Spout with flame mitigation

Abstract

A foldable pouring spout (50) for a container comprises a base end (54), an outlet end (52) having a smaller flow cross-section than the base end, and a foldable tapered portion (58) connected between the base end and the outlet end. A basket-shaped flame arrestor (10) extends across the flow cross-section of the base end and accommodates the folded pouring spout. The flame arrestor facilitates a flow of ambient air into the container through the extended pouring spout so that the container contents may be dispensed without glugging.

Description

1SPOUT WITH FLAME MITIGATIONBackground of the invention

[0001] To aid the dispensing of liquid and other flowable contents from a container, it is known to provide a nestable and extensible pouring spout. A base end of the spout is sealingly securable about the periphery of a dispensing opening in the container. An outlet end of the spout has a smaller flow cross-section than the base end. The spout comprises a foldable tapered portion between these two ends. With the tapered portion in a folded configuration, the outlet end of the spout is nestable within the base end, for compact storage of the spout within the container. With the tapered portion unfolded to an extended position, the spout extends outwardly away from the container for controlled pouring out of the contents from the thus extended outlet end. The outlet end of the spout has a thicker wall, and is therefore stiffer than, the foldable tapered portion. A removable and re-closable closure cap is usually fitted to the spout outlet end to seal it.

[0002] For improved safety, it is known to provide flame arrestors in the dispensing openings of containers for flammable liquids. These flame arrestors typically comprise a wire mesh or similar screen placed across the flow path of the container outlet to divide the flow path into an array of small apertures. A flame front reaching the arrestor screen from outside the container is slowed down and broken into different smaller pieces or flamelets within the apertures. The arrestor screen absorbs and conducts away part of the heat from the flamelets and can cool the burning gas below its auto-ignition temperature. The flame front is thus quenched and prevented from reaching and igniting vapour from the flammable liquid within the container. The risk of fire and explosion from combustion of the container contents is thereby reduced. The arrestor screen is often made of metal, for example welded stainless steel wire gauze; although other materials (including plastics), and other structural forms providing the necessary array of small apertures, can also be effective. The effectiveness of the arrestor screen may be improved by setting it back within the container neck which thereby acts as a cowl to further slow and reduce turbulence in an approaching flame front.2

[0003] There are difficulties in fitting such a flame arrestor to a nestable and extensible pouring spout of the kind described above. When in the nested configuration, the outlet end and the folded tapered portion of the spout pass through and occupy the flow cross-section of the base end. A flame arrestor screen therefore cannot easily be fitted across the base end of the spout. The arrestor screen cannot be fitted within the foldable tapered portion, as this would prevent the required folding and unfolding. There are also difficulties in fitting a flame arrestor screen in the spout outlet end, particularly at the more effective position set back near to the foldable tapered portion. Heat staking different materials together may not produce a strong bond. This part of the spout also typically undergoes some flexing movement as the spout is unfolded and re-folded. An arrestor screen heat staked or adhesively secured at its periphery across this part of the spout may therefore become loose and ineffective, either by opening up an edge gap, or by falling out altogether.

[0004] Furthermore, the flame arrestor screen is a partly solid barrier placed across the flow path of the spout. When positioned across the already narrow outlet end of the spout, it will further narrow the available flow cross-section and restrict the flow of fluid being dispensed from the container. The problem is exacerbated in the case of an otherwise sealed, substantially rigid container. Because it restricts the flow, the flame arrestor screen easily becomes completely wetted or submerged in the fluid outflow. Even in the case of quite mobile fluids, if the entire surface of the flame arrestor screen is submerged in or wetted by the fluid, surface tension within the small apertures may be sufficient to prevent any air from entering the container as the fluid contents are drained out. Then as the fluid drains without replacement by ambient air, a partial vacuum develops within the container, sufficient to prevent any more fluid from draining out. Emptying of the container may then cease altogether, or at the very least become highly irregular (“glugging” flow). The nominally rigid container may also undesirably collapse or pulsate under atmospheric pressure and the partial vacuum. The present invention aims to mitigate at least some of these problems.Summary of the invention

