GB2340820A

GB2340820A - Collapsible bag for emergency closure of drainage grid

Info

Publication number: GB2340820A
Application number: GB9818076A
Authority: GB
Inventors: Martin John Freeman
Original assignee: British Polythene Industries Ltd
Current assignee: British Polythene Industries Ltd
Priority date: 1998-08-20
Filing date: 1998-08-20
Publication date: 2000-03-01
Also published as: GB9818076D0

Abstract

A temporary grid closure for placing over a drainage grid to prevent spillage entering the drain, comprising a bag (34) having a restricted opening (56) through which the bag can be filled with fluid at a point remote from the drainage grid, the bag having means by which the bag can be carried from the remote point to the drainage grid and laid on top of the latter to seal it. The carrying means may be apertured flaps (68,70) or other handles. Alternatively, a seam may be formed along the top of the bag to receive an alongate rod or rope, the opposite ends of which can be held to carry the bag. The bag is of plastics material with deep gussets (22) to form a generally pyramid-shaped structure when filled. Bags may be made of different materials, and colour-coded accordingly, for use with different spillages.

Description

2340820 Title: Emergency drainage grid closure

Field of invention

This invention concerns a collapsible device which can rapidly be filled with fluid to provide a temporary closure for placing over a drainage grid to seal the latter and prevent liquid or particulate material from passing through the grid into the drainage system below.

Background to the invention

Grid closures as aforesaid may be carried by vehicles which attend road or industrial accidents and which can sometimes result in the spillage of noxious or poisonous chemicals. They may also be stored on industrial sites, airports, farms and the like where spillages can occur. In order to prevent the spillage from entering the drainage system it is necessary to provide a device which can be placed over the drainage grids to prevent the spillage from flowing through the grids into the underground pipework of the drainage system associated therewith.

since there may be a number of grids in the vicinity of an accident, an emergency services vehicle such as a fire and rescue appliance, needs to carry a plurality of such grid closures. For this reason such devices have been designed in the form of fully collapsible bags of sheet plastics material which occupy very little space on the appliance and which can be quickly filled with water, sand or earth and placed over the grids in question whilst a spillage is dealt with. The reduced volume when collapsed facilitates the storage of collapsed grid closures on industrial sites, airports, farms and the like.

2 Prior art

A grid closure is known in the form of a gusseted sheet plastics bag.

The act of filling the bag causes the gussets to invert causing the bag to bulge and spread so as to form a pyramid-like shape. If the bag has been positioned over a rectangular drainage grid then as the bag spreads out, so the base of the pyramid-like structure covers the grid and the weight of the contents of the bag holds the structure in place over the grid, thereby preventing the ingress of liquid or particulate material such as powder, from entering the drainage system via the grid.

When no longer required the bag can be emptied and disposed of. If, as is usual, the bag has been filled with water, this can simply be poured down the drain.

If the bag is too heavy to lift to pour the contents away, it can be simply slashed or otherwise punctured to allow the contents to spill out, after which it can be removed from the grid.

Disadvantage of the grior art device When filled with for example water the bag can be very heavy and the prior design of bag cannot readily be lifted and carried any distance, even by two men. This has dictated that the bag has to be filled in situ over the grid which is to be sealed.

Typically two operators are required, one to hold the bag in place and the other to fill it, typically using water from a hose. Since it is difficult to carry the filled bag, the operators have tended to stand on opposite sides of the grid which is to be covered. Since by their nature the grids are located at low points to facilitate the drainage of surface 3 water into them, the result is that any liquid spillage will tend to have reached the drainage grids before the emergency services have arrived, and the operators, albeit wearing protective clothing, may well have to stand in some depth of chemical whilst not only positioning, but also filling the bag.

This increases the operators exposure to the spillage, and if the bag has to be repositioned after filling, the wet slippery surface of the material from which the bag is constructed mitigates against safe and convenient handling of the bag, and there is always the risk of an operator slipping and falling whilst trying to manhandle the slippery container.

object of the present invention The present invention seeks to provide an improved design of grid closure which enables the filling of the device with water or other bulking agent away from a grid, and facilitates the movement of the filled device to enable it to be placed over the grid.

