WO2022020606A1

WO2022020606A1 - Further improvements in integral double-walled containers

Info

Publication number: WO2022020606A1
Application number: PCT/US2021/042798
Authority: WO
Inventors: Alan Mark Crawley; Jonathan K. EICKHOFF; Braxton J. BRAGG; Jeffrey A. Mann
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-07-23
Filing date: 2021-07-22
Publication date: 2022-01-27
Anticipated expiration: 2023-01-23

Abstract

An integral double-walled container apparatus 14 with the structure of two integrally connected and adjacent containers 2 and 15 extending in the same direction with an air gap 9 between them, formed as a single body out of thermoformable material, of a thin-walled nature suitable for mass-production and of a structure where one of the containers is slightly larger 2 and non-inverted and one of the containers is slightly smaller 15 and at least partially in an inverted state, and whereby there are at least one or more protrusions 13 integral to inverted portions 11a and/or 12a of the smaller container, whether they are themselves inverted or whether they remain non-inverted during smaller container inversion, and which do not substantially distort the shape/form of the at least partially inverted smaller container 15.

Description

FURTHER IMPROVEMENTS IN INTEGRAL DOUBLE-WALLED CONTAINERS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to New Zealand Provisional Application Serial No. 766475, filed July 23, 2020, which is expressly incorporated by reference herein.

FIELD OF THE INVENTION

This invention relates to mass-producible integral double-walled containers, formed as single bodies from thermoformable material with the structure of two integrally connected and adjacent containers extending in the same direction with an air gap between them, and having at least one protrusion on at least one inverted portion of the integral double-walled container structure.

BACKGROUND OF THE INVENTION

According to Cambridge Dictionary, a container is "a hollow object, such as a box or a bottle that can be used for holding something, especially to carry or store it".

As used herein, a container may be a beaker, bowl, carafe, clam-shell, cup, fast-food container, food container, glass, mug, pot or tumbler, or any other derivative of container denoting a partially or fully enclosed space capable of holding liquid and/or solid content.

As used herein, the term protrusion denotes any structure inwardly and/or outwardly extending from a wall surface of an integral double-walled container, and may equally be substituted with projection, contour, shape, outline, arrangement, erection, construction, embodiment, fabrication, nodule, bump or protuberance, or any other derivative of protrusion denoting a shape or form extending in either direction, whether outwardly and/or inwardly, from a wall surface.

As used herein, the term "thermoformable material" denotes any material suitable for heat-softening, and while in a heat-softened state, suitable for reforming under the application of pressure into alternate shapes/forms via any known heat-forming means, including but not limited to the processes of thermoforming and blow-forming. There are countless low-cost containers made globally each year which are suitable for mass-production. Issues relating to low-cost production include but are by no means limited to:

• Low cost thermoformable materials,

• Thin wall sections/light empty-weight,

• High production speed,

• High degree of recyclability,

• Maximising stackability to minimise logistics and storage costs, and

• Small number of production processes.

Currently, almost all mass-produced containers are single-walled by nature. The prime reasons are that current production processes are either incapable of making integral double-walled containers, or currently utilised production methods that may be capable of producing integral double-walled containers result in commercially cost-prohibitive piece costs, primarily due to the resulting containers having thick walls and therefore prohibitively high material costs.

As used here, the term "integral double-walled container" denotes an integral double-walled container with the structure of two integrally connected and adjacent containers with an air gap between them and formed as a single body, with a methodology for construction that follows the steps of:

• Blow-forming a structure in the form of two integrally connected containers, with one container being slightly larger and the other container slightly smaller, and with the two containers extending in opposite directions,

• Then at least partially inverting the smaller container such that it extends in the same direction as, and at least substantially interior to, the larger container,

• Thereby forming a structure of two integrally connected and adjacent containers with an air gap between them, formed as a single body.

There are any number of market-driven reasons for the likes of cost-effective integral double-walled containers, some of which may include the following but would not be limited to:

• The formation of fully recyclable coffee cups,

• The formation of cold cups that do not form condensation on outside walls,

• The formation of cold cups that extend beverage shelf life,

• The formation of cold cups that extend ice retention,

• The formation of containers that extend the time contents remain hot and/or cold,

• The formation of containers that extend content shelf-life, • The formation of containers that extend the life of potted plants,

• Any combination thereof, or

• Any other market-driven reasons obvious to those versed in the art.

In order to achieve such an integral double-walled container structure, the smaller container to be at least partially inverted is taught to preferentially include simple large-radius walls, as such wall shapes are readily invertible, given that even when in a heat-softened state, the more complicated the geometric shape/form to be inverted, the greater the difficulty of inversion.

However, the incorporation of one or more protrusions on one or more wall surfaces of inverted smaller containers may provide additional benefits to a user, and therefore a solution is desirable for the provision of protrusions that may either themselves invert or may remain non-inverted during smaller container inversion, and once the smaller container has been at least partially inverted, do not substantially distort inverted smaller container shape/form. It may also be desirable to include one or more protrusions for the purpose of nesting two or more cups together while maintaining an air gap between the cups so that they may de-nest easier. In one embodiment the protrusion may be a ring or other physical feature that follows the circumference of the surface. The one or more protrusions or the ring could either be on the inner surface of the inner smaller container or on the outer surface of the outer larger container.

