US20100072165A1

US20100072165A1 - Plastic container

Info

Publication number: US20100072165A1
Application number: US12/560,301
Authority: US
Inventors: Alexander Schau
Original assignee: Krones AG
Current assignee: Krones AG
Priority date: 2008-09-15
Filing date: 2009-09-15
Publication date: 2010-03-25
Also published as: CN101708783B; EP2163483B1; CN101708783A; EP2163483A1; DE102008047450A1

Abstract

A plastic container (1) including a bottom (2) having a cross section deviating from a circular cross section, with an injection point (4) being provided in a central area of this bottom (2). According to the invention, the bottom (2) has at least two first radially extending main ribs (6 a , 6 b) which extend in a straight line across the bottom (2) in such a way that a geometric connection line (L1) extends through the injection point (4), with the injection point (4) being located in a first recess (12) of the bottom (2), which recess (12) extends in the direction of the internal space of the plastic container (1) and which recess (12) separates the two first main ribs (6 a , 6 b) from each other.

Description

The present invention relates to a plastic container which may be used in particular for beverages. In the area of the beverage producing industry, an increasing number of plastic containers compared to glass bottles have recently been used. In this connection, the most varied basic shapes or cross sections for such plastic bottles are known. On the one hand, such plastic containers often have circular cross sections, but it is also known to provide such containers with a rectangular or square cross section. The latter embodiment particularly provides benefits with regard to an effective use of space in storage as well as with regard to secure standing.
In addition, endeavours are being made towards a continuous reduction of the consumption of material during the production of such containers. This leads to a continuously increasing reduction of the thickness of the walls and also the bottom of such containers. On the other hand, however, it is important to make sure that the bottle walls and in particular also the bottom of such containers is made sufficiently stable to withstand, on the one hand, the inherent weight of a full bottle and, on the other hand, any internal pressure developing, in particular in the case of carbonised beverages. In the prior art, carbonised beverages are always filled into bottles having a circular cross section. Such containers, however, are accompanied by a greater consumption of material, a limited pressure resistance as well as a lower tipping stability due to the circular cross section.
WO 2006/067590 A1 describes a bottle bottom made from a plastic material. To be more precise, reinforcement recesses are provided therein, which extend transversely in relation to this bottle bottom, with a continuous main rib being disposed in the bottom. The bottom itself has a square cross section with rounded corners. The main ribs as mentioned extend up to an injection point of the container. With such a design of the bottle bottom, enhanced stability may be achieved, particularly in the area of the injection point, however, unfavourable stress distributions may occur because of the layout of the corresponding reinforcement ribs.
The present invention is therefore based on the objects of further enhancing the stability of levels of plastic bottles and in particular of increasing the pressure resistance. In addition, also the amount of material required for producing such plastic bottles is to be further reduced.
According to the invention, this is achieved by means of a plastic container according to claim 1. Advantageous embodiments and further developments are the subject matters of the dependent claims.
A plastic container according to the invention comprises a bottom having a cross section deviating from a circular cross section, with an injection point being provided in a central area of this bottom.
According to the invention, the bottom has at least two first radially extending main ribs, which extend in a straight line across the bottom in such a way that a geometric connection line extends through the injection point. Further, the injection point is located in a first recess of the bottom, which preferably extends in the direction of the internal space of the plastic container and which separates the two first main ribs from each other. Preferably, this recess has a circular shape and completely surrounds the injection point.
In other words, the bottom has a dome-shaped structure in the area of the recess or the injection point, with the injection point itself preferably being located in the centre of this dome-like structure.
A cross section deviating from a circular cross section is understood to mean in particular, but not exclusively, a square or a rectangular cross section, with a square cross section also being a cross section which has more or less acutely rounded corners and has sections between these corners, which extend essentially in a straight line.
By means of separating the two main ribs and owing to the recess, an enhanced stability of the bottom is achieved. In particular, the mentioned recess contributes to an increase of the stability in the central area of the bottom. Preferably, the two main ribs will reach up to the recess or will come into contact with it. In this way, a particularly stable skeleton may be produced particularly in the area of said recess. The term ribs as mentioned below is understood to mean in particular recesses which extend in a straight line, preferably in the direction of the internal space of the container. By means of these ribs, a material reinforcement is achieved without having to considerably increase the wall thickness in the area of the bottom. Further, by means of these ribs, the secure standing of the container on its bottom surface may be enhanced.
In the case of a further advantageous embodiment, the bottom has two second main ribs which extend across the bottom in a straight line in such a way that a geometric connection line extends through the injection point. In other words, these two second main ribs, too, extend from the injection point or a longitudinal axis of the container in a radial direction. By means of these two further main ribs, the stability may also be enhanced in other directions of the bottom.
