Bulk bag lid

Abstract

A bulk bag lid 10, used to secure a bulk bag with tethering straps (40, 42, fig. 4), comprises a frame 11 for locating on and around side walls of the bulk bag, and one or more strap retaining structu

Description

The present invention relates to a bulk bag lid for use when securing a bulk bag with tethering straps and to an associated method of securing a bulk bag with tethering straps. Bulk bags are often used to store and transport dry bulk construction materials such as sand, gravel or soil. A bulk bag is typically made of a flexible material, such as polypropylene fabric. The bulk bag has an upper opening defined by a side wall or walls which become self-supporting once the bulk bag is filled with its contents through the opening. When transporting a filled bulk bag to a construction site, the bag is typically lifted onto a platform of a delivery vehicle or trailer via a forklift or a crane arm. In many cases, the bulk bag is not secured to the platform during transportation. Instead, the inherent weight and friction of the filled bulk bag is relied upon to keep the bulk bag in place on the platform. This can, however, be extremely dangerous, for example if the delivery vehicle or trailer moves drastically and / or is involved in a road traffic incident. Accordingly, in order to secure a bulk bag to the platform, a tethering strap may be attached to the platform at one side of the bulk bag, passed across the top of the bulk bag, and then attached to the platform at the opposite side of the bulk bag. The tethering strap may then be tightened, for example with a ratchet. However, these arrangements can compress the contents of the bulk bag in an uneven manner, often causing the contents of the bulk bag to become divided and disrupted by the tethering strap. This in turn can lead to reduced tension in the tethering strap, which can ultimately result in an insecure and unsafe load. Furthermore, the actual contents of the bulk bag are not particularly secured or protected by the tethering strap. It is therefore desired to provide improved arrangements for securing bulk bags with tethering straps. According to an aspect of the present invention there is provided a bulk bag lid for use when securing a bulk bag with tethering straps, the bulk bag lid comprising: a frame for locating on and around one or more side walls of the bulk bag; and one or more strap retaining structures for retaining one or more tethering straps laterally on the bulk bag lid. According to another aspect of the present invention there is provided a method of securing a bulk bag with tethering straps, the method comprising: placing a bulk bag lid as described herein in any aspect or embodiment on top of the bulk bag, wherein the frame is located on and around the one or more side walls of the bulk bag; and securing one or more tethering straps across the bulk bag lid, wherein the one or more tethering straps are retained laterally on the bulk bag lid by the one or more strap retaining structures. As will be appreciated, embodiments of the present invention can allow a bulk bag to be attached to a platform securely using one or more tethering straps. In particular, when the one or more straps are tightened to secure the bulk bag to the platform, those straps can provide an even and secure retaining force across the top of the bulk bag via the frame. The frame can also act to secure and protect the contents of the bulk bag. Furthermore, by providing one or more strap retaining structures (e.g. on the frame), the tethering straps can be prevented from slipping laterally off the bulk bag lid, and this can allow the bulk bag to be secured in a highly reliable manner. ln embodiments, the one or more side walls of the bulk bag may define an upper opening to the bulk bag. The upper opening to the bulk bag may be substantially regularly shaped, such as rectangular (including substantially square). Thus, the frame may be substantially regularly shaped, such as rectangular (including substantially square). The bulk bag may comprise one or plural (e.g. four) side walls. Thus, the frame may comprise one or plural (e.g. four) frame members, i.e. corresponding respectively to the one or plural side walls. Each frame member may comprise a top frame portion (e.g. top frame panel). The top frame portion may be located on top of a corresponding bag side wall in use. The top frame portion may be arranged substantially horizontally in use. Each frame member may comprise an outer frame portion (e.g. outer frame panel). The outer frame portion may be located outwardly of a corresponding bag side wall in use. The outer frame portion may be arranged substantially vertically in use. Each top frame portion may be joined to a corresponding outer frame portion. Each top frame portion may be substantially perpendicular to a corresponding outer frame portion. These embodiments can allow the bulk bag lid to be used with a substantially cuboid bulk bag. In embodiments, the periphery of the frame (e.g. each outer frame portion) may comprise an outward step. The outward step can facilitate locating the bulk bag lid on the bulk bag and / or can provide some additional rigidity to the bulk bag lid. The outward step can also facilitate the stacking and / or nesting of plural similar bulk bag