Summa::y of the invention According to the broadest aspect of the present invention, a temporary grid closure as aforesaid includes carrying means to facilitate lifting and carrying the device when filled.

In one arrangement the carrying means comprises one or more straps, seam welded or otherwise secured to the bag in the form of handles.

In another embodiment a seam is formed along an upper edge of the bag through which an elongate rod or rope can be threaded to allow opposite ends of the rod or rope to be held by one or more operators.

According however to a preferred aspect of the invention, 4 flaps of sheet plastics material extend from the sides of the bag, the flaps containing apertures which form hand holds to enable the bag to be held for filling, and for carrying and placement.

By providing the hand holds on opposite sides of the bag, it is convenient for two operators to carry a filled bag between them.

A preferred embodiment of the invention involves the provision of a plurality of overlying flaps on each side, each of which is welded to the bag and each having a hand-held aperture therein aligned with the other flaps on that side.

By providing a number of such flaps, each welded to the bag, so the handles so formed are sufficiently strong to enable them to be used to lift the weight of the filled bag, without rupturing.

The converging seams between the trapezoidal sections of the panels reduce the cross-sectional area of the bag with height, and this tends to make the structure self-supporting when filled, giving the bag stability and keeping the centre of gravity low, which is-of value when in place as a closure and when being carried.

According to a preferred method of manufacture, a grid closure embodying the invention may be constructed from a sleeve of sheet plastics material by flattening the sleeve, folding opposite regions of the sleeve inwardly to form two equal gussets so that there are four layers of plastics material joined by one internal and two external folds on each side of the central region of the sleeve, seam welding completely across one end of the sleeve and gussets to close of f that end, seam welding diagonally from points approximately half way up the height of the bag -to two spaced apart points at the other open end of the bag, the two points being close to the open ends of the internal folds of the two gussets, and seam welding the overlying sheets of plastics material forming each gusset close to the open end, and parallel thereto, to merge with the two diagonal seams at the two said spaced apart points, to close off the open end except between the two said points.

The seam welds closing the upper ends of the gusset folds may be separate - one for each of the four gussets or more preferably the four layers of sheet plastics material forming each pair of gussets on each side of the opening may be seam welded as one, so as t.o create two four-ply flaps or ears, one on each side of the central opening.

openings to provide hand holds may be formed by punching holes in or otherwise aperturing the four layers of sheet plastics material fo-z-ning each of the gussets on either side of the two diagonal seams.

A preferred material from which the bags are formed is polythene, although any suitable sheet plastics material may be used. -ifferent plastics materials may be selected depending --n the nature of chemicals with which they are expected -_: be used.. Where bags are manufactured from materials s-.;:.table for use with different spillages, they may be cclour-zol-4.ed or otherwise marked to indicate their suitabili:y fcr different spillages. ill now be described by way of example with The inventLcn -Ar. reference::-- the accompanying drawings, in which:

Figure 1 ill-.;s-trates a drainage grid; Figure 2 illust.rates a prior art grid closure bag;

Figure 3 is a perspective of the Figure 2 bag, showing the shape that it adopts after it has been filled with water; Figure 4 is a side elevation of a grid closure bag constructed in accordance with the invention; Figure 5 is a top plan view of the Figure 4 bag; Figure 6 is a similar plan view, but this time after the bag has been filled with water; and Figure 7 is a perspective -view of the bag of Figure 6.

Detailed description of drawings

A common drainage grid typically of cast iron is depicted in Figure 1 as comprising a rectangular rebated metal frame 10 in which is received an apertured rectangular casting 12 containing a plurality of parallel equally spaced apart slots 14, 16 etc. Rain water can pass through the slots 14, 16 to the drainage system below the grid. To assist in conveying away surface water, the frame 10 is normally located at a low point in a roadway, drive, car parking area or concrete or tarmac apron, so that water will tend to run downhill towards it.

A spillage of liquid from a road tanker or storage tank will likewise tend to run towards the drain and will, unless stopped, flow into the drainage system.

The prior art bag of Figures 2 and 3 was designed to provide a convenient way of quickly, temporarily covering the slots 14, 16 etc in the grid 12 to stop the continual ingress of a chemical spillage into the drainage system below the grid.