In this connection, the recess preferably separates also the two second main ribs from each other, and here again the main ribs will particularly preferably extend up to the recess or will even protrude into the recess. In a further preferred embodiment, the first geometric connection line extends essentially perpendicularly with respect to the second geometric connection line. In this way, the two first main ribs and the two second main ribs form a cross which extends across the bottle bottom.
The two main ribs or tie rods, which are preferably disposed at right angles to one another, preferably have an internal radius of between 30 mm and 60 mm, preferably between 35 mm and 50 mm and particularly preferably between 40 mm and 50 mm. All of the main ribs will, as mentioned, preferably be interrupted by the recess or the central dome, with the injection point being at the centre of this recess. The recess will here preferably have a radius of between 4 mm and 25 mm, preferably between 6 mm and 20 mm and particularly preferably between 8 mm and 15 mm. The main ribs or tie rods advantageously start at the run-out of this recess.
The wall thickness at the starting point of the main ribs at the recess is advantageously relatively high, so that a high pressure stability is achieved. On the other hand, the size of the diameter of the recess is important for the steepness of the main ribs and is thus also a determining factor for the amount of material needed. Due to the fact that the injection point is withdrawn into the recess, which means is displaced towards the inside of the container, the ground clearance is enhanced when the container is in contact with the ground.
Due to the fact that preferably four main ribs or tie rods are used, the pressure resistance of the container is enhanced. The four main ribs spread the internal pressure more homogeneously over the square cross section. In this way, a bottom having a pressure stability of up to an internal pressure of more than 3 bar will be obtained. Further, a low material input and also a large tipping angle will be ensured.
By means of this cross of the main ribs, a high stability of the bottom and thus of the entire container may be achieved. Preferably, at least one main rib extends to an edge of the bottom. In a further advantageous embodiment, each of the main ribs extends up to the bottom edge which is respectively associated therewith. Advantageously, the respective main ribs will not only extend up to the edge of the bottom, but will also extend beyond it into an area of the container which joins on to the bottom, such as for example a curved transitional area in which the bottom merges into the lateral wall of the container.
In a further advantageous embodiment, the bottom has a symmetrical cross section. Preferably, the bottom is designed in such a way that there are several geometric axes of symmetry. For example, it is possible that the first main ribs and also the second main ribs each form axes of symmetry of the bottom. Advantageously, the bottom is symmetrically designed also in respect of the layout of the individual main ribs or the recesses in which the main ribs are located.
In a further advantageous embodiment, the edge of the bottom has four sections extending essentially in a straight line. A straight section is here understood to mean a section that has a radius of curvature of more than 300 mm. Further, the edge of the bottom preferably has four corner sections having a specified radius of curvature. Thus, an altogether essentially square cross section is provided which has four straight sections and, between respective ones of these straight sections, corner sections having a specified radius of curvature.
In a further advantageous embodiment, a secondary rib is located between at least one first main rib and at least one second main rib, which secondary rib extends along a geometric line which in its turn extends through the injection point. Thus, also the secondary rib extends in the above-mentioned radial direction and contributes in this way to the stability of the bottom, in particular in the area between the main ribs.
Preferably, the bottom has four secondary ribs between the main ribs. In this preferred embodiment, as mentioned above, the four main ribs thus form a cross and also the four secondary ribs form a cross, since here, too, the extension lines of these secondary ribs particularly preferably extend perpendicularly in relation to each other.
In a further advantageous embodiment, each of the secondary ribs is shorter than each of the main ribs. Here, the secondary ribs preferably don't extend up to the above-mentioned recess and particularly preferably they don't extend to the edge of the container either. Preferably, the connection lines of each of two secondary ribs extend essentially perpendicularly in relation to one another.
In a further advantageous embodiment, the main ribs extend either parallel or perpendicularly in relation to the straight sections. Preferably, the main ribs extend starting from the recess up to the respective straight edges, which edges meet or intersect essentially in the centre thereof. In this embodiment, the connection lines of the secondary ribs preferably extend in the direction of the rounded corners, or put more accurately, preferably in the geometric centre of these corners.

Further advantages and embodiments will become evident from the attached drawings, wherein:

FIG. 1 shows a view of a container according to the invention;

FIG. 2 shows a top view of a bottom of a container according to the invention;

FIG. 3 shows the bottom of FIG. 2 for illustrating different perspectives;

FIG. 4 shows a view of the bottom of FIG. 3 along the line A-A of FIG. 3;

FIG. 5 shows a detail of the view shown in FIG. 4;

FIG. 6 shows a view of the bottom shown in FIG. 3 along the line B-B of FIG. 3;

FIG. 7 shows a view of the bottom of FIG. 3 along the line F-F of FIG. 3;

FIG. 8 shows a lateral view of a bottom according to the invention.

