GB2157153A - Thin walled container made from plastics material - Google Patents

Abstract

Thin walled containers, preferably beakers of plastics material, intended to be fitted together into rod-like stacks and which, in the stacks, form between the bottoms of adjacent containers, respective chambers to accommodate filling, for example powdered coffee, are provided in the peripheral wall with a stacking ring 15 and a holding ring 16. The holding ring 16 is constructed with two superposed annular parts 16a, 16b of which, in the stack, one annular part 16a of a container is opposite the other annular part 16b of the adjacent container. Constructed in the annular parts 16a and 16b are peripheral rows of cap-shaped projections of which the projections 19 of one peripheral row protrude towards the interior of the container and the projections 20 of the other peripheral row project towards the outside of the container. When the containers are fitted together in the stack, the projections 19 and 20 which are in an oppositely disposed relationship are impressed partially and resiliently into one another so creating a reliable grip which can be reliably and smoothly overcome by the application of limited axial force when the containers are to be moved apart in an axial direction. <IMAGE>

Description

SPECIFICATION Thin walled container made from plastics material The invention relates to a thin-walled container made from plastics material, the container preferably being of beaker form, having a peripheral wall widening-out from the bottom to the top rim, into which are integrally moulded bracing, holding and guide means for fitting together a desired number of such containers to form a rod-like stack, accompanied by the formation of cavities between the bottoms of adjacent containers to accommodate measured quantities of filling substances such as coffee powder and the like, and for reliable separation of the containers from the stack.

Thin-walled containers of this type are known from German Utility Models 80 07 815 and 80 07 816. Where these containers are concerned, a stacking ring limiting the axial inter-fitment of containers, and wall zones which clamp together the fitted-together containers are provided. These clamping wall zones may be disposed as annular zones adjacent the stacking ring or may take the form of annular ribs remote from the stacking ring.

These clamping wall zones do however necessitate very accurate fitting together of the containers in order to achieve a definite holding effect. Such an accurate fitting together cannot, however, be achieved in practice when making mass produced articles. Therefore, in the case of the known containers, irregularity often produces a situation where the containers are jammed together so strongly that it is scarcely possible to single them out, or to an absence of any holding force between adjacent containers in the stack, so that a lack of holding force at such points allows the stack to separate so that the filling escapes in transit or when the stack of containers is used.

In other containers of this type mentioned at the outset, such as are known, for example, from AU PS 255 194, the snapping-together of the periph eral container walls is sought in annular zones so that there is a firm grip established among containers which are fitted into one another in an adjacent relationship. In the case of the known containers, this can be attempted by peripherally extending inter-engaging snap-action ribs or by a scale-like or flake-like construction of the peripheral wall of the container. However, the construction of such snap-action means likewise calls for high precision in order to achieve the necessary holding action. Such high accuracy cannot, however, be achieved in practice when mass produced articles are being made.

Known from British Patent No. 1 525 132 are containers of the type mentioned at the outset in which holding means are provided in the fashion of peripheral rows of lozenge-shaped or rhombic projections and stud-shaped mating elements adapted to be passed between these lozengeshaped projections. Also the lozenge-shaped projections and stud-shaped mating elements must be very precisely constructed in order on the one hand to guarantee a reliable and accurate mutual gripping of the fitted-together containers and on the other a smooth separation of the containers. A row of lozenge-shaped projections and stud-like elements engaging between them tends to result in the separation of such a holding means on the periphery of the container being uneven so that the container tends to tilt when it is isolated from the stack.

In contrast, the object of the invention is substantially to improve containers of the type mentioned at the outset in that the bracing, holding and guide means afford a reliable grip between the fitted-together containers even without the need of high precision while when the containers are separated from the stack a ready release of the holding means and a smooth, safe and non-tilting sliding apart of the containers can be achieved.

According to the invention, this problem can be solved in that the bracing, supporting and guide means comprise a stacking ring having a top stacking shoulder and a bottom stacking shoulder and, in functional co-operation with this stacking ring a holding ring having at least two superposed annular parts, and in that when 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 in at least one of these annular parts of the holding ring there is integrally moulded, and encircling the container, at least one row of bulbous projections which so project inwardly andlor outwardly in an annular part of the holding ring which coincides with the outer container or inner container that, when the containers are fitted together, these projections undergo elastic deformation as they are pressed against one another or against a smooth annular part of the holding ring.

The invention ensures that, for example, in the case of a holding ring consisting of two annular parts with, in each case, a row of convex projections extending around the container, these projections become elastically deformed into one another and grip with an elastically resilient counteraction when the containers are pushed together in an axial direction. The result is a reliable and resilient gripping of the containers which are pushed axially together into a stack.According to the invention, however, it is also possible to have bulbous projections integrally formed into only one annular part of the holding ring, so that when the containers are fitted together, these projections are elastically pressed against a (prior to fitment) smooth annular part of a stacking ring, and to the same extent a reliable gripping of the fitted-together containers is achieved as in the case of an embodiment in which bulbous projections are formed into each annular part of the holding ring.