lids. Thus, the bulk bag lid may be stackable and / or nestable with other similarly shaped bulk bag lids. These embodiments can help to reduce the amount of space needed to store the lids when not in use. ln embodiments, each strap retaining structure may comprise a retaining rib, ridge or wall, for example having one or more lateral blocking surfaces. Each strap retaining structure may extend outwardly and / or horizontally, e.g. across the top frame member. Each strap retaining structure may also or instead extend downwardly and / or vertically, e.g. across the outer frame member. Each strap retaining structure may accordingly laterally retain a tethering strap that runs over the sides of the frame. The strap retaining structures may also provide additional rigidity to the frame. The bulk bag lid may comprise one or more pairs of strap retaining structures, with the strap retaining structures of each pair being spaced apart for receiving and retaining a tethering strap therebetween. The strap retaining structures of one or more of the pairs may be provided on adjacent sides of the frame, for example for receiving and retaining a corner-to corner and / or diagonal tethering strap therebetween. The strap retaining structures of one or more of the pairs may also or instead be provided on the same side of the frame, for example for receiving and retaining a side-to-side and / or non-diagonal tethering strap therebetween. Two pairs of the strap retaining structures may be provided on opposite sides or opposite corners of the frame for receiving and retaining a tethering strap in a cooperative manner. One or more of the strap retaining structures may have one or more projecting structures projecting therefrom. Each projecting structure may have a contact face for laterally retaining a tethering strap thereagainst. One or more of the projecting structures may be substantially triangular. For example, a projecting structure of a particular strap retaining structure may have a (e.g. diagonal) contact face which is angled so as to be aligned with a (e.g. diagonal) contact face of a projecting structure of another particular strap retaining structure for laterally retaining a (e.g. diagonal) tethering strap thereagainst in a cooperative manner. The particular strap retaining structure and the another strap retaining structure may, for example, be located on adjacent sides of the frame. These embodiments can help to maintain one or more tethering straps in multiple orientations on the bulk bag lid. In embodiments, the frame (e.g. the outer frame member) may comprise one or more lifting structures (e.g. grooves, channels, hooks, loops, eyelets, etc.) for receiving a lifting device used to place the bulk bag lid on top of the bulk bag. The lifting device may, for example, be a placer tool, such as that which is provided by Cargo Stop International Limited for use with the ProPole® system. Alternatively, the lifting device may be the forks of a forklift or the hook of a crane arm. In embodiments, adjacent sides of the frame may be joined at corners. The comers may be substantially right-angled corners. Again, these embodiments can allow the bulk bag lid to be used with a substantially cuboid bulk bag. Each corner may comprise a corner piece for maintaining tension about the perimeter of the frame. In some embodiments, one or more of the corners may be substantially or entirely solid and / or impermeable (e.g. to liquids such as water). Thus, one or more of the corners may comprise a corner region which is substantially or entirely solid and / or impermeable (e.g. to liquids such as water). These embodiments can help to increase the rigidity of the lid and / or to protect the bulk bag contents, e.g. from inclement weather. In other embodiments, one or more of the comers may comprise a corner region which is substantially or entirely open. The open corner region may be configured such that the corners of the bulk bag are not contacted by the bulk bag lid. These embodiments can help to further reduce the amount of material needed to form the bulk bag lid and / or can help to protect the corners of the bulk bag from damage. In some embodiments, the bulk bag lid may be substantially or entirely solid and / or impermeable (e.g. to liquids such as water). Thus, the bulk bag lid may comprise a frame which is substantially or entirely solid and / or impermeable (e.g. to liquids such as water). The bulk bag lid may comprise a central region which is substantially or entirely solid and / or impermeable (e.g. to liquids such as water). These embodiments can help to increase the rigidity of the lid and / or to protect the bulk bag contents, e.g. from inclement weather. In other embodiments, the bulk bag lid may comprise a central region which comprises a mesh or net and / or which is substantially permeable (e.g. to gases such as air). These embodiments can help to reduce the amount of material needed to form the bulk bag lid and / or allow the contents of the bulk bag to breathe, whilst still providing at least a degree of tension and thus rigidity across the bulk bag lid. In yet other embodiments, the bulk bag lid may comprise a central region which is substantially or entirely open. These embodiments can help to further reduce the amount of material needed to form the bulk bag