MXPA04012450A - Collapsible container. - Google Patents

Abstract

A collapsible container with angularly related multiple folding sections, each section extending at an angle to the vertical, and flexure zones between adjacent sections for flexibly moving the sections between a first open position in the expanded container and a second position folded upon itself in the collapsed container, the flexure zones resisting movement of the sections in both the fully expanded container and the collapsed container, as well as any intermediate position wherein only selected flexure zones are in an open position.

Description

FOLDING CONTAINER BACKGROUND OF THE INVENTION The present invention relates generally to molded plastic containers commonly used for a variety of purposes including storage of both food and non-food items, such containers preferably being adapted to receive an appropriate seal or cap . More specifically, the invention has to do with containers of this type which, instead of being of rigid construction as is the case with a conventional bowl, can be folded or folded to a compact position when empty to facilitate convenient storage. Such containers, in the form of cups, bowls and the like, are generally known in the art and have many forms. These include foldable cups or cups formed of telescopingly stacked annular wall elements that slide relative to each other between a fully open position and a folded position. Since the wall elements are not integrally formed, and slide freely between them, there is a substantial possibility of leakage, and its use except for drinking liquids, is not practical. Another form of collapsible container more pertinent to the present invention is illustrated in Patent No. 5,439,128 issued to Fishman on August 8, 1995. In the Fishman container, the wall elements are integrally molded and are composed of a series of both vertical and angled elements alternately stacked to define the wall of the container. The elements, in the angular joint between them, are integrally joined by thin film hinges around which the wall elements are bent. The true downward action of bending and folding of the Fishman elements requires that the elements contract to adapt to the motion of bending. This need for a true contraction of the elements themselves, in addition to bending over the film hinges, seems to be so significant that, at least in some cases as seen in Figure 3 of Fishman, it requires quite a few central relief slots in each of the inclined wall elements, and this apparently could cause an inherent weakening of those wall elements. It can also be seen that, when the Fishman container is folded, the reciprocating vertical wall elements of the open container retain their vertical orientation perpendicular to the base wall. Thus, it is clear that the Fishman container is not susceptible to injection molding in the folded position, as would be commercially advantageous due to the large economies in the production of the molds and the molding processes. SUMMARY OF THE INVENTION A main object of the present invention is to provide a collapsible container that presents or forms a substantially rigid receptacle in its open or expanded position, and which, with a suitable cover or quick-closing seal attached thereto, provides a container for waterproof and practical storage for, for example, an appropriate or similar food. The container is very convenient and provides a portable solution especially desirable for food "on the move" as in picnics, for those people who bring their own food to work, and other cases when you want to have temporary storage. The collapsible nature of the container, which is folded into an almost fully compacted configuration and of minimum height, especially with seal mounted thereon to confine any residue in the now empty container, allows to store or pack the used container conveniently in a "brown bag" , a backpack, a picnic basket, or similar, for cleaning and new use later.