BRIEF DESCRIPTION OF THE PRIOR ART

U.S. Patent Number 9,339,979 teaches a double-walled thermal barrier cup thermoformed as a single piece out of thermoplastic material with at least one rib maintaining partial spacing between inner and outer walls, and with the as-formed cup having a sealed insulation space.

PCT/IB2017/056558 teaches a method for producing a double-walled container with the structure of two integrally connected and adjacent containers extending in the same direction with an air gap between them, and wherein the inversion of the second container is executed while fully enclosed inside of a mould having a dual-container shaped cavity configuration.

PCT/IB2019/050684 teaches a method for producing a double-walled container with the structure of two integrally connected and adjacent containers extending in the same direction with an air gap between them, and wherein the inversion of the second container is executed by means whereby the material elastic limit is not exceeded and thereby wall damage does not occur.

While all three prior art teach mass-producible integral double-walled containers with an at least partially inverted smaller container as part of the integral structure, none teach protrusions integral to the wall structure of the smaller container that may or may not themselves invert during smaller container inversion.

The object of the present invention is to overcome some of the disadvantages with integral double- walled containers, whereby protrusions integral to the smaller container may or may not invert during smaller container inversion and do not substantially distort the shape/form of the as-inverted smaller container.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention there is provided an integral double-walled container apparatus with the structure of two integrally connected and adjacent containers extending in the same direction with an air gap between them, formed as a single body out of thermoformable material, of a thin-walled nature suitable for mass-production and of a structure where one of the containers is slightly larger and non-inverted and one of the containers is slightly smaller and at least partially inverted, and whereby there are at least one or more protrusions integral to inverted portions of the smaller container, whether they are themselves inverted or whether they remain non-inverted during smaller container inversion, and which do not substantially distort the shape/form of the at least partially inverted smaller container.

There are many ways to form integral double-walled containers, including but by no means limited to:

• Blow-forming as a thick-walled structure by means of extrusion blow moulding and then at least partially inverting some of the as-blow formed structure,

• Forming by whatever means as two separate containers then joining together, such as by means of spin welding, and

• Blow-forming as a thin-walled integral structure by means of stretch blow moulding and then at least partially inverting some of the as-blow formed structure, as taught in prior art PCT/IB2019/050684. In order to be cost effective for mass-production applications, an integral double-walled container needs to be:

• Formed as a single body,

• Have the thinnest viable wall thickness possible, and

• Have a high degree of wall thickness uniformity.

The preferred means of production is therefore by stretch blow moulding and at least partially inverting some of the as-blow formed structure as taught in prior art PCT/IB2019/050684, however any economically viable means of producing integral double-walled containers known to those versed in the art may equally be employed.

The intent is for the integral double-walled container to have highly uniform average wall thicknesses of less than 1 mm, and preferably between 0.10 and 0.5 mm.

Factoring in thermoformable material costs and ease of recyclability, the preferred material is polypropylene (PP), however depending on the integral double-walled container's specific market application, any thermoformable material may equally be used.

The thermoformable material used may be oil based or bio-based, clear/transparent, semi-transparent or opaque, of its natural resin colour or of any colour or combination of colours to suit an application, a single resin type or a blend of resin types, a single layer of one resin or multiple layers of alternate resins, or any combination thereof.

During inversion of the smaller container from an exterior position in a direction opposite to the larger container into an at least substantially interior position extending in the same direction as the larger container, a profiled inversion piston is used having a shape/form necessary to aid inversion, typically in the form of a fully profiled shape that conforms to the final interior inverted wall shape of the smaller container.

As a result of smaller containers being at least partially inverted, outer surface walls of an as-blow formed smaller container that invert transpose to become inner surface walls of an as-inverted smaller container, and vice versa, inner surface walls of an as-blow formed smaller container that invert transpose to become outer surface walls of an as-inverted smaller container. As a result of this "inner surface to outer surface" and "outer surface to inner surface" wall transposition during at least partial inversion of a smaller container, it will be obvious to those versed in the art that the likes of a substantially 360° wall protrusion in an as-blow formed smaller container, whether inwardly projecting and/or outwardly projecting, could create substantial distortion in an at least partially inverted smaller container.

As by example, a substantially 360° rib feature extending outwardly on an as-blow formed smaller container would transpose into a substantially 360° non-inverted rib feature extending inwardly on an as-inverted smaller container, with the result that the originally larger-circumference rib feature would transpose into a smaller-circumference rib feature, thereby causing substantial distortion due to trying to force material from a larger into a smaller circumference rib feature shape/form.

And vice versa as by example, a substantially 360° rib feature extending inwardly on an as-blow formed smaller container would transpose into a substantially 360° non-inverted rib feature extending outwardly on an as-inverted smaller container, with the result that the originally smaller-circumference rib feature would transpose into a larger-circumference rib feature, thereby causing substantial distortion due to trying to stretch to assume a smaller into a larger circumference rib feature shape/form.

