EP1871631A1

EP1871631A1 - Fuel tank inlet device

Info

Publication number: EP1871631A1
Application number: EP06709737A
Authority: EP
Inventors: Richard Nigel Fowler
Original assignee: TruckProtect Ltd
Current assignee: TruckProtect Ltd
Priority date: 2005-04-04
Filing date: 2006-02-14
Publication date: 2008-01-02
Also published as: WO2006106283A1

Abstract

An inlet device (1) for a tank, the device comprising an attachment portion (2) adapted to allow the device to be secured to a tank or filler neck thereof and an inlet body portion (5) for the receipt of liquid, the inlet body portion comprising an inlet (12) for the ingress of liquid and an outlet for the egress of liquid into a tank, the inlet body portion comprising a wall portion (7) depending from a first end of the device at or in the vicinity of the inlet to an end portion (9) associated with a second end of the device, the end portion having an inner surface (9a) for the receipt of liquid and an outer surface (9b), the outlet being provided by a plurality of bores (10a-e) in a part (21) of the wall portion associated with the end portion and the inner surface of the end portion being shaped so as to direct liquid towards one or more of said bores, the inner surface of the end portion being provided with a surface of revolution for directing liquid towards one or more of said bores, one or more of said bores extending from a bore inlet (18) for the receipt of liquid to a bore outlet (19) for the egress of liquid, wherein the bore outlet has a greater cross-sectional area than the corresponding bore inlet.

Description

Fuel tank inlet device

The present invention relates to fuel tank inlet devices, particularly, but not exclusively, those fuel inlet devices that inhibit the theft of fuel from a fuel tank fitted with such a device.

Fuel tank inlet devices are known that inhibit the theft of fuel from fuel tanks. Many of these devices comprise an attachment portion to allow the device to be secured to a fuel tank and a body portion for the receipt of fuel that, in use, extends inside the fuel tank (typically of a vehicle) . The body portion is of sufficient size to accommodate a nozzle of a fuel delivery system. The body portion is typically provided with holes through which the fuel may flow into the fuel tank. The holes are sufficiently small so as to inhibit passage therethrough of a hose or the like for siphoning the fuel from the fuel tank. Such devices are often prone to backflow; fuel is not transmitted sufficiently quickly through the holes into the device, causing a back-pressure which may cause the fuelling nozzle to temporarily cease fuelling or may cause discharge of fuel from the fuel tank either by welling or spitting; this is obviously undesirable.

Devices have been modified in various ways in order to reduce or minimise the backflow problem. Some devices provide extra holes in the device; one device has no end wall, but rather a wedge-shaped member that allows passage therepast of fuel, but inhibits the passage therepast of a siphon tube. The device of Blau provides an end wall with a wedge shape which urges fuel to the sidewalls of the device. Such devices still present backflow problems, at least at very high speeds of filling. Furthermore, there are other possible problems with these known devices in relation to fitting and security.

The object of the first aspect of the present invention is to overcome or mitigate one or more of the above-mentioned problems .

In accordance with a first aspect of the present invention there is provided a fuel tank inlet device for inhibiting theft of liquid fuel from a fuel tank, the device comprising an attachment portion adapted to allow the device to be secured to a fuel tank or filler neck thereof and a fuel inlet body portion for the receipt of fuel, the fuel inlet body portion comprising an inlet for the ingress of fuel and an outlet for the egress of fuel into a fuel tank,

the fuel inlet body portion comprising a wall portion depending from a first end of the device at or in the vicinity of the inlet to an end portion associated with a second end of the device,

the end portion having an inner surface for the receipt of fuel from a nozzle and an outer surface,

wherein the outlet is provided by a plurality of bores in a part of the wall portion associated with the end portion and the inner surface of the end portion is shaped so as to direct fuel towards one or more of said bores. The device of the present invention provides for filling of fuel tanks at high flow rates whilst nonetheless securing against fuel theft.

The term "said bores" used hereafter refers to the plurality of bores in the part of the wall portion associated with the end portion. Hence, the terra ^ΛΛat least one of said bores" refers to at least one of the plurality of bores in the part of the wall portion associated with the end portion. The term "said ,bores" does not refer to apertures or other flow channels that may be found, for example, in the end portion.

The term "the part of the wall portion associated with the end portion" is that part of the wall portion that is in the vicinity of the end portion. Such a wall portion typically provides those flow channels that are closest to the end portion. In use, said bores are generally the lowest flow channels through which fuel may flow.

