[0001] The present invention concerns an anti-siphon inlet device. The invention also concerns an insert for use in an inlet device and a kit comprising such an insert.

[0002] Anti-siphon inlet devices which permit filling of a tank to which the device is fitted, but inhibit removal of liquid therefrom, are well-known to those skilled in the art. Such anti-siphon inlet devices are sometimes fitted on fuel tanks to inhibit access to the fuel. In use, a fuelling nozzle is typically placed into the inlet device and fuel leaving the nozzle passes through holes provided in the device. The holes allow fuel into the fuel tank, but the holes are sufficiently small to inhibit the passage there through of a siphoning tube of a size practical to facilitate siphoning of fuel from the fuel tank. While such devices inhibit unwanted removal of fuel, they can also inhibit entry of fuel into the fuel tank, especially at high fuel flow rates. This can cause "pooling" or "puddling" of fuel in the device and subsequent shut-off of the pump and/or can also lead to "splashback" (ejection) of fuel from the device, both of which are undesirable. Furthermore, there is a move within some sections of the vehicle fuelling industry to increase the fuel flow rates supplied by pumps. Also, large fuel flow rates are typically used to fuel devices with large fuel tanks, such as those used in the mining and agricultural fields. Fuel tank inlet devices which are capable of handling high fuel rates are therefore desirable.

[0003] The present invention seeks to mitigate one or more of the above-mentioned problems. Alternatively, or additionally, the present invention seeks to provide an improved anti-siphon inlet device.

SUMMARY OF THE INVENTION

[0004] In accordance with a first aspect of the present invention there is provided an anti- siphon inlet device for inhibiting theft of liquid from a tank of liquid, the device comprising: a body portion comprising an inlet at one end and comprising one or more outlet apertures, remote from the inlet, for the egress of liquid into a tank; and first and second mesh members, each extending laterally across the body portion.

[0005] It has been found that the provision of two laterally-extending mesh members may help reduce "pooling" and/or "splashback" and may help to allow faster filling of a tank, such as a fuel tank. For the avoidance of doubt, a mesh typically comprises a network of strands of material, with apertures for the passage of fluid therethrough. A mesh may be formed from a network of wire or other such strands, for example, or may be formed by stamping and/or expanding a stamped substrate.

[0006] The anti-siphon device is typically a fuel tank inlet device for inhibiting theft of fuel from a fuel tank. Therefore, references to "liquid" below also include "fuel" when the anti-siphon device is a fuel tank inlet device.

[0007] The first and second mesh members are typically spaced apart from one another (i.e. there is a gap between the two mesh members), at least for one or more portions of the first and second mesh members. The first and second mesh members may, for example, contact each other in one region, but may be spaced in another region.

[0008] The first and second mesh members are typically spaced in a direction along the length of the body portion. The second mesh member will be more proximate to the inlet than the first mesh member. The first mesh member may be provided with an aperture for the passage of a fastener therethrough. The aperture may be sufficiently large to permit the passage therethrough of all of a fastener, including any fastener head (such as a bolt head or screw head). The fastener would then secure the second mesh member to the rest of the device. This is of particular benefit if the first and second mesh members are connected together, for example, if both the first and second mesh members are part of an insert. Such an arrangement inhibits possible pushing together of the first and second mesh members if the fastener head does not pass through the first mesh member. Alternatively, the fastener may pass through both the first and second mesh member, with the shaft (but not the head) of the fastener passing through the first and second mesh members.

[0009] The first and second mesh members may be attached to the body portion. The first and second mesh members may be individually attached to the body portion.

[0010] The first and second mesh members may be substantially parallel with one another. A spacer may be provided, optionally associated with, and optionally extending along, the length of the bolt. The bolt may be located within the spacer. The spacer is optionally substantially incompressible so that when the nut or rivet is used to secure the first and second mesh members in place, the spacer is not compressed by the riveting/nut tightening process, thereby inhibiting the squeezing together of the first and second mesh members. This may help maintain a spacing between the first and second mesh members when the nut or rivet is used to secure the insert.

[0011] The spacing of the first and second mesh members may therefore be approximately the same over the area of the first and second mesh members. The spacing of the first mesh member and the second mesh member may vary by less than 2mm, optionally less than 1mm and optionally less than 0.5mm. The standard deviation in spacing of the first mesh member and the second mesh member may vary by less than 2mm, optionally less than 1mm and optionally less than 0.5mm across the area of the inner surface.

[0012] Alternatively, the first and second mesh members may not be parallel with one another. Such an arrangement may be facilitated, for example, by there being no spacer. In such a case, the spacing of the first and second mesh members may be smaller in a central region than in an outer region. For example, if the first and second mesh members are generally frustoconical or conical, then the spacing of the first and second mesh members at or proximate to the base is greater than the spacing at the apex or top of the cone or frusto-cone. For example, both the first and the second may be conical or frustoconical, but the cone or frusto-cone apex angle may be mutually different.