[0005] Accordingly, the present invention provides a fluid dispensing fitment for a container, the fitment comprising:3a foldable pouring spout having:a base end sealingly attachable about a dispensing opening of the container; an outlet end having a smaller flow cross-section than the base end; and a foldable tapered portion connected between the base end and the outlet end, the fitment further comprising a flame arrestor extending across the flow cross-section of the base end, the flame arrestor comprising:an annular side wall within which the pouring spout is at least partially nested when folded, anda foraminous, flame-arresting end wall positioned opposite to the pouring spout so that fluid dispensed from the container flows through the foraminous end wall into the pouring spout;the annular side wall having at least one foraminous, flame arresting region distributed about its circumference, whereby ambient air passes through the pouring spout, through an upper part or parts of the annular side wall’s foraminous, flame arresting region(s) and into the container, to replace the dispensed fluid. Due to the circumferential distribution of the foraminous, flame arresting region or regions of the annular side wall and the necessarily larger cross-section contained by the annular side wall than the base end of the pouring spout, an upper part or parts of the annular side wall’s foraminous, flame arresting region(s) will remain available for passage of ambient air as the container is tilted more and more to pour out the contents. This upper foraminous part will be under lower hydrostatic head from the undispensed fluid remaining within the container, compared to the lowest part of the pouring spout. Ambient air can therefore continue to flow into the container, even if the entire foraminous end wall of the flame arrestor is wetted by or submerged in the flow of fluid being dispensed. The fluid flow out of the container is therefore easily controlled and remains steady even at high flow rates, and the container does not collapse or pulsate.

[0006] Flow resistance through all foraminous parts of the flame arrestor when the full container is close to fully inverted may be made sufficient to prevent the outflow of dispensed fluid from completely filling the pouring spout. This helps to maintain reliable ambient airflow into the container to replace the dispensed fluid.4

[0007] Flow resistance through all foraminous parts of the flame arrestor when the full container is tipped substantially onto its side with the pouring spout substantially in the lowest possible position, may be made sufficient to prevent the outflow of dispensed fluid from completely filling the pouring spout. Again (somewhat less conservatively), this helps maintain reliable ambient airflow into the container to replace the dispensed fluid.

[0008] In either case, the flow resistance may be made as low as otherwise possible, to permit the highest possible steady fluid flow rates.

[0009] The flame arrestor and foldable pouring spout may be formed as separate components or subassemblies. The flame arrestor may thereby be retrofitted to, or used in conjunction with, an otherwise substantially standard foldable pouring spout of generally known kind.

[0010] The base end of the foldable pouring spout and a rim of the annular side wall of the flame arrestor may comprise respective annular flanges by which the foldable pouring spout and the flame arrestor are sealingly attachable about a dispensing opening of the container.

[0011] The flame arrestor may comprise an out-turned flange at a rim of the annular side wall axially opposite to the end wall and received in an annular groove by which the base end of the pouring spout is sealingly attachable about the dispensing opening of the container.

[0012] The flame arrestor may be secured to the foldable pouring spout to form an assembly installable in or on a container.

[0013] The flame arrestor may be sealingly securable to the container’s dispensing opening and the foldable pouring spout may be secured and sealed to the flame arrestor to form an assembly installable in or on the container’s dispensing opening.

[0014] The foraminous, flame-arresting end wall may comprise a foraminous insert. For example, this insert may be a metal mesh held in a groove formed in an inner surface of the annular side wall of the flame arrestor. The metal mesh may be secured in the groove by a snap ring.

[0015] Alternatively, the foraminous, flame-arresting end wall and the annular side wall of the flame arrestor may be integrally formed and the end wall may5comprise a plurality of apertures. For effective flame mitigation while allowing high fluid outflow rates, the apertures of the end wall may form a grid pattern.

[0016] The at least one foraminous, flame arresting region distributed about the circumference of the annular side wall of the flame arrestor may comprise a plurality of apertures integrally formed in and distributed about the circumference of the annular side wall. The apertures of the annular side wall may form a grid pattern.

[0017] The at least one foraminous, flame arresting region distributed about the circumference of the annular side wall of the flame arrestor may comprise a plurality of apertures each covered by a foraminous insert. The foraminous insert covering the apertures may comprise an annular metal mesh secured adjacent to the apertures.

[0018] The foraminous, flame-arresting end wall of the flame arrestor may comprise a foraminous region of smaller diameter than the diameter of the annular side wall. This may help to ensure the ambient airflow into the container remains unobstructed by the outflow of the container contents as they are dispensed.