In order to resolve this potential to at least substantially distort an as-inverted smaller container, there are at least two possibilities:

• Invert at least one or more of the protrusions at the same time as inversion of a smaller container, or

• Limit, relative to smaller container circumference, the size and/or form of any one or more protrusions so that they at least minimise the chance of inverted smaller container distortion.

Given that smaller container inversion is achieved by means of a profiled inversion piston having the shape/form of a fully profiled shape that conforms to the final interior inverted wall shape of the smaller container, and typically as a back-pressure is applied interior to the as-blow formed integrally connected smaller and larger containers during inversion, the technical difficulty of inverting any one or more large protrusions integral to the smaller container during inversion is very high, and even if integral protrusion inversion could be achieved in conjunction with smaller container inversion, the likelihood of the inverted smaller container ending up physically trapped on the profiled inversion piston due to the formation of undercuts between the now-inverted smaller container and the profiled inversion piston is equally very high. Conversely, if the size of any one or more protrusions on an as-blow formed smaller container are limited in size relative to smaller container circumference, such that once the smaller container has been inverted the size/shape/form of the one or more protrusions remain substantially unchanged, whether or not they invert at the same time as smaller container inversion, then the likelihood of distortion to any one or more protrusions, and more importantly, the likelihood of as-inverted smaller container distortion is minimised.

Therefore, when one or more protrusions are incorporated into a wall or walls of a smaller container as part of the as-blow formed structure, they need to be of limited size relative to smaller container circumference, and of a shape/form such that they:

• Do not inhibit the smaller container inversion process,

• Do not substantially change shape/form during smaller container inversion, whether or not they themselves invert at the same time, and

• Once a smaller container has been inverted, do not substantially distort the shape/form of inverted portions of a smaller container.

This can be achieved by means of protrusion design that:

• Limits protrusion size relative to smaller container circumference,

• Are of a shape/form that exhibits a high degree of flexibility such that as a smaller container is inverted, one or more protrusions are able to at least substantially flexibly conform to the as- inverted smaller container wall shape, and

• Do not substantially distort inverted portions of a smaller container, whether or not the protrusions themselves invert or instead remain non-inverted.

In the event that protrusion design requires a more rigid protrusion structure that could result in significant smaller container distortion once inverted, this can be resolved by adjusting the smaller container shape/form to be a combination of one or more curved surface sections without protrusions or only with highly flexible protrusion shapes/forms, integrally interconnected with one or more substantially flat surface sections upon which anyone or more rigid protrusion shapes/forms are located.

In this way, as a smaller container is inverted, any one or more curved surface sections transpose into substantially mirror inverse-curved surface sections, whereas any one or more substantially flat surface sections transpose into substantially mirror inverse-flat surface sections. If the one or more substantially mirror inverse-curved surface sections incorporate protrusions with a highly flexible shape/form, then distortion of the inverted smaller container in such substantially mirror inverse-curved sections is minimised due to the flexibility of the protrusions at least substantially conforming to curvature transposition.

If the one or more substantially mirror inverse-flat surface sections incorporate protrusions, whether of highly flexible shape/form and/or of high rigidity shape/form, then distortion of the inverted smaller continuer in such substantially mirror inverse-flat surface sections is equally minimised as the lack of any curvature of the one or more substantially mirror inverse-flat surfaced sections will not be substantially affected by integral protrusions, whatever their shape/form during inversion and whether or not they themselves invert during smaller container inversion, as the transposition is from "substantially flat" to "substantially mirror inverse-flat".

Whatever the shape/form of any one or more protrusions, and whether protrusion themselves invert or remain non-inverted during smaller container inversion, in order to minimise or remove any potential for undercuts forming during the inversion process that might cause an at least partially inverted smaller container to become mechanically trapped on a profiled inversion piston, modifications to the shape/form of the profiled inversion piston may be required in piston areas that conform to any protrusions on an as-inverted smaller container.

Such shape/form modifications to a profiled inversion piston may:

• Completely remove any possibility of undercuts forming between a profiled inversion piston and an as-inverted smaller container, whilst still enabling the profiled inversion piston to at least substantially perform its inversion function, or

• At least minimise the possibility of undercuts forming between a profiled inversion piston and an as-inverted smaller container such that the as-inverted smaller container may be mechanically ejected off of the profiled inversion piston by whatever ejection means deemed necessary, whilst still enabling the profiled inversion piston to at least substantially perform its inversion function.

In a first preferred embodiment, there is provided an integral double-walled container with the structure of two integrally connected and adjacent containers extending in the same direction with an air gap between them, formed as a single body out of thermoformable material, of a thin-walled nature suitable for mass-production, and where the at least partially inverted smaller container comprises one or more substantially mirror inverse-curved surface sections integrally connected with one or more substantially mirror inverse-flat surface sections, and whereby there are one or more substantially rigid small-sized protrusions integral to one or more substantially mirror inverse-flat surface sections that remain non- inverted during smaller container inversion and do not substantially distort the shape/form of the at least partially inverted smaller container.

