WO2000007886A1

WO2000007886A1 - Plastic container with low profile base

Info

Publication number: WO2000007886A1
Application number: PCT/US1999/016955
Authority: WO
Inventors: Jizu J. Cheng; Jeffrey D. Krich
Original assignee: Crown Cork & Seal Technologies
Priority date: 1998-08-06
Filing date: 1999-07-27
Publication date: 2000-02-17
Also published as: AU5233299A

Abstract

A plastic container (10) for packaging a liquid such as bottled water includes a finish portion (12), a main body (16), and a footed base (18) that possesses a unique low profile configuration that creates enough surface area in the base to adequatly minimize reaction stress forces that might occur from pressurization of the container (10), but that aesthetically minimizes the presence of the footed base (18). The base is unitary with a lower end of the main body and includes a plurality of support feet (20) at a bottom end thereof and a corresponding plurality of valleys that are positioned between adjacent support feet (20). The base further has a major height (HB) that is defined as the vertical distance between a lowermost extension (24) of the support feet and an uppermost point (26) of the base, and a major diameter DB that is defined as the diameter of the base at its point of maximum diameter. The low profile configuration of the base is defined as a ratio HB/DB that is within a range of about 0.05 to about 0.45.

Description

PLASTIC CONTAINER WITH LOW PROFILE BASE

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to the field of container making, and more specifically to blow molded plastic bottles, such as the PET bottles that are in common use today for packaging soft drinks such as soda. 2. Description of the Related Technology

During the last twenty-five years or so, there has been a dramatic shift in the packaging of carbonated beverages, particularly, soft drinks, away from glass containers and toward plastic containers. The plastic containers initially took the form of a two-piece construction, wherein a plastic bottle having a generally hemispherical bottom was applied a separate base cup, which would permit the bottle to be stood upright. The hemispherical bottom was seen as the most desirable shape for retaining the pressure generated by the carbonation within the container. Pressures in such containers can rise to 100 p.s.i. or more when the bottled beverage is exposed to the sun, stored in a warm room, car trunk, or the like. Such plastic containers represented a significant safety advantage over glass containers when exposed to the same internal pressures. However, the two-piece construction was not economical because it required a post molding assembly step, and, also a separation step prior to reclaiming or recycling the resins forming the bottle and base cup. During this period of development, various attempts were made to construct a one-piece, self-supporting container that would be able to retain the carbonated beverages at the pressures involved. Such a one-piece container requires the design of a base structure which will support the bottle in an upright position and will not bulge outwardly at the bottom. A variety of designs 1/1 were first attempted, with most following one of two principal lines of thought. One line of designs involved a so-called champagne base having a complete annular peripheral ring. Examples of such bottles are found in U.S. Pat. Nos. 3,722,726; 3,881,621; 4,108,324; 4,247,012; and, 4,249,666. Products incorporating the champagne-type base have waned in recent years, having been replaced in large part by so-called "footed" bases, which include a plurality of feet that protrude downward from a curved bottom. Examples of this variety are to be found in U.S. Pat. Nos. 3,598,270; 4,294,366; 4,368,825; 4,865,206; and, 4,867,323. In recent years, the latter type of design has achieved primacy in the marketplace. Champagne-type bases are still popular, though, for packaging certain beverages as bottled waters. Recent trends in the bottled water industry, such as the use of pressurized gas within contains to provide a stiffening effect, have led some bottlers to contemplate the use of footed bases. Footed bases are in general superior to champagne- type bases for holding pressurized contents, because their greater surface area reduces the average stress reaction force in the base area. Some customers have become acclimated, though, to the aesthetic effect of the champagne-type base for certain brands of bottled waters, and may be resistant to any packaging of these products in a footed-type container.

There is a need, then, for a container that approximates the aesthetic effect of a container having a champagne-type base, but that provides the protection against stress reaction forces that is afforded by a container of the type that has a footed base.

SUMMARY OF THE INVENTION

It is, therefore, an object of the invention to provide a container that approximates the aesthetic effect of a container having a champagne-type base, but that provides the protection against stress reaction forces that is afforded by a container of the type that has a footed base. In order to achieve the above and other objects of the invention, a plastic container according to a first aspect of the invention includes a finish portion; a main body; and a base that is unitary with a lower end of the main body, the base comprising a plurality of support feet at a bottom end thereof and a corresponding plurality of valleys that are positioned between adjacent support feet, the base further having a major height H_B that is defined as the vertical distance between a lowermost extension of the support feet and an uppermost point of the base, and a major diameter D_B that is defined as the diameter of the base at its point of maximum diameter; and wherein the base is given a low profile configuration, the low profile configuration being defined as a ratio H_B/D_B; and wherein H_B D_B is within a range of about 0.05 to about 0.45.

