40 comprises a first generally vertical surface 41 and a second generally vertical surface 43 of smaller circumference with these two surfaces being joined by a horizontal surface 42 (FIGS. 2 and 3). Second vertical surface 43 is then joined to the sides 10 of container 1 by a second generally horizontal surface 44. This step-like construction provides the top edge of the container with considerable resistance to fraying and splitting. It also gives rigidity to the sides 10 of the container and prevents them from bowing laterally outwardly.

The sides 10, first vertical surface 41 and second vertical surface 43 are all radiused i.e., given an arcuate curvature at the corner of the container 1 as is shown in FIG. 4. In order to further strengthen rim 40 at these corners, the radii of first curved surface 41, second curved surface 43 and the curve between sides 10, represented by the letters a, b, and 0 respectively, areslightly different. Thus, radius of curvature a of first vertical surface 41 is the shortest, while radius of curvature c of sides 10 is the greatest. This minimizes the tendency of the container to bow inwardly or outwardly at its corners and provides resistance to the forces of 5 twisting which would otherwise tear container 1 at these corners.

The sides and bottom are joined at the bottom corners of container 1 at beveled corner 50. Because these corners are beveled, the plastic does not have as far to flow when the container is molded and thus, beveled corners 50 are thicker than are conventional corners. This in itself adds strength to these bottom corners. Further, the bevel provides resistance to twisting forces and thereby further strengthens the bottom corners of the container.

Each separate side 10 is also joined to container 20 along a beveled bottom edge 60. Bevel 60 need not be nearly as pronounced as bevels 50. This provides the bottom edges with resistance against twisting and thereby prevents bottom edge tearing which so frequently occurs in current prior art devices.

Thus, it can be seen that this invention provides a plastic container which is considerably more rigid than prior art containers and yet which can be made with the same amount of plastic. It is resistant to oil canning at its bottom. lt is resistant to bulging at its sides. Tearing along the top edges is minimized by a unique stepped rim construction 40. Tearing at the top corners is minimized by providing each step with a different radius. The bottom corners 50 are beveled to provide added thickness and strength to the container. Finally, the bottom edges 60 are beveled to provide resistance to twisting and splitting.

It is understood that the above is merely a preferred embodiment of the invention and that many changes and alterations can be made thereof without departing from its spirit and broader aspects. Further, the theoretical explanations of the manner in which the features of this invention strengthen the container are not meant to be exhaustive and it may well be that these features provide added strength for reasons other than those outlined above.

What is claimed is:

l. A polygonal, polymeric container having a plurality of sides and a bottom forming a polyhedron, the improvement in said container comprising: a stepped rim at the top thereof formed by first and second generally vertical surfaces joined by a first generally horizontal surface, and a third generally vertical surface joined to said second generally vertical surface by a second generally horizontal surface; said first surface being the outermost, said third surface being innermost and said second surface beingintermediate, relative to said container; said first, second and third generally vertical surfaces being curved at the corners of said container, with the radius of curvature for each surface being different whereby collapsing of the container at these corners is resisted.

2. The container of claim 1 in which said first surface has the shortest radius of curvature at each corner and said third surface has the longest radius of curvature at each corner.

3. A polygonal polymeric container having sides and a bottom, said container comprising: said bottom comprising a generally flat portion, a many sided frustropyramidal portion projecting upwardly from said generally flat portion, and a generally vertical, upstanding annular shoulder wall joining said fiat bottom portion and the sides of said many sided frustro-pyramidal portion; the sides of said frustro-pyramidal portion being flat side segments, the number of which exceeds the number of sides for said container; said shoulder wall being disposed at a definite angle to the sides of said frustro-pyramidal portion and to said flat bottom portion, the angle between said flat side segments of said frustro-pyramidal portion and said shoulder wall being less than on the interior of said frustro-pyramidal portion, whereby the combination of said generally vertical shoulder wall and said frustro-pyramidal portion resists inversion of the container bottom with filling of the container.

4. The polymeric container of claim 3 in which the top perimeter of the container comprises a stepped rim formed by first and second generally vertical surfaces joined by a generally horizontal surface and the sides of said container being joined to said second vertical surface by another generally horizontal surface; said first and second vertical surfaces and the juncture of said sides being curved, with the radius of curvature for each of said first, second and side juncture surfaces being different; said first surface having the shortest radius of curvature and said side surface juncture having the longest radius of curvature.

