GB2154854A - Thin walled container consisting of plastics material - Google Patents

Abstract

A thin-walled container of plastics material having a bottom 13, an upper rim and peripheral wall widening out from the bottom to the rim and which by inter-nesting can form a rod-like stack with like containers so that the bottoms of adjacent containers are spaced apart to allow the resulting spaces to hold a material for example powdered coffee, includes a stacking ring 15 between an upper stacking shoulder end lower stacking shoulder and, co-operating functionally with this stacking ring, a holding ring 16 having two axially-adjacent annular parts 16a, 16b. When two said containers are fitted together, the upper annular part of the holding ring on the outer container and the lower annular part of the holding ring on the inner container overlap and each of these annular parts of the holding ring includes at least one circumferential ring of domed projections 19,20 which in one annular part 16a project towards the interior of the container and in the other part 16b project towards the outside of the container. <IMAGE>

Description

SPECIFICATION Thin walled container consisting of plastics material The invention relates to thin-walled containers consisting of plastics material, preferably of beaker shape, having a peripheral wall widening out from the bottom to the upper rim and into which bracing, holding and guide means are integrally moulded for the fitment together of a desired number of such containers into a rod-like stack while forming between the bottoms of adjacent containers spaces suitable for holding measured quantities of filling, such as powdered coffee, and for reliably isolating the containers from the stack.

Thin-walled containers of this type are known from German Utility Models Nos. 80 07-815 and 80 07 816. Where these containers are concerned, a stacking ring limiting the axial fitment of the containers together and wall zones which clampingly secure the fitted-together containers in relation to one another are provided. These clamping wall zones may be provided as annular zones adjacent to the stacking ring or may be remote from the stacking ring and take the form of annular ribs. These clamping wall zones do, however, make it necessary for the containers to fit together very precisely in order to achieve a specific retaining action. Such an accurate fitment together cannot, however, be achieved in practice, where articles are massproduced.Therefore, in the case of the known containers, irregularity either produces such pronounced jamming that isolation of the containers is hardly possible, or the absence of such retaining force between adjacently stacked containers means that, at those places where the retaining force is impaired, the stack has a tendency to come apart, the contents with which the container is filled falling out during transport or when the stack of containers is used.

In the case of other containers of the type mentioned at the outset, such as are known, for example, from AU PS 255 194, the mutual interlocking of the peripheral wall of the containers in annular zones is desired in order firmly to hold on one another the adjacent containers which are fitted into one another. In the case of the known containers, an attempt can be made to achieve this by peripherally extending, interengaging locking ribs or by the peripheral wall of the containers being of scale-like construction. However, the construction of such interlocking arrangements likewise calls for high precision in order to achieve the necessary holding effect. However, in mass production of articles, it is for practical purposes not feasible to achieve such high accuracy.

British Patent No. 1 525 1 32 discloses containers of the type mentioned at the outset wherein holding means in the form of peripheral rows of lozenge-shaped projections are formed, together with stud-shaped mating elements which it is intended should be introduced between these lozenge-shaped projections. Also these lozenge-shaped projections and the stud-shaped mating elements must be constructed with high precision in order on the one hand to guarantee a reliable accurate mutual gripping of the containers when these are fitted one into another and on the other in order to guarantee smooth loosening of the containers.However, a row of lozenge-shaped projections and stud-like elements intended to engage between them have a tendency to render loosening of such a holding means on the periphery of the container irregular so that the container has a tendency to tilt when it is isolated from the stack.

In contrast, the object on which the invention is based is one of substantially improving containers of the type mentioned at the outset in that the bracing, holding and guide means afford a reliable gripping together of the interengaged containers even without the need for high precision, while upon isolation of the containers from the stack, easy slackening of the holding arrangements and a smooth, reliable and tiliting free sliding of the containers one out of another is guaranteed.