[0019] The foldable tapered portion of the pouring spout may be connected to the base end by a membranous web forming an annular living hinge. The living hinge forms a highly mobile flexure zone, whereby when the spout is pulled out for pouring out the container contents, the foldable tapered portion can pass through the base end and snap into a position closely adjacent to a surrounding inner wall of the base end, without bulging inwardly away from this inner wall, and therefore without constricting the flow passageway through the pouring spout. The outward flow of the container contents and the inward flow of ambient air to the upper part or parts of the annular side wall’s foraminous, flame arresting region(s) and then into the container, are thus facilitated.Brief description of the drawings

[0020] The invention and some of its further optional features and advantages, may be further understood from the following description of illustrative embodiments, made with reference to the drawings, in which:FIG. 1 is a perspective view of a flame arrestor which can be used together with a foldable pouring spout to form a fluid dispensing container fitment embodying the present invention;6FIG. 2 is a bottom plan view of the flame arrestor of FIG. 1;FIG. 3 is a side view taken on arrow III in FIG. 2;FIG.4 is a cross-sectional view on line 1V-1V in FIG. 2;FIG. 5 is a top plan view of the flame arrestor of the preceding figures;FIG. 6 is a perspective view of the fluid dispensing container fitment comprising a foldable pouring spout assembled with the flame arrestor of the preceding figures; FIG. 7 is a top plan view of the fitment of FIG. 6;FIG. 8 is a side view taken on arrow Vlll in FIG. 7;FIG.9 is a cross-sectional view taken on line IX-IX in FIG. 7;FIG. 10 is a bottom plan view of the fitment shown in FIGs. 6-9;FIG. 11 is an enlarged view of part of FIG. 9, showing portions of an installed crimp ring and a container neck profile;FIG. 11A corresponds to FIG. 11, but shows an alternative configuration of the flame arrestor and foldable pouring spout base end;FIG. 11B corresponds to FIGs. 11 and 11A, but shows yet another configuration of the flame arrestor and foldable pouring spout base end;FIG. 12 is a perspective view of another form of flame arrestor which can be used together with a foldable pouring spout to assemble a fluid dispensing container fitment embodying the present invention; the flame arrestor being shown prior to installation of a flame-arresting end wall mesh;FIG. 13 is a bottom plan view of the flame arrestor of FIG. 12;FIG. 14 is a cross-sectional view corresponding to FIG. 4, but showing the flame arrestor of FIGs. 12 and 13;FIG. 15 is a perspective view of the fluid dispensing fitment comprising a foldable pouring spout assembled with the flame arrestor of FIGs. 12-14, and with the flamearresting end wall mesh installed in the flame arrestor;FIG. 16 is a cross-sectional view corresponding to FIG. 9, but showing the fitment of FIG. 15;FIG. 17 is an enlarged view of the portion of FIG. 16 within the chain dotted line XVII; FIG. 18 is a perspective view shown in half-section, of a modified form of the flame arrestor and fitment shown in FIGs. 12-17;7FIG. 19 is a perspective view from above, of another example of a flame arrestor which may be used in embodiments of the invention;FIG. 20 is a side view of another flame arrestor which can be used together with a foldable pouring spout to form a fluid dispensing container fitment embodying the present invention;FIG. 21 is a bottom perspective view of the flame arrestor of FIG. 20, showing one form of end wall configuration, andFIG. 22 is a bottom perspective view of the flame arrestor of FIG. 20, showing another form of end wall configuration.Detailed description of illustrative embodiments

[0021] Figures 1-5 show a first example of a flame arrestor 10 which can be used together with a foldable pouring spout to form a fluid dispensing container fitment embodying the present invention. In this first example the flame arrestor 10 is formed in one piece, e.g. from injection-molded PCR resin. It has the general form of an open-topped basket, which partially encloses an interior space 12. The flame arrestor 10 has an annular side wall 14 of large enough depth and internal diameter for the interior space 12 to accommodate the folded pouring spout. In use, the flame arrestor 10 depends into a container beneath an upper filling and discharge opening thereof. The pouring spout is foldable to be stowed away within the container in the usual way. When thus folded, the pouring spout extends through the open top of the flame arrestor 10 and is at least partially nested within the interior space 12. When unfolded to the dispensing position, the pouring spout vacates the interior space 12.

[0022] A base of the flame arrestor 10 opposite to the open top and the pouring spout is formed by a foraminous, flame-arresting end wall 16 positioned so that fluid dispensed by tipping up the container flows through the foraminous end wall 16 into the pouring spout. The foraminous end wall 16 for example contains an array of mostly square-sectioned, small through holes 18. However, other hole shapes, sizes, and configurations may additionally or alternatively be used, as maybe determined to be necessary to pass the applicable flame tests; such as set out in ASTM standards F3429, F3326, F2874, F2517 and F852. The end wall 16 may additionally include strengthening / stiffening features, such as a pair of diametral ribs 20 intersecting one8another at right angles. Other suitable strengthening arrangements (or none) may be used, depending on the area, shape, and thickness of the end wall 16 and the forces imposed upon it by the fluid when filling and emptying the container.

