Multi-spring hinge base for plastic bottles

Abstract

A movable base for a PET beverage container that can withstand internal pressure changes during hot filling and cooling processes. The container comprises an opening at the top, a sidewall, and a multi-spring hinge base portion comprising multiple footed portions and a plurality of radiating compound tension ribs. The base foot portion has a specific curved geometry that allows it to move inward and to resist moving outward in response to pressure changes. A foot tension rib within the base is comprised of an outer spring hinge, a central folding hinge, and a push-up spring hinge and can be radially offset from a push-up tension rib, or else be aligned or contiguous. The compound tension ribs provide structural support and flexibility to the base. The movable base reduces the risk of base roll-out, improves container stability, and provides for an even base movement during the hot-filling process and a spring return following a cooling of a heated liquid within.

Description

[0001] MULTI-SPRING HINGE BASE FOR PLASTIC BOTTLES

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a container, in particular a multi-spring hinge base for a plastic container.

[0004] BACKGROUND OF THE INVENTION

[0005] PET (polyethylene terephthalate) is a widely used material for producing beverage containers, especially for hot-filled products such as juices, teas, and sports drinks. PET containers have many advantages, such as light weight, transparency, recyclability, and resistance to breakage. However, PET containers also have some drawbacks, such as sensitivity to temperature and pressure changes. During the hot filling and cooling process, the container is exposed to high temperatures and pressures, followed by rapid cooling and depressurization. This causes a vacuum to form inside the container, which can result in deformation and collapse of the container, especially at the base portion. To prevent this, various designs of the base have been proposed, such as petaloid, champagne, and panel bases. However, these designs have some limitations, such as complexity, cost, and aesthetic issues.

[0006] It is an object of the invention to provide a container with a multi-spring hinge base which overcomes or at least partially ameliorates some of the abovementioned drawbacks or which at least provides the public with a useful choice.

[0007] In this specification, where reference has been made to external sources of information, including patent specifications and other documents, this is generally for the purpose of providing a context for discussing the features of the invention. Unless stated otherwise, reference to such sources of information is not to be construed, in any jurisdiction, as an admission that such sources of information are prior art or form part of the common general knowledge in the art. For the purpose of this specification, where method steps are described in a sequence, the sequence does not necessarily mean that the steps are to be chronologically ordered in that sequence, unless there is no other logical manner of interpreting the sequence.

[0008] BRIEF DESCRIPTION OF THE INVENTION

[0009] According to an aspect, the invention may be said to broadly comprise of a multispring hinge base for a plastic container, the multi-spring hinge base including a conical push-up having a variable angular displacement in a circumferential or radial array and a plurality of compound tension rib structures arranged radially around a longitudinal axis of the container. The plurality of compound tension rib structures comprises a plurality of foot tension ribs and a plurality of push-up tension ribs. The foot tension ribs and the push-up tension ribs are disconnected from each other.

[0010] In some configurations, the plurality of foot tension ribs may be radially separated by a plurality of inner foot portions having a concave or curved surface, wherein the plurality of foot tension ribs may comprise three sections: (i) an outer- spring-hinge; (ii) an outer push-up spring hinge; and, (iii) a central folding hinge that connects the outer spring hinge to the outer push-up spring hinge.

[0011] In some configurations, the push-up-tension rib may comprise two sections: (i) an inner push-up spring hinge; and (ii) a central suspension ridge that connects the inner push-up spring hinge to a centre of a push-up top.

[0012] In some configurations, the inner foot portion may comprise a concave surface, when viewed from the underside of the container, configured to move inward and outward in response to pressure changes.

[0013] In some configurations, the concave surface may arc a geometry of the inner foot portion away from a standing surface and in a direction of a neck of the container thereby creating more distance between the inner foot portion and a contact surface of the container, and creating greater roll-out protection under a positive pressure build-up during a hot-filling process prior to cooling of the container.

[0014] In some configurations, the concave surface may act as a spring arch to resist against outward expansion under internal positive pressure.

[0015] In some configurations, the foot tension ribs and the push-up tension ribs may be radially offset from each other.

[0016] In some configurations, the foot tension ribs and the push-up tension ribs may be radially offset at an angle.

[0017] In some configurations, the foot tension ribs and the push-up tension ribs may be radially aligned with each other.