In furtherance of the main object of the invention, it is also an object of the invention to provide a method of molding the container in its folded position as a means of achieving maximum savings in molding apparatus and methods., and in providing a molded product that is compact and yet fully expandable to a relatively rigid and self-supporting position. A significant aspect of the container of the invention is its ability to deploy incrementally, one section at a time, to vary the capacity thereof and at the same time to remain in any folded position incrementally. Other desired features of the invention are to provide a container that can be washed in a dishwasher in its bent position and can be stacked there in the same manner as conventional dishes, a container that remains open when in use and remains closed when stored. stored, and a container that maximizes usable space for packaging in a shipping carton as well as for storage in the home. In order to achieve the improved and highly practical container of the invention, the peripheral wall, which extends between a substantially rigid base and a substantially rigid upper ring adapted to receive a quick seal, includes a series of generally rigid and annular wall sections. or peripherally continuous joined to adjacent sections in fixed annular apex-forming joints directed alternately inwardly and outwardly relative to the interior of the container. These sections have annular portions of each other that are relatively flexible. The wall sections, in the expanded or open position of the container, are themselves angled alternately inwards and outwards relative to the interior of the container and relative to the vertical, with the wall sections, in sequence upwards from the base to the upper ring, each being generally diametral or peripheral, progressively larger than the base. The configuration thus formed for the expanded container will be that of an inverted truncated cone with the wall sections substantially staggered outwardly and upwardly from the base. This in turn allows a directly downward folding of the wall sections in a concentric and concentric relation with the base and with the upper ring around the folded and folded wall sections. The actual folding action of the relative wall sections relative to each other takes place within a flexure portion in an apex area between the sections where each of the wall sections is attached to the immediately adjacent wall section or sections. to it and has a thickness that is less than that of the sections on each side of it. The thicker sections are both more rigid than the flexure portions and have a much more limited flexibility. The thinner portions, in the expanded position of the container, form arcuate continuations of the thicker wall sections, forming an arc greater than 90 degrees and, until physically moved over the center during a folding of the container, provide a important degree of rigidity to the wall sections for the full height of the container wall. With the application of a positive physical force that causes the upper ring and the base to bend together, the flexible portions between the wall sections will flex laterally in the direction of the fold in flexible hinge mode, and this flexure makes possible true folding while minimizing any tendency in the wall sections to flex laterally or move while the wall sections are folded over one another. Each of the flex zones formed by the thinner portions is bordered at each edge thereof by thicker adjacent wall sections. When the arc of the flexure area is reduced to less than 90 degrees, and moves over the center, the resistance inherent to the movement of the flexure area is overcome and the folded area takes a dome-shaped configuration of less than 90_degrees . When moving from the closed state to the open or vice-versa, each flexure zone will be bent and slightly deformed until it exceeds its stable position and turns to the other position.

A molded and folded container according to the invention is such that rigid and opposite wall portions define a generally triangular interstitial space formed by two walls diverging from the vertical in a range between approximately 8 ° and approximately 40 °. However, for reasons that will become apparent below, a range between about 10 ° and about 16 ° is preferred.