During smaller container inversion, curved wall portions of a smaller container that invert transpose from their original curved form into a substantially mirror inverse-curved form and substantially flat wall portions of a smaller container that invert transpose from their original substantially flat form into a substantially mirror inverse-flat form.

Any one or more protrusions of large size with respect to smaller container circumference that are integral to inverting portions of a smaller container will almost certainly substantially resist transposition from curved into substantially mirror inverse-curved and/or transposition from substantially flat into substantially mirror inverse-flat and thereby cause distortion of inverted smaller containers in proximity of any protrusions.

However, any one or more protrusions of small size relative to smaller container circumference and of highly rigid design that are integrally located on substantially flat inverting portions of a smaller container will provide little if any hindrance to transposition from substantially flat into substantially mirror inverse-flat and thereby will cause little if any distortion of inverted smaller containers in proximity of any protrusions, and will themselves at least substantially retain their original as-blow formed shape/form during and following smaller container inversion.

As the one or more protrusions are highly rigid by design and of limited size with respect to smaller container circumference, it is preferred that they remain non-inverted during at least partial smaller container inversion, however inversion of highly rigid protrusions equally may occur either during or following smaller container inversion, whether as part of integral double-walled container formation or manually effected at any time by a user.

Whatever the shape/form of any one or more protrusions, in order to minimise or remove any potential for undercuts forming during the inversion process that might cause an at least partially inverted smaller container to become mechanically trapped on a profiled inversion piston, modifications to the shape/form of the profiled inversion piston may be required in piston areas that conform to any protrusions on an as-inverted smaller container.

Such shape/form modifications to a profiled inversion piston may:

In a second preferred embodiment, there is provided an integral double-walled container with the structure of two integrally connected and adjacent containers extending in the same direction with an air gap between them, formed as a single body out of thermoformable material, and of a thin-walled nature suitable for mass-production, and whereby there are at least one or more highly flexible small sized protrusions integral to the smaller container that may themselves invert during smaller container inversion, may remain non-inverted during smaller container inversion, or may alternately be manually inverted by a user at any time during or following smaller container inversion, and whether at any point inverted or non-inverted, do not substantially distort the shape/form of the at least partially inverted smaller container.

Any one or more protrusions of large size with respect to smaller container circumference that are integral to inverting portions of a smaller container will almost certainly substantially resist transposition from curved into substantially mirror inverse-curved and/or transposition from substantially flat into substantially mirror inverse-flat and thereby cause distortion of inverted smaller containers in proximity of any protrusions, however any one or more protrusions of small size respect to smaller container circumference and of highly flexible design that are integral to inverting portions of a smaller container will almost certainly flex and/or conform their shape/form during transpose from curved into substantially mirror inverse-curved and/or substantially flat into substantially mirror inverse-flat and thereby cause little if any distortion of inverted smaller containers in proximity of any protrusions.

In order to achieve a shape/form that is highly flexible, preferred protrusion designs are of a size that is small with respect to smaller container circumference and preferably comprise conical-shapes, cylindrical-shapes, high-radius curves and/or compound curves.

As the one or more protrusions are highly flexible by design and of limited size with respect to smaller container circumference, they may:

• Invert at the same time as at least partial smaller container inversion,

• Remain non-inverted during at least partial smaller container inversion then continue to remain non-inverted,

• Remain non-inverted during at least partial smaller container inversion and then be mechanically inverted by a user, whether at the same time as smaller container inversion or at some later time, by whatever mechanical means of user choice, and for whatever reason deemed necessary as part of design function and/or user choice, or

• Any combination thereof.

Such shape/form modifications to a profiled inversion piston may:

It will be apparent to those versed in the art that any combination of the preferred embodiments as taught are equally possible.

Further aspects of the invention, which should be considered in all its novel aspects, will become apparent from the following description, which is given by way of example only.

BRIEF DESCRIPTION OF DRAWINGS

Examples of the invention will become apparent from the following description which is given by way of example with reference to the accompanying drawings which:

Fig. 1 shows a three-dimensional cross-section view of an as-blow formed integral double-walled container with the structure of two integrally connected containers, with one container being slightly larger and the other container slightly smaller, and with the two containers extending in opposite directions, formed as a single body out of thermoformable material, and of a thin-walled nature suitable for mass-production according to any preferred embodiment of the present invention;

Fig. 2 shows a three-dimensional cross-section view of the same integral double-walled container of Figure One following at least partial inversion of the smaller container, with the structure of two integrally connected and adjacent containers extending in the same direction with an air gap between them according to any preferred embodiment of the present invention;

Fig. 3 shows a three-dimensional cross-section view of the same as-blow formed integral double-walled container of Figure One where the smaller container comprises one or more curved surface sections and one or more substantially flat surface sections, and whereby there are at least one or more substantially rigid small-sized protrusions integrally located on one or more substantially flat surface sections of the smaller container according to a first preferred embodiment of the present invention;