According to a second aspect of the invention, a plastic container includes a finish portion; a main body; and a base that is unitary with a lower end of the main body, the base comprising a plurality of support feet at a bottom end thereof and a corresponding plurality of valleys that are positioned between adjacent support feet, the base further having a major height H_B that is defined as the vertical distance between a lowermost extension of the support feet and an uppermost point of the base, and a major diameter D_B that is defined as the diameter of the base at its point of maximum diameter; and wherein the base is given a low profile configuration, the low profile configuration being defined as a ratio H_B/D_B; and wherein H_B/D_B is within a range of that is sufficient to create enough surface area in the base to adequately minimize reaction stress forces that might occur from pressurization of the container, but that is also small enough to aesthetically minimize the presence of the footed base.

These and various other advantages and features of novelty that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a perspective view of a container that is constructed according to a preferred embodiment of the invention; FIGURE 2 is an elevational view of the container shown in FIGURE 1 ; and

FIGURE 3 is a bottom plan view of the container shown in FIGURES 1 and 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to FIGURE 1 , a plastic container 10 that is constructed according to a preferred embodiment of the invention for packaging a liquid such as bottled water includes a finish portion 12, a neck portion 14, a main body 16, and a footed base 18. Container 10 is preferably fabricated from a material including polyethylene terephthalate (PET). Base 18 possesses a unique low profile configuration that creates enough surface area in the base 18 to adequately minimize reaction stress forces that might occur from pressurization of the container 10, but that aesthetically minimizes the presence of the footed base 18.

As may best be seen in FIGURE 2, base 18 is unitary with a lower end of the main body 16 and includes a plurality of downwardly projecting support feet 20 at a bottom end thereof. Base 18 further includes a corresponding plurality of valleys 22 that are positioned between adjacent support feet 20.

Base 18 further has a major height H_B that is defined as the vertical distance between a lowermost extension 24 of the support feet and an uppermost point 26 of the base, and a major diameter D_B that is defined as the diameter of the base at its point of maximum diameter. In order to adequately minimize reaction stress forces that might occur from pressurization of the container 10, while further aesthetically minimizing the presence of the footed base 18, the low profile configuration of the base is defined as a ratio H_B/D_B . Preferably, the ratio Hβ/D_B is within a range of about 0.05 to about 0.45. More preferably, H_B/D_B is within a range of about 0.20 to about 0.35. In the most preferred embodiment, H_B/D_B is within a range of about 0.25 to about 0.30. In the illustrated embodiment, H_B/D_B is about 0.28. Preferably, in a container 10 that has a volumetric capacity of about eight fluid ounces, D_B is within a range of about 50mm to about 65mm; and H_B is within the range of about 10mm to about 20 mm. More preferably, D_B is within a range of about 55 mm to about 59 mm and H_B is within the range of about 13 mm to about 18 mm. In the illustrated embodiment, D_B is about 57 mm and H_B is about 15.94 mm. It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims

WHAT IS CLAIMED IS:

1. A plastic container, comprising: a finish portion; a main body; and a base that is unitary with a lower end of said main body, said base comprising a plurality of support feet at a bottom end thereof and a corresponding plurality of valleys that are positioned between adjacent support feet, said base further having a major height H_B that is defined as the vertical distance between a lowermost extension of said support feet and an uppermost point of said base, and a major diameter D_B that is defined as the diameter of the base at its point of maximum diameter; and wherein said base is given a low profile configuration, said low profile configuration being defined as a ratio H_B/D_B; and wherein H_B/D_B is within a range of about 0.05 to about 0.45.

2. A plastic container according to claim 1, wherein H_B/D_B is within a range of about 0.20 to about 0.35.

3. A plastic container according to claim 2, wherein H╬▓/D_B is within a range of about 0.25 to about 0.30.

4. A plastic container according to claim 1 , wherein said container has a volumetric capacity of about eight fluid ounces, wherein D_B is within a range of about 50mm to about 65mm; and wherein H_B is within the range of about 10mm to about 20mm.

5. A plastic container according to claim 4, wherein D_B is within a range of about 55mm to about 59mm; and wherein H_B is within the range of about 13mm to about 18mm.

6. A plastic container according to claim 1, wherein said container is fabricated from a material including polyethylene terephthalate (PET).

7. A plastic container, comprising: a finish portion; a main body; and a base that is unitary with a lower end of said main body, said base comprising a plurality of support feet at a bottom end thereof and a corresponding plurality of valleys that are positioned between adjacent support feet, said base further having a major height H_B that is defined as the vertical distance between a lowermost extension of said support feet and an uppermost point of said base, and a major diameter D_B that is defined as the diameter of the base at its point of maximum diameter; and wherein said base is given a low profile configuration, said low profile configuration being defined as a ratio H_B/D_B; and wherein H_B/D_B is within a range of that is sufficient to create enough surface area in the base to adequately mimmize reaction stress forces that might occur from pressurization of the container, but that is also small enough to aesthetically minimize the presence of the footed base.