GB2187431A - Stackable containers with stand rings - Google Patents

Abstract

A stand ring, for a container having a top wall joined to a sidewall by a top seam and a bottom wall joined to a side wall by a bottom seam, has a peripheral flange 30 for engagement with the bottom wall at a peripheral margin 18 within the compass of the bottom seam 13 of the container, a dependent wall 31 portion extending from either the radially inner periphery of the flange 30 or the radially outer periphery (Figures 14 and 15) to a reinforced stand bead 32 enterable into the compass of the top seam 22 of a like container to rest on the top wall 24 of the container. The stand ring may be welded or adhered to the bottom of the drum so that it is replaceable. The stand bead 32 is integrally formed with the wall portion and may be bent or rolled outwardly or inwardly. The wall portion 31 preferably flares outwardly, eg at an angle of 15 DEG to the ring axis. At least one aperture is provided in the wall portion for the reception of a lifting fork. The container is preferably of square cross section and of metal. The stand ring may be stamped from sheet metal and subsequently stamped, rolled and folded into shape or may be injection molded using a polymeric material. The flange may have a depending skirt portion which is a close fit with the interior surface of the bottom seam (Figures 10 and 11). <IMAGE>

Description

SPECIFICATION Polygonal stackable containers This invention relates to a stand ring for a container stackable upon another like container and more particularly but not exclusively to drums of substantially square cross section provided with a stand ring adapted for engagement with the top of a like drum.

In United States Patent 4,485,924, two such rectangular drums are described in which a bottom component of the drums is shaped to permit entry of a portion into the compass of the top seam of a like drum until the weight of the upper drum is delivered by the component on to the top seam of the lower drum so thatthe upper drum is supported and restrained from lateral shift. The load of the upper drum is transmitted downwardly through drum walls, the bottom component and upper seam of the lower drum onto the side walls ofthe lowerdrum.

In a first embodiment described in US.4,485,924 the bottom component isarectangularskirtorring which is attached at the folded seam which joins the side wall to the bottom of the drum. The extremity of the skirt is shaped tofitwithin and rest on the top of a like drum. In a second embodiment described in US.4,485,924the bottom wall of the drum is provided with support members in the form of a hollow foot at each corner. The corner portion of each hollow foot is provided with buttress-like bead which projects laterally for engagement with the top seam of a like drum when the feet are entered into the compass of the seam. In both these embodiments the weight of an upper drum is passed onto the top seam of a drum below.

European Patent Application published 0156653 describes a modification of the drum with hollow feet in which each hollow foot is provided with a protective shoe or wear plate. In one embodiment the shoe is shaped to provide the necessary stacking bead to pass the load of an upper drum ontothetop seam of a like drum beneath.

In orderto achieve a stable stackthe bottom component or shoe must enter the compass of the top seam of a lower drum to achieve lateral stack stability and the bottom component or shoe must rest on the slender profile of the top seam.

It is in the nature offilled drumsofthe orderof200 litres capacity to be heavy so that accidental impact on the seams or bottom can cause plastic deformation to make the prior art bottom components (reviewed above) unable to fit properly with a damagedtopseam.The priorartstacking means reviewed above are not readily replaceable without disturbing the bottom of the drum.

The present invention provides a stand ring fora container having atop wall joined to a side wall buy a top seam and a bottom wall joined to the sidewall by a bottom seam characterised in that the ring comprises a peripheral flange for engagement with a peripheral margin within the compass of the bottom seam of the container, a dependent wall portion extending from the inner periphery of the flange to a reinforced stand bead enterable into the compass of thetopseam of a like containerto rest on the top wall. It is therefore possible to stack containers which have suffered some damage and, if need be, replace a damaged stand ring.

The dependent wall portion may flare outwardly from the inner periphery of the flange towards the reinforced stand bead.

The stand ring may be provided with elongate slots in the dependent wall to permit insertion of the forks of a fork lifttruck.