Fig. 4 shows a three-dimensional cross-section view of the same integral double-walled container of Figure Three following at least partial inversion of the smaller container according to the same first preferred embodiment of the present invention;

Fig. 4a shows a two-dimensional view of the same integral double-walled container of Figure Three prior to inversion, views of a substantially rigid small-sized protrusion progressively before, during and after the inversion process, and the integral double-walled container of Figure Four upon completion of the inversion process according to the same first preferred embodiment of the present invention;

Fig. 5 shows a three-dimensional cross-section view of the same integral double-walled container of Figure Four in a multiple stack configuration whereby substantially rigid small-sized protrusions may serve a design function according to the same first preferred embodiment of the present invention;

Fig. 6 shows a three-dimensional cross-section view of the same as-blow formed integral double-walled container of Figure One with at least one or more substantially flexible small-sized protrusions integral to the smaller container according to a second preferred embodiment of the present invention;

Fig. 7 shows a three-dimensional cross-section view of the same integral double-walled container of Figure Six following at least partial inversion of the smaller container and with all protrusions non- inverted according to the same second preferred embodiment of the present invention;

Fig. 8 shows a three-dimensional cross-section view of the same integral double-walled container of Figure Seven following at least partial inversion of the smaller container and with at least some protrusions inverted according to the same second preferred embodiment of the present invention;

Fig. 9 shows a three-dimensional cross-section view of the same integral double-walled container of Figure Eight in a multiple stack configuration whereby substantially flexible small-sized protrusions, whether inverted or non-inverted, may serve a design function according to the same second preferred embodiment of the present invention;

Fig. 10 shows a two-dimensional view of two of the same integral double-walled containers of Figure Seven in the process of being stacked together according to the same second preferred embodiment of the present invention;

Fig. 11 shows a two-dimensional view of the same two integral double-walled containers of Figure Ten once in a stacked configuration according to the same second preferred embodiment of the present invention; and

Fig. 12 shows a two-dimensional view of the two integral double-walled containers of Figure Eleven mechanically engaged by means of an inverted substantially flexible small-sized protrusion according to the same second preferred embodiment of the present invention.

DETAILED DESCRIPTION

It will be appreciated that terminology such as "inwardly" and "outwardly", "inner" and "outer" , "upper" and "lower" etc. as used in this specification refer to the orientations shown in the drawings and orientations obvious to those versed in the art. The terms are used to indicate relative orientations but should not be considered to be otherwise limiting. Referring to Fig. 1, a three-dimensional cross-section view of an as-blow formed integral double-walled container 1 with the structure of two integrally interconnected containers 2 and 3 is depicted with one container being slightly larger 2 and the other container slightly smaller 3 with both containers integrally conjoined 4, and with the two containers extending in opposite directions, formed as a single body out of thermoformable material, and of a thin-walled nature suitable for mass-production according to any preferred embodiment of the present invention.

In the as-blow formed state, the smaller container 3 prior to inversion has wall surface 5 that is an outer wall and wall surface 6 that is an inner wall.

Referring to Fig. 2, a three-dimensional cross-section view of the same integral double-walled container 1 of Figure One is depicted following as least partial inversion of the smaller container 8, thereby forming an integral double-walled container 7 with the structure of two integrally connected and adjacent containers 2 and 8 extending in the same direction with an air gap 9 between them according to any preferred embodiment of the present invention.

Following the inversion process to form the integral double-walled container 7, the now at least partially inverted smaller container 8 has been transposed such that the as-blow formed wall surface 5 of Figure 1 that was an outer wall has been transposed into wall surface 5a that is now an inner wall surface, and the as-blow formed wall surface 6 of Figure 1 that was an inner wall surface has transposed into wall surface 6a that is now an outer wall surface.

As a result of this "inner surface to outer surface" and "outer surface to inner surface" wall transposition during at least partial inversion into smaller container 8, it will be obvious to those versed in the art that the likes of a substantially 360° wall protrusion in an as-blow formed smaller container 3 of Figure One, whether inwardly projecting and/or outwardly projecting, could create substantial distortion in an at least partially inverted smaller container 8.

Referring to Fig. 3, a three-dimensional cross-section view of the same as-blow formed integral double- walled container 1 of Figure One is depicted as an as-blow formed integral double-walled container 10 where the smaller container 3 is a combination of one or more substantially curved surface sections 11 and one or more substantially flat surface sections 12, and whereby there are at least one or more substantially rigid small-sized protrusions 13 integrally located on one or more substantially flat surface sections 12 according to a first preferred embodiment of the present invention.

The smaller container 3 may have at least one or more substantially rigid small-sized protrusions 13 extending outwardly from substantially flat surface sections 12 (as depicted), extending inwardly, or any combination thereof.

Referring to Fig. 4, a three-dimensional cross-section view of the same as-blow formed integral double- walled container 10 of Figure Three is depicted following at least partial inversion of the smaller container 15 thereby forming an integral double-walled container 14 with the structure of two integrally connected and adjacent containers 2 and 15 extending in the same direction with an air gap 9 between them according to the same first preferred embodiment of the present invention.