The term "bore" is not limited to those fluid flow paths that may be made by drilling or boring, and is not restricted to flow paths having a generally cylindrical shape. It includes fluid flow paths of a more general nature, such as those that may be made using milling. As such, the shape of the bore is not limited in any way, the bore permitting egress of fuel into the fuel tank from the inlet device.

It is preferred that the inner surface of the end portion is shaped so as to direct fuel towards the majority of said bores, and preferably all of said bores. It is preferred that the inner surface of the end portion is inclined towards the wall portion. It is preferred that more than one (and optionally each) of said bores faces a part of the inner surface of the end portion and that each of said parts is inclined towards the corresponding bore.

It is preferred that the inner surface of the end portion is provided with a surface of revolution for directing fuel towards one or more of said bores. A surface of revolution is a surface that may be generated by rotating a two- dimensional curve (the term "curve" including a straight line) about an axis. Such surfaces of revolution may, for example, be conical, frusto-conical, horn shaped (for example, Gabriel's horn) or paraboloid. The axis of revolution of the surface of revolution may be coincident with the longitudinal axis of the device.

The inner surface of the end portion is preferably provided with a conical, frusto-conical, pyramidal or frusto- pyramidal portion for directing fuel towards one or more of said bores. The sides of the conical, frusto-conical, pyramidal or frusto-pyramidal portion may be convex, concave or preferably straight. Such an arrangement provides an effective mechanism for facilitating the egress of fuel from the device into the fuel tank. "Pyramidal" means a shape having a polygonal base and triangular sides extending to an apex. Examples of such shapes are a tetrahedron and the classic four-sided, square based pyramidal shape of the ancient Egyptian pyramids. "Frusto-pyramidal" refers to a truncated pyramidal shape in the same way as "frusto- conical" refers to "conical". The conical, frusto-conical, pyramidal or frusto-pyramidal surfaces do not have to be azimuthally symmetrical; for example, a conical surface may not be a surface of revolution.

At least one (and preferably a plurality) of said bores may be adjacent to, or extend to, said end portion. The location of said bores adjacent to, or extending to, the end portion facilitates fast flow of fuel from the device to the fuel tank.

The outlet may be further provided by a plurality of apertures in the end portion. Apertures in the end portion further facilitate fuel flow from the device to the fuel tank. The outlet may further be provided by a plurality of apertures in the wall portion in addition to said bores provided in that part of the wall portion proximate to the end portion. Said apertures are, in use, above the part of the wall portion in proximity to the end portion. Said apertures assist in removing fuel from the device.

One or more (and preferably each) of said bores may extend from a bore inlet for the receipt of fuel from a nozzle to a bore outlet for the egress of fuel. The bore outlet may have a greater cross-sectional area than the corresponding bore inlet.

The cross-sectional area of said bore may increase continuously from the bore inlet to the corresponding bore outlet. Such flared bores decrease the resistance to flow of liquid compared to a conventional bore where the cross- sectional area at the bore inlet is the same as at the bore outlet . It is preferred that one or more (and preferably each) of said bores defines a bore surface in the wall portion. The bore surface is bounded by the bore inlet and the bore outlet. It is preferred that, in use, the bore surface has a lower bore surface portion and an upper bore surface portion. The lower bore surface portion may extend, in use, downwardly from the bore inlet to the bore outlet. In this case, the lower portion of the bore outlet is lower, in use, than the lower portion of the bore inlet. Such an arrangement aids fast egress of fuel from the inlet device.

It is preferred that the inner surface of the end portion is provided with a single (i.e. only one) surface of revolution for directing fuel to said bores, or a single conical, frusto-conical, pyramidal or frusto-pyramidal portion. This provides an effective structure for facilitating the egress of fuel from the device to the fuel tank.

The end portion is preferably provided with a border region between the wall portion and the said surface of revolution or conical, pyramidal, frusto-conical or frusto-pyramidal portion. This facilitates a simple manufacturing process.

The border region is preferably provided around the perimeter of said^' surface of revolution, the conical, pyramidal, frusto-conical or frusto-pyramidal portion. The border region may have a width of from 0.5 to 5mm, and more preferably from 1 to 3mm.