To this end the prior art bag was formed with two similar deep gussets housing internal folds shown by dotted lines 18, 20 in Figures 2 and 3. The bag is shown filled with water in figure 3 and here the gussets have become opposite side walls 22, 24 of a pyramid-like structure as a result of the pressure of the

7 water.

The gusset panels 22, 24 have a truncated triangular shape, and the two converging edges are seam welded along 26, 28 in the case of panel 22 (and along 30, 32 in the case of panel 24) to two similarly truncated panels 34, 36 which form the other two opposed side panels of the pyramid.

In fact each of the panels 22, 24, 34 and 36 can be thought of as being a generally rectangular lower region and an upper trapezoidal region, as best seen in Figure 2, and the seam welds such as 26, 28 'only extend along the inclined edges of the trapezoidal regions. The -vertical parallel edges of each lower region in fact are formed by folds in what in that region of the device is an endless loop of sheet material.

The lower end of the device is closed off by flattening the gussets and seam welding across from one side to the other, along line 38.

When filled with water the lower region of the bag below the ends of the four welds 26, 28, 30, 32 spreads out causing the lower regions of the gussets to triangulate and fold back along the fold lines shown by dotted lines 40, 42, 44 and 46 in Figure 3. Transverse folds 48 and 50 form in the gusset panels 22, 24 between the lowermost ends of the seam welds 26, 28 in the case of panel 22, and 30, 32 in the case of panel 24.

In the same way panels 34, 36 fold along the lines between their lower rectangular regions and their upper generally triangular regions as denoted by folds 52, 54 in Figure 3.

The opening 56 at the apex of the truncated pyramid permits water to be introduced into the interior of the bag using a hosepipe, although other filling material such as sand, earth, gravel etc may be employed.

1 1 8 A preferred material for the device shown is polythene sheet and the resulting smooth sloping sides of the filled structure do not allow it easily to be picked up or moved.

In accordance with the invention, the modified structure shown in Figures 4 to 7 incorporates flaps generally designated 58, 60 beyond the converging seams 26, 30 in each of which are formed apertures 62, 64 to serve as handgrips by which the filled pyramid-shaped structure can be gripped for carrying either by one or two people.

The flaps are similar in configuration to the lower regions of the gussets as described in relation to Figures 2 and 3 and are formed from four folded layers of sheet material. All four layers are seam welded parallel to the upper edge 66 along lines 68, 70, although if it is preferred to leave the four gussets separate at the upper end of the device, the upper edges of each of the four gusset folds may be seam welded separately.

The openinas 652, 64 are conveniently formed by die punching.

A plan v-Jew from above of the unfilled bag of Figure 4, is shown in 'Figure 5. This shows the layers of material forming the compcsite flaps 58, 60 between the central unwelded region forming the filling opening 56.

Figure 6 is a similar plan view but now after the bag has been filled with water. This demonstrates how the two folds 72, 74 forming the flaps 58 and the two folds 76, 78 forming the flap 60, may splay apart under the water pressure except in the region of the upper welds 68, 70.

This causes separation of the openings 80 and 82 in the folds 22, 24, and likewise the openings 84, 86 in the folds 76, 78 (which are normally in closely proximate alignment so as to define ef f ectively single openings 62, 64 (see Figure 4)).

9 The filled structure is shown in Figure 7, which again shows how the two splayed apart folds 72, 74 and their respective openings 80, 82, but also shows that by welding across the top of the folds as at 68 and 70 the flaps remain close enough to allow an operator to grasp both folds and pull them together by inserting his hand through at least one of the two adjoining openings 80, 82, and lifting in the direction of arrow 88. The act of lifting causes the two folds 72, 74 to come together.

Filling is achieved by pouring water (or sand etc) through the opening 56 in the direction of arrow 90.

Since the construction of the devices of Figures 2 and 3 and of Figures 4 to 7 are generally similar in other respects, the same reference numerals have been employed in both sets of Figures to denote common features.

Claims

1. A temporary grid closure comprising a collapsible bag which can be f illed with fluid, said closure including carrying means to facilitate lifting and carrying the device when filled.

2. A closure according to claim 1, wherein the carrying means comprises one or more straps, seam welded or otherwise secured to the bag in the form of handles.

