WO1996028368A1

WO1996028368A1 - Flexible container for bulk material

Info

Publication number: WO1996028368A1
Application number: PCT/EP1996/000846
Authority: WO
Inventors: Olav Skyllingstad
Original assignee: Norsk Hydro Technology B.V.
Priority date: 1995-03-10
Filing date: 1996-02-28
Publication date: 1996-09-19
Also published as: AU4944096A; NO974111L; NO974111D0

Abstract

A flexible container (1) for the filling, transportation and storage of bulk material, which container (1) is of the type including an upper section (3) having at least one lifting loop (26), side walls and a bottom, at least part of the surface of the lifting loop (26) or loops (26) being provided with a first material (25) showing limited attractive or adhesive physical characteristics towards a defined second material (23) brought into contact with the first material (25).

Description

Flexible container for bulk material.

The invention relates to a flexible container for the filling, transportation and storage of bulk material, said container being of the type including an upper section having at least one lifting loop, side walls and a bottom. Such a container is known from EP-A-1 18.1 1 2.

In the handling and especially the storage of these containers it is customary to stack containers on top of each other, as seen in the height a number of layers of containers are piled up. The transport and stacking up is mostly done by fork lift trucks or special dedicated equipment also with fork. In case of a fork lift truck, one or more containers are lifted and transported in that the fork is inserted in the loop or loops of the containers. Dedicated equipment is as a rule provided with hook type implement, to which the loop or loops can be attached. In order to be able to pick up the container easily, it is an advantage that the loop or loops during storage maintain a substantially upright position, so that the loop or loops are open and the fork or hook can easily be inserted into the loop or loops. In the known containers this has been obtained by a suitable chain of material forming the loop.

However in case of storage of the container in a number of superimposed layers, the loops of the containers in the lower layers are compressed, by the superimposed layer or layers of containers.

Upon removal of the higher layers it is not guaranteed that the loop or loops have sufficient resilience to come back to the original upright position. It is then impossible to introduce the fork or hook into the loop without special help or efforts. Mostly it means a collapsed loop must be put in its upright open position by hand.

This means an additional handling, requiring either a second person or having the handling equipment operator to interrupt its handling activity to do the same. Furthermore it may be a dangerous and complicated manipulation especially if a number of layers of containers are stacked on top of each other, because this may when using the standard containers constitute a height of 3 meters and more.

It is an object of the invention to provide a container of the above mentioned type which is so designed that the above cited problems can be avoided.

This object is achieved in that at least part of the surface of the lifting loop or loops is provided with a first material showing limited adhesive characteristics towards a defined second material brought into contact with the first material. In this way it is possible to bring a piece of second material into contact with the loop, in order to be able to lift the loop with respect to the remainder of the container, thereby bringing the loop in an upright open position. By ensuring that the adhesive force between the first and second material is not too great, it can be obtained that only the loop is lifted without moving the container as a whole, thereby avoiding uncontrolled movement of the container. Preferably the materials used as first and second material are

Velcro-type materials. This type of material exhibit an adhesive force which is sufficient to perform the lifting of the loop without further movement of the container. As soon as the loop is in its upright position the whole weight of the container must be lifted, and this exceeds the adhesive force between the two materials.

Preferably the first material is the woolly material of the velcro-type materials. As is generally known, velcro type materials consist of two different textile materials. One material is mostly called the female or woolly material and has a soft and woolly appearance. One good example of such a material is called velours. The other material is more a hook-like material, i.e. it consists of a number of small hooks fixed to a sheet like material. For the function of the lifting the loop it is irrelevant whether the one or the other material is fixed to the loop. However, the woolly material is as a rule cheaper and less susceptible to damages and contamination.

It may be advantageous to provide the second material to the bottom of each container.

In this way it can be achieved that the lifting loop or loops of a lower container is automatically lifted to its or their upright position by lifting the top container.

This solution is not always possible as the containers are often positioned in a staggered way, so that the lifting of the loop or loops is not always guaranteed.