In the event that the end portion is provided with a conical or frusto-conical portion, it is preferred that the angle at the apex (or projected apex for a frusto-conical shape) as defined by θ=2tan^"1 (d/2h) is from 90 to 140 degrees, and preferably from 100 to 120 degrees, where "d" is the diameter of the base of the cone and "h" is the height of the cone (or projected height of the cone in the case of a frusto-conical shape) . In the event that the end portion is provided with a pyramidal or frusto-pyramidal region, the angle between a face of the pyramid and the adjacent wall portion may be from 45 to 70 degrees and preferably from 50 to 60 degrees.

It is preferred that the outer surface of the end portion is shaped to correspond to the shape of the inner surface of the end portion. For example, if the inner surface of the end portion is substantially conical, it is preferred that the outer surface of the end portion has a similar conical shape. In this manner, the thickness of the end portion may be reduced; this is advantageous is helping to reduce backflow.

It is preferred at least one of said bores is provided with a blocking member for inhibiting ingress of a siphon tube into the fuel tank.

It is preferred that more than one (and more preferably each) of said bores is provided with a blocking member. It is preferred that each of said bores that is provided with a blocking member is associated with the same blocking member.

It is preferred that the device is provided with a single (i.e. only one) blocking member.

At least one of the blocking members may be readily removable. It is further preferred that at least one of the of the blocking members may be readily reattachable to the device.

It is preferred that at least one of the blocking members is resiliently deformable. This facilitates the removal from, and reattachment to, the device.

It is preferred that at least one blocking member abuts against the outer surface of the wall portion. Such an arrangement is effective in facilitating the egress of fuel into the fuel tank. The location of the blocking member against the outer surface of the wall portion is effective in permitting egress of fuel into the fuel tank. The outer surface of the wall portion may be provided with a recess for receiving the blocking member.

Such an arrangement is effective in securely locating a blocking member.

At least one blocking member may be arcuate. It is preferred that at least one blocking member is annular. It is preferred that said blocking member comprises a split ring.

It is preferred that the attachment portion and the body portion are integrally formed. The attachment portion and body portion may be machined from a block of metal, such as aluminium.

Alternatively, the attachment portion may be formed separately from the wall portion. The wall portion may be formed from metal sheet. The end portion may, at its thickest part, be from 2mm to 20mm thick, preferably from 2mm to 10mm thick and most preferably 5mm to 8mm thick.

The inlet device may be provided with a plurality of engagement members, each of which may be retracted from a first position in which each engagement member abuts the filler neck or fuel tank so as to inhibit removal of the device from a fuel tank to a second, retracted position in which the device may be removed from the fuel tank.

Such a device may be fitted to a fuel tank without puncturing the fuel tank or filler neck and may be removed from the fuel tank.

The attachment portion may comprise one or more lugs, such as those that form a male part of a bayonet fitting. A bayonet fitting is a convenient way of attaching the device to the fuel tank because fuel tanks are often provided with a fuel-cap receiving portion that comprises a female part of a bayonet fitting.

It is preferred that the end of each engagement member abuts against the filler neck or fuel tank when in the first position.

It is preferred that, in the first position, the engagement members extend laterally or radially from the body portion or the attachment portion. It is preferred that, in the first position, the engagement members engage an inner surface of the fuel tank or filler neck.

The inlet device in the region of the engagement members may have an inside for the receipt of fuel from a fuel nozzle. It is preferred that the engagement members in the first position project outside the device. It is preferred that, in the second position, the engagement members are retracted at least partially inside the device. The engagement members may be accessible from the inside of the device so as to be movable between the first and second positions. The engagement members may be provided with a configuration for the receipt of a tool (such as a hexagonal aperture or cross-shaped aperture) .

It is preferred that at least one of the engagement members is elongate.

Each of the engagement members may be provided with a screw thread to facilitate movement of the engagement member from the first position to the second position.

It is preferred that one or more blanking members is provided to inhibit access to the engagement members when the engagement members are in the first position so as to inhibit the user from moving the engagement member from the first position to the second position. Whilst it may be desirable for the device to be removable from a fuel tank, it is often desirable to make removal difficult so that the device may not be removed without effort. It is preferred that at least one blanking member is provided on the inside of the device. It is preferred that at least one blanking member inhibits access to the configuration for the receipt of a tool (if such a configuration is provided on the engagement members) .

It is preferred that one blanking member is associated with a plurality and preferably all of the engagement members. In this latter case, one blanking member inhibits access to all engagement members .

It is preferred that at least one of the blanking members is arcuate, and preferably annular or semi-annular. This provided a convenient geometry for many devices.

It is preferred that at least one of the blanking members has an outer surface and an inner surface.