lid, can allow the contents of the bulk bag to breathe and / or can allow visual inspection of the contents. The central region in question may be substantially regularly shaped such as rectangular (including substantially square). In embodiments, at least some or all of the bulk bag lid (e.g. the frame at least) may be of unitary construction. At least some or all of the bulk bag lid (e.g. the frame at least) may be formed of polymeric (e.g. moulded) material. These embodiments can help to provide a bulk bag lid which is robust, lightweight, and easy to manufacture. The bulk bag lid may have rotational symmetry, for example at least two-fold or at least four-fold rotational symmetry. The bulk bag lid may have reflective symmetry, for example at least one or at least two lines of reflective symmetry. These embodiments can allow the bulk bag lid to be used in the same way in different orientations. In embodiments, the bulk bag lid may have a width in the range 50cm-150cm, for example in the range 75cm-125cm, for example approximately 100cm. The bulk bag lid may have a length in the range 50cm-150cm, for example in the range 75cm-125cm, for example approximately 100cm. The bulk bag lid may have a depth in the range 5cm-20cm, for example in the range 10cm-15cm. These dimensions are suitable for use with most bulk bags. The depth towards the centre of the bulk bag lid (e.g. along each side) may be greater than the depth towards the comers of the bulk bag lid. The depth of the bulk bag lid (e.g. along each side) may vary in a curved and / or arched manner. These embodiments can help to redistribute the pressure of the one or more tethering straps away from the centre of the bulk bag lid and towards the corners of the bulk bag lid. In embodiments, the one or more tethering straps may comprise one or more webbing straps. The one or more tethering straps may secure the bulk bag lid (and the bulk bag) to a platform, such as a vehicle or trailer platform. The method may comprise attaching one or more ends of the one or more tethering straps to the platform. The method may further comprise operating one or more ratchets for the one or more tethering straps to tighten the tethering straps down onto the bulk bag lid. As will be appreciated, the method may be performed in respect of plural bulk bag lids for respective bulk bags and / or in respect of plural tethering straps for a given bulk bag lid. One or more of the tethering straps may run vertically up a corner of the bulk bag, diagonally (e.g. corner to corner) across the bulk bag lid, and vertically down an opposite corner of the bulk bag. One or more of the tethering straps may also or instead run vertically up a side of the bulk bag, straight (e.g. side to side) across the bulk bag lid, and vertically down an opposite side of the bulk bag. One or more of the tethering straps may also or instead run diagonally up a side of the bulk bag, diagonally across the bulk bag lid, and then diagonally down an adjacent side of the bulk bag. Although the present invention has been described herein primarily with reference to bulk bags, it will be appreciated that the lid could also be used when securing other similarly shaped loads to a platform, for example when securing plural (e.g. cuboid) stacked objects, such as bricks or blocks, to a platform. It will also be appreciated that the terms “horizontal”, “vertical”, “top”, “upper”, “up”, “down”, and the like are with reference to the bulk bag in normal use, e.g. when located on a substantially horizontal platform with the opening being uppermost. By way of example only, embodiments of the invention will now be described in detail with reference being made to the accompanying drawings in which: Figure 1 is a top perspective view of a bulk bag lid according to an embodiment of the present invention; Figure 2 is a base perspective view of the bulk bag lid of Figure 1; Figure 3 is a partial perspective view of the bulk bag lid of Figure 1 together with a placer tool; Figure 4 is a top view of the bulk bag lid of Figure 1 together with tethering straps; and Figure 5 is a top perspective view of a bulk bag lid according to another embodiment of the present invention. Figures 1 and 2 show a bulk bag lid 10 for use when securing a bulk bag to a platform with webbing tethering straps. In this embodiment, the lid 10 is of unitary construction and is formed of moulded polymeric material. As is conventional, the bulk bag may comprise a horizontal base wall and four vertical side walls which define a substantially square upper opening. The bulk bag may be made of flexible material, such as polypropylene fabric, which is self-supporting and cuboid in shape when filled with dry bulk material such as sand, gravel or soil. The lid 10 accordingly comprises a square frame 11 comprising four frame members 12 for locating on and around the four side walls of the bulk bag such that the upper opening is completely covered by the lid 10. Each frame member 12 comprises a horizontal top frame panel member 14 which is located on top of a corresponding bag side wall in use and a vertical outer frame panel member 16 which is located outwardly of the corresponding bag side wall in use. In this embodiment, the outer frame panel member 16 further comprises an outward step 17 that facilitates locating