This development according to the invention with bulbous projections pressed elastically against one another or bulbous projections which are elastically deformed against a smooth annular part of the stacking ring does, however, and in a very advantageous manner, make it possible to achieve a smooth and practically jerk-free separation of fitted-together containers. This results from the resili ent movement generated in the bulbous projections or in the smooth annular part of the holding ring when the containers are pulled apart.All these functions relationships are achieved without the containers having to be fitted together in any particularly precise fashion, so that even in the case of mass produced articles, the stacked containers are held reliably together under virtually identical force conditions regardless of dimensional fluctuations within the tolerances inevitable with mass produced articles.

Preferably, the annular part should be provided with at least one row of bulbous projections extending around the container while the other annular part should be constructed with a substantially cylindrical annular wall part. It is possible to construct in the upper part of the holding ring and encircling around the container a row of bulbous projections which protrude into the interior of the container, while the other part of the holding ring comprises a substantially cylindrical annular wall part of such elasticity that the bulbous projections of a container fitted over them project elastically and radially inwardly into them. As experiments have shown, this simple embodiment with a two part holding ring satisfies the need for a firm grip of containers which are fitted together into a stack and for the subsequent jerk-free separation of the containers.At the same time, this construction proves advantageous in terms of the manufacture of such containers, as must be expected of even mass produced articles, but to an extent which has not hitherto been achieved by the known beakers which have a far more complicated structure (mini mal tolerance range).

Alternatively, however, it is also possible to construct in the lower part of the holding ring and extending around the container a row of bulbous projections protruding towards the outside of the container, while the other part of the holding ring has a substantially cylindrical annular wall part of such elasticity that the bulbous projections of an inserted container can become radially outwardly and elastically impressed into it.

According to a further idea underlying the invention, it is however also possible to form in each of the annular parts of the holding ring and extending around the container at least one row of bulbous projections which in one annular part, preferably the upper annular part, protrude towards the inte rior of the container while in the other annular part of the holding ring they protrude towards the out side of the container. In the case of this embodi ment of the invention, when the containers are fitted together, the bulbous projections in the thin caontainer wall snap elastically into one another like springs and grip one another with an elastic and resilient reciprocal action.At the same time, this elastic and resilient reciprocal action of the inter-engaged bulbous projections achieves a partic ularly reliable and resilient gripping of the containers in the super-position of the mutually contacting stacking shoulders, but also a smooth and jerk-free separation of the fitted-together con tainers.

In order to impart additional strength to the container which has a very thin wall, it is possible according to the invention to have a stiffening ring integrally moulded into the peripheral wall of the container so that it extends around the container between the upper part and the lower part of the holding ring. At the same time, this embodiment according to the invention ensures that when the containers are fitted into one another and separated from one another, the annular parts which form the holding ring are fixed in their position, so further enhancing the advantages of a reliable grip and jerk-free separation of the containers which are achieved by the invention.

It also falls within the scope of the invention that this stiffening ring extending around the container is constructed as an additional holding ring, providing a further improvement of the holding properties when the containers are fitted together.

In a preferred embodiment of the invention, the bulbous projections are intended to be cap-shaped.

These cap-shaped projections possess particularly high elasticity, this shaping also, by favourable sliding and guiding properties, having an ideal influence on the fitting-together and separation of the containers. At the same time, such a construction is easily achieved at the manufacturing stage.

Preferably, the bulbous or cap-shaped projections within one peripheral row of projections should be spaced apart by the same amount from one another in order thus to achieve a substantially even distribution of forces around the container periphery. On the other hand, it is recommended that the bulbous or cap-shaped projections in one annular part be disposed at a greater distance from one another than the amount by which the bulbous or cap-shaped projections in the other annular part of the holding ring are spaced apart. In consequence, whenever two containers are fitted together, every conceivable juxtaposition of the bulbous or cap-shaped projections will periodically recur on the periphery of the holding ring. There will then again be an even distribution of forces over the total periphery without the containers having to be pushed together in a preferred mutual relationship.

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

In a preferred embodiment of the invention, the bulbous or cap-shaped projections in the upper an nular part of the holding ring are directed towards the interior of the container, are constructed with the larger diameter and possibly the greater radius of curvature and are disposed at the smaller distance apart from one another. In consequence, the more intensely deforming bulbous or cap-shaped projections of greater diameter and greater radius of curvature generally only come in contact with a single bulbous or cap-shaped projection of the other group and thus have clearly defined conditions of deformation, whereas it is unimportant if a cap-shaped projection of smaller diameter or smaller radius of curvature simultaneously engages two cap-shaped projections of larger diameter or larger radius of curvature.

