Base having a flexible vacuum area

What claimed is:




1. A non-round base structure for blow-molded container having rectangular sidewalls, comprising: support heel comprising bearing edge flexible vacuum absorbing area having outer portion roughly ellipsoidal inner portion, said outer portion merging with container rectangular sidewalls said inner portion merging with central concave wall; central concave wall having apex plurality ribs extending outward apex along concave wall, each rib having rounded edge extending outward interior container; whereby vacuum absorbing area ribs cooperate enhance structural integrity container by rigidifying said central concave wall by providing multiple paths interengageable surfaces that make it difficult for deflection, once initiated, propagate undesired distortion.


2. The non-round base structure for blow-molded container claim 1, wherein outer portion roughly ellipsoidal.


3. The non-round base structure for blow-molded container claim 2, wherein flexible vacuum absorbing area enhances support bearing edge upon container filling.


4. The non-round base structure for blow-molded container claim 2, wherein flexible area defines cord length between inner portion outer portion, cord length no more than about 25% longer its longest point than its shortest point.


5. The base structure according claim 1, wherein ribs form substantially symmetric array.


6. The base structure according claim 5, wherein array substantially star-shaped.


7. The base structure according claim 1, wherein there are least about six ribs.


8. The base structure claim 1, wherein vacuum flexible area partially surrounds area defined by concave wall.


9. The base structure claim 8, wherein vacuum flexible area separated into two roughly symmetrical areas by recessed structures opposite sides concave wall.


10. A base structure according claim 1, wherein said base structure comprises polyethylene terephthalate.


11. A non-round base structure for blow-molded container having rectangular sidewalls, comprising: support heel comprising bearing edge flexible vacuum absorbing area having roughly rectangular outer portion roughly ellipsoidal inner portion, said outer portion merging with container rectangular sidewalls said inner portion merging with central concave wall; central concave wall having apex plurality ribs extending outward apex along concave wall, each rib having rounded edge extending outward interior container; whereby vacuum absorbing area ribs cooperate enhance structural integrity container by rigidifying said central concave wall by providing multiple paths interengageable surfaces that make it difficult for deflection, once initiated, propagate undesired distortion.


12. The non-round base structure for blow-molded container claim 11, wherein flexible vacuum absorbing area enhances support bearing edge upon container filling.


13. The non-round base structure for blow-molded container claim 11, wherein flexible area defines cord length between inner portion outer portion, cord length no more than about 25% longer its longest point than its shortest point.


14. The base structure according claim 11, wherein ribs form substantially star-shaped, symmetric array.


15. The base structure claim 11, wherein vacuum flexible area partially surrounds area defined by concave wall.


16. The base structure claim 15, wherein vacuum flexible area separated into two roughly symmetrical areas by recessed structures opposite sides concave wall.


17. A base structure according claim 11, wherein said base structure comprises polyethylene terephthalate.


18. A non-round base structure for blow-molded container having rectangular sidewalls, comprising: support heel comprising bearing edge flexible vacuum absorbing area having roughly ellipsoidal outer portion roughly ellipsoidal inner portion, said outer portion merging with container rectangular sidewalls said inner portion merging with central concave wall, wherein flexible vacuum absorbing area adapted enhance support bearing edge upon container filling defines cord length between inner portion outer portion that no more than about 25% longer its longest point than its shortest point; central concave wall having apex plurality ribs extending outward apex along concave wall form substantially star-shaped symmetric array, each rib having rounded edge extending outward interior container; whereby vacuum absorbing area ribs cooperate enhance structural integrity container by rigidifying said central concave wall by providing multiple paths interengageable surfaces that make it difficult for deflection, once initiated, propagate undesired distortion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e)(1) provisional application No. 60/398,021, filed Jul. 24, 2002.

BACKGROUND OF THE INVENTION

1. Field Invention

The present invention relates generally blow-molded container having base structure which enhances structural integrity container, more particularly non-round base structure having heel-push-up design.

2. Related Art

Many beverage products are sold consuming public plastic containers such those that are shown U.S. Pat. No. 5,005,716 (Eberle), U.S. Pat. No. 4,108,324 (Krishnakumar et al.), U.S. Pat. No. 4,134,510 (Chang). The design plastic containers must take into account container's structural integrity, manufacturing cost mass-produce container, aesthetic appearance container eye consumer.

A hot-fillable plastic beverage container must structurally sound withstand various forces relating so-called “hot-fill” process. Moreover, it must withstand rough handling during transportation ultimate consumer. A “hot-fill” process procedure by which containers are filled with beverage high temperature after which containers are capped. As beverage cools within container, stresses strains develop container due changes volume contents. Containers that store products under pressure, such carbonated beverages, also experience pressure changes due changes ambient temperature. A commercially satisfactory container structure must not only withstand these forces structural viewpoint, but it must also present aesthetically pleasing appearance ultimate consumer.