FIG. 1 shows a container 1 according to the invention. This container has a mouth 3 as well as a wall body 5 and a bottom 2. It is also possible that stabilisation ribs are located in the area of the wall body.
FIG. 2 shows a top view from below of a bottom according to the invention. It can be seen here that this bottom has an essentially square cross section, i.e. a wall 20 with straight sections 22 as well as rounded corners 24. An injection point 4 is provided in the centre of this bottom.
This injection point in its turn is located within a recess 12 which extends in the direction of the inside of the container, i.e. into the figure plane of FIG. 2.
The reference numerals 6 a and 6 b relate to first main ribs which extend horizontally in FIG. 2. Here, these main ribs 6 a and 6 b each adjoin with the recess 12. Put more accurately, these main ribs each have curved projections which protrude into the recess 12. In this way, a particularly stable embodiment of the bottom is achieved. The two first main ribs 6 a, 6 b extend along the geometric line L1. The two main ribs 6 a, 6 b are located within a recess 9 which is symmetrical in relation to this line L1. This recess 9 extends, as the main ribs themselves, towards the inside, i.e. in the direction of the inside of the container.
The reference numerals 8 a and 8 b relate to two further main ribs which extend essentially perpendicularly in relation to the first main ribs 6 a and 6 b. These two main ribs 8 a and 8 b extend along a geometric line L2 as shown in FIG. 2. These second main ribs 8 a, 8 b, too, are located in recesses 9.
The individual recesses 9 are symmetrical in relation to the respective lines L1, L2. The recesses 9 together with the actual ribs contribute to the reinforcement of the bottom. It would also be possible to define the entirety of the respective main rib 6 a, 6 b, 8 a, 8 b and their recess 9 as a main rib.
The reference numeral 7 denotes an end section of the individual main ribs 6 a, 6 b, 8 a, 8 b. This end section protrudes into the recess 12 and interrupts in these positions the otherwise circular cross section of this recess. This type of transition provides a particularly high stability of the bottom.
In the main ribs 6 a, 6 b, 8 a, 8 b shown, also secondary ribs 16 a, 16 b, 18 a and 18 b are provided. Of these, the two secondary ribs 16 a, 16 b extend along the geometric line N1 and the two secondary ribs 18 a and 18 b extend along the geometric line N2. It can be seen that the secondary ribs are shorter than the main ribs and extend on the one hand neither up to the recess 12 nor up to the edge 20. The geometric line N2 is offset by 45 degrees with respect to the geometric line L1. The two geometric lines N1 and N2, too, are perpendicular with respect to one another.
The secondary ribs 16 a, 16, 18 a, 18 b are also disposed in recesses 19, and these recesses, too, extend in an axis-symmetrical manner with respect to the lines N1, N2.
FIG. 3 shows a view corresponding to that in FIG. 2, with the exception that different perspectives for the following figures are illustrated.
FIG. 4 shows a section of the bottom shown in FIG. 3 along the line A-A from FIG. 3. Here, particularly the two main ribs 6 a and 6 b which merge into the recess 12 can be seen. In this connection it can be seen that the two main ribs 6 a and 6 b in their lower areas merge into a curved section of the recess 12. In the top view of the main rib 8 b it can also be seen how this is located within the recess 9. In the embodiment shown in FIG. 4, the main ribs 6 a and 6 b have a constant radius of curvature which is preferably between 20 mm and 80 mm, particularly preferably between 30 mm and 60 mm and especially preferably between 40 mm and 50 mm.
FIG. 5 shows a detail of the view shown in FIG. 4. What can be seen here is the transition between the recess 12 of the injection point 4 and the first main rib 6 b. In this area there is a curvature, the radius of curvature of which increases starting from the area 32 up to the area 34, and in the area 35 there is an almost straight area which is immediately followed by the main rib 6 b.
FIG. 6 shows a section through the bottom along the lines B-B from FIG. 3, i.e. a view of the secondary ribs 16 a, 16 b. What can be seen in detail here are the secondary ribs 16 a and 16 b as well as again the recess 12 and the injection point 4 in the centre thereof. In this case, the curvature of each of these secondary ribs 16 a, 16 b decreases towards the outside or increases towards the inside. The areas 36 extend in an almost straight line, i.e. the secondary ribs are no longer or hardly at all present here. This can also be seen in FIG. 2.
In the points or areas E, the secondary ribs 16 a, 16 b, 18 a, 18 b merge into the bottom surface 40 towards the outside. Thus, in these areas as well as preferably also in the area 36, the secondary ribs 16 a, 16 b, 18 a, 18 b have tangential run-ins and run-outs with respect to the bottom surface 40. This may be recognised by the fact that in these areas each of the secondary ribs merges into the areas 40 of the bottom 2 between these ribs. In this way, the formation of folds in the short legs of the containers 1 may be avoided.
In a preferred embodiment, the diameter of the recess 12 is two to eight times larger than the diameter of the injection point, preferably between 2.5 and 6 times, particularly preferably between 3 times and 4 times larger.
FIG. 7 shows a section of the bottom from FIG. 3 along the lines F-F from FIG. 3, i.e. an area in which neither a main rib nor a secondary rib extends. In this area, particularly the extension of the bottom surface 40 may be seen in an area in which there are neither main ribs nor secondary ribs. What can be seen here is that the radius of curvature increases initially from the area 42 up to the area 44 and then decreases abruptly into the area 46. In a 48 [sic] there is also a curvature, but in the opposite direction.
FIG. 8 shows a lateral view of the bottom 2 according to the invention. Here, too, it may be seen that the main ribs 6 a extend much further upwards, i.e. in the direction of the mouth 3 of the container, than the respective secondary ribs 16 a, 18 b.
The reference numeral 50 relates to short legs which are respectively formed between a main rib and a secondary rib. These short legs support the container 1. In the embodiment shown in FIG. 1, the container has eight of these short legs 50.
All of the features disclosed in the application document are claimed as essential to the invention, in as far as they are novel compared to the prior art either individually or in combination.