[0018] In some configurations, the foot tension ribs and the push-up tension ribs may be radially aligned at an angle.

[0019] In some configurations, the foot tension ribs and the push-up tension ribs may be contiguous with each other.

[0020] In some configurations, the foot tension ribs and the push-up tension ribs may be disconnected from each other.

[0021] In some configurations, the foot tension ribs and the push-up tension ribs may overlap at a variable inner radius located between a push-up geometry and an outer foot and tension rib geometry.

[0022] In some configurations, the multi-spring hinge base may include seven foot tension ribs and seven push-up tension ribs. In some configurations, the multi-spring hinge base may include more than seven foot tension ribs and seven push-up tension ribs.

[0023] In some configurations, the central folding hinge may comprise a top spring surface and an angle between each of the sides of the central folding hinge may be between about 5 and 60 degrees. In some configurations, the angle may be between about 10 and 35 degrees. In some configurations, the angle may be between about 5 and 30 degrees and may create an acute angle providing less resistance to inward and outward movement of the top spring surface. In some configurations, the angle may be between about 30 and 60 and may create an acute angle providing more resistance to inward and outward movement of the top spring surface.

[0024] In some configurations, the central suspension ridge may create an outward angular displacement portion from the conical push-up.

[0025] According to another aspect, the invention may be said to broadly consist in a method of blow molding a container. The blow molded container comprises a multispring hinge base as defined hereinabove in the first aspect. The muti-spring hinge base comprises a plurality of central suspension ridges configured to provide an effective lower surface area contacting a flowing plastic of a heated preform.

[0026] According to another aspect, the invention may be said to broadly comprise of a multi-spring hinge base for a PET beverage container, comprising (a) an array of foot tension ribs radially separated by inner foot portions, each foot tension rib including: i. an outer spring hinge; ii. an outer push-up spring hinge; and, iii. a central folding hinge connecting said outer spring hinge to the outer push-up spring hinge; (b) an array of push-up tension ribs, each comprising: i. an inner push-up spring hinge; and, ii. a central suspension ridge connecting said inner push-up spring hinge to a push-up top. The variable inner radius, located between a central push-up portion and an inner foot region, is configured such that the radial size and position of each inner push-up spring hinge and paired outer push-up spring hinge are adjustable relative to said variable inner radius. The combined radial dimension of any pair comprising an inner push-up spring hinge and an outer-push-up-spring-hinge (10) is between 1.5 mm and 10.0 mm. During inversion, overlapping segments of said spring hinge pairs on the variable inner radius disrupt continuity of the hinge surface at the variable inner radius.

[0027] Other aspects of the invention may become apparent from the following which is given by way of example only and with reference to the accompanying drawings.

[0028] As used herein the term “and / o means “and" or “or”, or both.

[0029] As used herein “(s)” following a noun means the plural and / or singular forms of the noun. The term “comprising" as used in this specification and claims means “consisting at least in part of." When interpreting statements in this specification and claims which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as “comprise" and “comprised’ are to be interpreted in the same manner.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will now be described by way of example only with reference to the drawings in which:

[0032] FIG. 1 is an isometric view of a container with a muti-spring hinge base, constructed and operative in accordance with embodiments of the present invention;

[0033] FIG. 2 is an isometric view of a container with a muti-spring hinge base, constructed and operative in accordance with another embodiment of the present invention;

[0034] FIG. 3 is an elevation view of the container of FIG. 1 , constructed and operative in accordance with embodiments of the present invention;

[0035] FIG. 4 is an underneath view of the container of the container of FIG. 1 , constructed and operative in accordance with embodiments of the present invention; FIG. 5 is a cross-sectional view of the multi-spring base of the container of FIG.

[0036] 4 taken along plane A-A, constructed an operative in accordance with embodiments of the present invention; and,

[0037] FIG. 6 is a cross-sectional view of the multi-spring base of the container of FIG.

[0038] 5 under vacuum pressure, constructed and operative in accordance with embodiments of the present invention.

[0039] DETAILED DESCRIPTION

[0040] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the various principles of the present invention. However, those skilled in the art will appreciate that not all these details are necessarily always required for practicing the invention.