Following the inversion process to form the integral double-walled container 14, the now at least partially inverted smaller container 15 has been transposed such that:

• The as-blow formed substantially curved wall surface 11 of Figure Three that was an outer wall surface has been transposed into a substantially mirror inverse-curved surface 11a that is now an inner wall surface, and

• The as-blow formed substantially flat wall surface 12 of Figure Three that was an outer wall surface has been transposed into a substantially mirror inverse-flat surface 12a that is now an inner wall surface.

Equally, any inner wall surfaces that have inverted have transposed into outer wall surfaces.

As a result of this "inner surface to outer surface" and "outer surface to inner surface" wall transposition during at least partial inversion of smaller container 15, it will be obvious to those versed in the art that the likes of a substantially 360° wall protrusion in an as-blow formed smaller container 3 of Figure Three, whether inwardly projecting and/or outwardly projecting, could create substantial distortion in an at least partially inverted smaller container 15.

Flowever, any one or more protrusions of small size relative to smaller container circumference and of highly rigid design 13 that are integrally located on substantially mirror inverse-flat surfaces 12a of an inverted smaller container 15 will have provided little if any hindrance during transposition from substantially flat 12 into substantially mirror inverse-flat 12a and thereby will cause little if any distortion of inverted smaller containers in proximity of any protrusions, and will, whether inverted themselves or remaining non-inverted, at least substantially retain their original as-blow formed shape/form during and following smaller container inversion.

As shown in figure 4a, the protrusion 13 is shown in its original state prior to inversion outwardly projecting from the smaller container 3 wall of the integral double-walled container 10 of Figure Three and is highlighted by view 13a, then shown progressively in orientation views 13b, 13c and 13d during the process of smaller container 3 inversion, until it reaches its final fully inverted state in view 13e whereby it is projecting inwards from the now inverted smaller container 15 wall of the integral double- walled container 14 of Figure Four.

As the one or more protrusions 13 are highly rigid by design and of limited size with respect to smaller container circumference, they will typically remain non-inverted during at least partial smaller container 15 inversion (as depicted), however inversion of highly rigid protrusions equally may occur either during or following smaller container inversion, whether as part of integral double-walled container formation or manually effected at any time by a user.

Whatever the shape/form of any one or more protrusions 13, in order to minimise or remove any potential for undercuts forming during the inversion process that might cause an at least partially inverted smaller container 15 to become mechanically trapped on a profiled inversion piston (not depicted), modifications to the shape/form of the profiled inversion piston may be required in areas that conform to any protrusions 13 on an as-inverted smaller container 15.

Such shape/form modifications to a profiled inversion piston may:

• Completely remove any possibility of undercuts forming between a profiled inversion piston and an as-inverted smaller container 15, whilst still enabling the profiled inversion piston to at least substantially perform its inversion function, or

• At least minimise the possibility of undercuts forming between a profiled inversion piston and an as-inverted smaller container 15 such that the as-inverted smaller container 15 may be mechanically ejected off of the profiled inversion piston by whatever ejection means deemed necessary, whilst still enabling the profiled inversion piston to at least substantially perform its inversion function. In the event that modifications to the shape/form of the profiled inversion piston are required and it transpires that such modifications do materially affect profiled inversion piston performance, additional means of inversion assist may be employed, including but not limited to:

• The application of additional air pressure, whether an increase or decrease in any area, or a combination thereof,

• The application of additional mechanical inversion means, or

• Any other means obvious to those versed in the art.

Referring to Fig. 5, a three-dimensional cross-section view of the same integral double-walled container 14 of Figure Four is depicted in a multiple stack configuration 16 whereby substantially rigid small-sized protrusions 13 may serve a design function according to the same first preferred embodiment of the present invention.

As depicted, in at least some embodiments, some of the substantially rigid small-sized protrusions 13 on the substantially mirror inverse-flat surfaces 12a may be used as a stack feature, whereby as multiple integral double-walled containers 14 are nested, substantially rigid small-sized protrusions serving as stack features 13 restrict the stack height and thereby ensure that multiple integral double-walled containers 14 do not stick together and can thereby freely and individually be removed from the stack as and when required by a user.

Any number of other usages of substantially rigid small-sized protrusions 13 will be obvious to those versed in the art, whether used jointly or severally.

Referring to Fig. 6, a three-dimensional cross-section view of the same as-blow formed integral double- walled container 1 of Figure One is depicted as an as-blow formed integral double-walled container 17 where the smaller container 3 has at least one or more substantially curved surface sections 18, and whereby there are at least one or more substantially flexible small-sized protrusions 19 integrally located on any one or more substantially curved surface sections 18 according to a second preferred embodiment of the present invention.

The smaller container 3 may have at least one or more substantially flexible small-sized protrusions 19 extending outwardly from substantially curved surface sections 18 (as depicted), extending inwardly, or any combination thereof. In order to achieve a shape/form that is highly flexible, preferred protrusion designs are of a size that is small with respect to smaller container circumference and preferably comprise conical-shapes, cylindrical-shapes, high-radius curves and/or compound curves.