The holding ring is preferably disposed adjacent to and either above or below the stacking ring. As a result, the stabilising effect on the holding ring, produced by the stacking shoulders, can be fully exploited. It is also possible to incorporate the holding ring into the stacking ring in that an annular part of the holding ring is disposed between the stacking shoulders. The combination formed by adjacent or mutually incorporated disposition of stacking ring and holding ring ought preferably to be located in the lower marginal zone of the peripheral wall of the container so that for practical purposes it lies at the upper peripheral edge of the filling receiving chamber which is formed on the bottom of the container.As an advantageous further development, it is possible to construct below the lower stacking shoulder of the stacking ring a centring ring and above the upper annular part of the holding ring at least one guide ring located in the peripheral wall of the container and projecting like a piston ring. This guarantees a particularly reliable axial guiding of the containers when they are separated singly from the stack, so that disturbance or other agitation of the filling which is disposed in the bottom of the container can be avoided.

The location of the combination of stacking ring and holding ring on the peripheral wall of the container can assuredly also be disposed elsewhere, for example at the upper marginal zone of the peripheral wall of the container. The stacking ring and the holding ring may also be disposed separately, for example one being located in the lower marginal zone and the other in the upper marginal zone of the peripheral wall of the container. Even when so separated, a functional co-operation of stacking ring and holding ring is guaranteed via the peripheral wall of the container which connects the two zones, even though the stabilising effect of the stacking shoulders on the holding rim is no longer available.

An embodiment of the invention will be described in greater detail hereinafter with reference to the accompanying drawings, in which: Figure 1 shows, fitted one into another, three drinking beakers in a preferred embodiment of the invention, the two outer beakers being shown in section and the innermost beaker being shown in side elevation; Figure 2 shows on an enlarged scale the detail 2 from Fig. 1; Figure 3 is a functional diagram of the capshaped projections in the holding ring:: Figure 4 shows on an enlarged scale the detail 4 from Fig. 1; Figure 5 shows a section through a further preferred embodiment of drinking beaker according to the invention, two such beakers being fitted one into the other, and Figure 6 shows a section through two drinking beakers of yet another preferred embodiment of the invention, the beakers being fitted one into the other.

In the example illustrated, the beakers 10 have, sub-divided into four portions, an integral peripheral wall 11 which at its top edge merges into a flanged-over lip ring 12 and at its bottom edge into the beaker bottom 13. The bottom-most zone 14 of the peripheral wall 11 extends under the stacking ring 15 and corresponds substantially to the chamber intended to hold the filling, for example powdered coffee. Formed above the stacking ring 15 is a holding ring 16 having an upper annular part 16a and a lower annular part 16b. Adjacent the top of the holding ring 16a and occupying substantially the height of the beaker 10 is the zone 17 of the peripheral wall 11 in which are constructed peripherally extending ribs 18 which resemble piston rings.

Formed in the upper annular part 16a of the holding ring 16 is an encircling row of cap-shaped projections 19 which protrude towards the interior of the container. In the lower annular part 16b of the holding ring 16 there are cap-shaped projections 20 which protrude towards the outside of the container. As Fig. 1 also shows, the lower annular part 16b of the holding ring 16 merges along its bottom edge into the upper stacking shoulder 21 while formed between stacking ring 15 and the lowest part 14 of the peripheral wall is the bottom stacking shoulder 22. A centring ring 23 is constructed in the bottom zone 14 of the peripheral wall, adjacent to the bottom stacking shoulder 22.

As in particular Figs. 2 and 3 show, the capshaped projections 19 constructed in the upper annular part 16a and protruding towards the interior of the container are disposed all round at regular spacings A19 and are constructed with a diameter D10 and a radius of curvature R,g. The cap-shaped projections 20 in the lower annular part 16b are spaced apart over the entire periphery by a regular interval A20, have a diameter D20 and a radius of curvature R20. The radius of curvature R,g of the cap-shaped projections 19 is greater than the radius of curvature R20 of the cap-shaped projections 20. The diameter D19 of the cap-shaped projections 19 is greater than the diameter D20 of the capshaped projections 20.Finally, the reciprocal spacing A10 of the cap-shaped projections 19 is considerably smaller than the reciprocal spacing A20 of the cap-shaped projections 20. 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 15, is so attuned to the width of the holding ring 16 and the width of the upper annular part 16a and of the lower annular part 16b that when the two beakers 10 and 10b are fitted together fully, in other words when the lower stacking shoulder 22 of the inner beaker 10b is resting on the upper stacking shoulder 21 of the outer beaker 10a, the lower annular part 16b in the holding ring 16 of the inner beaker 10b is opposite the upper annular part in the holding rim of the outer beaker 10a, in fact so that the centre points of curvature M19 and M20 of the oppositely disposed cap-shaped projections 19 and 20 lie substantially in a plane at a right-angle to the beaker axis.