[0041] Reference is now made to FIGs. 1 to 4, which are schematic illustrations of containers with a multi-spring hinge base, constructed and operative in accordance with some embodiments of the invention. FIGs. 1 and 2 include the following numerical references:

[0042] 1. Multi Spring-Hinge Base;

[0043] 2. Inner Foot Portion;

[0044] 3. Central Push-up Portion;

[0045] 4. Top Spring Surface;

[0046] 5. Compound Tension Rib;

[0047] 6. Variable Inner Radius;

[0048] 7. Foot Tension Rib;

[0049] 8. Central Folding Hinge;

[0050] 9. Outer Spring Hinge;

[0051] 10. Outer Push-up Spring Hinge;

[0052] 11. Push-up Tension Rib;

[0053] 12. Inner Push-up Spring Hinge;

[0054] 13. Central Suspension Ridge; and,

[0055] 14. Push-up Top The present invention provides a novel design of a moveable multi spring-hinge base for a PET beverage container that can overcome the problems of the prior art. The movable base can and / or may be configured to adapt to the vacuum pressure during the hot filling and cooling processes. The movable base can also and / or may also be configured to maintain the shape and stability of the container. The movable base may comprise an outer annular base wall or chime, a plurality of base foot portions having a contact surface and an inner foot portion, and a plurality of compound tension ribs. The chime may be connected to the body of the container and may form a circular opening at the bottom. The base foot may be attached to the base wall and may extend radially inward. The base foot may have a specific curved geometry within an inner foot portion that allows it to move inward and outward in response to pressure changes. The plurality of compound tension ribs may be arranged circumferentially around the base wall and the base foot. The compound tension ribs may be offset from each other and may extend from the base wall to the base foot. In an embodiment of the invention, the compound tension ribs extend into a central push-up portion of the base. The compound tension ribs provide structural support and flexibility to the base. The movable base reduces the risk of container deformation and improves the appearance and stability of the container, providing increased contact surface stability and decreased outward movement under internal raised pressures, and increased inward movement under lowered internal pressures.

[0056] The moveable base may be divided into two portions. When considering a distance measured horizontally from the longitudinal axis of the container to the lower bumper of the container, the inner half of the distance primarily may encompass the central push-up portion and associated push-up tension ribs. The outer half of the distance may be generally occupied by the foot geometry and the associated foot tension ribs. The central push-up portion and the foot portions may be connected by a variable inner radius (6) created between the circumferential radius C and radius D illustrated on FIG. 4 and also connected in preferred embodiments by multiple compound tensions ribs comprising the foot tension ribs and the push-up tension ribs. As can be seen in FIGs. 5 and 6, in response to vacuum forces, the variable inner radius (6) may comprise a moveable radius [3 adjacent the outer push-up spring hinge (10) and a moveable radius y adjacent the inner push-up spring hinge (12), each having a different angular radius of curvature. Each radius of curvature may change or reduce as the central push-up portion may move vertically upward and away from a contact plane defined by the contact surfaces of the feet, while the outer foot and tension rib geometry may invert away from a contact plane defined by the contact surfaces, articulating from an outer radius. The angular radius of curvature a of the central suspension ridge 13 may not change as the moveable radius [3 and the moveable radius y move and change in curvature.

[0057] The plurality of compound tension ribs (5) extend radially outward from a centre of the base and are arranged in a pattern around the longitudinal axis of the container. The plurality of compound tension ribs (5) may generally comprise of two primary portions: a push-up tension rib (11 ) and a foot tension rib (7). The push-up tension rib (11 ) may be located in the base push-up area and located in the inner most half of the moveable base. The foot tension rib (7) may be located on the outer most half, near the outer circumference of the moveable base

[0058] When the two portions of the compound tension rib (5) are alternating in radial position from each other, and are not contiguous or aligned or geometrically connected, then each of the inner push-up spring hinge (12) and the outer push-up spring hinge (10) may be arranged or configured to act as spring hinges independent of each other.

[0059] When the two portions of the compound tension rib (5) are aligned in a co-linear fashion with each other, and are contiguously connected, then the inner push-up spring hinge (12) and the outer push-up spring hinge (10) may form a contiguous spring hinge.