Referring to Fig. 7, a three-dimensional cross-section view of the same as-blow formed integral double- walled container 17 of Figure Six is depicted following at least partial inversion of the smaller container 21 thereby forming an integral double-walled container 20 with the structure of two integrally connected and adjacent containers 2 and 21 extending in the same direction with an air gap 9 between them according to the same second preferred embodiment of the present invention.

Following the inversion process to form the integral double-walled container 20, the now at least partially inverted smaller container 21 has been transposed such that the as-blow formed substantially curved surface 18 of Figure Six that was an outer wall has been transposed into a substantially mirror inverse-curved surface 18a that is now an inner wall surface.

As a result of this "inner surface to outer surface" and "outer surface to inner surface" wall transposition during at least partial inversion of smaller container 21, it will be obvious to those versed in the art that the likes of a substantially 360° wall protrusion in an as-blow formed smaller container 3 of Figure Six, whether inwardly projecting and/or outwardly projecting, could create substantial distortion in an at least partially inverted smaller container 21.

Flowever, any one or more protrusions of small size relative to smaller container circumference and of highly flexible design 19 that are integrally located on substantially mirror inverse-curved surfaces 18a of an inverted smaller container 21 will have provided little if any hindrance during transposition from substantially curved 18 into substantially mirror inverse-curved 18a and thereby will cause little if any distortion of inverted smaller containers in proximity of any protrusions, and will, whether inverted themselves or remaining non-inverted, at least substantially retain their original as-blow formed shape/form during and following smaller container inversion.

As the one or more protrusions 19 are highly flexible by design and of limited size with respect to smaller container circumference, they will typically remain non-inverted during at least partial smaller container 21 inversion (as depicted), however inversion of highly flexible protrusions 19 equally may occur either during or following smaller container inversion, whether as part of integral double-walled container formation or manually effected at any time by a user.

Whatever the shape/form of any one or more protrusions 19, in order to minimise or remove any potential for undercuts forming during the inversion process that might cause an at least partially inverted smaller container 21 to become mechanically trapped on a profiled inversion piston (not depicted), modifications to the shape/form of the profiled inversion piston may be required in areas that conform to any protrusions 19 on an as-inverted smaller container 21.

Such shape/form modifications to a profiled inversion piston may:

• Completely remove any possibility of undercuts forming between a profiled inversion piston and an as-inverted smaller container 21, whilst still enabling the profiled inversion piston to at least substantially perform its inversion function, or

• At least minimise the possibility of undercuts forming between a profiled inversion piston and an as-inverted smaller container 21 such that the as-inverted smaller container 21 may be mechanically ejected off of the profiled inversion piston by whatever ejection means deemed necessary, whilst still enabling the profiled inversion piston to at least substantially perform its inversion function.

In the event that modifications to the shape/form of the profiled inversion piston are required and it transpires that such modifications do materially affect profiled inversion piston performance, additional means of inversion assist may be employed, including but not limited to:

• The application of additional mechanical inversion means, or

• Any other means obvious to those versed in the art.

Referring to Fig. 8, a three-dimensional cross-section view of the same integral double-walled container 20 of Figure Seven is depicted in the form of an integral double-walled container 22 with at least one or more of the substantially flexible small-sized protrusions 19 inverted according to the same second preferred embodiment of the present invention. Any protrusion, whether substantially rigid or substantially flexible, is capable of being inverted dependent on the degree of inversion force/pressure applied, whether pressure by means of a gas, or force by mechanical means.

As regards substantially flexible small-sized protrusions 19, due to their inherent flexibility they are typically easy at any time to invert, and may be inverted:

• As part of the process of smaller container inversion (not depicted), or

• By the application of a force or pressure 23 onto the substantially flexible small-sized protrusions 19 at any time by a user such that it inverts into a substantially mirror-inverted flexible small sized protrusion 24.

The inversion by a user of a substantially flexible small-sized protrusion 19 into a substantially mirror- inverted flexible small-sized protrusions 24 may be for any reason, whether by design or choice.

Referring to Fig. 9, a three-dimensional cross-section of an integral double-walled container 26 is depicted in a multiple stack configuration 25 whereby substantially flexible small-sized protrusions 19 and/or substantially mirror-inverted flexible small-sized protrusions 24 may serve a design function according to the same second preferred embodiment of the present invention.

The integral double-walled container 26 as depicted is the integral double-walled container 22 of Figure Eight with at least one or more substantially flexible small-sized protrusions 19 and at least one or more substantially mirror-inverted flexible small-sized protrusions 24 with the addition of at least one rib feature 27 in the non-inverting larger container 2.

As an example of protrusion design function, and whether as depicted as outwardly protruding substantially flexible small-sized protrusions 19, or whether alternately substantially rigid small-sized protrusions and/or any form of inverted protrusion, protrusions integral to an inverted smaller container 21 may be used as mechanical means to keep a larger container 2 and an inverted smaller container 21 at least substantially separated in order to at all times during usage maximise and preserve the air gap 9.