5. The polymeric container of claim 4 which comprises a polyhedron, the corners formed by the intersection of adjacent ones of said sides and said bottom of said container being beveled.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2587909 *Feb 17, 1947Mar 4, 1952Elizabeth M ShermanMolded pulp egg carton
US2752970 *Jun 29, 1954Jul 3, 1956Tupper Earl SRectangular container and hermetical seal therefor
US2814427 *Nov 18, 1954Nov 26, 1957Keyes Fibre CoMolded pulp plant container
US3055540 *Feb 9, 1961Sep 25, 1962J E Plastics Mfg Corp NContainer and closure therefor
US3080997 *Apr 12, 1961Mar 12, 1963Theodore G BrownDisposable ash tray
US3178051 *Sep 26, 1962Apr 13, 1965Illinois Tool WorksContainer and lid
US3203611 *Jul 10, 1962Aug 31, 1965Haveg Industries IncInsulated nestable container and method of making the same
US3344974 *Aug 18, 1965Oct 3, 1967Illinois Tool WorksComposite container package
US3426939 *Dec 7, 1966Feb 11, 1969Young William EPreferentially deformable containers
US3520441 *Jan 2, 1969Jul 14, 1970Dow Chemical CoContainer
US3539552 *Mar 17, 1969Nov 10, 1970Dow Chemical CoStackable thin walled tubs
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4113095 *Nov 26, 1976Sep 12, 1978Van Dorn CompanyTray-type processed food containers
US4416906 *Jul 13, 1981Nov 22, 1983Golden Valley Foods Inc.Microwave food heating container
US4416907 *Sep 30, 1982Nov 22, 1983Golden Valley Foods Inc.Process for preparing food packages for microwave heating
US4660734 *Apr 4, 1986Apr 28, 1987The Vollrath CompanySteam table pan
US4828112 *Jun 12, 1987May 9, 1989Polar Ware CompanyMetal transport pan
US5035327 *Nov 15, 1990Jul 30, 1991The Vollrath Company, Inc.Receptacle adaptable for nested stacking
US5236097 *Nov 4, 1991Aug 17, 1993Hoover Universal Inc.Plastic container with improved base structure
US5423453 *Aug 18, 1994Jun 13, 1995Mobil Oil CorporationMicrowaveable container
US5615798 *Sep 8, 1994Apr 1, 1997Ropak CorporationContainer incorporating liquid draining means, and related method
US5819975 *Oct 8, 1996Oct 13, 1998Dover Corp.Dispenser sump
US6079587 *Jan 15, 1999Jun 27, 2000Plymouth Manufacturing, Inc.Sloping container bottom with drain
US6398062 *Nov 28, 2000Jun 4, 2002J J Fluid Containment, Inc.Disposable waste fluid containment device
US6543268Apr 2, 2002Apr 8, 2003J. L. Clark, Inc.Deep drawn candle can with formed safety bottom
US6648631Jan 27, 2003Nov 18, 2003J. L. Clark, Inc.Deep drawn candle can with formed safety bottom
US7247017Feb 17, 2004Jul 24, 2007S.C. Johnson & Son, Inc.Melting plate candles
US7591646Jul 17, 2007Sep 22, 2009S. C. Johnson & Son, Inc.Heat exchange method for melting plate candle
US8613249Aug 3, 2007Dec 24, 2013Conagra Foods Rdm, Inc.Cooking apparatus and food product
EP0694478A1 *Jun 30, 1995Jan 31, 19964P Rube Göttingen GmbHCup-shaped container
Classifications
U.S. Classification220/675, 206/119, 220/606, 229/406, 220/608, 220/604, 220/659
International ClassificationB65D1/40, B65D1/42, B65D1/22, B65D1/26
Cooperative ClassificationB65D1/26, B65D1/42
European ClassificationB65D1/26, B65D1/42
Legal Events
DateCodeEventDescription
Apr 8, 1985AS02Assignment of assignor's interest
Owner name: R.L. ADAMS PLASTICS,INC.
Effective date: 19850313
Owner name: RONALD L. ADAMS FAMILY TRUST A,TRUST DATED APR. 16
Apr 8, 1985ASAssignment
Owner name: ADAMS RONALD, L.,FAMILY TRUST A
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:CARRIGAN PLASTIC ,INC., A CORP OF MI;REEL/FRAME:004391/0818
Effective date: 19850312
Owner name: R.L. ADAMS PLASTICS,INC.
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:RONALD L. ADAMS FAMILY TRUST A,TRUST DATED APR. 16,1971;REEL/FRAME:004391/0820
Effective date: 19850313