The stand rings may be attached to the bottom wall by spot welds or adhesive so that it is replaceable.

Various embodiments of the stand ring will now be described by way of example and with reference to the accompanying drawings in which: Figure lisa side view of a prior art stacking arrangement, depicted half sectioned; Figure2 is a sectioned side view of a drum with a stand ring on a like drum; Figure 3 is a plan view of the top ofthe drum in Figure 2; Figure4is an underplan viewofthe drum of Figure 2; Figure 5is a perspective view of ourfirst embodimentofthestand ring; Figures 6, 7 & are plan, underplan and sectional views of the stand ring of Figure 5; Figure 9 is an enlarged fragmentary section ofthe ring of Figure 5 when stacked;; Figure 10 isaframentary section of a second embodiment of the ring; Figure 11 is a fragmentary section of a third embodimentofthe ring; Figure 12 is a fragment of a rolled metal section; Figure 13 is a modified embodimentofthe ring made from the section of Figure 12; Figure 14is afifth embodimentofthe ring; and Figure 15 is the rolled section from which the ring of Figure 14 is made.

Figure 1 shows an upper prior art drum 1 stacked upon a lower like drum 2 which is standing on the ground. Each drum has a top wall 3joined to a side wall 4bya top seam 5 and a bottom wall 6 joined to thesidewall4bya bottom seam 7.

Astand ring 8 of square plan shape is attached at the bottom seam 4to each drum. The stand ring has an upright wall which extends from the bottom seam 4to an inwardly directed ledge overthetop seam 5a of the lower drum 2. A base plug portion 9 of the ring extends into the compass of the top seam 5a to restrain the top drum 1 from lateral shift on the lower drum 2.

Acentral aperture 10, in each ofthefoursides of the ring 8, permits insertion of a fork of a forklifttruck beneath the drums for lifting.

Figure 2 shows that in contrastto the prior art reviewed, our drums 11,12 have a conventional bottom seam 13joining the bottom wall 14tothe sidewall 15.

The bottom wall 14 of upper drum 11 comprises peripheral material 16 folded into the bottom seam 13, an annularwall 17 extending fromtheseam material into the side wall 15to support a closure panel having aflatperipheral margin 18 and acentral panel 19 held offsetfrom theflat peripheral margin 18 by a flared annulus 20.Whilst it is necessary for the annularwall 17to extend into the sidewall 15 in orderto provide access for a support roll during roll forming of the side walls to end wall seam the shape oftheflaredannulusandcentral panel may be of various chosen shapes; for example the straight lines at the corners of the central panel in Figures 3 and 4 may be replaced by curves.

Thetopwall of both drums is very similarto the bottom wall as may be seen in Figures 3 and 4. The top wall comprises peripheral seam material 21 folded intothetop seam 22, an annularwall 23 extending into the side wall 15 to support a closure panel having a flat peripheral margin 24 and a central panel 25 held above the flat peripheral margin 23 by aflared annulus 26. The annularwall 23, peripheral margin 24and flared portion 26 serve as a channel to collect rainwater running off the raised central panel 25 so that the closures 27,28, best seen in Figure 3, are kept dry. The top and bottom seams 22, may be double seams, or if desired, treble seams.

Figures 2 and 4 show a first embodiment of a stand ring 29 having a flatflange 30 fixed to the flat peripheral margin 18 of upper drum 11. Awall portion 31 extends from the inner periphery ofthe flange 30 in a direction downwardly and outwardly to a reinforced rim in the form of a folded hem 32.

The folded hem 32 is supported on the flat peripheral margin 24 of the top of iower drum 12. The upper drum 11 is restrained against lateral shift by engagement ofthe hem 32 with the annularwall 23 of the top of lower drum 12. Apertures 33 in wall 31 provide access fortheforks of a forklift truck. Itwiil be noted that the top of each aperture 33 is above the bottom seam 13so theforks act on the bottom seam during lifting.