It is preferred that the inner surface of at least one blanking member is, in use, substantially flush with an adjacent surface. It is preferred that the outer surface of at least one blanking member is stepped. At least one blanking member may be provided with an upper portion and a lower portion, the maximum outer dimension of the upper portion being greater than that of the lower portion. This is particularly effective when the blanking member is annular.

It is preferred that at least blanking member frictionally engages with a surface of the fuel inlet body portion or the attachment portion to resist removal of the at least one blanking member. This resists removal of the blanking member from the fuel inlet body portion or the attachment portion. It is preferred that at least one blanking member is a tamper-evident blanking member. At least one blanking member may be frangible or readily plastically deformable. This is so that attempting to remove the blanking member may cause it to break, for example, by being plastically deformed into a folded configuration. The deformed or broken blanking member cannot subsequently be placed back in position in the device, and it is therefore evident that the device has been tampered with.

The wall portion may provide a convenient tubular structure. The wall portion may be generally cylindrical in shape. Examples of such shapes include a right circular cylindrical shape or a square-section cylindrical shape.

There are many conventional methods for securing an anti- theft fuel inlet device to a fuel tank or filler neck so as to resist removal of the device. One such method is by using fixtures that penetrate the fuel tank or filler neck; this is obviously undesirable because the holes made by such fittings may allow potentially dangerous fuel to escape from the fuel tank, even when the holes are "filled" with rivets or the like. Escape of fuel from fuel tanks may allow fuel to seep onto roads causing a slip hazard. Puncturing the tank also potentially renders the tank more vulnerable to larger-scale leakage in the event of accidents when rivets or other such fittings may snap or loosen, leaving a clear channel for leakage. Another method is to use some form of adhesive. Such adhesives may permanently attach the device to the fuel tank and this may not be desired. Furthermore, if the device is removed, residues of adhesive may be left on the device and/or tank which require removal. Many adhesives also take a considerable time to cure and a fuel tank should not be fuelled until curing is complete. Adhesives may degrade in time to produce an imperfect seal. Furthermore, even very strong adhesives do not typically resist removal by a twisting action, as may be imparted using a stilson tool or large spanner as a lever. Adhesives typically require each surface to be adhered to be very clean. It is also difficult to assess how much adhesive to use; too little or too much adhesive may cause problems.

Several methods have been proposed to overcome the problems of puncturing the fuel tank or using adhesive. One such device uses a spring-loaded wedge that allows a device with a bayonet fitting to be turned into place, but does not allow the device to be readily removed. This device also has barbs that inhibit removal of the device. Such barbs are designed to either prevent removal of the device or would apparently be broken or at least damaged if the device is removed.

The fuel tank inlet device of the second aspect of the present invention seeks to overcome or mitigate against at least one of the problems presented in the prior art.

In accordance with the second aspect of the present invention there is provided a fuel tank inlet device for inhibiting theft of liquid fuel from a fuel tank, the device comprising a fuel inlet body portion for the receipt of fuel, the fuel inlet body portion comprising an inlet for the ingress of fuel and an outlet for the egress of fuel into a fuel tank, the inlet device being provided with a plurality of engagement members, each of which may be retracted from a first position in which each engagement member abuts the filler neck or fuel tank so as to inhibit removal of device from fuel tank to a second, retracted position in which the device may be removed from the fuel tank.

The device may comprise an attachment portion adapted to allow the device to be secured to a fuel tank or filler neck thereof.

It is preferred that, in the first position, the engagement members extend laterally or radially from the fuel inlet body portion or the attachment portion.

It is preferred that, in the first position, each engagement member (and preferably the end thereof) abuts an inner surface of the fuel tank or filler neck. The inlet device in the region of the engagement members may have an inside for the receipt of fuel from a fuel nozzle. It is preferred that the engagement members in the first position project outside the device. It is preferred that, in the second position, the engagement members are retracted at least partially inside the device. The engagement members may be accessible from the inside of the device so as to be movable between the first and second positions. The engagement members may be provided with a configuration for the receipt of a tool (such as a hexagonal or cross-shaped aperture) .

It is preferred that each of the engagement members is elongate.