[0013] The mean spacing of the first and second mesh members may be from 0.5 to 30mm, optionally from 0.5m to 20mm, optionally from 0.5 to 10mm, optionally from 1.0 to 5.0mm, optionally from 1.5 to 4.5mm and optionally from 2.0 to 4.0mm. [0014] The first and second mesh members may have essentially the same shape. For example, if the first mesh member is circular, the second mesh member may be circular. Both the first and second mesh members may, for example, be concave in shape. For example, the first and second mesh members may be approximately conical or firusto- conical in shape. Alternatively, the first and second mesh members may not be the same shape.

[0015] The device may comprise a filter for removing particulate from a liquid. The filter may comprise a gauze, typically a nylon or metal gauze. The apertures provided in the filter for the passage of liquid therethrough are typically smaller than the apertures provided in one or both of the first and second mesh members. The filter may be provided at any suitable location in the device. For example, the filter may be provided remote from the inlet and proximate to the outlet. The filter may be located between the first and second mesh members.

[0016] The body portion may comprise a wall portion and an end portion remote from the inlet. The wall portion may be provided with said outlet apertures for the egress of liquid into a tank. The end portion may be provided at or near the end of the wall portion.

[0017] The body portion is typically made from non-mesh material. For example, the body portion is typically made from a substantially rigid, non-deformable material, such as aluminium. The body portion may, for example, be machined from a block of metal, such as aluminium.

[0018] The end portion may have an inner surface for the receipt of liquid, and one or both of the first and second mesh members optionally having approximately the same shape as the inner surface of the end portion. The first mesh member may optionally be proximate to, and the second mesh member less proximate to, the end portion. For example, if the inner surface of the end portion is conical or frusto -conical in shape, the first and second mesh members may be conical or, alternatively, frusto-conical. The first mesh member may optionally be substantially parallel to the inner surface of the end portion. The spacing of the first mesh member and the inner surface of the end portion may be approximately the same over the area of the inner surface. The spacing of the first mesh member and the inner surface of the end portion may vary by less than 2mm, optionally less than 1mm and optionally less than 0.5mm across the area of the inner surface. The standard deviation in spacing of the first mesh member and the inner surface of the end portion may vary by less than 2mm, optionally less than 1mm and optionally less than 0.5mm across the area of the inner surface. The mean spacing of the first mesh member and the inner surface of the end portion may be from 0.5 to 30mm, optionally from 0.5 to 20mm, optionally from 0.5 to 10mm, optionally from 1.0 to 5.0mm, optionally from 1.5 to 3.5mm and optionally from 2.0 to 3.0mm.

[0019] The mesh members are optionally made from metal. The mesh members may be made from weave wire mesh formed by weaving wires together. The mesh members may alternatively be made by stamping or otherwise cutting a substrate, optionally expanding the cut or stamped substrate. The wires may optionally have a thickness of from 0.2 to 1.0mm, optionally from 0.3 to 0.7mm and optionally from 0.4 to 0.6mm.

[0020] The apertures formed in the first and second mesh members are typically of a relatively uniform size. The sieve size provided by the first and second mesh members is optionally from 0.6 to 5.6mm, optionally from 0.6 to 3.0mm, and optionally from 0.6 to 2.0mm. The apertures need not be of any particular shape. They may be square or diamond-shaped, for example.

[0021] One or both of the first and second mesh members are optionally located proximate to one or more of said outlet apertures provided in the body portion. For example, the closest part of one or both of the first and second mesh members to said one or more outlet aperture is optionally located no more than 35mm away, optionally no more than 30mm away, optionally no more than 25mm away, optionally no more than 20mm away, optionally no more than 15mm away, optionally no more than 10mm away and optionally no more than 5 mm away, from said one or more outlet aperture. Without wishing to be bound by theory, it is thought that the location of the first and second mesh members close to the outlet apertures may disrupt or "break-up" the flow of liquid close to the outlet apertures, thereby facilitating flow of the liquid out of the device, and/or the mesh members "break-up" the flow of liquid to reduce the flux of liquid impacting the end of the device. [0022] The first and second mesh members may be provided as part of an insert which is located within the body portion. The insert may comprise an insert wall portion. The insert is optionally formed from mesh. The insert wall portion is optionally shaped to conform to the shape of the body portion proximate to the insert wall portion. For example, if the internal surface of the body portion is substantially cylindrical, then the insert wall portion is optionally cylindrical. The insert may be sized to be comfortably received within the body portion so that the insert wall portion is proximate to the adjacent internal surface of the body portion, the mean spacing between the insert wall portion and the adjacent internal surface of the body portion optionally being no more than 30mm, optionally no more than 20mm, optionally no more than 10mm, optionally no more than 5mm and optionally no more than 3 mm. Optionally, the insert wall portion may touch the corresponding internal surface of the body portion.

[0023] The insert wall portion may be disposed around one or both of the first and second mesh members.

[0024] The insert wall portion may extend from a first end associated with the inlet to a second end remote from the inlet. One or both of the first and second mesh members may be located at, or proximate to, the second end of the wall portion. The insert wall portion may extend past the first mesh member, optionally by no more than 30mm, optionally by no more than 20mm, optionally by no more than 10mm, optionally by no more than 8mm, optionally by no more than 5mm, optionally by at least 1mm and optionally by at least 1.5mm. This provides a portion of wall which protrudes past the first and second mesh members and facilitates the positioning of the first mesh member in spaced relationship from the end portion (if present) of the device.

