DE29615303U1 - Plastic container - Google Patents

Description

Georg Ut&zgr; Holding AG

Augraben 2-4, CH-5620 Bremgarten

Plastic containers

The invention relates to a plastic container for transporting and storing goods with a rectangular base and walls rising from this base, the underside of the base being provided with stiffening ribs formed thereon, pointing perpendicularly away from the base and running parallel to the outline of the base.

Such containers, which are manufactured using the injection molding process, are designed in such a way that they can be stacked next to and on top of each other on standardized pallets or in standardized storage racks, for example, with optimal use of space.

In the simplest case, such a container consists of a smooth, unreinforced base and smooth walls, possibly with handles molded onto the sides.

When loaded, the container is subject to strong deformation forces, which twist it and, above all, cause the base to bend significantly, so that not only elastic, i.e. reversible, but also plastic deformations occur in the base.

This means that the container on a flat surface only has point contact with it. On a conveyor belt, this leads to dancing, i.e. a movement around the vertical central axis. In automated conveyor lines, where the direction of transport can also change, such an unstable, dancing container quickly becomes a disruptive factor, as it moves diagonally in the conveyor line.

national position and thereby bring the entire transport line to a standstill.

In order to keep such deformations as low as possible, the bottoms of the containers are reinforced. This is done, for example, by ribbing the bottom of the base.

Containers are known which have a rib on the bottom following the edge contour, one in the middle of the bottom and two ribs provided between the middle rib and the edge rib, whereby all ribs have the same height.

This does result in a certain increase in stability. However, as already explained above, the ribbed base can be deformed not only elastically but also plastically when subjected to greater loads in the shelf, so the inner ribs always come to rest first when transported on a conveyor belt, such as a roller belt. This causes the dancing movement described above, whereby the container rotates around its central axis, since there is only a point-like contact between the rib resting on it and the base.

To further increase stability, a flat plastic plate has been welded onto the ribbed base, i.e. onto the ribbed edges. With the same load, the deflection in this variant is significantly lower than with the simple ribbed base described above, which means that the risk of dancing can be minimized but not completely eliminated.

The disadvantage of this alternative, however, is the complex manufacturing process, as the additional plate has to be welded on in a second step.

In addition, another alternative is known in which the raised floor is not designed to be continuous, but is only formed in the edge area.

The bottom can bend without the container bouncing, but the container then only rests on the inner edges of this partial double bottom, which is not desirable when rolling on a roller conveyor, and in addition, these inner edges are not necessarily straight, but can be wavy due to the manufacturing process, so that when transported on roller conveyors, the container's own movement is similar to bouncing.

The corrugation in the edges is caused by partial rib connections arranged perpendicular to the edge line.

The production of such a double floor is extremely complicated, as tool cores have to be drawn to create the partial double floor. In contrast to the normal double floor, the closed profile of the double floor is replaced by a U-profile, which consists of the edge of the partial double floor and the unreinforced floor area in between. However, since such a U-profile can be deformed much more easily with the same force than a double floor (area moment of inertia), the deflection in this variant is much higher than in the double floor, which leads to the disadvantageous edge position described above.

Due to the manufacturing process (tool cores to be drawn), the double bottom is open to the outside and is therefore susceptible to contamination. In addition, longer cycle times are required during injection molding of the container due to the poor cooling in the core area.

The invention is therefore based on the object of designing a plastic container of the type mentioned at the beginning in such a way that it is easy to manufacture and the ribs are arranged and designed in such a way that after plastic deformation, dancing on the transport path is reliably excluded.

The invention solves this problem by providing a plurality of parallel ribs in the bottom edge area

is provided, the distance between which is approximately in the order of magnitude of the rib heights, whereby the imaginary envelope of the rib edges towards the middle of the floor has a rising course towards the floor surface.

Further advantageous embodiments are the subject of the subclaims.

The arrangement and design of the ribs according to the invention results in an increase in the stability of the floor itself, while being simple to manufacture without the use of core pulls. But what is even more important: if deflection does occur as a result of greater loading and the associated plastic deformation, it is guaranteed that the floor always rests on the subsurface with at least two adjacent ribs and this definitely prevents any dancing.