It is preferred that one or more blanking members is provided to inhibit access to the engagement members when the engagement members are in the first position so as to inhibit the user from moving the engagement member from the first position to the second position. Whilst it may be desirable for the device to be removable from a fuel tank, it is often desirable to make removal difficult so that the device may not be removed without effort, suitable tools and skill. It is preferred that at least one blanking member is provided on the inside of the device. It is further preferred that at least one blanking member inhibits access to the configuration for the receipt of a tool (if such a configuration is provided on the engagement members) . It is preferred that one blanking member is associated with a plurality and preferably all of the engagement members. In this latter case, one blanking member inhibits access to all engagement members .

It is preferred that at least one of the blanking members is arcuate, and preferably annular or semi-annular. This provided a convenient geometry for many devices .

It is preferred that the inner surface of at least one blanking member is, in use, substantially flush with an adjacent surface. It is preferred that the outer surface of at least one blanking member is stepped. At least one blanking member may be provided with an upper portion, and a lower portion, the maximum outer dimension of the upper portion being greater than that of the lower portion. This is particularly effective when the blanking member is annular.

It is preferred that at least one blanking member frictionally engages with a surface of the fuel inlet body portion or the attachment portion to resist removal of the at least one blanking member. This resists removal of the blanking member from the fuel inlet body portion.

It is preferred that at least one blanking member is a tamper-evident blanking member. At least one blanking member may be frangible or readily plastically deformable. This is so that attempting to remove the blanking member may cause it to break, for example, by being plastically deformed into a folded configuration. The deformed or broken blanking member cannot subsequently placed back in position in the device, and it is therefore evident that the device has been tampered with.

The fuel inlet body portion may comprise a wall portion depending from a first end of the device at or in the vicinity of the inlet to an end portion associated with a second end of the device, the end portion having an inner surface for the receipt of fuel from a nozzle and an outer surface, wherein the outlet is provided by a plurality of bores in the region of the wall portion associated with the end portion and the inner surface of the end portion is shaped so as to direct fuel towards one or more of said bores.

This provides a convenient arrangement for facilitating the rapid egress of fuel from the inlet device to the fuel tank.

The fuel inlet device of the second aspect of the present invention may comprise those features described above in relation to the fuel inlet device of the first aspect of the present invention. For example, the inner surface of the end portion may be provided with a surface of revolution or a conical, frusto-conical, pyramidal or frusto-pyramidal portion for directing fuel to said bores.

The inlet device of the present invention will now be described with reference to the following figures of which: Figure 1 is a schematic side-on view of an embodiment of a device in accordance with the present invention; Figure 2 is a schematic cross-section through the device of Figure 1; Figure 3 is an view of a portion of the device of Figure 1 showing grub-screws that are used to inhibit unwanted removal of the device and the blanking member that is used to inhibit access to the screws;

Figure 4a shows a perspective view of one of said bores in the part of the wall portion associated with the end portion; and

Figure 4b shows a cross-sectional view through said bore of Figure 4a.

Figures 1 and 2 show a side-on view and a cross-sectional view respectively of an embodiment of an inlet device in accordance with the present invention, wherein the inner surface of the end portion of the device is provided with a conical portion for directing the fuel to the wall portion. The fuel tank inlet device is shown generally by reference numeral 1 and inhibits theft of liquid fuel from a fuel tank to which the device is attached. The device 1 comprises an attachment portion shown generally by reference numeral 2 adapted to allow the device 1 to be secured to a fuel tank or filler neck thereof, a fuel inlet body portion shown generally by the reference numeral 5 for the receipt of fuel, the fuel inlet body portion 5 comprising an inlet 12 for the ingress of fuel and an outlet for the egress of fuel into a fuel tank. The fuel inlet body portion 5 comprises a wall portion 7 depending from a first end of the device associated with the inlet 12 to an end portion 9 associated with a second end of the device 1. The end portion 9 has an inner surface 9a associated with the receipt of fuel from a nozzle and an outer surface 9b associated, in use, with a fuel tank, and the inner surface 9a of the end portion 9 is shaped so as to direct fuel towards bores (exemplified by reference numerals 10a-e) in the part 21 of the wall portion 7 associated with the end portion 9.

The device 1 is generally made from aluminium and may essentially be made by machining from a single block of metal. This enables the device to be made easily and cheaply. The fuel inlet body portion 5 is of a generally tubular form, having an inner surface 22 associated with the receipt of fuel from a nozzle and an outer surface 23 that is, in use, associated with a fuel tank. The inner 22 and outer 23 surfaces are separated by a cylindrical wall portion 7 forming the sides of the fuel inlet body portion and an end portion or end wall 9 at the end of the fuel inlet body portion 5 remote from the inlet 12. The cylindrical wall is generally about 7mm thick. Holes 6 are provided to allow fumes to vent from the device.