Figures 5 to 8 depict the first embodiment ofthe ring detail to show that the ring is manufactured as a separate component so that it may be fixed to the flat peripheral margin 18 eithertemporarily or permanently. If adhesives, such as can be destroyed by heat, are used the fixture may be temporary. If howeverthering is welded to the margin 18the fixture may be permanent.

In Figures 5,6 and7itcan be seenthatthe ring is substantiallysquareforfitting onto a square drum.

Each side of the ring is provided with two apertures denoted 33 so that each may receive a fork of a forklifttruck and the drum be supported without risk oftilting.

Referring to Figure 6 it will be noticed thatthe periphery of flange 30 lies within the periphery of the reinforced rim a hem 32. This is because the flange 30 only needs to be wide enough to achieve satisfactory fixing to the bottom of the drum. Spot welds distributed around the flange, each weld being ofthe order of 3 mm. diameter, will suffice.

Referring to Figure 9 it will be seen thatthe wall portion 31 of the ring extends at an angle A"to the support surface below, namely the flat peripheral margin 24 of the top of lower drum 12, and the base of hem 32 is ata distance "d" from the annularwall 23 so thatthe hem 32 of the stand ring does not interfere with top seam of lower drum 12.

The benefit of flaring the wall portion 31 isthata clearance space between the wall portion 31 and bottom seam is provided so that if desired the drum may be lifted by applying the lifting forks to the underside ofthe bottom seam and so straddling support ring for lateral stability instead of using the apertures 33 in the ring.

The choice of angle A" is governed by consideration ofthe need for straddling clearance and the basic necessity for columnarstrength in the wall 31 which mustsupporttheweightofthe drum and anydrumsstacked on top of it. If the wall 31 is upright (A = 90 ) one has maximum strength for any chosen cross sectional area of wall 31 but the hem 32 is then ata larger distance "d" from the annularwall 23 so the opportunity for lateral shift is increased and the load of an upper drum is supported buy a more flexible part ofthetop of a drum beneath.It is desirable that clearance distance "d" be about Smm all round. A practically useful angle A" is 85" which permits "straddle lifting" but angles in the range 75" to 90" are useful fora stand ring about 150 mm tall.

The maximum shearing force arising from the evenly distributed contents on the bottom wall portion 18 occurs where itjoinsthe annularwall 17.

Figure 10 shows a second embodiment of the ring with a modified flange 30 which is extended outwardlytoreachtheannularwall 17. A dependent skirt portion 34 is a light push fit in the annularwail 17 so that adhesive applied to the flange 30 and particularly the skirt portion 34 will be in a shear mode of loading when in use.

The flange 30 and skirt portion serve to stiffen the bottom wall atthis region of high shearing force and the hollow defined bytheskirtportion 34flange30 and wall 31 serves to confine a flame used to release the adhesive when the stand ring needs to be replaced.

Figure 11 shows a third embodiment ofthe ring in which the flange 30 and skirt portion 34 are as described with reference to Figure 10. In Figure 11 the wall 31A is upright and terminates in a curl of generous radius in order to achieve a contact point on the curl with support surface somewhat nearer the seam of a drum beneath. One possible benefit arising from the embodiment of Figure 11 is that it may be manufactured by rolling a fiat strip to the section part shown in Figure 12. The flange portion ofthe rolled section is then cut at lines "2" and the section is folded to a square and if desired the adjacent ends are welded together to make a fourth embodiment of the stand ring as shown in Figure 13.

The flange 30, the wall 31Aand hem 32Adenoted in Figure 13 are identified in Figure 12 by like numbers in parenthesis.

Figure 14 shows a fifth embodiment of the stand ring which, although spreading supporttothe bottom wall and permitting replacement, does not permit straddle lifting of a drum. However, this fifth embodiment can be manufactured economically from a rolled section. In Figure 14the stand ring comprises a flange 40 from the outer periphery of which depends an upright wall 41 terminating at an inwardly directed curl 42. Corresponding flange, wall and curl portions are denoted by like numbers in parenthesis on the rolled sheet metal section in Figure 15. The section is cropped at mitred notches 43 to facilitate folding at dashed lines to facilitate folding to shape. If desired the mitred abutments may be welded.