[0025] The device may comprise a means for inhibiting removal of the insert. The means for inhibiting removal of the insert may comprise a means for securing the insert in position. Therefore, the insert may be secured in position. For example, the insert may be attached to another part of the device, such as the body portion. The insert may be attached to the end portion of the device, for example, using a bolt. A nut or rivet may be used to facilitate attachment of the insert to the end portion using a bolt. The bolt may extend through one or both of the first and second mesh members. Alternatively, the insert may be positioned without being secured in place. A spacer may be provided as mentioned above, optionally associated with, and optionally extending along, the length of the bolt. The bolt may be located within the spacer. The spacer is optionally substantially incompressible so that when the nut or rivet is used to secure the insert in place, the spacer is not compressed by the riveting/nut tightening process, thereby inhibiting the squeezing together of the first and second mesh members. This may help maintain a spacing between the first and second mesh members when the nut or rivet is used to secure the insert.

[0026] One or both of the first and second mesh members may be provided with an aperture for the passage of a bolt there through. The aperture may typically be located centrally in relation to the first and/or second mesh member provided with said aperture.

[0027] The body portion may be substantially tubular. The body portion may be substantially cylindrical (i.e. has approximately the same cross sectional shape and size along its length). The body portion may be elongate.

[0028] The device may comprise an attachment portion for attaching the device to a tank or a filler neck thereof. The attachment portion may comprise a skirt spaced from the body portion, defining a space there between for the receipt of a filler neck of a tank. The attachment portion may comprise a first configuration for mating with a second configuration provided on a tank or a filler neck so as to secure the device to the tank or filler neck. The first and second configurations may, for example, comprise screw threads or bayonet fittings.

[0029] The device may comprise a nozzle support for keeping a filling nozzle in spaced relationship from said outlet apertures.

[0030] The body portion typically defines an interior for the receipt of a filling nozzle. At least a portion of the support may be located in said interior.

[0031] The nozzle support may comprise one or more of a recess or a protrusion, for example. A recess may be formed in or on the body portion. A protrusion may protrude from the body portion. [0032] The body portion may comprise a wall portion, typically a substantially cylindrical wall. At least a portion of the support may be located inwardly of the wall portion.

[0033] The support may comprise one or more arcuate portions. The one or more arcuate portions may protrude inwardly of the wall portion of the body portion. The support may comprise one or more hemi-annular or annular portions. The hemi-annular or annular portion may protrude inwardly of the wall of the body portion.

[0034] The support may comprise an elongate member, optionally a single elongate member i.e. the support comprises one (and only one) elongate member. At least a portion of the single elongate member may be located in the interior of the body portion. Each end of the single elongate member may be located in the wall of the body portion. If the body portion is substantially cylindrical, the single elongate member may form a chord across the substantially cylindrical body portion. Any elongate member may have any appropriate cross-sectional shape; for example, any elongate member may have a cross-section which is circular, elliptical, square, rectangular or triangular.

[0035] The support may comprise a plurality of elongate members, for example, a first elongate member and second elongate member. The first and second elongate members are typically spaced along the height of the device. For example, the first elongate member may be closer to the inlet than the second elongate member.

[0036] The support may be arranged to keep the end of a filling nozzle optionally at least 10mm, optionally at least 20mm, optionally at least 30mm, optionally at least 40mm and optionally at least 50mm from the end of the device.

[0037] The device may comprise an end remote from the inlet, the support being located closer to said end than to said inlet.

[0038] As mentioned above, the first and second mesh members may be provided as part of an insert which is located within the body portion. The support may inhibit removal of the insert from the body portion of the device. This may be achieved, for example, by arranging the support between the insert and the inlet. In this connection, it is preferred if the support comprises one or more elongate members. Such elongate members may be arranged across the device body portion to inhibit removal of the insert. [0039] The device may comprise a means for securing the device to a tank or filler neck. The means for securing the device may comprise one or more screws or bolts, for example. The means for securing the device may abut or otherwise engage the tank or filler neck, without penetrating the tank or filler neck. This is particularly advantageous when the tank is used to store fuel or other flammable liquid. The device may comprise one or more blanking members for inhibiting access to the means for securing the device once those means for securing the device are in place. Alternatively or additionally, the means for securing the device may comprise a removable head portion. The head portion may be removed once the device is secured to the tank or filler neck to inhibit removal of the means for securing the device.

[0040] The end portion may be provided with one or more outlets for the egress of liquid into a tank. The inner surface of the end portion may be shaped to direct liquid to one or more of the outlet apertures provided in the wall portion, for example, if said outlet apertures are provided in the wall portion adjacent to the end portion. The inner surface may be angled to direct liquid to one or more of the outlet apertures provided in the wall portion. The inner surface may comprise a surface of revolution, such as a cone, frusto- cone, horn, trumpet, paraboloid or half-lemon shape. The inner surface may be substantially circular.