The end portion is typically around 7mm thick. Such a thickness resists physical damage to the end portion 9 that may be caused by trying to force a bar or rigid object through the end portion so that a siphon tube may be inserted through a damaged device into the fuel tank. The outer surface 9b of the end portion is shaped to correspond to the inner surface 9a of the end portion i.e. the outer surface 9b is also provided with a conical portion. This arrangement ensures that the thickness of the end portion is large enough to resist attack but thin enough to permit fuel to egress into the fuel tank at a desired rate. It has been found that if the outer surface is not so shaped (for example if the outer surface is flat) then the fluid flow path through the end portion itself is longer, resulting is potentially unacceptable back flow.

Apertures are provided in the end portion 9 and are exemplified by reference numerals 14. The apertures 14 are provided to permit egress of fuel from the device. The apertures 14 extend from the inner surface 9a to the outer surface 9b of the end portion 9, and are substantially parallel to the longitudinal axis of the device.

Apertures (exemplified by reference numeral 8) are provided in the region of the wall portion 7 above the end portion 9. These apertures are elongate, the long axis of each aperture being substantially parallel to the longitudinal axis of the device 1. Such geometry is effective at facilitating fast egress of fuel into the fuel tank. The end portion 9 does not direct fuel to apertures 8.

Said bores exemplified by reference numerals 10a-e are in the lower part 21 of the wall portion, proximate to the end portion 9. The inner surface 9a of end portion 9 is provided with a conical portion which is readily visible in Figure 2. The angle θ (as shown in Figure 2) is about 110.degrees. The conical shape directs incoming fuel towards said bores 10a-e formed in part 21 of the wall portion 7 proximate to the end portion 9. The geometry of each of said bores 10a-e is shown in more detail in Figures 4a and 4b. Figure 4b is a cross- sectional view taken through plane 0-0 of said bore shown in perspective in Figure 4a. Each bore is provided with a bore inlet 18 associated with the inner surface 22 of the wall portion and a bore outlet 19 associated with the outer surface 23 of the wall portion 7. In use, a fuel nozzle is inserted into the fuel inlet device and fuel is discharged into the device and out into the fuel tank through said bores 10a-e. The fuel enters the bore inlet 18, passes through the bore and into the fuel tank via the bore outlet 19. The cross-sectional area of the bore outlet 19 is greater than the bore inlet 18 and this helps prevent backflow in the device. Furthermore, referring to Figure 4, the bore surface 20 comprises an upper portion 20b and a lower portion 20a. The lower portion 20a extends downwardly from the bore inlet 18 to the bore outlet 19. This also helps inhibit backflow in the device. The angle, α, is about 45 degrees.

Referring to Figures 1 and 2, a blocking member 11 in the form of a split ring is provided for all of said bores 10a-e in the part 21 of the wall portion 7 associated with the end portion 9. The blocking member 11 is located in a recess formed in the outer surface 23 of the wall portion 7. The blocking member inhibits passage of a siphon tube through said bores 10a-e. Furthermore, by being placed on the outer surface of the device, the resistance to flow is less than if it was placed on the inner surface of the device. Such a removable and replaceable blocking member is readily available and simple to fit. The blocking member is relatively narrow having a width of about l-2mm or so; a thin blocking member does not significantly inhibit egress of fuel from the device, but inhibits ingress into the fuel tank of a siphon tube. A blocking member that is integral with the wall portion could be used, but manufacture of a narrow, integral blocking member would be difficult and expensive. The blocking member 11 has been omitted from Figures 4a and 4b for the purpose of clarity.