[0060] When the two portions of the compound tension rib (5) are alternating in radial position from each other but are not perfectly out of synchronisation in their alternating placement, and are not contiguously connected, then each of the inner push-up spring hinge (12) and the outer push-up spring hinge (10) may be arranged or configured to act as spring hinges independent of each other.

[0061] The configuration of the compound tension rib (5) components can be aligned and contiguous, or unaligned and disconnected, or aligned and disconnected, or unaligned and connected. The specific interaction between the components of the compound tension rib, and the variably angled push-up and specifically curved foot geometry, controls the movement of the multi spring-hinge base during the hot-filling and cooling phases of the container life cycle more efficiently than found in prior art.

[0062] Adjacent to a variable inner radius (6), or in the location of the variable inner radius (6), the two portions of the compound tension rib (5), the push-up-tension rib (11 ) and the foot-tension rib (7), may meet or overlap. The outer push-up spring hinge (10) of the foot-tension rib (7) controls the spring rate of the foot tension rib (7) and therefore the propensity of the top spring surface (4) to move and activate. The inner push-up spring hinge (12) of the push-up-tension rib controls the spring rate of the push-up-tension rib (11 ) and therefore also controls the propensity of the top spring surface (4) to move and activate. Larger hinge portions slow the movement of the base down and require more internal pressure to be present to move the base inward or outward. This is particularly useful when configuring a base to resist “base roll-out” whereby the geometry of a base will roll-out below the standing surface in response to internal pressure after filling and capping, making the container unstable on the line and prone to tipping and otherwise causing production issues.

[0063] The foot tension ribs (7) of the base may generally comprise of an outer-spring- hinge (9), a central-folding-hinge (8), and an outer push-up spring hinge (10). The outer push-up spring hinge (10) may be adjacent to the base push-up, and the outer-spring- hinge (9) may terminate near the outer edge of the movable base. The central folding hinge (8) may include a top spring surface (4) that is closer to the upper portion or neck finish of the container and connects the outer push-up spring hinge (10) and the outer- spring-hinge (9). The side profile of the central-folding-hinge (8) radiating from the centre of the container to the outside, may be either substantially straight or arced in a vertical direction, and the profile of the top spring surface (4) may also be substantially straight or arced in a transverse direction.

[0064] The central profile of the top spring surface (4) of the central-folding-hinge (8), if revolved about the longitudinal axis of the container, may determine a spring-surface panel that may be vertically offset from the bottom surface of the container comprising the heel or chime region or outer annular wall, the contact surface and the inner foot portion (2).

[0065] During an increase in positive pressure within the container during the initial phases of the hot-filling process, the top spring surface (4) may be configured to start angled in a convex manner downwards, or horizontally flat relative to the tabletop, or angled in a concave and upward position relative to the contact plane. The top spring surface (4) may be configured to move downward in direction to become increasingly convex as the internal positive pressure exerts force on the multi spring-hinge base.

[0066] The outer push-up spring hinge (10) and the outer-spring-hinge (9) of the foot tension rib (7) may be configured to affect resistance to this outward movement. A bigger outer or inner spring-hinge relative to the central folding hinge (8) length, will increase the resistance to outward and inward movement of the top spring surface (4).

[0067] The central folding hinge (8) may generally consist of the central profile section profile running along the centre of the central folding hinge (8). This profile may define the top spring surface (4) and may be the profile theoretically revolved about the longitudinal axis of the container to define a spring surface panel. This top spring surface (4) may define the degrees of movement that the multi-spring hinge base is configured to articulate and adjust the volume within the container when a vacuum is induced. Adjacent to the central profile are the two sides of the central folding hinge (8). These central folding hinge (8) sides may connect the centre of the central folding hinge (8) to the feet of the multi spring-hinge base (1 ). The central folding hinge (8) sides can be straight, or substantially straight, or otherwise curved in a multitude of ways, however, the sides may define hypothetical angles between the inner edge adjacent to the top spring surface (4) of the central folding hinge (8) profile, and the outer edge adjacent to the inner foot portions (2) of the multi-spring hinge base(1 ), and this angle when measured between each sides of the central folding hinge (8) may be between 5 and 60 degrees, but more preferably between 10 and 35 degrees.