Expansion of the container from its folded position involves a push or pull down on the base while the upper ring moves vertically upwards of that. As the flex portions unfold and move to arcs greater than 90 degrees, the wall will tend to become rigid and in effect immobilize the container in the open position. Additional features, objects, and advantages of the invention will be observed as the construction and details of the invention are further discussed. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top perspective view of the container of the invention in its open or expanded position; Figure 2 is a top perspective view of the fully folded container; Figure 3 is a cross-sectional view of the expanded container; Figure 4 is a cross-sectional view of the folded container; Figure 5 is an enlarged detailed view of the area designated A in Figure 3; Figure 6 is an enlarged detailed view of the area designated B in Figure 4; Figure 5A is a view similar to Figure 5 illustrating a modified construction; Figure 6A is a view similar to Figure 6 illustrating the modified construction; Figures 7, 8 and 9 illustrate sequentially a way of opening, or closing the wall sections using sequential twisting or ratchet action; Figure 10 is a cross-sectional view similar to Figure 4 with the seal adapted to the folded container, - Figure 11 is transverse detail of a modified pressure stop in the base provided with a pull-bar; and Figures 12-22 illustrate a further embodiment and correspond in sequence to Figures 1-11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the characteristics of the embodiment of Figures 1-11 are identified by two-digit numbers. Similar characteristics in the embodiment of Figures 12-22 are identified by the same numbers with the number 1 as a prefix. Referring now more specifically to the drawings, the collapsible container 10 comprises a base 12, an upper ring 14 and a collapsible wall 16 which extends between them. The base 12 is a substantially rigid element that includes a bottom 18 with an upright and peripheral base wall 20. The base, which may be flat, preferably includes a central pressure area or stop 24 that extends slightly upwards from any appropriate configuration, such as a dome to assist in the expansion of the container, as described below. The base will also preferably have a series of small foot-defining buttons 26 or a continuous foot projection not shown, which depends on the bottom of the base 18. The upper ring 14, includes a continuous or annular ring wall with a peripheral flange 30 directed horizontally and outward approximately halfway up the wall of the ring 28. The upper ring 14, similar to the base 12, is substantially rigid and is of greater diameter or other non-circular transverse area than the base 12 for to be able to surround the base in the folded position of the container, as in Figure 4, at a sufficient distance outside that to accommodate the folded wall of the container between them. The flange of the upper ring 30 provides additional lateral stiffness to the upper ring and a convenient means for handling the bowl, especially when it is full. In addition, the flange of the ring 30, when the folded bowl is to be opened, allows a user to easily reach the fingers around and below this flange 30 and press down with the thumbs into the domed pressure area of the base 24 for vertically and forcefully expand the base and the upper ring relative to each other. As an alternative to pressure on the area 24, especially with a large bowl, the pressure can be applied sequentially around the bottom of the base 18 immediately adjacent to the wall of the base 20 peripherally around. As desired, and as best seen in Figures 1 and 2, the flange of the ring 30 may be extended slightly outwards or increased in diametrically opposite portions to define fastening handles 32. The molding of the base and the ring Superior as separate entities of the wall is preferred method of molding that allows to provide a much greater rigidity to these components relative to the sections of the wall, where the true action of extending and folding occurs, by using polymers of different degrees of rigidity, and / or flexibility. The side wall of the container 16 is constituted by a series of annular or peripherally continuous wall elements or sections 34, wherein the lower section surrounds and is intimately bonded, for example in an autogenous manner during a multi-component molding process, to the wall 20 of the base 12 and seated on a support shoulder 21 slightly above the bottom of the base. In the embodiment of Figure 5A, the lower or bottom section, having a height a little less than the remaining sections above, is integrally attached to a thin base portion 22 projecting upwards which, as the wall of the container folds, will define a flexure zone between this lower wall section and the base. The wall sections 34, upward of the connection of the lower section with the base, are inclined outwards and inwards in relation to the interior of the container and with the vertical with each section attached to the section immediately above in apices or portions of apex directed alternately outwardly and inwardly which respectively form the angled joints as they are generally designated at 36 and 38. Noting Figure 5, the upper or upper section 34 is joined by a portion of flexure to a collar 37 directed upwards, received and intimately fixed within the lower portion of the wall of the ring 28, for example in the manner suggested with respect to the lower section. In the embodiment of Figures 5A and 6A, the upper section 34 is integral, or otherwise intimately and peripherally joined with, the lower edge portion of the upper ring 14. Observing the open container, each of the wall sections alternatively inclined is of a predetermined thickness and of limited flexibility with respect to the flexure portions or portions 40 joining the adjacent sections 34. The flex portions 40 are relatively thinner than the sections 34 and substantially equal in thickness to the extended portion. 22 of the base in Figure 5A. The zones or portions of flexure 40 generally define the joint at an angle, 36 or 38, between each section and the section immediately adjacent thereto. As has been noted, the height of these portions 40 of reduced thickness is substantially less than that of the sections 34. These portions of flexure zone 40, in the expanded or open position of the container, again observing Figure 5, form, in to the wall sections 34 inclined outwards, continuations of the inner face of the corresponding portion 34 below, and, with respect to the wall sections inclined inwards, are continuations of the outer face of the corresponding wall section. Thus formed, the thicker wall sections on each side of these flex zone portions 40, and the angle thereof, inherently define the direction of the folding action.; note in particular the fold sequence suggested in Figure 8. It will also be appreciated that, prior to folding, the flexure zones 40 and the positioning of these zones 40 between adjacent sections provide a degree of stability over the center to avoid the inadvertent folding of the wall 16. Said stability can only be overcome by applying sufficient vertical positive pressure, forcing the upper ring and the base to meet vertically to effect a movement on the center of the flexure zones 40 and a folding action of "instantaneous action" of the zones to the folded position. Once the folding action has started, each flexure zone 40 involved is distorted slightly until it moves to what could be considered a position on the center, at which point it turns to the folded position. In this way, any tendency of the container to have automatic or accidental closure, especially with something inside the container, is minimized.