[0041] As mentioned above, the body portion may be provided with one or more outlet apertures for the egress of liquid into the tank. Such apertures may be adjacent to the end portion, if present. One or more of said outlet apertures may be elongate. The body portion may be provided with a first set of outlet apertures extending around the perimeter of the body portion, one or more of those outlet apertures being elongate. The first set of outlet apertures may be proximate to, and optionally adjacent to, the end portion, if present. The body portion may be provided with a second set of outlet apertures extending around the perimeter of the body portion, one or more of those outlet apertures being elongate. The second set of outlet apertures may be proximate to the first set of outlet apertures. One or more of said outlet apertures may extend lengthways around the perimeter of the body portion. One or more outlet apertures may extend lengthwise along the body portion. One or more outlet apertures may extend to the end portion, thereby forming an outlet for liquid in the end portion.

[0042] The body portion may comprise a group of a plurality of slots spaced around the periphery of the body portion, each slot extending along the length of the body portion. Said group of plurality of slots is typically located closer to the inlet than said outlet apertures.

[0043] The body portion may comprise a plurality of gas inlet apertures located proximate to the inlet. Such apertures are typically circular, and each is typically smaller in area than the outlet apertures or the slots.

[0044] According to a second aspect of the present invention there is also provided an insert for use in the inlet device according to the first aspect of the present invention. The insert of the second aspect of the present invention may comprise those features described above in relation to the inlet device of the first aspect of the present invention. The insert of the second aspect of the present invention may be retro-fitted to an inlet device to provide improved flow characteristics to that device.

[0045] According to a third aspect of the present invention there is also provided a kit comprising an insert in accordance with the second aspect of the present invention and a means of inhibiting removal of the insert from an inlet device. The means of inhibiting removal of the insert may comprise a means of attaching the insert to an f inlet device, and may comprise those features described above in relation to the inlet device of the first aspect of the present invention. The means of inhibiting removal of the insert from an inlet device may, for example, comprise a nozzle support. The kit of the third aspect of the present invention may be used to retro-fit the insert to an inlet device to provide improved flow characteristics to that device.

[0046] According to a fourth aspect of the present invention there is provided an anti- siphon inlet device for inhibiting theft of liquid from a tank, the device comprising: a body portion comprising an inlet at one end for the receipt of a filling nozzle and comprising one or more outlet apertures, remote from the inlet, for the egress of liquid into a tank; and a nozzle support for keeping a filling nozzle in spaced relationship from one or more outlet apertures.

[0047] It has been found that a support which keeps a filling nozzle spaced away from the bottom of the anti-siphon device may reduce the risk of "pooling" or "puddling" which may cause unwanted temporary cessation of the filling process. The support will also not substantially interfere with the passage of liquid from a filling nozzle to one or more outlet apertures. As with the anti-siphon device of the first aspect of the present invention, the anti-siphon device of the fourth aspect of the present invention is optionally a fuel tank inlet device for inhibiting theft of fuel from a fuel tank.

[0048] The body portion typically defines an interior for the receipt of a filling nozzle. At least a portion of the support may be located in said interior.

[0049] The nozzle support may comprise one or more of a recess or a protrusion, for example. A recess may be formed in or on the body portion. A protrusion may protrude from the body portion.

[0050] The body portion may comprise a wall, typically a substantially cylindrical wall. At least a portion of the support may be located inwardly of the wall.

[0051] The support may comprise one or more arcuate portions. The one or more arcuate portions may protrude inwardly of the wall of the body portion. The support may comprise one or more hemi-annular or annular portions. The hemi-annular or annular portion may protrude inwardly of the wall of the body portion.

[0052] The support may comprise an elongate member, optionally a single elongate member i.e. the support comprises one (and only one) elongate member. At least a portion of the single elongate member may be located in the interior of the body portion. Each end of the single elongate member may be located in the wall of the body portion. If the body portion is substantially cylindrical, the single elongate member may form a chord across the substantially cylindrical body portion. Any elongate member may have any appropriate cross-sectional shape; for example, any elongate member may have a cross-section which is circular, elliptical, square, rectangular or triangular. [0053] The support may comprise a plurality of elongate members, for example, a first elongate member and second elongate member. The first and second elongate members are typically spaced along the height of the device. For example, the first elongate member may be closer to the inlet than the second elongate member.

[0054] The support may be arranged to keep the end of a filling nozzle optionally at least 30mm, optionally at least 40mm and optionally at least 50mm from the end of the device.

[0055] The device may comprise an end remote from the inlet, the support being located closer to said end than to said inlet.

[0056] The device optionally comprises an insert located within the body portion of the device, the insert being arranged to permit the passage therethrough of liquid. The insert typically comprises an insert wall portion which is typically substantially cylindrical in shape. The insert may be formed from mesh.

[0057] The insert wall portion is optionally shaped to conform to the shape of the body portion proximate to the insert wall portion. For example, if the internal surface of the body portion is substantially cylindrical, then the insert wall portion is optionally cylindrical. The insert may be sized to be comfortably received within the body portion so that the insert wall portion is proximate to the adjacent internal surface of the body portion, the mean spacing between the insert wall portion and the adjacent internal surface of the body portion optionally being no more than 30mm, optionally no more than 20mm, optionally no more than 10mm, optionally no more than 5mm and optionally no more than 3mm. Optionally, the insert wall portion may touch the corresponding internal surface of the body portion.