the lid 10 on the bulk bag and provides some additional rigidity to the lid 10. The outward step 17 also facilitates the stacking of plural similar bulk bag lids. The lid 10 further comprises various strap retaining structures having lateral blocking surfaces for retaining tethering straps laterally on the lid 10. In particular, the lid 10 comprises first strap retaining ribs 18, second strap retaining ribs 20, and third strap retaining ribs 22. Only three of the ribs 18, 20 and 22 are referenced in the drawings - the lid 10 has both four-fold rotational symmetry and two lines of reflective symmetry, such that the remaining unreferenced ribs are the same as (or at least reflected versions of) those which are referenced. In this embodiment, each rib 18, 20, 22 extends horizontally outwardly across a top frame panel member 14 and then vertically downwardly across the corresponding outer frame panel member 16. In this embodiment, the third ribs 22 further comprise triangular projecting structures 30 having a diagonal contact face for laterally retaining a tethering strap thereagainst. The third ribs 22 further comprise lifting grooves 32 for receiving a lifting device in the form of a placer tool 33 therein. As is shown in Figure 3, the placer tool 33 comprises projections 34 for insertion into the grooves 32 and a coupling 35 (which in this case is a screw-threaded coupling) for removably attaching a pole (not shown) to the placer tool 33. The placer tool 3 and / or pole may, for example, be those which are provided by Cargo Stop International Ltd as part of the ProPole® system. In use, the lid 10 is placed on top of a bulk bag, for example using the placer tool 33, with the frame 11 being located on and around the side walls of the bulk bag. Tethering straps are then placed across the lid 10 with those tethering straps being retained laterally on the lid 10 by the ribs 18, 20, 22. The tethering straps are attached to the platform and are tightened by operating ratchets for the tethering straps. For example, as is shown in Figure 4, a pair of first ribs 18a and 18b on adjacent sides of the frame 11 can be used to receive and laterally retain a corner-to-comer diagonal tethering strap 40 therebetween. In this case, the tethering strap 40 runs vertically up a comer of the bulk bag, diagonally across the lid 10, and vertically down an opposite corner of the bulk bag. Similarly, a pair of projecting structures 30a and 30b on third ribs 22a and 22b on adjacent sides of the frame 11 can be used to laterally retain a side-to-side diagonal tethering strap 42 in a cooperative manner. In this case, the tethering strap 42 runs diagonally up a side of the bulk bag, diagonally across the lid 10, and then diagonally down an adjacent side of the bulk bag. For another example, a pair of ribs 18a and 20a on the same side of the frame 11 can be used to receive and laterally retain a side-to-side tethering strap 44 therebetween. Similarly, a pair of third ribs 22a and 22c on the same side of the frame 11 can be used to receive and laterally retain a side-to-side tethering strap 46 therebetween. In these cases, the tethering straps 44 and 46 run vertically up a side of the bulk bag, straight across the lid 10, and vertically down an opposite side of the bulk bag. As is shown, a similar arrangement of pairs of ribs is provided on an opposite side and / or corner to laterally retain the tethering straps on the lid 10 in a cooperative manner. Referring again to Figures 1 and 2, adjacent frame members 12 of the frame 11 are joined at right-angled corners 24. Each comer 24 comprises a corner piece 26 for maintaining tension about the perimeter of the frame 11. In this embodiment, each corner 24 comprises a corner region 28 which is entirely solid and impermeable to liquids. The lid 10 further comprises a central region 36 which is also entirely solid and impermeable to liquids. This can help to increase the rigidity of the lid 10 and to protect the bulk bag contents from inclement weather. In this embodiment, the lid 10 has a width of approximately 100cm and a length of approximately 100cm, and is therefore suitable for use with most bulk 5 bags. The lid 10 also has a depth of approximately 13.5cm, although the depth of the lid 10 does curve slightly in an arched manner such that the depth of the lid 10 is greater towards the centre of each side 12 and is lesser towards the corners 24. This helps to redistribute the force applied by the tethering straps away from the centre of each side 12 and towards the corners 24. 10 Figure 5 shows a bulk bag lid 50 according to another embodiment. The features of the lid 50 of Figure 5 are substantially the same as those of the lid 10 of Figures 1 and 2, and so a detailed discussion of those features will not be repeated. In this embodiment, however, each corner 24 comprises a corner region 52 which is entirely open such that the corners of the bulk bag (or other 15 similar load such as bricks or blocks) are not damaged by the lid 50. Also, in this embodiment, the bulk bag lid 50 comprises a meshed central region 54 which helps to reduce the amount of material needed to form the bulk bag lid 50 and allows the contents of the bulk bag to breathe, whilst still providing at least a degree of tension and thus rigidity across the bulk bag lid 50.