As noted in the drawings, the adjacent sections 34, in the folded position of the container, form V or triangular openings opposite each other. The center line of each V-shaped opening is generally perpendicular to the horizontal plane of the folded container. This structure is significant since it allows the injection mold to separate to eject the molded part. The divergence angle between folded and adjacent sections 34 has a possible overall range of 8o to 40 °, with the preferred range being 10 °. and 16 °. An angle of 10 ° is considered optimal to achieve a desired balance between the stiffness of the container in the open position and the force necessary to fold or expand the container. This angle is also considered, as a practical matter, to be the smallest angle that allows uniform ejection of the molded part of the mold. As can be seen, as the angle increases, the stiffness of the open container decreases. With particular attention to Figures 7-9, it is noted that, if desired, both opening and folding of the container can be facilitated by applying pressure sequentially around the container or by rotating the container while applying pressure to provide a stepped or ratchet effect on the wall sections 34 instead of immediately positioning each flexure area in its entirety at one time. Figure 9 is of special interest when displaying the partially folded or unfolded container for use as desired or requiring reduced capacity. In such a position, the container is fully functional for receiving and storing food and the like, and the seal 42, as well as in the open container of Figure 3, is also fully functional since the upper ring is dimensionally stable in each position of the container .

Upon noting Figure 3 in particular, it is observed that the general stepping outwardly of the sections upwards from the base to the upper ring forms, in the open container, a conical and truncated configuration, generally inverted. Upon noticing again Figures 7-9, as the container folds vertically, the flex zones 40 fold between adjacent sections to assume a generally domed configuration. Thus the adjacent wall sections are folded to bring the greater and thicker height of the sections in concentric relation and generally parallel to each other, with the angle between adjacent sections being preferably between approximately 10 ° and 16 °, with the sections aligned laterally and surrounding said base between the wall of the base 20 and the wall of the upper ring 28. This can be better visualized in the cross-sectional detail of Figure 6.