According to the invention, this problem is resolved in that the bracing, holding and guide means comprises a stacking ring with an upper stacking shoulder and lower stacking shoulder and, co-operating functionally with this stacking ring, a holding ring having two superposed annular parts, and in that, when the containers are fitted together, the upper annular part of the holding ring on the outer container and the lower annular part of the holding ring on the inner container overlap, and in that there is integrally moulded into each of these annular parts of the holding ring at least one encirciling row of cup-shaped projections which in one annular part project towards the interior of the container and in the other part project towards the outside of the container.

By reason of the invention, when the containers are pushed into one another after the fashion of snap-action springs, these cupshaped projections modify their shape elastically, engage into one another and grip with an elastic, springing reciprocal action. At the same time, this elastic springing reciprocal action of the inter-engaged and deformed cupshaped projections achieves a reliable and springing grip of the containers in a superposed location of the mutually contacting stacking shoulders. By reason of the manner in which the thin-walled cup-shaped projections function, when the fitted-together containers are separated from one another, springing movements are created in the cupshaped projections to permit of a smooth and practically jerk-free separation of the contain ers.All these functional inter-actions are achieved without any particular accuracy of fit among the containers, so that even in the case of mass-produced articles, a reliable gripping-together of the stacked containers is achieved under virtually identical force conditions, regardless of fluctuations in dimension within the inevitable range of tolerances found in mass-produced articles.

Preferably, the cup-shaped projections ought within a peripheral row of projections by spaced-apart by the same intervals in order thus to achieve substantially even distribution of forces around the periphery of the container. On the other hand, it is advisable for the cup-shaped projections in one annular part to be disposed at a greater reciprocal spacing than the interval between the spaced-apart cup-shaped projections in the other annular part of the holding ring. As a result, whenever two containers are fitted together, every conceivable opposing position of the cup-shaped projections will periodically reccur at the periphery of the holding ring. Over the entire periphery there will then again be an even distribution of forces without the containers having to be fitted together in one preferable related position.

The cup-shaped projections disposed in one and the same peripheral row ought preferably also to be of the same diameter and have the same radius of curvature. On the other hand, it is recommended that the cup-shaped projections in the upper annular part have a larger diameter than the cup-shaped projections in the lower part of the holding ring. The cupshaped projections of larger diameter and the cup-shaped projections of a larger radius of curvature exhibit thereby the lesser spring force so that preferably the cup-shaped projections with the smaller diamater and the smaller radius of curvature are more strongly impressed into the cup-shaped projections of the larger diameter and the larger radius of curvature.

In a preferred embodiment of the invention, the cup-shaped projections in the upper annu lar part of the holding ring are directed towards the interior of the container, are constructed with the larger diameter and if applicable the larger radius of curvature and are disposed at the smaller distance apart from one another. As a result, the more intensely deforming cup-shaped projections of larger diameter and/or larger radius of curvature will generally come in contact only with one single cup-shaped projection of the other group and so will undergo a clearly defined deformation behaviour, whereas it is unimportant if one cup-shaped projection of smaller diameter or smaller radius of curvature simultaneously engages two cup-shaped projections of larger diameter of larger radius of curvature.

The holding ring is preferably disposed adjacent to the stacking ring either above or below the stacking ring. In consequence, the stabilising action on the holding ring which is produced by the stacking shoulders can be fully exploited. It is also possible to clamp the holding ring in the stacking ring in that one annular part of the holding ring is disposed between the stacking shoulders. The combination formed by adjacent or inter-clamped dispostion of stacking ring and holding ring ought preferably to belocated in the lower marginal area of the peripheral wall of the container so that it lies virtually on the upper peripheral edge of the contents receiving chamber which is formed in the bottom of the container.For advantageous further development of the embodiment, there is below the lower stacking shoulder of the stacking ring a centring ring while above the upper annular part of the holding ring there is at least one guide ring constructed in the peripheral wall of the container and protruding therefrom like a piston ring. This guarantees a particularly reliable axial guiding of the containers when they are separated, so that any swirling up or other turbulence in the contents of the bottom of the container is avoided.