[0058] The insert wall portion may extend from a first end associated with the inlet to a second end remote from the inlet. A first end portion may be located at, or proximate to, the second end of the wall portion. The first end portion may extend across the space formed by the insert wall portion. The first end portion permits the passage therethrough of liquid. The insert wall portion may extend past the first end portion, optionally by no more than 30mm, optionally by no more than 20mm, optionally by no more than 10mm, optionally by no more than 8mm, optionally by no more than 5mm, optionally by at least lmm and optionally by at least 1.5mm. This provides a portion of wall which protrudes past the first end portion and facilitates the positioning of the first end portion in spaced relationship from the end portion (if present) of the device.

[0059] The insert optionally comprises a second insert end portion located above the first insert end portion. For the avoidance of doubt, the first and second insert end portions are analogous to the first and second mesh members of the device of the first aspect of the present invention. The first and second insert end portions may be substantially parallel with one another. A spacer may be provided, optionally associated with, and optionally extending along, the length of a bolt. The bolt may be located within the spacer. The spacer is optionally substantially incompressible so that when the nut or rivet is used to secure the first and second insert end portions in place, the spacer is not compressed by the riveting/nut tightening process, thereby inhibiting the squeezing together of the first and second insert end portions. This may help maintain a spacing between the first and second insert end portions when the nut or rivet is used to secure the insert.

[0060] The spacing of the first and second insert end portions may therefore be approximately the same over the area of the first and second insert end portions. The spacing of the first and second insert end portions may vary by less than 2mm, optionally less than 1mm and optionally less than 0.5mm. The standard deviation in spacing of the first and second insert end portions may vary by less than 2mm, optionally less than 1mm and optionally less than 0.5mm across the area of the inner surface.

[0061] Alternatively, the first and second insert end portions may not be parallel with one another. Such an arrangement may be facilitated, for example, by there being no spacer. In such a case, the spacing of the first and second insert end portions may be smaller in a central region than in an outer region. For example, if the first and second insert end portions are generally frustoconical or conical, then the spacing of the first and second insert end portions at or proximate to the base is greater than the spacing at the apex or top of the cone or frustocone.

[0062] The mean spacing of the first and second insert end portions may be from 0.5 to 30mm, optionally from 0.5m to 20mm, optionally from 0.5 to 10mm, optionally from 1.0 to 5.0mm, optionally from 1.5 to 4.5mm and optionally from 2.0 to 4.0mm. [0063] The first and second insert end portions may have essentially the same shape. For example, if the first insert end portion is circular, the second insert end portion may be circular. Both the first and second insert end portions may, for example, be concave in shape. For example, the first and second insert end portions may be approximately conical or frusto-conical in shape.

[0064] The body portion may comprise a wall portion and an end portion remote from the inlet. The wall portion may be provided with said outlet apertures for the egress of liquid into a tank. The end portion may be provided at or near the end of the wall portion.

[0065] The body portion is typically made from non-mesh material. For example, the body portion is typically made from a substantially rigid, non-deformable material, such as aluminium. The body portion may, for example, be machined from a block of metal, such as aluminium.

[0066] One or more (optionally more than one and optionally each) of the insert wall portion, first insert end portion (if present) and second insert end portion (if present) comprise or are optionally formed from mesh. The first and second inert end portions may be made from weave wire mesh formed by weaving wires together. The mesh members may alternatively be made by stamping or otherwise cutting a substrate, optionally expanding the cut or stamped substrate. The wires may optionally have a thickness of from 0.2 to 1.0mm, optionally from 0.3 to 0.7mm and optionally from 0.4 to 0.6mm.

[0067] The apertures formed in the first and second mesh members are typically of a relatively uniform size. The sieve size provided by the first and second mesh members is optionally from 0.6 to 5.6mm, optionally from 0.6 to 3.0mm, and optionally from 0.6 to 2.0mm. The apertures need not be of any particular shape. They may be square or diamond-shaped, for example.

[0068] If the device comprises an insert, the support may inhibit removal of the insert from the body portion of the device. This may be achieved, for example, by arranging the support between the insert and the inlet. In this connection, it is preferred if the support comprises one or more elongate members. Such elongate members may be arranged across the device body portion to inhibit removal of the insert. [0069] The device may comprise an attachment portion for attaching the device to a tank or a filler neck thereof. The attachment portion may comprise a first configuration for mating with a second configuration provided on a tank or a filler neck so as to secure the device to the tank or filler neck. The first and second configurations may, for example, comprise screw threads or bayonet fittings.

[0070] The device may comprise a means for securing the device to a tank or filler neck. The means for securing the device may comprise one or more screws or bolts, for example.