Upon noting Figures 3, 9 and 10, it is noted that the seal 42 lends itself for instant fastening to the upper ring 14 appropriately in any position assumed by the container. To facilitate this interconnection, the upper portion of the wall of the upper ring 28, above the circumferential flange 30, can be tilted slightly outwardly to be received within a peripheral groove directed downwardly in the seal. It will be appreciated that, since the folded wall sections are located, in any position of the container, concentrically positioned inwardly of the substantially rigid upper ring 14, the seal 42 functions as an appropriate lock for the open container, the partially expanded container , and the folded container where compacted storage position is achieved. As already noted, when the container needs to be opened before use, it is only necessary to put the fingers around the peripheral flange 30 of the upper ring and, with a thumb or both, press down on the lower thrust stop 24 projecting upwards from the center of the bottom of the base 18. Alternatively, pressure can be exerted on the bottom itself sequentially around the periphery thereof. Even more, instead of having direct pressure on the stop 24 or the bottom 18, and taking into account Figure 11, a cross member 44 can be provided diagonally through the recess or concave depression formed by the stop on the bottom face of the bottom 18. This cross member 44 can be physically held by the user's fingers to pull directly down on the base of the container, moving the base downward relative to the top ring and expanding the wall sections. Referring again to Figure 6, it is noted that the lower foldable wall section 34 will act as a limit to the folding down of the remaining wall sections and the upper ring relative to the base wall, retaining the sections and the upper ring slightly above a support plane defined by the bottom of the base and support feet on it by which the support of the container, both expanded and folded, is on the base and feet of the base instead of on the areas of flexure much thinner. Referring now more specifically to the embodiment illustrated in Figures 12-22, the basic components of this embodiment substantially duplicate. those of the previously described embodiment, and as such, have been designated by the same reference numbers with the number 1 as a prefix. Thus, the container 110 is composed of a base 112, an upper ring 114, and a collapsible wall 116 of rigid and alternating wall sections 134 and flexure portions or portions 140. The container 110, as well as with the first embodiment, is it expands and at the same time folds in the manner previously described and, in the folded position, is configured in such a way as to allow a practical and preferred molding of the container in this position. Accordingly, the wall sections 134, in the folded position, define opposite V-shaped openings, where the angle between the sections, having a possible range between 8 ° and 40 °, will preferably be in the range between 10 ° and 16 ° with an optimum angle of 10 °. Each V-shaped opening has the center line thereof extending from the apex defined by the converging sections 134, and perpendicular to the horizontal plane of the folded container. In the expanded or open position of the container, the wall sections 134 are at a relative angle to each other, greater than 90 ° ·, and to the vertical as defined by a perpendicular to the base. In order to improve the folding and unfolding action of the wall sections 134, each wall section 134 at its edges is bevelled, as well as at 135, to provide a gradual transition between the wall section 134 and the adjacent flexure portion 140. This differs from the somewhat abrupt transition area of the first embodiment; note in particular Figures 5 and 6. As with the first embodiment, the flex zone portions 140, in the open position of the container, form, with respect to the wall sections 134 inclined outwardly of Figure 16, continuations of the inside face of the corresponding section 134 below it. Similarly, the flex zone portions 140, relative to the 134 inwardly inclined wall sections, are continuations of the outer face of the corresponding wall section 134. This relationship, as described above, will inherently tend to define the direction of the folding action; note in particular the fold sequence suggested in Figure 19, as well as Figure 8 described above.