Therefore it is preferred to fix the second material to a part of a lifting device, which can be brought into contact with the first material after lifting the container. In case of a fork lift truck the second material may be fixed to the underside of the forward end portion of each fork.

Other advantages and features of the invention will be indicated in the following description, reference being made to the annexed drawings. In the drawings there is,

Fig. 1 a schematic representation of a number of flexible intermediate containers stacked upon each other,

Fig. 2 a side-view of the top part of a container according to the invention, Fig. 3 a side-view of a lifting device to be used with a container according to the invention.

In Fig. 1 there is represented a number of containers 1 , generally designated as flexible intermediate bulk containers. The containers can have a construction as generally described in EP-A-1 1 8.1 1 2. In this specification there is described a container having a single loop used as lifting handle for the container, but it will be clear that other type of containers may be used as well, such as containers having two or more lifting loops. Furthermore there is no need to have the loop made as described in this specification, but other loop- constructions can be used, such as e.g. described in WO-A-

9214659 and WO-A-921 6438. But also containers wherein the loops are made of material different from the material of the sidewalls of the container may be used. These containers 1 are stacked on top of each other in a number of rows as is usually done in warehouses and the like. The first row 5 is put on the normal ground level. On top of the first row there is a second row 6 of containers. In Fig 1 these containers are stacked in a pyramid way, but it is clear that they may also be stacked in another way on top of each other, e.g. so that on top of each container and in line therewith there is a container of the second row 6. On top of the second row 6 there is a third row 7 of containers 1 , also stacked in a staggered way.

As shown in Fig. 1 the loop or loops 3 of the containers 1 of the first row 5 are pressed down by the weight of the containers 1 of the higher rows 6 and 7. In the same way the loop or loops of the second row 6 are pressed down by the weight of the containers of the third row 7. In case more than three rows are used, also the loops 3 of the third row 7 of containers 1 would be pressed down etc.

In fig. 1 there is also shown a fork lift truck 10, an equipment which is often used to handle containers of the type according to the invention. Such an equipment consists of an automotive part 1 1 whereby the fork lift truck 10 can be moved in a substantial horizontal plane, and a lifting part 1 2, commonly provided with two forks 1 3 and 14. Generally the forks 1 3 and 14 are fixed to an implement 1 5, which can moved in a substantial vertical direction along guiding means 1 6 fixed to the front part of the automotive part 1 1 of the fork lift truck 10. In its most simplified form a container 1 can be displaced by means of the fork lift truck 10 by simply introducing one of the forks 1 3 or 14 into the opening 4 formed by the loop and lifting the container 1 from its rest position by means of the lifting part 1 5. After movement of the truck 10 to the right position the bag is lowered either on the floor, on top of another container as shown in fig. 1 or on another transport means such as a truck or railroad wagon. In a more sophisticated manner two or more containers are handled in one movement by a fork lift truck 10, in that the distance between the two forks 1 3 and 1 4 is equal to the distance between the loops 3 between two neighbouring containers 1 .

In fig.3 there is represented an auxiliary device 20 which may be fixed to the front part of each fork 1 3 or 14 of the fork lift truck 1 0. In fact the auxiliary device 20 consists of a hooklike member 21 whereby a more positive grip of the container 1 becomes possible. In this way unintentional falling down of the container from the fork

1 3 or 14 can be avoided, as the container 1 is hanging on the lowest point of the hooklike member 21 of the auxiliary device 20. A problem with the commonly used flexible intermediate containers will be immediately clear from Fig. 1 . As soon the top row 7 of containers 1 has been removed, and there is a need to transport the second row 6, it is not guaranteed that the lifting loops 3 of that second row 6 are all in the position shown in Fig. 1 for the third row 7 of the containers 1 . In a number of cases and circumstances the loops 3 of the second row 6 of containers 1 - and the same applies to the first row 5 - will be pressed down and collapsed and will not recover to the upright position as shown in the top layer 7. This means that the fork 1 3 or 1 4 of the fork lift truck 1 0 cannot be entered into the opening 4 under the lifting loop 3. In the traditional flexible intermediate container it means that the operator of the fork lift truck 10 or his assistant has to climb on top of the containers and to lift the lifting loop 3 into a position wherein the fork 13 or 14 of the fork lift truck 10 could be entered into the opening 4 under the loop 3. Apart from the fact that this is a waste of time as one has to wait until the loop is actually lifted, it can be a dangerous operation especially in case a number of layers of containers are stacked on top of each other. In practice it is not uncommon to have four layers of containers 1 on top of each other so that one has to climb on top of the third layer, which is almost at a level of 2 meters and more above ground level. As this is not a levelled surface and especially as containers at the edge of a pile which normally will be taken first are susceptible of collapsing, accidents are frequently reported.