[0023] The annular side wall 14 has at least one foraminous, flame arresting region 22 distributed about its circumference. Therefore, when the container is tilted to pour out the contents, ambient air can pass inwards through the pouring spout, through an upper part or parts of this foraminous region 22, and into the container, to replace the dispensed fluid. As shown in Figures 1-4, the foraminous region 22 comprises an array of small, square sectioned through holes 24 disposed in an annular band, close to the open end of the flame arrestor 10 and spaced from the foraminous end wall 16. Again, other hole shapes, sizes, and configurations may additionally or alternatively be used, as may be determined to pass the applicable flame tests. For added strength and rigidity, the array of through holes 24 may comprise solid interruptions 26 extending axially within the annular side wall 14. In the illustrated example, four such interruptions 26 are shown, in corresponding positions to the ends of the ribs 20. Again, other suitable strengthening / stiffening arrangements (or none) may be used, depending on the area, shape, and thickness of the annular side wall 14 and the forces imposed upon it by the fluid when filling and emptying the container.

[0024] The annular side wall 14 may include a step or taper 28, and / or an edge region 30 of the end wall 16 may be non-foraminous (solid). Thus, the upper part or parts of the foraminous region 22 (holes 24) of the annular side wall 14 when it is tilted will be higher than the uppermost holes 18 in the foraminous end wall 16. This helps to establish and maintain the flow of ambient air through the extended pouring spout and into the container as the container is tilted and the contents flow out through the foraminous end wall 16 and through those foraminous regions of the annular side wall 14 (holes 24) which are submerged in the flow.

[0025] The number, configuration, size, and shape of the through holes 18 should be sufficient to provide an acceptable fluid flow rate as the container is emptied. However, if the combined outflow through the foraminous end wall 16 and through the submerged foraminous regions of the annular side wall is not sufficient to completely fill the extended pouring spout, this will help to maintain the inflow of ambient air through the spout. Then glugging can be substantially prevented at any9flow rate as the container contents are poured out. For example, the number of holes 18 and 24 for a pouring spout having a given minimum cross-sectional area in a container for a fluid of given properties (e.g. having a given viscosity at a given temperature) may be selected such that the fluid flow does not completely fill the spout cross section when the full container is tipped onto its side with the spout lowermost; or perhaps even when the container is tipped to a close-to-inverted orientation.

[0026] Figures 6-11 show the flame arrestor 10 of the preceding figures assembled with a foldable pouring spout 50 to form the fluid dispensing fitment 100. The foldable pouring spout 50 may be formed for example as a one-piece injection molding made from a flexible material such as LDPE, or another suitable polymer compatible with the container contents. The foldable pouring spout 50 is of generally tubular form, to allow the container contents to be dispensed through it. FIG. 9 shows in full lines the spout 50 in an as-molded, folded configuration in which its smaller diameter outlet end 52 is nested within its larger diameter base end 54. In this folded configuration a rim 56 of the spout outlet end 52 may lie substantially flush with an upper surface 57 of the spout base end 54. The spout base and outlet ends 54, 52 are sealingly interconnected by a foldable tapered portion 58 of the spout 50. The spout base end 54 may comprise a downwardly facing circumferential groove 60 e.g. profiled to fit and make a fluid-tight seal with industry standard pail opening profiles or other industry standard container dispensing opening profiles. Alternatively, the base end 54 of the foldable pouring spout 50 may be configured for insert-molding into a container wall or lid - see e.g. US5967376, US9108771, and W02021 / 198022. The open upper end of the annular side wall 14 of the flame arrestor 10 is provided with an out-turned flange 32 configured to fit within the upper, inner corner of the profile of the groove 60. Therefore when the base end 54 of the foldable pouring spout 50 is sealingly attached about the dispensing opening of the container, the flame arrestor 10 is secured to extend across the flow cross-section of the base end 54. Similarly, where the spout base end 54 is configured for insert molding into a container wall or lid, the out-turned flange 32 may be configured to be likewise insert molded into the container wall or lid adjacent to the spout base end 54.10

[0027] The outlet end 52 of the foldable pouring spout 50 may be fitted with a removable and replaceable closure, such as a screw cap 62. Additionally or alternatively, the spout outlet end 52 may be sealed by a tear-out membrane (not shown; e.g. at the position of the slight step 64 in the bore of the spout outlet end shown in FIG. 9). The closure 62 may be provided with bail handles 66 by which the spout outlet end can be pulled upwardly, to pull the spout outlet end 52 and most of the foldable tapered portion 58 through the spout base end 54. The spout 50 is then in its unfolded, extended configuration, ready for dispensing the container contents. The spout outlet end 54 and most of the foldable tapered portion 58 thereby vacate the interior space 12 of the flame arrestor 10.