[0071] The body portion of the device may comprise an end portion remote from the inlet. The end portion may be provided with one or more outlets for the egress of liquid into a tank. The inner surface of the end portion may be shaped to direct liquid to one or more of the outlet apertures provided in a wall portion of the body portion, for example, if said outlet apertures are provided in the wall portion adjacent to the end portion. The inner surface may be angled to direct liquid to one or more of the outlet apertures provided in the wall portion. The inner surface may comprise a surface of revolution, such as a cone, frusto-cone, horn, trumpet, paraboloid or half-lemon shape.

[0072] As mentioned above, the body portion may be provided with one or more outlet apertures for the egress of liquid into the tank. Such apertures may be adjacent to the end portion, if present. One or more of said outlet apertures may be elongate. The body portion may be provided with a first set of outlet apertures extending around the perimeter of the body portion, one or more of those outlet apertures being elongate. The first set of outlet apertures may be proximate to, and optionally adjacent to, the end portion, if present. The body portion may be provided with a second set of outlet apertures extending around the perimeter of the body portion, one or more of those outlet apertures being elongate. The second set of outlet apertures may be proximate to the first set of outlet apertures. One or more of said outlet apertures may extend lengthways around the perimeter of the body portion.

[0073] The body portion may comprise a group of a plurality of slots spaced around the periphery of the body portion, each slot extending along the length of the body portion. Said group of plurality of slots is typically located closer to the inlet than said outlet apertures.

[0074] The body portion may comprise a plurality of gas inlet apertures located proximate to the inlet. Such apertures are typically circular, and each is typically smaller in area than the outlet apertures or the slots. The gas inlet apertures permit gas to flow from the surrounding tank space, into the device via the inlet apertures and then out of the device via the inlet.

[0075] It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the inlet device of the first aspect of the invention may incorporate any of the features described with reference to the insert of the second aspect of the invention and vice versa. For example, the inlet device of the first aspect of the present invention may comprise any of the features of the inlet device of the fourth aspect of the present invention, for example, and vice versa.

DESCRIPTION OF THE DRAWINGS

[0076] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:

[0077] Figure 1 shows a stylised cross-sectional view of part of an inlet device according to a first embodiment of the invention;

[0078] Figure 2 shows a perspective view of part of the inlet device according to the first embodiment of the invention, the mesh insert omitted for clarity;

[0079] Figure 3 shows a perspective view of part of an inlet device according to a second embodiment of the invention, the mesh insert omitted for clarity;

[0080] Figure 4 shows a perspective view of an inlet device of a third embodiment of the invention;

[0081] Figure 5 shows a perspective view of the mesh insert which forms part of the inlet devices of the first, second and third embodiments of the invention; [0082] Figure 6 shows a stylised partial cross-sectional view of part of an inlet device according to an embodiment of the first and fourth aspects of the invention;

[0083] Figure 7 shows a plan view of the inlet device of Fig. 6;

[0084] Figure 8 shows a cross-sectional plan view of part of the inlet device of Figs. 6 and 7;

[0085] Figure 9 shows an external perspective view of the inlet device of Figs. 6 to 8;

[0086] Figure 10 shows an external perspective view of the bottom of the inlet device of Figs. 6 to 9;

[0087] Figure 11 shows a simplified cross-sectional view of part of a further example of an inlet device in accordance with an embodiment of the first and fourth aspects of the present invention.

DETAILED DESCRIPTION

[0088] A first embodiment of an inlet device in accordance with the present invention will now be described with reference to Figures 1, 2 and 5. In this case, the inlet device is a fuel tank inlet device. The fuel tank inlet device is denoted generally by reference numeral 1 and comprises a body portion 2 extending from inlet 3, and one or more outlet apertures (only one of which, 4, is labelled). First 502 and second 503 mesh members extend across the space defined by body portion 2. A set 5 of outlet apertures 4 is provided, the set of apertures extending around the perimeter of the body portion 2. Each outlet aperture 4 is elongate, extending lengthwise around the perimeter of the body portion 2. A Circlip ® 6 is provided to inhibit passage of a siphon tube through the outlet apertures 4. The body portion 2 comprises a substantially cylindrical wall portion 19 which extends from the inlet 3 to an end portion 7. Body portion 2 is machined from aluminium and is substantially rigid. End portion 7 has inner 21 and outer 22 surfaces, both of which are substantially conical in overall shape (apart from the apertures formed in the surfaces). Fuel outlet passages (one of which is labelled 20) are provided in the end portion 7. Wall portion 19 and end portion 7 effectively form a "cage" into which a filling nozzle may be inserted. Fuel from a fuelling nozzle passes through the outlet apertures 4 and the fuel outlet passages 20 in the end portion 7. The "cage" structure inhibits access to the fuel tank. Furthermore, the various apertures and passages provided in the device 1 are sufficiently small to prevent passage there through of a siphon tube of a width which would allow removal of fuel from a fuel tank at a practical rate. The "cage" structure is formed by machining the wall portion 19 and end portion 7 from a block of aluminium, thereby providing a sturdy, yet lightweight, barrier.