According to the invention all these problems can be avoided. According to the invention and as shown in Fig. 2 the loop or handle 3 of each container 1 is at least partially covered by a first material 25 which shows defined attractive or adhesive physical characteristics with respect to another second material.

Usually the containers 1 of the type according to the invention have a lifting loop which is made out of the material of the sidewalls of the container and in fact constitutes an elongated and integrated portion thereof. In practice and for different purposes this loop is covered by a sleeve 26, as is described in the EP-A- 1 18.1 1 2, which sleeve 26 commonly has a different color with respect to the container material so that it is clearly visible by the operator handling the containers.

In Fig 2 the sleeve is indicated by 26. According to the invention it is possible to have this sleeve 26 at least partially made out of a first material which shows the required attractive or adhesive physical characteristics. On the other hand it is also possible to partially or totally cover an already available sleeve 26 by such a material. Partially in this context means that such material may be available in stripes extending along the circumference of the handle or loop 3, or as isolated islands in whatever form or configuration on a support material extending around the loop 3. Important is that the active surface of the material is sufficient to perform the operation to be described later.

How big this surface should be is dependent of the physical character which is used to generate the attractive or adhesive force. It is possible to use materials showing adhesive characteristics of the glue-tγpe. In this case the nature of the second material cooperating with this type of first material is not critical provided it does show some affinity to the gluetype material. Otherwise it may be possible to use first materials showing magnetic characteristics, either as permanent magnet but preferably as ferromagnetic material, in which case the second material cooperating with this type of material should be a ferromagnetic material or a material showing permanent or electromagnetic characteristics respectively Preferably however the first material covering at least partially the loop is of the velcro-type materials. Velcro-type materials consist of two surface layers which when brought into contact show a strong but limited adhesive force towards each other. This force may be overcome after which the two surface layers can be brought in contact again in order to obtain the same adhesive force between them. Generally one surface layer, mostly called the female layer show a soft, woolly appearance, whereas the other surface layer shows a hooklike surface, i.e. it consists of a large number of small hooklike members standing substantially upright on a supporting surface. According to the invention the female material or the woolly material is used to partially cover the loop 3 of the container 1 . The second material can be applied to different other members. So it is possible to use as second material the bottom portion of the container 1 . The advantage of this solution is that the material is automatically there where it is needed or at least in the neighbourhood. The problem however is the contamination and fatiguing of the material, which will be prohibitive in case of magnetic or velcro-type systems. Especially the hooklike material is very sensitive to contamination. Another advantageous place for the second material is the underside of the lifting equipment, so as in case of a fork lift truck 10 the underside of a fork 13 or 14. Such a solution is shown in Fig 3. In practice and as already explained the end portion of the fork 13 or 14 of a fork lift truck 10 is provided with a hooklike member 21 . This member can be fixed to a hollow guiding element 23 which can be slidably fixed to the end portion of a fork 13 or 14. To the underside of the hooklike member 21 there is provided a piece 23 of the second material, which in case of velcro-type material is a piece of the male or hooklike material. In order to avoid that the second material becomes contaminated when the fork 1 3 or 14 of the fork lift truck 10 is lowered until ground level, the underside of the guiding element or another part of the underside of the fork may be provided with a cam 24, which has a dimension enabling it to maintain the piece 23 of second material free from the ground.