As a further example of protrusion and rib design function, when multiple integral double-walled containers 26 are placed in a multiple stack configuration 25, substantially mirror-inverted flexible small sized protrusions 24 integral to an inverted smaller container 21 may align with at least one rib feature 27 in a larger container 2 thereby creating an interlock arrangement 28 which may serve any number of purposes, including:

• Keeping multiple integral double-walled containers 26 interlocked together following usage for more efficient means of refuse stacking,

• Provide an interactive fun/play feature for the likes of children whereby once completed its use as a container, may enable multiple integral double-walled containers 26 to rotatingly interlock for whatever reason or purpose, or

• Any other usage obvious to those versed in the art.

Referring to Fig. 10, a two-dimensional view of two of the same integral double-walled containers 20 of Figure Seven are depicted in the process of being stacked together 30.

The direction of stacking 31 shows one upper integral double-walled container 20 moving in a downwards direction into a second lower integral double-walled container 20. Any one or more protrusions of small size relative to smaller container circumference and of highly flexible design 19 integral to either or both integral double-walled containers 20 remain in their as-formed orientation.

At least one of the integral double-walled containers 20 has at least one rib feature 27 on an exterior surface. The rib feature 27 may be of any shape or form and may be:

• A 360 degree circumferential rib as depicted, or

• Of any alternate circumferential orientation such as in the form of a spiral thread form (not depicted),

• Any combination thereof, or

• Of any shape, form, orientation and combination obvious to those versed in the art.

Referring to Fig. 11, a two-dimensional view of the same two integral double-walled containers 20 of Figure Ten are depicted once in their final stacked orientation 32.

Referring to Fig. 12, a two-dimensional view of the same two integral double-walled containers 20 of Figure Eleven are depicted with the lower integral double-walled container 20 remaining as depicted in Figure Eleven and with the upper integral double-walled container 20 of Figure Eleven having been manual adjusted by a user to be an integral double-walled container 22 of Figure Eight. Once the two integral double-walled containers 20 are stackingly orientated as depicted in Figure 11, a user may manually apply a force 23 to at least one of the highly flexible protrusions 19 in the upper integral double-walled container in the stack, thereby inverting the at least one highly flexible protrusion 19 into a substantially mirror-inverted flexible small-sized protrusions 24 to thereby create a mechanical engagement 28 with the rib feature 27 of the lower integral double-walled container 20, this creating a mechanically engaged integral double-walled container stack 33.

By means of the mechanical inversion 23 and resulting mechanical engagement 28, a lower integral double-walled container 20 is now mechanically engaged with an upper integral double-walled container 22. The mechanical engagement may be for any known form, or combination of forms, including:

• The ability for the two integral double-walled containers to rotatingly engage (as depicted),

• The ability for the two integral double-walled containers to threadingly engage (not depicted),

• Any combination thereof, or

• Any means of mechanical engagement obvious to those versed in the art.

Any two or more integral double-walled containers can thus be progressively stacked, by any combination of mechanical engagement means (not depicted).

Any number of other usages of substantially flexible small-sized protrusions 19 will be obvious to those versed in the art, whether used jointly or severally.

Where in the foregoing description reference has been made to integers or components having known equivalents, then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope or spirit of the invention. Any one or more elements that comprise any embodiment may equally be combined in any order into further embodiments readily apparent to those versed in the art.

Claims

WHAT IS CLAIMED IS:

1. A double-walled container apparatus with the structure of two integrally connected and adjacent containers extending in the same direction with an air gap between them, formed as a single body out of thermoformable material, and of a thin-walled nature suitable for mass-production, and of a structure where one of the containers is slightly larger and non-inverted and one of the containers is slightly smaller and at least partially inverted, and whereby at least one or more protrusions are integral to inverted portions of the smaller container that do not substantially distort the shape/form of the at least partially inverted smaller container.

2. An apparatus according to claim 1, wherein at least one or more of the protrusions integral to inverted portions of the smaller container have not themselves invert during smaller container inversion.

3. An apparatus according to claim 1, wherein at least one or more of the protrusions integral to inverted portions of the smaller container have themselves invert during smaller container inversion.

4. An apparatus according to claim 1, wherein at least one or more of the protrusions integral to inverted portions of the smaller container have been mechanically inverted by a user.

5. An apparatus according to claim 1, wherein the smaller container comprises at least one or more substantially mirror inverse-flat sections and/or at least one or more substantially mirror-inverse curved sections.

6. An apparatus according to claim 1, wherein the one or more protrusions are integrally located on least one or more substantially mirror-inverse flat sections and/or on at least one or more substantially mirror inverse-curved sections.

7. A protrusion according to all previous claims, wherein the shape/form of the protrusion is highly flexible, of a size that is small with respect to smaller container circumference and preferably comprise conical-shapes, cylindrical-shapes, high-radius curves and/or compound curves.

8. A protrusion according to all previous claims, wherein the shape/form of the protrusion is highly rigid and of a size that is small with respect to smaller container circumference.

9. A protrusion according to all previous claims, wherein at least one or more of the protrusions have a design function, whether in an inverted or non-inverted state.