[0089] It has been found that incorporating first 502 and second 503 mesh members helps decrease the risk of undesirable backflow and splash-back. The first 502 and second 503 mesh members are provided as part of a mesh insert 500. The mesh insert 500 comprises the first 502 and second 503 mesh members located between, and towards the bottom of, an approximately cylindrical insert wall 501. The first mesh member 502 is located just above (in this case, about 2.5mm above) the bottom of the insert wall 501 so that a portion 504 of the mesh wall 501 is located below the first mesh member 502. This portion 504 effectively provides a spacer between the first mesh member 502 and the inner surface 21 of the end portion 7 as can be seen from Figure 1. The mean spacing between the inner surface 21 and the bottom of the first mesh member is about 2.5mm. The mean spacing between the first 502 and second 503 mesh members is about 3mm. The first 502 and second 503 mesh members are shaped to have approximately the same shape as the inner surface 21 of the end portion 7. The insert wall 501 extends part- way up the device wall portion 19.

[0090] The insert 500 is attached to the body portion 2 by a bolt 50 which passes through an aperture 54 provided in the end portion 7, and also through apertures (not shown) provided in the first 502 and second 503 mesh members. The bolt 50 is capped by a rivet 52. The bolt 50 comprises a bolt head 51 which abuts the underside of end portion 7. A cylindrical spacer 55 is provided around the shaft of the bolt 50, the spacer 55 inhibiting crushing of the first 502 and second 503 mesh members during the riveting process. A washer 53 is provided between rivet 52 and spacer 55.

[0091] Further apertures are provided in wall portion 19 of the device. A set 8 of two rows of apertures 9 is provided above outlet apertures 4. The apertures 9 are slot-shaped, with the slots extending vertically. These apertures 9 are primarily used as fuel outlets. [0092] A further set 14 of apertures 13 is provided above set 8. The apertures 14 are circular and are primarily provided to allow gas to leave the fuel tank during the fuelling process.

[0093] Device 1 is provided with a plurality of screw-threaded apertures, one of which is labelled 11. Grub screws are inserted through screw-threaded apertures to attach the device 1 to a fuel tank.

[0094] A seal-forming washer 12 is provided to form a liquid-tight seal when the device 1 is mounted onto a fuel tank filler neck.

[0095] The mesh insert is formed from wire having a thickness of about 0.55mm. The sieve size is about 1.6mm (US mesh grade 12). The first 502 and second 503 mesh members are welded to the insert wall 501 which is formed by bending a sheet of mesh into a cylindrical shape and welding the edges of the sheet to form a cylinder.

[0096] A second embodiment of an inlet device in accordance with the present invention will now be described with reference to Figures 3 and 5. The inlet device is a fuel tank inlet device. The mesh insert 500 is the same as that described above in relation to the first embodiment of a device, and the mesh insert is located in the device of Fig. 3 in substantially the same manner as the insert 500 is located in the device of Fig. 2. The mesh insert 500 has been omitted from Fig. 2 for the purpose of clarity. The device is denoted generally with reference numeral 101. The device 101 comprises a body portion 102 extending from an inlet 103. The body portion 102 is provided with two sets 105a, 105b of outlet apertures (only two of which are labelled 104a, 104b) for the egress of fuel into a fuel tank, each set 105a, 105b of outlet apertures extending around the perimeter of the body portion 102. The end portion 107 is provided with a plurality of outlet passages, one of which is labelled 120. The end portion 107 has a conical inner surface (not labelled) for directing fuel to outlet apertures 104a, 104b. A set 108 of slots 109 extends around the periphery of wall portion 119 above outlet apertures 104a, 104b, the slots 109 extending vertically. A set 1 14 of circular gas vent apertures 113 is provided above slots 109. Grub screws 121 are used to attach the device 101 to a fuel tank filler neck.

[0097] A third embodiment of an inlet device in accordance with the present invention will now be described with reference to Figures 4 and 5. The inlet device is a fuel tank inlet device. The mesh insert 500 is the same as that described above in relation to the first embodiment of a device. The device is denoted generally with reference numeral 201. The device 201 comprises a body portion 202 extending from an inlet 203. The body portion 202 is provided with two sets 205a, 205b of outlet apertures (only two of which are labelled 204a, 204b) for the egress of fuel into a fuel tank, each set 205a, 205b of outlet apertures extending around the perimeter of the body portion 202. The end portion 207 is provided with a plurality of outlet passages (now shown). The end portion 207 has a conical inner surface (not labelled) for directing fuel to outlet apertures 204a, 204b, substantially the same as described above in relation to the device of Fig. 3. A set 208 of slots 209 extends around the periphery of wall portion 219 above outlet apertures 204a, 204b, the slots 209 extending vertically. A set 214 of elongate gas vent apertures 213 is provided above slots 209. Locking flange 250 is provided to secure the device 201 to a tank filler neck provided with a recess to receive such a flange. A second locking flange (not visible) is provided on the other side of the device 201. Grub screws (not shown) are used to secure the device 201 to a fuel tank filler neck so as to inhibit unwanted removal therefrom.