With special reference to Figures 16 and 17, it is observed that the. The lower wall section 134 is taller than the wall sections above it, and extends to the full height of the wall of the base 120 upright and peripheral. The lower end of this lower wall section 134 bends below the bottom 118 of the base 112 and enters a reception recess 119, in order to in effect define a portion of the support plane of the container. As can be seen, the increased area of overlap between the lower portion of the wall of the container and the base strengthens the joint between them. The interconnection between the vessel wall and the upper ring is effected by a laterally directed collar 137, attached to the higher wall section 134 by the higher flex portion 140. The collar 137 includes a locking bead 139 directed upwardly on the outer edge thereof and both the collar 137 and the bead 139 are received within a corresponding interlocking recess found in the base of the annular ring wall 128. The ring upper 114, as with ring 14 described above, includes an integral annular ring flange 130 projecting upward, providing both lateral stiffness to the upper ring and a convenient means for handling and handling the bowl. As a means for facilitating clamping of the flange, it is proposed to provide an integral dependent clamping bead 131 peripherally around the outer edge portion of the flange 130. A last area of variation between the embodiments is seen in Figure 12, and the various transverse views of the container 110. As seen by comparing these figures with the figures of the first embodiment, the base 112 includes a central pressure area or stop.124 that extends upwardly and is substantially enlarged. This increases the area over which the pressure to open, in particular, can be applied, facilitating the handling of the container and at the same time having a tendency to further strengthen the fund 118, otherwise flat. As noted in Figure 22, the lower thrust stop 124 may be provided with a cross member 144 for purposes already noted with respect to the cross member 44. Also, as described with respect to the first embodiment, a seal 142 may be provided, suitable for instantaneous placement to the upper ring 114. Such a seal, in light of the folding and expanding mode of the container with the concentrically folded wall sections, will constitute an appropriate lock for the container, either fully open, fully folded, or partially expanded. With reference to Figure 21 in particular, it is noted that the wall sections 134 folded down, and more particularly the flexure portions 140 directed downwards are retained slightly above the support plane defined by the bottom of the base and / or the feet of support, providing a more stable support and avoiding interconnection of the flexurally thinner areas with a support surface. The container thus described is designed in a configuration utilizing a "network" of flex zones. It is not an accordion shape that stretches to open and close like a spring. Instead, the flat storage container functions to open and close based on a principle of "opposite angles". In known expandable containers, the containers are generally molded in an open or expanded configuration. Thus for those recipients the natural state is to be open, that is, those recipients would "prefer" to be open in exchange for any other position. Thus, when one tries to fold or fold these containers, the containers tend to want, as a spring, to reopen, that is to return to their natural state ... This is not the case with the container of the invention where the The container is preferably molded in a flattened or folded position. It is your initial natural state, which means that the recipient will initially prefer to stay in this closed configuration. There are multiple folds within the network of flexure zones. In the illustrated embodiment, three sets of independent activation zones are provided (more can be added to increase capacity if desired). As seen in Figure 9, each of the independently activated flexure zones has a second "natural" state or at rest when open, in which the fold will prefer to remain open independently of the remaining folds. In the current structure, both the action of folding the container and of expanding the container require individual manipulation of the folds. Positive action is required both to fold and unfold the container. This can be called the "opposite angles" principle. The angle of the fold in the closed position keeps the fold closed; the angle of the fold in the open position keeps the fold open. To move from the closed state to the open or vice-versa, the flexure zone suffers a bit of twisting and distortion until it overlaps the opposite angle and then changes to the configuration of the other position. This action results because the diameters of the flexure zones can not change. There is no other intermediate position for the fold. It is open or closed, or in the process of twisting (one side open and the other closed). It is not possible in this construction for an individual section to be, for example, half open while maintaining usable capacity. As already noted, an easy way to manipulate the flexure zones is the ratchet action on the container, first one side, then another, until reaching a partially or completely open position. The unique structure of the invention makes it possible for the container to remain flat when in the closed or folded position, and to continue to expand when in any open or partially open position. Because of the two "natural" states for the flexure zones, the container prefers to remain closed when folded flat and prefers to remain open when expanded. With the independent activation of the flexure zones in the network, it is possible to open the vessel to fixed partial capacities, since the vessel prefers to remain open in these partial configurations. This is of special value in maximizing and optimizing storage space, such as in a refrigerator, and space in a dishwasher when washing.

The collapsible container of the present invention has been described in the preferred embodiment as being of molded plastic, ie, synthetic polymers, having 'separate entities' constituting a base, an upper ring and a collapsible wall. The ? separate entities' in a preferred molding method can, for example, be realized with the use of molding apparatuses that make possible multiple molding stages of the base, the upper ring and the collapsible wall, and where it is possible to use a selection of polymers of various degrees of substantial rigidity and / or general rigidity. This also allows to vary the color or light transmissivity of the base, the upper ring and the folding wall. It can be appreciated that, as described with respect to the embodiment of Figures 5A and 6A, the container of the present invention can be molded into a unitary structure in essentially a single molding step. In addition, the preferred difference described with respect to the relative stiffness, or general, but more flexible stiffness of the base and upper ring compared to the collapsible wall, can be achieved in a single molding step by selecting appropriate thicknesses of the several portions. There is also the possibility of providing molding apparatus wherein a mold is configured to provide selected areas of the interior of the mold with polymers of varying degrees of rigidity or flexibility for the base, the top ring and the wall. It can be seen that a mold suitable for injection molding the wall portion in a folded condition must require a plurality of interdigitated, annular and concentric mold elements, generally triangular or V-shaped, carried by mold halves, which correspond to the number of wall sections that are folded over one another.

The foregoing is considered illustrative of the principles of the invention. Since modifications or changes can occur to those skilled in the art, it is not desired to limit the invention to the exact construction and manner of use described. Rather, one can have recourse to any modification or suitable equivalent falling within the scope of the invention as claimed.