Claims

1. A plastic container (1) including a bottom (2) having a cross section deviating from a circular cross section, with an injection point (4) being provided in a central area of this bottom (2), wherein the bottom (2) has at least two first radially extending main ribs (6 a, 6 b) which extend in a straight line across the bottom (2) in such a way that a geometric connection line (L1) extends through the injection point (4), with the injection point (4) being located in a first recess (12) of the bottom (2), which recess extends in the direction of the internal space of the plastic container (1) and which recess (12) separates the two first main ribs (6 a, 6 b) from each other.

2. The plastic container (1) as claimed in claim 1, wherein the two first main ribs (6 a, 6 b) reach up to the recess (12).

3. The plastic container (1) as claimed in claim 1, wherein the bottom (2) has two second main ribs (8 a, 8 b) which extend in a straight line across the bottom (2) in such a way that a geometric connection line (L2) extends through the injection point (4).

4. The plastic container (1) as claimed in claim 3, wherein the recess (12) separates the two second main ribs (6 a, 6 b) from each other.

5. The plastic container (1) as claimed in claim 3, wherein the first geometric connection line (L1) is located essentially perpendicularly in relation to the second geometric connection line (L2).

6. The plastic container (1) as claimed in claim 1, wherein the at least one main rib (6 a, 6 b, 8 a, 8 b) extends to an edge (20) of the bottom (2).

7. The plastic container (1) as claimed in claim 1, wherein the bottom (2) has a symmetrical cross section.

8. The plastic container (1) as claimed in claim 1, wherein an edge (20) of the bottom (2) has four sections (22) extending essentially in a straight line.

9. The plastic container (1) as claimed in claim 1, wherein the edge (20) of the bottom (2) has four corner sections (24) with a specified radius of curvature.

10. The plastic container (1) as claimed in claim 3, wherein between at least one first main rib (6 a) and at least one second main rib (8 a) a secondary rib (16 a) is located, this secondary rib extending along a geometric line (N) which extends through the injection point (4).

11. The plastic container as claimed in claim 10, wherein four secondary ribs (16 a, 16 b, 18 a, 18 b) are disposed between the main ribs (6 a, 6 b, 8 a, 8 b).

12. The plastic container as claimed in claim 10, wherein each secondary rib (16 a, 16 b, 18 a, 18 b) is shorter than each of the main ribs (6 a, 6 b, 8 a, 8 b).

13. The plastic container as claimed in claim 11, wherein the connection lines (N1, N2) of two secondary ribs (16 a, 16 b, 18 a, 18 b), respectively, are disposed essentially perpendicularly with respect to each other.

14. The plastic container (1) as claimed in claim 8, wherein the main ribs (6 a, 6 b, 8 a, 8 b) extend either parallel or perpendicularly to the straight sections (22)