[0098] An example of an embodiment of an inlet device in accordance with the first and fourth aspects of the present invention will now be described with reference to Figures 6, 7, 8, 9 and 10. The inlet device is a fuel tank inlet device which is denoted generally by reference numeral 1001 and comprises a body portion 1002 extending from inlet 1003, and one or more outlet apertures (only one of which, 1004, is labelled). A set 1005 of outlet apertures 1004 is provided, the set of apertures extending around the perimeter of the body portion 1002. Each outlet aperture 1004 is elongate, extending lengthwise around the perimeter of the body portion 1002. Each slot-like aperture 1004 extends to an end portion 1007. The body portion 1002 comprises a substantially cylindrical wall portion 1019 which extends from the inlet 1003 to the end portion 1007. Body portion 1002 is machined from aluminium and is substantially rigid. End portion 1007 has inner 1021 and outer 1022 surfaces, both of which are substantially conical in overall shape (apart from the apertures formed in the surfaces). Fuel outlet passages (one of which is labelled 1020) are provided in the end portion 1007. Wall portion 1019 and end portion 1007 effectively form a "cage" into which a fuelling nozzle may be inserted. Fuel from a fuelling nozzle passes through the outlet apertures 1004 and the fuel outlet passages 1020 in the end portion 1007. The "cage" structure inhibits access to the fuel tank. Furthermore, the various apertures and passages provided in the device 1001 are sufficiently small to prevent passage there through of a siphon tube of a width which would allow removal of fuel from a fuel tank at a practical rate. The "cage" structure is formed by machining the wall portion 1019 and end portion 1007 from a block of aluminium, thereby providing a sturdy, yet lightweight, barrier.

[0099] The device 1001 further comprises an insert 501 comprising first 502 and second 503 insert end portions across the space defined by insert wall portion 504. The insert 500 is made from a mesh in the form of wire. The mesh insert 500 comprises the first 502 and second 503 insert end portions located between, and towards the bottom of, an approximately cylindrical insert wall 504. The first insert end portion 502 is located just above (in this case, about 2.5mm above) the bottom of the insert wall 504 so that a portion 505 of the mesh wall 504 is located below the first insert end portion 502. This portion 505 effectively provides a spacer between the first insert end portion 502 and the inner surface 1021 of the end portion 1007 as can be seen from Figure 6. The mean spacing between the inner surface 1021 and the bottom of the first insert end portion is about 2.5mm. The mean spacing between the first 502 and second 503 insert end portions is about 3 mm. The first 502 and second 503 insert end portions are shaped to have approximately the same shape as the inner surface 1021 of the end portion 1007. The insert wall 504 extends part- way up the device wall portion 1019.

[00100] A further set 1014 of apertures 1013 is provided above set 1005. The apertures 1014 are circular and are primarily provided to allow gas to leave the fuel tank during the fuelling process.

[00101] Device 1001 is provided with a plurality of screw-threaded apertures, one of which is labelled 1011. Grub screws are inserted through screw-threaded apertures to attach the device 1001 to a fuel tank.

[00102] A seal-forming washer (not shown) is provided to form a gas-tight seal when the device 1001 is mounted onto a fuel tank filler neck. [00103] The mesh insert 501 is formed from wire having a thickness of about

0.55mm. The sieve size is about 1.6mm (US mesh grade 12). The first 502 and second 503 mesh members are welded to the insert wall 501 which is formed by bending a sheet of mesh into a cylindrical shape and welding the edges of the sheet to form a cylinder.

[00104] A nozzle support is provided in the form of a single elongate member 600 in the form of a bar of circular cross-section. The nozzle support supports a fuelling nozzle in spaced relationship to the bottom of the device, thereby reducing the likelihood of fuel pooling or puddling. The nozzle support is located approximately half the way up the device, and extends from one portion of the wall to another portion of the wall, effectively forming a chord across the substantially cylindrical body portion. The nozzle support is located above the mesh insert 501, thereby inhibiting removal of the insert 501 from the device.

[00105] A further example of an inlet device in accordance with the first and fourth aspects of the present invention will now be described with reference to Figures 11 The device of Fig. 11 is essentially the same as that of Figs. 6 to 10, apart from the support. The support 700 comprises two mutually spaced elongate members 701, 702. Elongate member 701 is located immediately above insert 501 and thereby inhibits removal of insert 501. Elongate member 702 is located nearer the inlet of the device.

[00106] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.

[00107] The examples above describe a fuel tank inlet device. Those skilled in the art will realise that the inlet devices of the present invention may be fitted to other tanks to inhibit theft of liquids other than fuel.

[00108] The embodiments above show the two meshes being provided as part of an insert comprising an insert wall. The meshes need not be provided as part of an insert. For example, each of the meshes may be attached to the main body (at a wall, for example) of the inlet device. [00109] The embodiments above show the insert being attached to the main body of the inlet device. While this is desirable, it is by no means essential.

[00110] The embodiments of Figs. 1 to 5 above show the use of a bolt and rivet to attach the insert to the main body of the inlet device. Those skilled in the art will realise that other means of attachment may be used. For example, the insert may be welded to the main body of the inlet device. If a rivet is used, a spacer may be provided which provides an abutment for the rivet to inhibit excessive deformation of the first and second mesh formations.

[00111] The embodiments above show the use of an inlet device with a conical or frusto-conical surface to direct fuel to apertures in a side wall of the device. While such a surface is desirable, it is not essential.

[00112] Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.