The price products sold consuming public affected extent by cost packaging. With plastic beverage containers, cost manufacturing container affected by cost plastic composing container. Therefore, if amount plastic container reduced (i.e., process known “light weighting”), cost manufacturing container reduced commensurately. However, achieving this goal it known that thinner walls base container become, greater need utilize imaginative designs provide container that commercially acceptable.

The desire decrease amount plastics used container resulted development different techniques design containers that structural integrity with minimal use plastic. It known that shape location structural elements such ribs, hinges, panels, like affect container's overall structural integrity. While various structural elements molded side panel base structure afford structural integrity, they must also visually appealing consumer.

Krishnakumar et al ('324) illustrate rounded container base structure, which employs various structural elements molded into base that enhances structural integrity. This base design series radially extending ribs, which allow base structure withstand variety applied forces which minimize use plastic.

Eberle ('716) discloses round base structure having central concavity convex heel. The heel surrounds concavity merges with concavity container sidewall. A plurality hollow convex ribs, distributed symmetrical array, interrupt outer surface concavity merge smoothly therewith, each rib extending longitudinally direction heel downwardly inner portion concavity. The wall bottom structure generally decreases thickness progressively innermost point concavity sidewall. The structure allows base withstand various stresses strains applied container also minimizes use plastic.

Chang ('510) shows round base, which employs series circumferential ribs combination with radial ribs provide desired degree structural integrity. The radial ribs intersect all circumferential ribs. The various ribs are solid.

The well known 1.75-liter Tropicana Twister® (a registered trademark Tropicana Products, Inc., 1001 13th Avenue, East Bradenton, Fla. 33506) plastic beverage container rounded heel/push-up base design with very narrow heel surface which functions horizontal bearing surface. However, 1.75-liter Tropicana Twister plastic beverage container contains no vacuum base flex area its base.

Although aforementioned containers base structures may function satisfactorily for their intended purposes, there remains continuing need for blow-molded plastic container having base structure which enhances container structural integrity while requiring minimum use plastic. Also, these base structures need aesthetically pleasing capable being manufactured conventional high-speed equipment.

BRIEF SUMMARY OF THE INVENTION

The substantially non-rounded base structure invention incorporates flexible vacuum absorbing area along with ellipsoid-shaped heel/push-up structure. The design allows for stable horizontal base capability reduce gram weight container while enhancing performance containers vacuum absorption capacity and/or broadens container design possibilities.

The more conventional method been use typical round bottle heel/push up style. This causes base heavier also less capable flexing for vacuum absorption that makes it more difficult light weight container.

The general function flexible vacuum absorbing area works by creating flex area between substantially non-round (e.g., ellipsoid-shaped) push-up heel radius bottle sidewall. This area relatively constant between non-round (ellipsoid-shaped) push-up heel radius bottle sidewall. In contrast, conventional rounded base more dramatic difference area corners container centers. The cord lengths which define flex area vary length but preferably do not exceed difference more than about twenty five percent. This difference allows flex area non-round push up function more efficiently during cooling for vacuum absorption also creates bearing edge for bottle sit more stably than existing like structures.

The present invention provides novel container base structure which improves overall structural integrity container which, addition, uses minimum plastic material. A further object present invention provide container base structure which does not detract aesthetics container even after it been subject various stresses strains associated with filling, transportation handling. A further object present invention provide container having improved base structure, which affords manufacture by high speed, automated equipment minimum cost.

The base structure support heel, which inner outer portion. The outer portion support heel merges with container sidewall. The inner portion support heel merges with central concave wall, central concave wall being surrounded by annular support heel.

The central concave wall plurality ribs. These ribs form symmetrical array. The specific number these ribs vary. The ribs concave surface cooperate enhance structural integrity container base.

Preferably, blow-molded container according present invention may suitably comprise polyethylene terephthalate, which also known more commonly PET. PET semi-crystalline thermoplastic. Depending its transformation state, PET found totally “amorphous” or “semi-crystalline” form. In latter case, its morphology comprised amorphous crystallized phases. In its amorphous state, PET's molecular chains are not organized, sort like big ball yarn. Conversely, its crystallized state, PET's molecular structure dense organized arrangement molecular chains.

Further objectives advantages, well structure function preferred embodiments become apparent consideration description, drawings, examples.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing other features advantages invention become apparent following, more particular description preferred embodiment invention, illustrated accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.