Referring to Figures I₁. 2 and 3, the device 1 is provided with a plurality of engagement members 4a-c, each of which may be retracted from (i) a first position in which an end of each engagement member engages the filler neck or fuel tank, so as to inhibit removal of device from fuel tank to (ii) a second, retracted position in which the device may be removed from the fuel tank. In each of Figures 1, 2 and 3 the engagement members 4a-c (in this case, grub screws) are in the first position. In this position, the ends of the grub screws engage with the inner surface of the filler neck of a fuel tank. This engagement inhibits removal of the device from the fuel tank. A blanking member 15 is provided to inhibit access to the engagement members 4a-c. Figure 2 shows the blanking member 15 in position. Figure 3 is a partially exploded view with the blanking member 15 removed from the device in order to show its shape. Note that only a part of the device is shown in Figure 3 for the purpose of clarity. The blanking member is annular in shape (see Figure 3) and has an upper portion 15a that has a larger external diameter than a lower portion 15b. The blanking member 15 is friction-fitted into place in the fuel inlet body portion 5 so as to be difficult to remove therefrom. Contrary to the suggestion of Figure 2, the inner surface of the blanking member 15 is flush with the inner surface 22 of the fuel inlet body portion. The three engagement members 4a-c are spaced equidistantly around the circumference of the fuel inlet body portion 5. In order to remove the device 1 from a fuel tank, the blanking member 15 is removed using a sharp-edged or bladed instrument, such as a chisel. The blade of the chisel is placed against the edge of the blanking member and the chisel hit hard. This causes the breakage or more typically the plastic deformation of the blanking member. The blanking member cannot be put back into the device. This provides a blanking member that is tamper-evident. The blanking member is made of aluminium and is readily plastically deformable.

The ends of the engagement members 4a-c (formerly covered by the blanking member 15) are provided with a slot or hexagonal recess for the receipt of a suitable removal tool. The engagement members 4a-c may then be accessed from the inside 16 of the device 1 and may be moved into a retracted position in which the ends of the engagement members 4a-c do not engage with the filler pipe and thus the device 1 may be removed from the fuel tank.

In order to install the device 1, the engagement members would be retracted, the device located in place by inserting the lugs 3a, b in the appropriate groove in the filler neck or in a fitment used to receive a filler cap (such a fitment having a female part of a bayonet fitting) . The device would then be rotated to urge the lugs into a locking position. An appropriate tool (such as an Allen key or a screwdriver) would then be used to move the engagement members 4a-c into the first position in which the end of each engagement member 4a-c engage with the filler neck of the fuel tank. Once the engagement members 4a-c are in the first position the blanking member 15 is urged into place (see Figure 2) .

Claims

1. A fuel tank inlet device for inhibiting theft of liquid fuel from a fuel tank, the device comprising an attachment portion adapted to allow the device to be secured to a fuel tank or filler neck thereof and a fuel inlet body portion for the receipt of fuel, the fuel inlet body portion comprising an inlet for the ingress of fuel and an outlet for the egress of fuel into a fuel tank,

the outlet being provided by a plurality of bores in a part of the wall portion associated with the end portion and the inner surface of the end portion being shaped so as to direct fuel towards one or more of said bores,

the inner surface of the end portion being provided with a surface of revolution for directing fuel towards one or more of said bores, one or more of said bores extending from a bore inlet for the receipt of fuel from a nozzle to a bore outlet for the egress of fuel, wherein the bore outlet has a greater cross-sectional area than the corresponding bore inlet.

2. A fuel tank inlet device according to claim 1 wherein the surface of revolution comprises a conical, frusto-conical, paraboloidal or horn-shaped portion for directing fuel towards one or more of said bores.

3. A fuel tank inlet device according to claim 1 or claim 2 wherein at least one of said bores is adjacent to, or extends to, said end portion.

4. A fuel tank inlet device according to any one of claims 1 to 3 wherein each bore inlet and bore outlet bounds a bore surface in the wall portion, the bore surface, in use, having a lower bore surface portion and an upper bore surface portion, wherein the lower bore surface portion extends downwardly from the bore inlet to the bore outlet.

5. A fuel tank inlet device according to any preceding claim wherein the inner surface of the end portion is provided with a single (i.e. only one) surface of revolution for directing fuel towards one or more of said bores.

6. A fuel tank inlet device according to any preceding claim wherein the end portion is provided with a border region between the wall portion and the surface of revolution for directing fuel towards one or more of said bores.

7. A fuel tank inlet device according to any preceding claim wherein the end portion is provided with a conical or frusto-conical region and the angle at the apex (or projected apex for a frusto-conical shape) as defined by θ=2tan^~1(d/2h) is from 100 to 120 degrees, where "d" is the diameter of the base of the cone and "h" is the height of the cone (or projected height of the cone in the case of a frusto-conical shape) .

8. A fuel tank inlet device according to any one preceding claims wherein the outer surface of the end region is shaped to correspond to the inner surface of the end region.

9. A fuel tank inlet device according to any preceding claim further comprising at least one blocking member to inhibit ingress of a siphon tube into the fuel tank, wherein at least one of said bores is provided with a blocking member.

10. A fuel tank inlet device according to claim 9 wherein at more than one of said bores is provided with a blocking member.