Claims (20)

1. CLAIMS 1. A collapsible container comprising a base, an upper ring and a wall fixed peripherally to said base and upper ring and extending between the two, said container being adjustable between an expanded position with the upper ring spaced up from said base and forming a container interior, and a folded position with said upper ring surrounding said base in a substantially concentric and spaced relation thereof, said wall comprising multiple peripherally continuous sections and extending upwards which, in the expanded position of said container, they move at an angle alternately outwardly and inwardly relative to the interior of the container, said sections, in the folded position of said container, being folded over one another and received concentrically generally between the base and the upper ring with the sections surrounding the base and in turn being circum given by said upper ring. The container of claim 1 wherein each said section, in the folded position of said container, is at an angle of divergence of 8 ° to 40 ° towards the adjacent sections. 3. The container of claim 2 wherein said sections are at an angle of 10 °. at 16 ° to the adjacent sections in the folded position. The container of claim 3 wherein said sections are at an angle of 10 ° toward the adjacent sections in said folded position. The container of claim 4 wherein, in said folded position, the adjacent sections form opposing V-shaped openings, each opening having a center line perpendicular to said base. The container of claim 5 wherein said sections include a lower section attached to said base, a section above attached to said upper ring, and intermediate sections between said lower and higher sections, each of said sections from said lower section and up to said higher section defining sequentially a peripherally enclosed area and generally progressively larger than said base. 7. The container of claim 6 wherein said sections extend from adjacent sections at obtuse angles in said expanded position of said container. 8. The container of claim 7 including flexure zones that join adjacent sections. .9 ... The container of claim 8 wherein the obtuse angles formed by the sections joined in the expanded position of the container, and upwardly from the base, move at an opposite angle and laterally inwardly and outwardly relative to the interior of the container and they define a series of inwardly directed angles and a series of outwardly angled angles, and the angles of each series, sequentially upward from the base, are decentered outward from the next lowest angle in that series by which means are defined a wall that extends upwards and outwards. 10. The container of claim 9 wherein said lower section encloses and remains attached to said base. The container of claim 8 wherein said base has a lower surface defining a bearing plane, said folded sections in the folded position of the container being positioned above said defined bearing plane. 12. The container of claim 11 wherein said lower section extends up and in part through said bottom surface of the base within said support plane. The container of claim 11 wherein said base includes a bottom with a central thrust stop projecting upward to define an area adapted to receive downward pressure thereon for downward movement of the base relative to the top ring and a corresponding expansion of the container wall. 14. The container of claim 13 wherein said top ring includes a circumferential flange extending outward and defines means for holding the top ring as pressure is applied to the push stop. 15. The container of claim 14 wherein said top ring includes an upright and peripheral wall, said flange extending peripherally peripherally around said ring wall, a generally rigid collar attached to said higher wall section by means of one of said flexure zones, said collar including a locking pearl directed upwards said top ring including a downwardly directed recess formed therein and receiving said collar and bead, interlocked to form one. fixed junction of said container wall to said upper ring. 16. The container of claim 15 wherein said flange of the upper ring includes an outer periphery with a bead directed downwardly and integral therewith and dependent thereon. The container of claim 13 wherein said thrust stop defines a concave recess that opens downwardly in said bottom of the base, and a manually operable pull bar transversally secured through said recess to be able to pull said base toward below relative to said upper ring. The container of claim 1 wherein said top ring includes an upwardly extending ring wall, and a separate seal that can be positioned on said top ring, and whose seal is fixed to said ring wall in the form of a ring. releasable both in the expanded position and in the folded position of said container. 19. The container of claim 1 wherein, in said folded position, adjacent sections form opposing V-shaped openings, and each said opening has a center line perpendicular to said base. 20. The container of claim 1, molded in said folded position.