FIG. 1 shows three-dimensional view rectangular container with ribbed vacuum side panel base structure invention;

FIG. 2 shows enlarged view base structure shown FIG. 1;

FIG. 3 shows planar view base structure shown FIGS. 1 2, illustrating ellipsoid shaped concave surface with symmetric array ribs with cross sectional cuts 5 — 5 6 — 6 identified;

FIG. 4 shows planar view base structure shown FIGS. 1 2, illustrating ellipsoid shaped concave surface with symmetric array ribs;

FIG. 5 shows cross section 5 — 5 FIG. 3, with shaded area illustrating relative thickness container wall;

FIG. 6 shows cross section 6 — 6 FIG. 3, with shaded area illustrating relative thickness container wall;

FIG. 7 shows planar view base structure where flex area shown stiple. The flex area typically does not exceed 25% difference cord length measured inside edge outside edge.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments invention are discussed detail below. In describing embodiments, specific terminology employed for sake clarity. However, invention not intended limited specific terminology so selected. While specific exemplary embodiments are discussed, it should understood that this done for illustration purposes only. A person skilled relevant art recognize that other components configurations used without parting spirit scope invention. All references cited herein are incorporated by reference if each had been individually incorporated.

Referring now drawings, FIG. 1 illustrates blow-molded plastic non-round container ( 1 ) such may used sale juices other non-carbonated beverages. The container rectangular sides. Such containers typically designed contain liquid volumes 64 ounces, gallon, or higher. The container ( 1 ) neck ( 2 ) defining opening allowing for filling pouring beverage. The neck ( 2 ) merges with rectangular sidewalls ( 20 ). The rectangular sidewalls ( 20 ) merge with non-round base structure ( 4 ) opposite neck. The container ( 1 ) designed receive cap (not shown) seal container confine beverage inside container. While sidewalls shown are rectangular, any substantially rectangular shape including square shape utilized. In such embodiment, base would shaped appropriately merge with sidewall.

When used hot-fill processing, container filled with beverage elevated temperature. The cap then installed container neck. As temperature beverage air decreases ambient temperatures, its volume decreases. The container its base structure must react reduction volume accommodate stresses strains while remaining structurally sound. Moreover, base must also capable withstanding various other forces, such changes internal pressure with carbonated beverages, usual handling forces.

The base structure present invention shaped withstand these various forces. The base structure reduces need for plastic, yet still enhances overall structural integrity container. To this end, seen FIG. 3, for example, base structure substantially ellipsoidal shaped support heel ( 21 ). The support heel ( 21 ) allows container ( 1 ) supported erect horizontal surface. The support heel ( 21 ) rounded forms continuous line contact with horizontal surface (not shown). Included support heel structure are recessed structures ( 27 ), which enhance horizontal stability container ( 1 ) when placed flat surface.

The support heel ( 21 ) inner outer portion, ( 22 ) ( 23 ), respectively. The outer portion ( 23 ) merges with container's rectangular sidewalls ( 20 ). The inner portion ( 22 ) annular support heel ( 21 ) upwardly inclined surface ( 24 ), which merges with central concave wall ( 25 ). The support heel ( 21 ) flexible region between inner portion ( 22 ) outer portion ( 23 ). The support heel ( 21 ) define cord length X, which extends substantially radial direction between inner portion ( 22 ) outer portion ( 23 ), shown FIG. 4. Preferably, cord length X does not change more by more than about 25% it extends around base ( 4 ) container ( 1 ). That is, cord length its longest point preferably no more than 1.25 times cord length its shortest point. For example, show embodiment FIG. 4, cord length X its shortest point 1.2 times X its longest point.

The central concave wall ( 25 ) provided with integral molded structural elements that provide base ( 4 ) with sufficient structural integrity withstand various forces acting container ( 1 ). To this end, central concave wall ( 25 ) plurality ribs ( 26 ), which extend center outward. The ribs rounded edge ( 28 ), which extends outward relative interior container. The ribs form symmetric array. See, e.g., FIGS. 2–4 7 .

As shown FIGS. 2–4 7 , central concave wall ( 25 ) illustrated with array six ribs. However, greater or fewer number ribs used so long function achieved.

Containers having this base structure design produced commercial quantities with high-speed equipment.

All references cited this specification are hereby incorporated by reference. The discussion references herein intended merely summarize assertions made by their authors no admission made that any reference constitutes prior art relevant patentability. Applicant reserves right challenge accuracy pertinency cited references.

The embodiments illustrated discussed this specification are intended only teach those skilled art best way known inventors make use invention. Nothing this specification should considered limiting scope present invention. All examples presented are representative non-limiting. The above-described embodiments invention may modified or varied, without departing invention, appreciated by those skilled art light above teachings. It therefore understood that, within scope claims their equivalents, invention may practiced otherwise than specifically described.