The location of the combination of stacking ring and holding ring on the peripheral wall of the container can certainly be chosen elsewhere, for example it may be at the upper rim zone of the peripheral wall of the container. It is also possible to locate the stacking ring separatively from the holding ring, for example locating one in the lower rim zone and the other in the upper rim zone of the peripheral wall of the container. Even when these zones are so separated, a functional interaction of stacking ring and holding ring is guaranteed via the peripheral wall of the container which connects them, even though there is no longer the stabilising effect of the stacking shoulders on the holding rim.

An example of embodiment of the invention is explained in greater detail hereinafter with reference to the accompanying drawings, in which: Figure 1 shows three inter-engaged drinking beakers in a preferred embodiment of the invention, the two outer beakers being shown in section and the innermost beaker being shown in a side elevation; Figure 2 is an enlarged view of the detail 2 in Fig. 1; Figure 3 is a functional diagram of the cupshaped projections in the holding ring, and Figure 4 is an enlarged view of the detail 4 in Fig. 1.

In the example illustrated, the bakers 10 have, sub-divided into four portions, one integral peripheral wall 11 which at its upper edge merges into a rolled-over lipped rim 1 2 and at its lower edge into the beaker bottom 1 3. The bottom-most zone 14 of the periph eral wall 11 extends below the stacking rim 1 5 and corresponds substantially to the cham ber for holding the contents, for example powdered coffee. Above the stacking ring 1 5 is formed a holding ring 1 6 having an upper annular part 1 6a and a lower annular part, 1 6b.Above and adjacent the holding ring 1 6a is that area 1 7 of the peripheral wall 11 which occupies substantially the height of the beaker 10 and in which are constructed ribs 1 8 which extend peripherally and protrude in the manner of piston rings.

Formed in the upper annular part 1 6a of the holding ring 1 6 is an encircling row of cup-shaped projections 1 9 which protrude towards the interior of the container. Constructed in the lower annular part 1 6b of the holding ring 1 6 are cup-shaped projections 20 which project towards the outside of the container. As is also shown in Fig. 1, the lower annular part 1 6b of the holding ring 1 6 merges at its bottom edge into the upper stacking shoulder 21 while the bottom stacking shoulder 22 is formed between the stacking ring 1 5 and the lowest peripheral wall part 1 4. Adjacent to the lower stacking shoulder 22 there is in the lowest peripheral wall zone 14 a centring ring 23.

As Figs. 2 and 3 in particular show, the cup-shaped projections 1 9 constructed in the upper annular part 1 6a and projecting towards the interior of the container are disposed all round at equal intervals A,g and are constructed with a diameter D,g and a radius of curvature Rl9. The cup-shaped projections 20 in the lower annular part 1 6b are evenly spaced apart by the interval A20 over the entire periphery have a diameter D20 and a radius of curvature R20. In this respect, the radius of curvature R,g of the cup-shaped projections 1 9 is greater than the radius of curvatur R20 of the cup-shaped projections 20.

The diameter D,g of the cup-shaped projections 19 is greater than the diameter D20 of the cup-shaped projections 20. Finally, the reciprocal gap A19 between the cup-shaped projections 1 9 is considerably smaller than the gap A20 by which the cup-shaped projections 20 are spaced apart.As Fig. 2 shows, the axial distance between the upper stacking shoulder 21 and the lower stacking shoulder 22, which determines the width of the stacking ring 1 5 is so suited to the width of the holding ring 1 6 and the width of the upper annular part 1 6a and of the lower annular part 1 6b that upon complete enter-engagement of the two beakers 1 Oa and 1 Ob, in other words when the lower stacking shoulder 22 of the inner beaker 10b is placed on the upper stacking shoulder 21 of the outer beaker 1 Oa, the lower annular part 1 6b in the holding ring 1 6 of the inner beaker 1 Ob is opposite the upper annular part in the holding rim of the outer beaker 1 0a, in fact such that the centre points of curvature M,g and M20 of the oppositely disposed cup-shaped projections 1 9 and 20 lie substantially in a plane at a right-angle to the beaker axis.