[0068] The angle between each side of the central folding hinge (8) may be specifically calibrated to adjust its resistance to movement. A more acute angle between each side of the central folding hinge (8) provides for less resistance to movement inward and outward of the top spring surface (4) and therefore lowers the pressure forces required to affect movement within the container. This effects both inward movement of the top spring surface (4) in response to vacuum and outward movement in response to positive pressure. A wider or larger angle between each side of the central folding hinge (8) may effectively increase the pressure required to move the sides and move the base through to a new position, either farther inward or outward.

[0069] The inner push-up spring hinge (12) of the push up tension rib (11 ) may also be configured to affect resistance to this outward movement of the inner foot portion (2). A larger inner push-up spring hinge (12) relative to the central folding hinge (8) length, increases the resistance to outward and inward movement of the top spring surface (4) and inner foot portions (2).

[0070] As best seen in FIGs. 5 and 6, a central portion of the push-up (3) may be closer to the upper portion and neck finish of the container and further from the contact surface of the container than the inner foot portion (2). The central portion of the pushup may be generally conical in shape and variable in conical angular displacement in a circumferential or radial array. The ‘effective’ angle of the conical portion underlying the push-up tension rib (11 ) with respect to a longitudinal axis (x-x) of the container may be greater than the angle on the opposite side of the conical portion. The variable angular displacement of the push-up sides creates variable inner radii in a radial displacement around the longitudinal axis and form important control mechanisms within the push up spring hinges and inner push up spring hinges through an array of changing and complex geometry. The central portion may further include a push-up tension rib (11 ) comprising a central suspension ridge (13), connecting an inner pushup spring hinge (12) at the bottom of the push-up tension rib (11 ) to the push-up top (14) comprising the centre of the push-up geometry at the top of the push-up. As can be seen, the central suspension ridge (13) of the push-up tension rib (11 ) may retain its angular setting during vacuum movement of the base, thereby preventing any movement within the central push-portion (3) itself from contributing to any vacuum compensation through local deformation. The central push-portion (3) may be moved upwards only under the directed forces of the compound tension rib (5).

[0071] During the container blowing process, as the blown preform makes contact with the push-up portion of the mold, the central suspension ridge (13) makes immediate contact with the flowing plastic of the preform and controls the flow of heated plastic material by directing or suspending it away from the central portion of the push-up (3). This helps guide the plastic material of the preform away from the push-up and towards the outer edge of the base, by providing a lower surface area contacting the flowing plastic and increasing the ability of the operator to move necessary plastic volume to the comers of the container and avoiding too much material being trapped in place around the central portion of the push-up (3).

[0072] Furthermore, this invention relates to the specific geometric shaping of the inner foot portion (2) located between the foot tension ribs (7) in the base. The geometry of the curved foot surface of the inner foot portion (2) of the base, which may be located in between the standing or contact surfaces and the central push-up, may be configured to be concave upwardly when viewing the underside of the container.

[0073] The concave shaping of the inner foot portion (2) may be configured to arc the foot geometry away from the contact or standing surface and in the direction of the neck of the container. When the container is responding to a positive internal pressure and the top spring surface (4) and majority of the base is moving towards the contact surface, this curved foot surface increases the distance the multi-spring hinge base will have to move before roll-out and performance failure will occur. The container will be more robust and be able to withstand more pressures and unintended forces on the filling line and will therefore be able to be deployed on more lines, especially those with older equipment.

[0074] The curved foot geometry specific curved surface may be configured to move inward in response to vacuum pressures more easily while simultaneously resistant to moving outward in response to positive pressure changes during the initial phases of the hot-filling process.

[0075] Furthermore, this invention relates to the specific shaping of the push-up geometry between the push-up tension ribs (11 ).

[0076] Furthermore, this invention introduces a sophisticated folding mechanism that enables controller horizontal articulation around spring hinges during vacuum phases, thereby reducing strain during hot-filling processes. This invention ensures structural integrity of the bottle or container sidewall while accommodating dynamic pressure changes. During cooling, internal vacuum forces draw the base inward, the top spring surface (4) transitions to a substantially horizontal plane and then inverts upwards in a concave manner when viewed from the base. During this inversion phase, and specifically as the top spring surface approaches, inhabits, and recedes from its substantially horizontal position, the various spring hinges are configured to facilitate horizontal distortion as well as vertical distortion. This is in contrast to horizontally rigid structures present in the industry today. This added ability to fold and compress more easily in the horizontal plane, as well as in the vertical plane, allows the base to invert at a lower vacuum state than otherwise would be necessary.