Preferably the piece 23 is not directly fixed to the hooklike member 21 , but is attached to it in a resilient way. This can be obtained by providing a rubber pad between the piece 23 and the hooklike member 21 . Preferably this is obtained by applying the piece 23 to the middle of a banded material part, the two ends of it being attached to the underside of the hooklike member 21 such that in the free situation the middle portion of the band part is hanging free from contact with respect to the hooklike member 21 . This gives some more freedom to the operator while handling the containers 1 , without the risk of damaging the top construction thereof.

The operation of the system will now be described reference being made to the use of a fork lift truck 10, but it will be clear that other equipment may be used as well, provided it is possible to use a piece of second material in the same way as with a fork lift truck. Further reference will be made to Fig. 1 .

In the situation as shown in Fig 1 the removing of the top layer of containers will not present any special problem as the loops 3 are all in an upright and open position. As soon as the top layer 7 has been removed, and dependent on the time and circumstances of the storage, the operator will find out that at least part of the loops of the second layer 6 of containers 1 will not have recovered their upright open position. In order to obtain that position for each individual container the operator approaches the top of such a container with the underside of one of the forks 1 3 or 14 which is provided with a piece 23 of second material as described above. Upon lowering the fork 1 3 or 14 at the place of the loop 3, the piece 25 of first material present on the loop of the container in question will be attracted or adhered by the piece 21 of second material on the fork 1 3 or 14. As soon as the operator has established this situation, he raises the forks 1 3 and 1 4, whereby and as a result of the attractive or adhesive force of sufficient strength, the loop 3 is raised to its upright or original position. As soon as the loop 3 has reached that position, the whole weight of the container 1 must be overcome in order to lift the forks further, or the there will be a tendency to lift the container 1 . As the attractive or adhesive force between the two materials is insufficient to lift the container, the connection between the two materials will be broken, so that the fork becomes free from the loop 3 of the container. The operator can now maneuver his fork lift truck 10 in such a way that either another loop of another container is brought in the upright position or penetrate one of the forks into one of the loops in the upright position, in order to transport one or more containers 1 .

If needed the fork lift truck 10 may be provided with mirror systems or periscope like systems enabling the operator to look on top of the upper layer of containers so that he can see what he is doing. In this way damage to the top construction of the containers can be avoided. As already stated the invention is not restricted to the use of fork lift trucks, but it is possible to use other types of equipment. In case of hoise crane or corresponding equipment provided with a hooklike member, it's possible to apply the second material to the underside of the hooklike member.

It is clear that numerous modifications can be applied to the inventive idea and that the invention is not restricted to what is actually described or shown in the drawings. The scope of the invention will be defined by the claims

Claims

1. A flexible container for the filling, transportation and storage of bulk material, said container being of the type including an upper section having at least one lifting loop, side walls and a bottom, c h a ra ct e r i ze d i n t h at at least part of the surface of the lifting loop or loops is provided with a first material showing limited attractive or adhesive physical characteristics towards a defined second material brought into contact with the first material.

2. Container according to claim 1, c h a ra ct e r i z ed i n th at the materials are velcro-type materials.

3. Container according to claim 2, c h a r a ct e r i ze d i n t h at the first material is the woolly material.

4. Container according to claim 1, c h a r a c t e r i ze d i n t h at the first material has a glue-type outside layer.

5. Container according to any of the preceding claims, c h a r a ct e r i z e d i n t h at the second material is fixed to the bottom of each container.

6. Container according to any of the preceding claims, c h a r a c t e r i z ed i n t h a t the second material is fixed to a part of th lifting device, and can be brought into contact with the first material before lifting the container.

7. Container according to claim 6, wherein the lifting device is a fork lift truck, c h a r a ct e ri z e d i n t h a t the second material is fixed to the underside of the forward end portion of each fork.

8. Container according to claim 7, c h a ra cte ri zed i n t h at the second material is connected in a flexible way to the fork.

9. Container according to claims 6 or 7, c h a r a ct e r i zed i n th a t a stop is provided to the underside of each fork so that contact between the floor and the second material is avoided.

u