Claims

1. A bulk bag lid for use when securing a bulk bag with tethering straps, the bulk bag lid comprising:a frame for locating on and around one or more side walls of the bulk bag; andone or more strap retaining structures for retaining one or more tethering straps laterally on the bulk bag lid.

2. A bulk bag lid as claimed in claim 1, wherein the frame is substantially rectangular.

3. A bulk bag lid as claimed in claim 1 or 2, wherein the frame comprises plural frame members.

4. A bulk bag lid as claimed in claim 3, wherein each frame member comprises a top frame portion for locating on top of a corresponding bag side wall in use.

5. A bulk bag lid as claimed in claim 3 or 4, wherein each frame member comprises an outer frame portion for locating outwardly of a corresponding bag side wall in use.

6. A bulk bag lid as claimed in claim 3, 4 or 5, wherein each frame member comprises a top frame portion that is substantially perpendicular to a corresponding outer frame portion.

7. A bulk bag lid as claimed in any one of the preceding claims, wherein the periphery of the frame comprises an outward step.

8. A bulk bag lid as claimed in any one of the preceding claims, wherein the bulk bag lid is stackable and / or nestable with other similarly shaped bulk bag lids.

9. A bulk bag lid as claimed in any one of the preceding claims, wherein each strap retaining structure comprises a retaining rib, ridge or wall.

10. A bulk bag lid as claimed in any one of the preceding claims, wherein each strap retaining structure has one or more lateral blocking surfaces.

11. A bulk bag lid as claimed in any one of the preceding claims, wherein the bulk bag lid comprises one or more pairs of strap retaining structures, with the strap retaining structures of each pair being spaced apart for receiving and retaining a tethering strap therebetween.

12. A bulk bag lid as claimed in claim 11, wherein the strap retaining structures of one or more of the pairs are provided on adjacent sides of the frame.

13. A bulk bag lid as claimed in claim 11 or 12, wherein the strap retaining structures of one or more of the pairs are provided on the same side of the frame.

14. A bulk bag lid as claimed in any one of the preceding claims, wherein one or more of the strap retaining structures has one or more projecting structures projecting therefrom, each projecting structure having a contact face for laterally retaining a tethering strap thereagainst.

15. A bulk bag lid as claimed in claim 14, wherein a projecting structure of a particular strap retaining structure has a contact face which is angled so as to be aligned with a contact face of a projecting structure of another particular strap retaining structure for laterally retaining a tethering strap thereagainst in a cooperative manner.

16. A bulk bag lid as claimed in claim 15, wherein the particular strap retaining structure and the another particular strap retaining structure are located on adjacent sides of the frame.

17. A bulk bag lid as claimed in any one of the preceding claims, wherein the frame comprises one or more lifting structures for receiving a lifting device used to place the bulk bag lid on top of the bulk bag.

18. A bulk bag lid as claimed in any one of the preceding claims, wherein adjacent sides of the frame are joined at corners.

19. A bulk bag lid as claimed in claim 18, wherein the comers are substantially right-angled corners.

20. A bulk bag lid as claimed in claim 18 or 19, wherein each corner comprises a corner piece for maintaining tension about the perimeter of the frame21. A bulk bag lid as claimed in any one of claims 18-20, wherein one or more of the corners are substantially or entirely solid and / or impermeable.

22. A bulk bag lid as claimed in any one of claims 18-20, wherein one or more of the corners comprises a corner region which is substantially or entirely open.

23. A bulk bag lid as claimed in any one of claims 1-22, wherein the bulk bag lid comprises a central region which is substantially or entirely solid and / or impermeable.

24. A bulk bag lid as claimed in any one of claims 1-22, wherein the bulk bag lid comprises a central region which comprises a mesh or net and / or is substantially permeable.

25. A method of securing a bulk bag with tethering straps, the method comprising:placing a bulk bag lid as claimed in any one of claims 1-24 on top of the bulk bag, wherein the frame is located on and around the one or more side walls of the bulk bag; andsecuring one or more tethering straps across the bulk bag lid, wherein the one or more tethering straps are retained laterally on the bulk bag lid by the one or more strap retaining structures.-17-

Images