[0077] The base may fold horizontally along strategic hinge points such as the central folding hinge (8). The sides of this hinge (8), which may connect to both the top spring surface (4) and the inner foot region (2), are engineered with angles that guide symmetric inward movement. This distributed folding guides and prevents uneven inversion of the base. The outer push-up spring hinge (10) and the inner push-up spring hinge (12) further enhance this functionality by acting as pivot points that allow localized bending while maintaining overall stability. During inversion, these hinges work in concert with the central folding hinge (8) to create a layered flexure pattern. The variable inner radius (6) at the base of the tension ribs ensures that stiffness is modulated precisely where needed - larger radii curves in the variable inner radius create stiffer sections that resist outward expansion under pressure, while more flexible zones enable smooth folding during vacuum.

[0078] The interaction between foot tension ribs (7) and push-up tension ribs (11 ) plays a significant role in this mechanism. Their radial arrangement - whether offset at specific angles or aligned - ensures that stress is transferred efficiently across ribs during folding. For instance, radially offset ribs allow independent flexure paths, while contiguous or overlapping designs reinforce localized load-bearing capacity. This redundancy ensures that the base inverts uniformly without forming sharp creases or experiencing uneven strain.

[0079] Additionally, the top spring surface (4) acts as a control plane for articulation, defining maximum and minimum bending limits to prevent over-flexure during the hot phase which would lead to base roll-out.

[0080] This multi-hinge architecture ensures that the base behaves as a self-regulating system during inversion. Under vacuum, horizontal folding around inner and outer push-up spring hinges facilitates base inversion. This is a notable advantage for preventing bottle sidewall deformation and ensuring durability in beverage packaging applications.

[0081] The present invention provides further refinements for tailoring the flexural behaviour of the multi-spring hinge base during pressure changes in hot filling and cooling processes. Specifically, by adjusting the radial size and position of the inner push-up spring hinge (12) and outer push-up spring hinge (10) relative to the variable inner radius (6), the flexure of the container during critical bottling phases can be precisely controlled.

[0082] The radial dimensions of any pair comprising an inner push-up spring hinge (12) and an outer push-up spring hinge (10) may be designed such that their combined radius falls within a range of 1 .5 mm to 10.0 mm. Varying radii values balance structural integrity with flexibility under both positive pressure during hot filling and vacuum- induced deformation during cooling or inversion.

[0083] During container inversion (e.g., when the top spring surface (4) transitions from a downwardly inclined place to a substantially horizontal plane, through to an upwardly inclined plane), the overlap of these spring hinge pairs over the variable inner radius (6) disrupts its surface continuity, enabling localized compression and distortion of this region. This disruption allows the variable inner radius (6) to absorb strain more effectively during inversion, since it has horizontal, as well as vertical, freedom of movement. Reducing the overall vacuum threshold within the container, prevents dents or otherwise unwanted deformation occurring in other parts of the bottle’s geometry.

[0084] The overlap positions between the inner push-up spring hinge (12) and the outer push-up spring hinge (10) may be strategically located on the variable inner radius (6) to break its continuous hinge surface into segments, or to otherwise increase the contiguous surface of the variable inner radius (6), thereby enabling, or restricting, horizontal distortion. Allowing for fine tuning, and precise control over the bottle base’s freedom of movement through the filling line.

[0085] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Claims

CLAIMS1. A multi-spring hinge base for a plastic container comprising: a conical push-up (3) having a variable angular displacement in a circumferential or radial array; and, a plurality of compound tension rib (5) structures arranged radially around a longitudinal axis of the container; wherein the plurality of compound tension rib (5) structures comprise a plurality of foot tension ribs (7) and a plurality of push-up tension ribs (11 ).

2. The multi-spring hinge base of claim 1 , wherein the plurality of foot tension ribs (7) are radially separated by a plurality of inner foot portions (2) having a concave or curved surface, wherein the plurality of foot tension ribs (7) comprise three sections:(i) an outer-spring-hinge (9);(ii) an outer push-up spring hinge (10); and,(iii) a central folding hinge (8) that connects the outer spring hinge (9) to the outer push-up spring hinge (10).