Whilst the invention is particularly applicable to drums made from sheet metals, such as mild steel, to have a capacity of about 200 litres, the principles taught may be applied to other containers. The stand ring may be stamped from sheet metal or alternatively may be made as described by section rolling, stamping the apertures and then folding to shape. However, the principles taught may be used to make a stand ring from a suitable polymeric material by injection moulding. Forexamplethe stand rings may be made by injection moulding a nylon or a polypropylene.

Claims (6)

1. A stand ring for a container having a top wall joined to a sidewall by a top seam and a bottom wall joined to a side wall by a bottom seam characterised inthatthe ring comprises a peripheral flange for engagement with a peripheral margin within the compass ofthe bottom seam of the container, a dependent wall portion extending from the inner periphery of the flange to a reinforced stand bead enterable into the compass of the top seam of a like container to rest on the top wall of the container.

2. Astandringaccordingtoclaim 1 whereinthe dependent wall flares outwardly from the inner periphery of the flange towards the reinforced stand bead.

3. A stand ring according to claim 2 wherein the dependentwall flares at an angle of 15" to the axis of the ring.

4. Astand ring according to any preceding claim wherein at least one aperture is provided in the dependent wall of the stand ring.

5. Astand ring according to any preceding claim wherein the stand ring is rectilinear in plan view and an aperture is provided in each of the four sides of the dependent wall portion.

6. A stand ring substantially as hereinbefore described with reference to Figures 2,4,5,6,7,8 and 9orFigure 10Or Figure 11 orFigures 12 and 13,or Figures 14 and 15 ofthe accompanying drawings.

6. Astand ring according to any preceding claim wherein reinforced stand bead is in the form of a folded margin integral with the dependent wall.

7. A stand ring according to any preceding claim wherein the flange has a dependent skirt portion adapted to be a close fit with the interior surface of the bottom seam.

8. Astand ring according to any preceding claim when fitted to the bottom wall of a container.

9. Astand ring according to claim 7wherein the stand ring is fixed to the bottom wall of the drum by adhesive or welding.

10. A stand ring substantially as hereinbefore described with reference to Figures 2,4,5,6,7,8 and 9, orFigure 10Or Figure 11 orFigures 12and 13,or Figures 14 and 1 5 of the accompanying drawings.

Amendments to the claims have been filed, and have the following effect: (a) Claims 1-10 above have been deleted or textuailyamended.

(b) New ortextually amended claims have been filed as follows:-

1. Astand ring for a container having a substantially rectilineartopwall held inboard ofthe containerbyanannularwall connected to a sidewall of the container by a top seam and a substantially rectilinear bottom wall held inboard of the container byan annularwall connected to the side wall bya bottom seam characterised in that the stand ring comprises a peripheral flange which is substantially rectilinear and enterable into the annularwall for engagement with the bottom wall; a dependent wall portion extending from the periphery of the flange at an angle no less than 75" to the flange to terminate in a folded margin on which the container may stand, and at least one aperture in each side of the dependent wall to permit insertion of lifting means.

2. Astand ring according to claim 1 wherein the dependent wall extends from the inner periphery of theflange.

3. A stand ring according to claim 1 wherein the dependent wall extends from the inner periphery of the flange and a dependentskirt extendsfrom the outer periphery of the flange fortightfitting engagement with the annular wall of the bottom seam.

4. Astand ring according to any preceding claim wherein the flange and folded margin are made in a flat strip of metal and thereafter the flanged strip is folded to a substantially rectilinear shape.

5. Astand ring according to any preceding claim when the flange is fixed to the bottom ofthe container by welding or by adhesive.