[0028] FIG. 11 shows the fitment 100 in position ready to be sealingly secured to a neck profile 72 of a container 70 or of a part of a container such as a lid (not shown). Accordingly, the term “container” as used herein should be construed to include such parts. A securing member 74 is permanently securable about a dispensing opening 76 of the container. In other words, the securing member cannot easily be removed without noticeable damage to it, to the container, or to the fitment 100. The securing member 74 may be a malleable (e.g. metallic) ring crimpable about the neck profile 72 formed around the dispensing opening 76. Alternatively, the securing member 74 may be a snap fit on or over the neck profile 72 of the container, for example a snap-fit ring; or the securing member 74 may be a screw-on ring with anti-backoff features. In all these instances, the securing member 74 may serve to secure the base end 54 of the foldable pouring spout 50 in sealed peripheral engagement about the dispensing opening 76 by compressing the circumferential groove 60 to close against the neck profile 72. However, the foldable pouring spout 50 may be secured to the container 70 in any suitable way; e.g. by insert molding, as previously mentioned.

[0029] The securing member 74 may also serve to secure the flame arrestor 10 to the foldable pouring spout 50 by trapping the out turned flange 32 in the groove 60. However, before the fluid dispensing fitment is installed in or on a container, its flame arrestor component may be independently secured to its foldable pouring spout component, thereby providing a complete, unitary assembly, convenient for installation and for handling in the supply chain. For example, the out turned flange 3211or an upper part of the annular side wall 14 may be bonded to the pouring spout base end 54, e.g. by a continuous annular bond or at an annular series of spots. The bonding may be carried out by any suitable means, e.g. by adhesive, or by solvent or ultrasonic welding or by heat staking. As an example, energy concentrating circumferential ridges 33 are indicated schematically in FIG. 11 for use in ultrasonically welding the flange 32 within the groove 60, to bond the flame arrestor 10 to the foldable pouring spout 50. Rather than the foldable pouring spout component of the dispensing fitment being securable to the container and the flame arrestor component being secured to the foldable pouring spout, the flame arrestor component may be sealingly securable to the container’s dispensing opening and the foldable pouring spout component secured and sealed to the flame arrestor. In this arrangement, the flame arrestor component may again for convenience be secured to the foldable pouring spout component before the resulting unitary fluid dispensing fitment is fitted to the container.

[0030] FIG. 11A shows an alternative arrangement in which the flame arrestor 10 is provided with a securing flange 54a incorporating a downwardly facing circumferential groove 60a which may be profiled to fit and make a fluid-tight seal with industry standard pail opening profiles or other industry standard container dispensing opening profiles 72. The larger diameter base end 54 of the foldable pouring spout 50 may be shaped as a substantially plain cylindrical band which is sealingly secured to the adjacent inner wall of the flame arrestor 10, at or near the securing flange 54a. For example, the base end of the end 54 of the foldable pouring spout 50 and the securing flange 54a of the flame arrestor 10 may be secured together by a continuous annular bond formed e.g. by adhesive, heat fusion, ultrasonic welding or in any other suitable way. For example, the base end of the end 54 of the foldable pouring spout 50 and / or the securing flange 54a of the flame arrestor 10 may be premolded with annular, energy directing ridges 33a for use in forming a continuous, annular, ultrasonically welded bond between them. The securing flange 54a of the flame arrestor 10 may be permanently secured to the container neck profile 72 by any suitable means, e. g., such as those mentioned above in relation to the spout base end 54 of FIG. 11; a metallic crimp ring 74 being shown in FIG. 11A by way of illustrative example.12

[0031] FIG. 11B shows an arrangement in which a securing flange 32 of the flame arrestor 10 is configured for either (a) insert-molding into a container wall or lid, or (b) for sealably bonding into an aperture in the container wall or lid, e.g. by ultrasonic welding or the like. The closure 62 may be a one-piece molding, which includes an integrally molded bail handle having an upstanding finger grip portion 55. A pair of such bail handles may be provided. The bail handle(s) may be attached to the rest of the closure 62 in known manner by living hinges and by frangible connections which are broken when the bail handles are raised and grasped to unscrew the closure from the outlet end of the foldable pouring spout 50, thereby providing a tamper evidencing feature. These frangible connections and living hinges are outside the section plane of FIG. 11B and are therefore not visible. The one-piece molding which includes the closure 62 may further include an e.g. ring-shaped anchor body 57 which is coupled to the closure 62 by a further frangible connection or connections. For example, the anchor body 57 may be frangibly attached to the bail handle(s) and / or to the rest of the closure 62. These further frangible connections are again outside the section plane of FIG. 11B and not visible. The configuration of the closure 62, its bail handle(s), and the anchor body 57, may be generally like the closure, bail handles, and anchor body shown and described in W02021 / 198022.