3. A closure according7 to claim 1, wherein a seam is formed along an upper edge of the bag through which an elongate rod or rope can be threaded to allow opposite ends of the rod or rope to be held by one or more operators.

4. A closure according to claim 1, wherein flaps of sheet material extend from the sides of the bag, the flaps containing apertures which form hand holds to enable the bag to be held for filling and for carrying and placement.

5. A closure according to claim 4, having hand holds on opposite sides of the bag.

6. A closure according to claim 4 or claim 5, having a plurality of overlying flaps on each side, each of which is welded to the bag and each having a hand-hold aperture therein aligned with the other flaps on that side.

7. A closure according to any of claims 1 to 6, wherein the collapsible bag is made of panels having trapezoidal sections interconnected by converging seams which reduce the crosssectional area of the bag with height.

8. A closure according to any of claims 1 to 7, made of sheet plastics material.

11

9. A closure according to claim 8, made of polyethylene sheet material.

10. A grid closure according to any of claims 1 to 9, constructed from a sleeve of sheet plastics material by flattening the sleeve, folding opposite regions of the sleeve inwardly to form two equal gussets so that there are four layers of sheet plastics material joined by one internal and two external folds on each side of the central region of the sleeve, seam welding completely across one end of the sleeve and gussets to close off that end, seam welding diagonally from points approximately half way up the height of the bag to two spaced apart points at the other open end of the bag, the two points being close to the open ends of the internal folds of the two gussets, and seam welding the overlying sheets of plastics material forming each gusset close to the open end and parallel thereto, to merge with the two diagonal seams at the two said spaced apart points, to close off the open end except between the two said points.

11. A closure according to claim 101 wherein the seam welds closing the upper ends of the gusset folds are separate, one for each of the four gussets.

12. A closure according to claim 10, wherein the four layers of sheet plastics material forming each pair of gussets on each side of the opening are seam welded as one, so as to create two four-ply flaps or ears, one on each side of the central opening.

13. A closure according to any of claims 10 to 12, wherein hand holds are formed by punching holes in or otherwise aperturing the four layers of sheet plastics material forming each of the gussets on either side of the two diagonal seams.

14. A closure according to any of claims 1 to 13, wherein bags are manufactured from materials suitable for use with different 12 spillages.

15. A closure acording to claim 14, wherein bags are colourcoded or otherwise marked to indicate their suitability for different spillages.

16. A method of use of the closure according to any of claims 1 to 15, wherein the bag is filled with fluid,at a point remote f rom the grid to be closed, and by means of said carrying means is than carried to the grid and laid over the grid to seal said grid and prevent passage of liquid or material therethrough.

17. A method according to claim 16, wherein the bag is filled with water at the remote point.

18. A method according to claim 16 or claim 17, wherein the bag is carried by the carrying means by at least two persons on opposite sides of the bag.

19. A temporary grid closure substantially as hereinbefore described with reference to the accompanying drawings.

20. A method of use of the grid closure of any of claims 1 to 15 and 19, substantially as hereinbefore described.

-i Amendments to the claims have been filed as follows 1. A temporary grid closure comprising a collapsible bag which can be filled with fluid, said closure including a pair of carrying means which are disposed at remote sides of the bag to enable two persons, one at each side, to lift and carry the device when filled.

3. A closure according to claim 1, wherein a seam is formed along an upper edge of the bag through which an elongate rod or rope can be threaded to allow opposite ends of the rod or rope to be held by one or more operators.

A closure according to claim 4, having hand holds on opposite sides of the bag.

9. A closure according to claim 8, made of polyethylene sheet material.

11. A closure according to claim 10, wherein the seam welds closing the upper ends of the gusset folds are separate, one for each of the four gussets.

12. A closure according to claim 10, wherein the four layers of sheet plastics material fo=ing each pair of gussets on each side of the opening are seam welded as one, so as to create two four-ply flaps or ears, one on each side of the central opening.

14. A closure according to any of claims 1 to 13, wherein bags are manufactured from materials suitable for use with different spillages.

16. A method of use of the closure according to any of claims 1 to 15, wherein the bag is filled with fluid at a point remote f rom the grid to be closed, and by means of said carrying means is than carried to the grid and laid over the grid to seal said grid and prevent passage of liquid or material therethrough.