This is achieved by arranging the parallel ribs close together, especially in the edge area. As you move towards the middle of the floor, the distance between the ribs becomes exponentially larger, or there are no further ribs at all in the middle of the floor.

The envelope of the rib edges has a rising course towards the base surface, at least towards the middle of the base end of the rib group. This can be linear or curved, so that the rib group has an approximately ball-shaped design.

If a container designed in this way - in a shelf resting only on the sides on square supports - is so heavily loaded that a plastic deformation of the base occurs, the deflection of the base is compensated by the rising course of the rib edge envelope in such a way that at least two ribs are still in contact with the base (rollers of a roller conveyor). The rising course of this envelope has the effect, particularly in the case of ribbing also provided in the middle of the base, that the ribs are so short here that they are not too short.

are formed in such a way that even in the event of extreme deflection, the edges of these ribs cannot come into contact with the ground. This ensures that only the ribbing of the edge area and here always at least two adjacent ribs ensure that the container stands securely.

In a preferred embodiment according to claim 2, the spacing of the ribs in the first area adjacent to the base edge is narrower than in the area adjoining it in the direction of the base center. For example, the first seven ribs have a constant spacing from the edge, while the following ones are each further apart from each other than their predecessors and are continuously reduced in height.

As mentioned, the close arrangement of a large number of ribs provides increased stability on the one hand, but also ensures that there are always enough ribs available as a base for any degree of deformation.

Since the containers hit their front edges when rolling onto the roller conveyor and when rolling off, which can cause disruptions in the transport process, claim 4 provides that the first rib, as seen from the edge, is made shorter than the ones that follow it, so that a run-on slope is created that ensures that the containers run on smoothly, since the rollers have height differences due to manufacturing. Of course, the run-on slope can also be made longer, for example by making the first two ribs shorter than the ones that follow, with the first rib again being shorter than the second.

Thus, the course of the rib edge envelope is designed to be approximately convex, whereby according to claim 5 the lateral, falling course forming the run-on slope is immediately followed by the rising course of the envelope, while in the design according to claim 3 between the falling, the run-on slope

sloping area and the rising area of the envelope a horizontal area is provided.

The invention is illustrated and described in more detail below with reference to drawings.

Show it:

Fig. 1: in cross section a container with ribbed bottom according to the invention,

Fig. 2: Container according to Fig. 1 in view from below,

Fig. 3: Container according to Fig. 1 under load,

Fig. 4: Container according to Fig. 3 in transport position,

Fig. 5: enlarged section of Fig. 4,

Fig. 6: alternative embodiment of the invention,

Fig. 7: Container in conventional rib design,

Fig. 8: a known container with double bottom,

Fig. 9: a known container with partial double bottom and

Fig. 10: Container according to Fig. 9 in loaded condition.

Fig. 1 shows a cross-section of a plastic container 1 with a rectangular outline and walls 3 rising vertically from the base 2, which are provided in the upper area with molded handles 4 and stiffening ribs 5 (not explained in more detail). In the lower area of the walls, holders 6 are provided for inserting labels.

Reinforcing ribs 7 pointing vertically downwards are formed on the underside of the base 2 and run parallel to the edge of the base.

The outermost rib 7a lies within the base area delimited by the walls 3, so that when two containers 1 are stacked on top of each other, the ribs 7, 7a dip into the container 1, thus ensuring safe stacking.

The design and arrangement of the ribs 7, 7a in this embodiment is as follows:

In a first region 8, viewed from the bottom edge, the ribs 7, 7a are arranged at a close distance a from one another, which is smaller than the height h of these ribs 7, 7a, wherein the first rib 7a, viewed from the edge, is shorter than the following ones, which each have the same height h.

The area 8 is followed by a second area 9 in which the distance between the ribs 7 increases steadily, with the exception of the distance from the central rib 7b to its predecessor. The heights h of the ribs 7 in this area 9 decrease steadily towards the center of the base, in this case linearly, so that the imaginary envelope 10 of the rib edges has an increasing course from the first area 8 towards the center of the base.