As Fig. 2 shows, the cup-shaped projections 20 which protrude towards the outside of the container and which are provided in the lower annular part 1 6b of the inner beaker 1 Ob press into those cup-shaped projections 1 9 in the upper annular part 1 6a of the holding ring 1 6 of the outer beaker 1 Oa which protrude towards the interior of the container.

As Fig. 3 shows, the differing intervals A,g and A20 between the cup-shaped projections 1 9 and the cup-shaped projections 20 ensure that a different ratio of engagement exists between the cup-shaped projections 1 9 and the cup-shaped projections 20. In the example shown in Fig. 3, the relationship between the distances A,g and the distances A20 is such that five smaller cup-shaped projections 20 are disposed opposite six larger cup-shaped projections 1 9. It can happen that a small cup-shaped projection 20 simultaneously engages two larger cup-shaped projections 1 9 or engages between two larger cupshaped projections 1 9.

As Fig. 4 shows, the guide rings 1 8 which project outwardly like piston rings are so constructed that these guide rings 1 8 of an inner beaker 1 Ob are also in light contact with the inner face of whichever is the outer beaker 1 Oa. Thus the outer beaker 1 Oa, when it is pulled from the stack of beakers, will have its inner face sliding over these guide rings so that the cup-shaped projections 1 9 and 20 are separated from one another in a substantially axially guided motion.

Claims (11)

1. A thin-walled container of plastics material having a bottom, an upper rim and peripheral wall widening out from the bottom to the rim and which by inter-nesting can form a rod-like stack with like containers so that the bottoms of adjacent containers are spaced apart to allow the resulting spaces to hold a material for example powdered coffee, wherein the container includes a stacking ring between an upper stacking shoulder and lower stacking shoulder, and, co-operating functionally with this stacking ring, a holding ring having two axially-adjacent annular parts and in that, when two said containers are fitted together, the upper annular part of the holding ring on the outer container and the lower annular part of the holding ring on the inner container overlap and in that each of these annular parts of the holding ring includes at least one circumferential ring of domed projections which in one annular part project towards the interior of the container and in the other part project towards the outside of the container.

2. Container according to claim 1, characterised in that the domed projections forming each ring are equally spaced apart.

3. Container according to claim 1 or 2, characterised in that the domed projections in one annular part are spaced apart from one another at a greater distance than the distance of the domed projections in the other annular part of the holding ring.

4. Container according to one of claims 1 to 3, characterised in that the domed projections forming each ring are of the same diameter and the same radius of curvature.

5. Container according to one of claims 1 to 4, characterised in that the domed projections in the upper annular part are of greater diameter than the domed projections in the lower part of the holding ring.

6. Container according to one of claims 1 to 5, characterised in that the domed projections in the upper annular part have a greater radius of curvature than the domed projections in the lower annular part of the holding ring.

7. Container according to one of claims 1 to 6, characterised in that the domed projections in the upper annular part of the holding ring are directed towards the interior of the container and are constructed with a greater diameter and optionally a greater radius of curvature while they are spaced apart from one another by the smaller spacing.

8. Container according to one of claims 1 to 7, characterised in that the holding ring is disposed adjacent to the stacking ring.

9. Container according to one of claims 1 to 7, characterised in that the annular part of the holding ring is housed between the stacking shoulders in the stacking ring.

10. Container according to claim 8 or 9, characterised in that the combination of stacking ring and holding ring is disposed in the lower rim area of the peripheral wall of the container.

11. Container according to claim 10, characterised in that a centring ring is constructed below the bottom stacking shoulder of the stacking ring while at least one guide-ring which projects outwards is constructed on the peripheral wall of the container above the upper annular part of the holding ring.

1 2. Container according to one of claims 1 to 7, characterised in that the stacking ring and the holding ring are separated for example one being disposed in the region of the bottom rim while the other is disposed in the region of the upper rim of the peripheral wall of the container.