11. A fuel tank inlet device according to claim 9 or 10 wherein the device is provided with a single blocking member.

12. A fuel tank inlet device according to claim 11 wherein the blocking member is readily removable.

13. A fuel tank inlet device according to claim 11 or 12 wherein the blocking member is resiliently deformable.

14. A fuel tank inlet device according to any one of claims 11 to 13 wherein the blocking member abuts against the outer surface of the wall portion, the blocking member being received in a recess provided in the outer surface of the wall portion.

15. A fuel tank inlet device according to any one of claims 11 to 14 wherein the blocking member is arcuate.

16. A fuel tank inlet device according to any preceding claim further comprising a plurality of engagement members, each of which may be retracted from a first position in which the engagement member abuts a filler neck or fuel tank so as to inhibit removal of device from fuel tank to a second, retracted position in which the device may be removed from the fuel tank.

17. A fuel tank inlet device according to claim 16 wherein, in the first position, each engagement member abuts an inner surface of the fuel tank or filler neck.

18. A fuel tank inlet device according to claim 16 or claim 17 wherein the inlet device in the region of the engagement members has an inside for the receipt of fuel from a fuel nozzle, the engagement members in the first position projecting outside the device,

wherein in the second position the engagement members are retracted at least partially inside the device.

19. A fuel inlet device according to any one of claims 16 to 18, wherein each engagement member is elongate and is provided with a configuration for the receipt of a tool.

20. A fuel tank inlet device according to claim 18 or 19 when dependent on claim 18 wherein the engagement members are accessible from the inside of the device so as to be movable between the first and second positions.

21. A fuel tank inlet device according to any one of claims 16 to 20, each of the engagement members being provided with a screw thread to facilitate movement of the engagement member from the first position to the second position.

22. A fuel tank inlet device according to any one of claims 16 to 21 further provided with one or more blanking members for inhibiting access to the engagement members when the engagement members are in the first position so as to inhibit the user from moving the engagement member from the first position to the second position, wherein the one or more blanking members are frangible or readily plastically deformable.

23. A fuel tank inlet device according to claim 22 wherein a single blanking member is associated with all of the engagement members .

24. A fuel tank inlet device according to claim 22 or claim 23 wherein at least one blanking member is, in use, provided on the inside of the device.

25. A fuel tank inlet device according to claim 19 and any one of claims 22 to 24 when dependent on claim 19 wherein, in use, at least one blanking member inhibits access to the configuration for the receipt of a tool .

26. A fuel tank inlet device according to any one of claims 22 to 25 wherein at least one of the blanking members is arcuate .

27. A fuel tank inlet device according to any one of claims 22 to 26 wherein at least one of the blanking members has an outer surface that is, in use, associated with at least one of the engagement members and an inner surface, wherein the inner surface of at least one blanking member is, in use, substantially flush with an adjacent surface.

28. A fuel tank inlet device according to any one of claims 22 to 27 comprising a single blanking member which is annular, the blanking member being provided with an upper portion and a lower portion, the maximum outer dimension of the upper portion being greater than that of the lower portion.

29. A fuel tank inlet device according to any one of claims 22 to 28 wherein at least one blanking member frictionally engages with a surface of the fuel inlet body portion or the attachment portion to resist removal of the at least one blanking member.

30. A fuel tank inlet device according to any preceding claim wherein the wall portion has a cylindrical tubular shape.

31. A fuel tank inlet device according to any preceding claim wherein the attachment portion and the body portion are integrally formed.

32. A fuel tank inlet device according to any preceding claim wherein the outlet is further provided by a plurality of apertures in the end portion.

33. A fuel tank inlet device for inhibiting theft of liquid fuel from a fuel tank, the device comprising a fuel inlet body portion for the receipt of fuel, the fuel inlet body portion comprising an inlet for the ingress of fuel and an outlet for the egress of fuel into a fuel tank,

the inlet device being provided with a plurality of engagement members, each of which may be retracted from a first position in which each engagement member abuts a filler neck or fuel tank so as to inhibit removal of device from fuel tank to a second, retracted position in which the device may be removed from the fuel tank.

34. A fuel tank inlet device according to claim 33 further provided with one or more blanking members for inhibiting access to the engagement members when the engagement members are in the first position so as to inhibit the user from moving the engagement member from the first position to the second position.

35. A fuel tank inlet device according to claim 34 wherein a single blanking member is associated with all of the engagement members .