[0032] The securing flange 32 of the flame arrestor 10 shown in FIG. 11B includes a depending collar 35 which may be snap-fitted into a correspondingly sized aperture in a container wall or lid. The collar 35 is surrounded by a radially outwardly extending portion 37 of the securing flange 32. Before fitment to the container, the pouring spout base end 54 may be bonded within and circumferentially sealed to the securing flange 32, e.g. using energy-directing ridges 33b as an aid to ultrasonic welding. Next, still before fitment to the container, the closure 62 may be screwed onto the outlet end of the foldable pouring spout 50 and the anchor body 57 permanently bonded to the securing flange 32 of the flame arrestor 10, e.g. using further energy directing ridges 59 as an aid to ultrasonic welding. The resulting assembly may be sealingly bonded by any suitable means (such as those previously described for bonding the foldable pouring spout and flame arrestor components together) to the portion of the container wall or lid surrounding the installation aperture; energy directing ridges 61 on the underside of the radially outwardly13extending portion 37 being shown by way of example as an aid to such bonding by ultrasonic welding. Yet alternatively, the resulting assembly may be insert molded into the container wall or lid, with the molded material of the wall or lid surrounding the anchor body 57 and the adjacent, radially outwardly extending portion 37 of the securing flange 32. Other variants are also possible, for example the pouring spout base end 54 may extend between the anchor body 57 and the radially outwardly extending portion 37 of the securing flange 32; or (more like the arrangement shown in W02021 / 198022) the depending collar 35 and radially outwardly extending portion 37 can be provided as parts of the pouring spout base end, with an upper rim of the flame arrestor side wall 14 secured and sealed to the pouring spout base end.

[0033] The foldable tapered portion 58 of the pouring spout 50 may be connected to the base end 54 by a membranous web 68 forming an annular living hinge. This forms a highly mobile flexure zone, whereby when the spout 50 is pulled out for pouring out the container contents, the foldable tapered portion 58 can pass through the base end 54 and snap into a position closely adjacent to a surrounding inner wall 55 of the base end, without bulging inwardly away from this inner wall, and therefore without constricting the flow passageway through the pouring spout 50. The outward flow of the container contents and the inward flow of ambient air to the upper part or parts of the annular side wall’s foraminous, flame arresting region 22 and then into the container 70, are thus facilitated. The web 68 delineates the innermost end of the extended pouring spout (the extended spout being indicated by the dotted lines 50a in Figure 9). The foraminous, flame arresting region 22 extends from approximately the level of the web 68 further inwardly into the container, whereby incoming ambient air leaving the tilted inner end of the extended pouring spout 50a easily rises unhindered through the uppermost parts (e.g. uppermost holes 24) of the foraminous, flame arresting region 22 of the flame arrestor 10 and into the container 70. When the foldable pouring spout 50 is in its extended position (indicated by the dotted lines 50a in Figure 9), the membranous web 68 can also extend a short distance radially inwardly, thereby helping the adjacent part of the pouring spout’s foldable tapered portion 58 to clear an inwardly protruding curled edge 78 of the securing member 74 (FIG. 11).14

[0034] Figures 12-17 relate to a fluid dispensing fitment 200 which may comprise a foldable pouring spout 50 substantially identical to that shown in the preceding figures, and a flame arrestor 110 generally similar to the flame arrestor 10 described above, but with differences or modifications explained below. Like references are used below to refer to like parts. Rather than being made as one part, the foraminous portion of the end wall 16 of the flame arrestor 110 is made to include a separate foraminous screen 116. Thus the end wall 16 in the preceding figures is reduced to the edge region 30, which surrounds a large central opening 130. The foraminous screen 116 may take any suitable form, for example a welded mesh made for example from stainless steel wire; or it may be made from a sintered metal, a sintered plastic, a porous mat of fibrous material, an open-celled foam material, a porous ceramic, or the like. The annular side wall 114 is provided with an annular retaining ridge 134 (FIG. 17) adjacent to the end wall edge region 30. As best seen in Figures 16 and 17, the perimeter of the foraminous screen 116 is secured against the inner face of the edge region 30. A snap ring 136 is inserted between the annular retaining ridge 134 and the perimeter of the foraminous screen 116 to hold it in place. Additionally or alternatively, the foraminous screen 116 may be secured in the remainder of the flame arrestor 110 by any other suitable means, such as by heat staking, ultrasonic welding, heat deformation of the annular side wall 116, insert molding, adhesive attachment, etc.