3. The multi-spring hinge base of claim 1 or 2, wherein the push-up-tension rib (11 ) comprises two sections:(i) an inner push-up spring hinge (12); and,(ii) a central suspension ridge (13) that connects the inner push-up spring hinge (12) to a centre of a push-up top (14).

4. The multi-spring hinge base of claim 2 or 3, wherein the inner foot portion (2) comprises a concave surface when viewed from the underside of the container and is configured to move inward and outward in response to pressure changes.

5. The multi-spring hinge base of claim 4, wherein the concave surface arcs a geometry of the inner foot portion away from a standing surface and in a direction of a neck of the container thereby creating more distance between the inner foot portion and a contact surface of the container, and creating greater roll-out protection under a positive pressure build-up during a hot-filling process prior to cooling of the container.

6. The multi-spring hinge base of claim 5, wherein the concave surface acts as a spring arch to resist against outward expansion under internal positive pressure.

7. The multi-spring hinge base of claim 1 , wherein the foot tension ribs (7) and the push-up tension ribs (11 ) are radially offset from each other.

8. The multi-spring hinge base of claim 1 , wherein the foot tension ribs (7) and the push-up tension ribs (11 ) are radially aligned with each other.

9. The multi-spring hinge base of claim 1 , wherein the foot tension ribs (7) and the push-up tension ribs (11 ) are radially offset at an angle.

10. The multi-spring hinge base of claim 8, wherein the foot tension ribs (7) and the push-up tension ribs (11 ) are radially aligned at an angle.11 . The multi-spring hinge base of claim 1 , wherein the foot tension ribs (7) and the push-up tension ribs (11 ) overlap at a variable inner radius (6) located between a pushup geometry and an outer foot and tension rib geometry.

12. The multi-spring hinge base of claim 1 , comprising seven foot tension ribs (7) and seven push-up tension ribs (11 ).

13. The multi-spring hinge base of claim 12, comprising more than seven foot tension ribs (7) and seven push-up tension ribs (11 ).

14. The multi-spring hinge base of claim 2, wherein the central folding hinge (8) comprises a top spring surface (4) and an angle between each of the sides of the central folding hinge (8) is between about 5 and 60 degrees.

15. The multi-spring hinge base of claim 14, wherein the angle is between about 10 and 35 degrees.

16. The multi-spring hinge base of claim 14, wherein the angle is between about 5 and 30 degrees and creates an acute angle providing less resistance to inward and outward movement of the top spring surface (4).

17. The multi-spring hinge base of claim 14, wherein the angle is between about 30 and 60 and creates an acute angle providing more resistance to inward and outward movement of the top spring surface (4).

18. The multi-spring hinge base of claim 2, wherein the central suspension ridge (13) creates an outward angular displacement portion from the conical push-up (3).

15. A method of blow molding a container, wherein the blow molded container comprises a multi-spring hinge base as defined in claim 14, the muti-spring hinge base having a plurality of central suspension ridges (13) configured to provide an effective lower surface area contacting a flowing plastic of a heated preform.

16. A multi-spring hinge base for a PET beverage container, comprising:(a) an array of foot tension ribs (7) radially separated by inner foot portions (2), each foot tension rib (7) including: i. an outer spring hinge (9); ii. an outer push-up spring hinge (10); and, iii. a central folding hinge (8) connecting said outer spring hinge (9) to the outer push-up spring hinge (10);(b) an array of push-up tension ribs (11 ), each comprising: i. an inner push-up spring hinge (12); and, ii. a central suspension ridge (13) connecting said inner push-up spring hinge (12) to a push-up top (14); wherein a variable inner radius (6), located between a central push-up portion (3) and an inner foot region (2), is configured such that the radial size and position of each inner push-up spring hinge (12) and paired outer push-up spring hinge (10) are adjustable relative to said variable inner radius (6);wherein the combined radial dimension of any pair comprising an inner push-up spring hinge (12) and an outer-push-up-spring-hinge (10) is between 1.5 mm and 10.0 mm; and, wherein, during inversion, overlapping segments of said spring hinge pairs on the variable inner radius (6) disrupt continuity of the hinge surface at the variable inner radius (6).

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