Fig. 2 shows the underside of the base 2, from which the arrangement and course of the ribs 7, 7a can be clearly seen.

Fig. 3 shows a container 1 designed according to Fig. 1 in the loaded state resting on square supports 11 of a storage rack.

The load is so great that a plastic deformation occurs in the base area, which gives the container base 2 a shape as shown in Fig. 4 (exaggerated), in which the container 1 is transported on a roller belt 12.

As can be seen more clearly from Fig. 5, two adjacent ribs 7 rest securely on the roller of the roller belt 12, while the ribs arranged to the left of them are raised from the ground, as are those arranged to the right of them, so that these latter cannot come into contact with the ground even if the ground 1 is strongly bent, and a point-like support which could lead to dancing is safely excluded.

Finally, Fig. 6 shows a second embodiment of the container 1 according to the invention, which differs from the previously described only in that reinforcing ribs 7 have been completely omitted in the center of the base.

Both embodiments have in common the design of the first and second rib regions 8 and 9. The fact that the first rib 7a is shorter than the ones following it results in a run-on slope that ensures problem-free running onto the roller belt and equally problem-free running off of it.

Fig. 7 to 10 show containers with conventional bottom designs that are part of the state of the art.

Fig. 7 shows a previously common ribbing, in which only seven ribs 7 with correspondingly large distances a from each other are provided.

Under a load as shown in Fig. 3 and 4, but also under lower loads, the base 2 bends so that only the central rib 7b comes into contact with the base, so that the container dances during transport on the conveyor belt 12, i.e. carries out rotating tilting movements which quickly lead to an undesirable container orientation.

In order to minimize the deflection of the floor under load, a plastic plate 13 is welded onto the ribs 7, 7b, as shown in Fig. 8. Despite the lower deflection, the dancing effect still occurs here.

It has therefore already been proposed (Fig. 9) to implement such a raised floor only partially, in the edge area.

However, the production is complex, since 14 core pulls have to be used to form the raised floor sections, which leads to the disadvantages already listed in the general description section.

As can be seen from Fig. 10, the floor 2 bends under load, but does not reach the ground. The container 1 rests on the inner edges 15 of the double floor sections 14. Since cross ribs (not shown) are provided in these sections 14, these cross rib connections result in a wave-shaped design of the inner edges 15, which means that an effect similar to dancing also occurs during transport on a roller belt 12.

Claims (1)

Georg Ut&zgr; Holding AG Augraben 2-4, CH-5620 Bremgarten Plastic containers Protection claims : 1. Plastic containers for the transport and storage of goods with a rectangular base and walls rising from this base, the underside of the base being provided with stiffening ribs moulded onto the base, pointing vertically away from the base and running parallel to the outline of the base, characterized, that a plurality of ribs (7a, 7b, 7) arranged parallel to one another are provided in the bottom edge region, the distance (a) between which is approximately in the order of magnitude of the rib heights (h), whereby the imaginary envelope (10) of the rib edges has a course that rises towards the bottom center in the direction of the bottom surface. 2. Plastic container according to claim 1,
characterized, that the distance (a) of the ribs (7a, 7) from one another in a first region (8) of the base (2) as seen from the edge is smaller than their height (h) and in a subsequent second region (9) in the direction of the center of the container base the ratio of distance (a) to height (h) is > 1, the imaginary envelope (10) of the rib edges having the rising course in the direction of the base surface at least in this second region (9). 3. Plastic container according to claim 2,
characterized, that in the first region (8) the ribs (7) arranged parallel to one another have constant heights (h). 4. Plastic container according to claim 2,
characterized, that the first rib (7a) seen from the edge is lower than the one following it. Plastic container according to claim 2 or 4, characterized in that the rising course of the imaginary envelope (10) of the rib edges begins in the edge region. 6. Plastic container according to one of claims 2 to 5, characterized in that the second rib area (9) reaches to the middle of the floor.