As Fig. 2 shows, the cap-shaped projections 20 in the lower annular part 16b of the inner beaker 10b press into the inwardly protruding cap-shaped projections 19 formed in the upper annular part 16a of the holding ring 16 of the outer beaker 10a.

As Fig. 3 shows, the differing spacings A10 and A20 between the cap-shaped projections 19 and the cap-shaped projections 20 will ensure differing engagement between the cap-shaped projections 19 and the cap-shaped projections 20. In the example shown in Fig. 3, the ratio between the distances Al9 and the distances A20 are such that five smaller cap-shaped projections 20 are opposite six larger cap-shaped projections 19. It can happen that a small cap-shaped projection 20 simultaneously engages two larger cap-shaped projections 19 or engages between two larger cap-shaped projections 19.

As Fig. 4 shows, the guide rings 18 which project outwardly like piston rings are so constructed that these guide rings 18 of an inner beaker 10b enjoy light contact with the inner surface of whichever is the outer beaker 10a. Thus, the outer beaker 10a, when pulled from the stack of beakers, has its inside face sliding on these guide rings so that the cap-shaped projections 19 and 20 are separated from one another with a substantially axially guided movement.

In the case of the example shown in Fig. 5 as a section through two containers fitted one into the other, the holding ring 16 which is adjacent the stacking ring 15 above the top stacking shoulder 21 consists of a lower substantially smooth cylindrical part 16b and an upper annular part 16a provided with cap-shaped projections 20 directed towards the interior of the container. Between the two annular parts 16a, 16b there is an integrally formed stiffening ring 16c which projects towards the interior of the container via shoulders. This stiffening ring 16c can however also be so constructed that, co-operating with the outer peripheral wall of a further container which is fitted into these two containers, it forms an additional holding ring.In accordance with the embodiment of beaker according to Fig. 2, also with the example shown in Fig. 5, the axial distance between the upper stacking shoulder 21 and the lower stacking shoulder 22 determines the width of the stacking ring 15 and is so attuned to the width of the holding ring 16 and the widths of the upper annular part 16a, the stiffening ring 16c which, via shoulders, is formed in the container wall, and of the lower annular part 16b, that when the two beakers 10a and 10b are fully inserted one into the other, in other words when the bottom stacking shoulder of the inner beaker 10b is supported on the upper stacking shoulder 21 of the outer beaker 10a, the lower and prior to insertion substantially smooth annular part 16b in the holding ring 16 of the inner beaker 10b is opposite the upper annular part of the holding ring of the outer beaker 10a on which there are cap-shaped projections 20 directed towards the inner container 10b. The inwardly protruding capshaped projections 20 on the upper annular part 16b of the outer container 10a press into and become elastically deformed on the lower annular part 16b of the inner container 10b on which there are no projections.By reason of the greater stability of the cap-shaped projections 20, the smooth lower annular part 16b of the inner container 10b becomes more or less elastically deformed so that when the containers are subsequently singled out or separated, there may remain a residual and inwardly directed minor indentation 24. This does not, however, have an adverse effect on the overall strength of the container but does offer the advantage of a firm grip and jerk-free isolation of the fitted-together containers.

In the case of the example of embodiment shown in Fig. 6, and in comparison with the containers shown in Fig. 5, the containers are of somewhat smaller diameter, the stiffening ring 16c formed on shoulders between them being directed towards the outside of the container. In contrast to the container in Fig. 5, there are in the lower annular part 16b of the holding ring 16 cap-shaped projections 20 which project towards the outside of the container and which, by co-operating with the substantially smooth upper annular part 16a of the outer container 10a can guarantee a reliable holding together of the stacked containers and jerk-free isolation of the containers. However, with regard to the width of the stacking ring 15, the width of the holding ring 16 and the matching of the widths of the annular parts 16a, 16b and of the integrally formed stiffening ring 16c, the same conditions must be observed as in the case of the beaker shown in Fig. 5.

Claims (1)

1. Thin-walled container made from plastics material preferably of beaker form, having a peripheral wall widening-out from the bottom to the top rim, into which are integrally moulded bracing, holding and guide means for fitting together a desired number of such containers to form a rod-like stack, accompanied by the formation of cavities between the bottoms of adjacent containers to accommodate measured quantities of filling substances such as coffee powder and the like, and for reliable separation of the container from the stack, characterised in that the bracing, supporting and guide means comprises a stacking ring having a top stacking shoulder and a bottom stacking shoulder and, in functional co-operation with this stacking ring a holding ring having at least two