[0035] The foraminous screen 116 may be formed from welded stainless steel wire mesh having the following properties:The resulting fitment 200 may meet the ASTM F3429 / F3429M-20 Standard Specification for Performance of Flame Mitigation Devices Installed in Disposable and Pre-Filled Flammable Liquid Containers.15

[0036] Figure 18 shows a further modified fluid dispensing fitment 300 which is generally similar to the fitment 200 shown in Figures 12-17, except that rather than being a substantially flat disk, the foraminous screen 216 comprises an inwardly depressed central zone 230 which is accommodated within the bore of the outlet end 52 of the folded pouring spout 50. The depth and / or configuration of the depressed central zone 230 may be chosen to optimize the spacing between this zone and the extended rim 56 of the spout outlet end 52 for best performance in flame mitigation tests. Additionally or alternatively, the depth and / or configuration of the depressed central zone 230 may be chosen to optimize the open flow area available through the flame arrestor 210 and hence optimize the fluid flow rate through the foldable pouring spout 50 for good high flow, glug free performance. The form and depth of the foraminous portion of the end wall 16 in the one-piece flame arrestor shown in Figures 1-10 may be similarly modified for similar purposes. The foraminous screen 216 may be made of any suitable pervious material, such as those described above with reference to the foraminous screen 116.

[0037] Figure 19 shows a further modified form of the flame arrestor 310 which may be generally similar to those of the preceding Figures (including their described variants in form and materials), except that rather than comprising an array of through holes in the annular side wall 14, the foraminous, flame arresting region 22 comprises a circumferentially spaced series of apertures or windows 322 each covered by a piece of foraminous material 324. This may be a wire mesh or any other suitable fluid-permeable material, such as those described above with reference to the foraminous screens 116 and 216. In the illustrated example, a single annular band of wire mesh 324 is secured inside the flame arrestor 310 adjacent to all the windows 322.However, this is not essential to the invention. The foraminous material may be placed inside and / or outside the apertures or windows 322 and individual or smaller groups of apertures or windows may be covered by individual pieces of foraminous material. The foraminous material may be secured in place in any suitable way, for example by heat staking, adhesive, or mechanical fixing, or combinations thereof. As a further alternative, the entire flame arrestor may be made from or covered by a foraminous material.16

[0038] FIG. 20 shows a typical side view of a further modified form of the flame arrestor 410 otherwise generally similar to the flame arrestor described with reference to FIGs. 1-5. However, the foraminous, flame arresting region 422 distributed about the circumference of the annular side wall 414 is incorporated into a tapered part 428 of the side wall 414. For ease of molding the associated through holes, the taper is provided in a series of steps 429, each of progressively decreasing diameter from top to bottom of the flame arrestor 410. Each step 429 is shown as containing a single circumferential row of through holes 424, though other numbers of rows and hole shapes and configurations in each step are possible. The holes of the circumferential foraminous region 422 are shown as extending into the side wall 414 below the tapered part 428, though this is optional; and the holes of this region may additionally or alternatively extend into the side wall 414 above the tapered part 428 of the side wall 414 (not shown).

[0039] FIG. 21 shows an integrally molded end wall 416 for the flame arrestor 410 of FIG. 20, which is configured like the end wall 16 shown in Figures 1-6. The end wall 416 has crossed diametral strengthening ribs 420 like the ribs 20 shown in FIGs.1,2 and 4-6. FIG. 22 shows an alternative, “open” base configuration for the flame arrestor 410 of FIG. 20. Like that of FIGs. 12-16, the base has a large central opening 530 for use with a separately formed foraminous screen (not shown). This screen may be retained against the base edge region 30a surrounding the opening 530 and held in place by an annular retaining ridge 534, e.g. using a snap ring (not shown), like the ring 136 shown in FIG. 17. One or more reinforcing ribs may extend across the opening 530 (e.g. a crossed diametral pair of ribs 520 as shown) to strengthen and support the screen when thus installed. Together with the edge region 30a, the reinforcing ribs 520 may also help to prevent the screen from being expelled by high pressure inflowing fluid, e.g. during filling of the container. Similar ribs may be provided in other “open base + separate screen” embodiments of the flame arrestor, e.g. in modifications of the arrangement shown in FIGs. 12-17.

Claims

17CLAIMS:

1. A fluid dispensing fitment for a container, the fitment comprising:a foldable pouring spout having:a base end sealingly attachable about a dispensing opening of the container and defining a flow cross-section;an outlet end having a smaller flow cross-section than that of the base end; and a foldable tapered portion connected between the base end and the outlet end, the fitment further comprising a flame arrestor extending across the flow cross-section of the base end, the flame arrestor comprising:an annular side wall within which the pouring spout is at least partially nested when folded, anda foraminous, flame-arresting end wall positioned opposite to the pouring spout so that fluid dispensed from the container flows through the foraminous end wall into the pouring spout;the annular side wall having at least one foraminous, flame arresting region distributed about its circumference, whereby ambient air passes through the pouring spout, through an upper part or parts of the annular side wall’s foraminous, flame arresting region(s) and into the container, to replace the dispensed fluid.

2. The fluid dispensing fitment of claim 1, in which flow resistance through all foraminous parts of the flame arrestor when the container is full and close to fully inverted, is sufficient to prevent the outflow of dispensed fluid from completely filling the pouring spout.

3. The fluid dispensing fitment of claim 1, in which flow resistance through all foraminous parts of the flame arrestor when the container is full and tipped substantially onto its side with the pouring spout substantially in the lowest possible position, is sufficient to prevent the outflow of dispensed fluid from completely filling the pouring spout.

4. The fluid dispensing fitment of claim 2 or 3, in which the flow resistance through all foraminous parts of the flame arrestor is as low as otherwise possible, to permit the highest possible steady fluid flow rates.

5. The fluid dispensing fitment of any preceding claim, in which the flame arrestor and the foldable pouring spout are formed as separate components or subassemblies.

186. The fluid dispensing fitment of claim 5, in which the base end of the foldable pouring spout and a rim of the annular side wall of the flame arrestor comprise respective annular flanges by which the foldable pouring spout and the flame arrestor are sealingly attachable about a dispensing opening of the container.

7. The fluid dispensing fitment of claim 5, in which the flame arrestor comprises an out-turned flange at a rim of the annular side wall axially opposite to the end wall and received in an annular groove by which the base end of the pouring spout is sealingly attachable about the dispensing opening of the container.

8. The fluid dispensing fitment of any preceding claim, in which the flame arrestor is secured to the foldable pouring spout to form an assembly installable in or on a container.

9. The fluid dispensing fitment of claim 5 in which the flame arrestor is sealingly securable to the container’s dispensing opening and the foldable pouring spout is secured and sealed to the flame arrestor to form an assembly installable in or on the container’s dispensing opening.

10. The fluid dispensing fitment of any preceding claim, in which foraminous, flame-arresting end wall comprises a foraminous insert.

11. The fluid dispensing fitment of claim 10, in which the foraminous insert comprises a metal mesh held in a groove formed in an inner surface of the annular side wall of the flame arrestor.

12. The fluid dispensing fitment of claim 11, in which the metal mesh is secured in the groove by a snap ring.

13. The fluid dispensing fitment of any of claims 1-9, in which the foraminous, flame-arresting end wall and the annular side wall of the flame arrestor are integrally formed and the end wall comprises a plurality of apertures.

14. The fluid dispensing fitment of claim 13, in which the apertures of the end wall form a grid pattern.

15. The fluid dispensing fitment of any preceding claim, in which the at least one foraminous, flame arresting region distributed about the circumference of the annular side wall of the flame arrestor comprises a plurality of apertures integrally formed in and distributed about the circumference of the annular side wall.1916. The fluid dispensing fitment of claim 15, in which the apertures of the annular side wall form a grid pattern.

17. The fluid dispensing fitment of any of claims 1-14, in which the at least one foraminous, flame arresting region distributed about the circumference of the annular side wall of the flame arrestor comprises a plurality of apertures each covered by a foraminous insert.

18. The fluid dispensing fitment of claim 17, in which the foraminous insert covering the apertures comprises metal mesh secured adjacent to the apertures.

19. The fluid dispensing fitment of any preceding claim, in which the foraminous, flame-arresting end wall comprises a foraminous region of smaller diameter than the diameter of the annular side wall.

20. The fluid dispensing fitment of any preceding claim, in which the foldable tapered portion is connected to the base end by a membranous web forming an annular living hinge.

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