WO2010043874A1

WO2010043874A1 - Fuel tank inlet device

Info

Publication number: WO2010043874A1
Application number: PCT/GB2009/002480
Authority: WO
Inventors: Ryan Wholey; Matthew Rose; Richard Forster
Original assignee: Tiss Limited
Priority date: 2008-10-15
Filing date: 2009-10-15
Publication date: 2010-04-22
Also published as: GB0818896D0; GB201108104D0; GB2476636A

Abstract

An anti-siphon fuel tank inlet device (30) comprises a generally tubular body (31) defining an inlet aperture at one end and one or more fuel flow apertures (34) remote from said inlet aperture. The device (30) also comprises means supported by the tubular body (31) for inhibiting the passage of a siphon tube through the tubular body (31) and an internal annular flange extending radially inwards into the tubular body (31) and defining a central opening for receiving the nozzle of a fuel dispenser. The device (30) further comprises means for opening and closing said opening, said means comprising a closure flap (41) which is spring biased into a closed position in which it bears against a face of the annular flange, the closure flap being movable against the spring biasing force into an open position to allow insertion of the nozzle of a fuel dispenser through said opening.

Description

FUEL TANK INLET DEVICE

The present invention relates to inlets for fluid tanks such as a vehicle fuel tank. In particular, the present invention relates to an anti-siphon inlet device for vehicle fuel tanks.

The theft of fuel by siphoning from the fuel tanks of vehicles, and in particular commercial road vehicles, is a recognised problem which has been addressed in the prior art by provision of a fluid tank inlet device incorporating structure to prevent insertion of a siphon tube into the tank. Such devices may be referred to as anti-siphon inlet devices.

Examples of known anti-siphon inlet devices which may be incorporated in an otherwise conventional fuel tank, or may be retrofitted to a conventional vehicle fuel tank inlet, are for instance disclosed in WO2007/110640. Various embodiments of the anti-siphon device disclosed, which comprise a tubular body which in use is secured to the normal tank inlet so that its outlet end extends a short distance into the tank. The tubular inlet is designed to receive a conventional fuel dispensing nozzle. An apertured baffle plate (e.g. metal grill) is provided within the tubular body to prevent insertion of a siphon tube but permit fuel flow through the tubular body. In one embodiment a float valve assembly is supported beyond the outlet end of the tubular inlet body to allow fuel to flow through the device into the tank. An obstruction is provided in a housing intermediate the tubular body and float valve to protect the float valve from tampering. In a simpler embodiment without the valve or additional obstruction, fuel flow apertures are provided in the wall of the tubular body above the baffle. Both embodiments are provided with a splash guard adjacent the inlet end of the tubular body.

The splash guard comprises an internal annular flange which extends inwardly from cylindrical wall of the tubular body and defines a circular opening of sufficient size to receive a conventional fuel dispenser nozzle whilst leaving a small air gap. The flange functions very effectively as a guard against splash back as fuel is dispensed into the tank through the inlet device. The gap between the flange and the dispenser nozzle ensures that sufficient air/fumes can escape from the tank to allow the tank to fill effectively. It is an object of the present invention to provide an improved anti-siphon fuel tank inlet device.

According to the present invention there is provided an anti-siphon fuel tank inlet device comprising a generally tubular body defining an inlet aperture at one end and one or more fuel flow apertures remote from said inlet aperture; means supported by the tubular body for inhibiting the passage of a siphon tube through the tubular body; an internal annular flange extending radially inwards into the tubular body and defining a central opening for receiving the nozzle of a fuel dispenser; and means for opening and closing said opening, said means comprising a closure flap which is spring biased into a closed position in which it bears against a face of the annular flange, the closure flap being movable against the spring biasing force into an open position to allow insertion of the nozzle of a fuel dispenser through said opening.

In some embodiments the face of the annular flange which the closure flap bears against when in said closed position faces away from the inlet aperture. In other embodiments the face of the annular flange which the closure flap bears against when in said closed position faces towards the inlet aperture.

In some embodiments the means for opening and closing said opening comprises a single closure flap.

In some embodiments the closure flap is generally circular. In other embodiments the closure flap is generally D-shaped.

In some embodiments an arm with a free end depends from the closure flap, the arm being pivotally mounted to the tubular body, by a portion intermediate its free end and the closure flap; and wherein the free end of the arm is linked to an anchor portion of the tubular member by a resilient biasing means. In some embodiments the arm passes though an aperture in the tubular body such that the free end of the arm is outside the tubular member. In some embodiments the closure flap comprises an engagement portion which may be pulled to move the closure flap from the closed position to the open position. In some embodiments the engagement portion of the closure flap is linked to a filler cap via a flexible elongate member.

In some embodiments the means for opening and closing said opening includes a second closure flap. In some embodiments said second closure flap is spring biased into a closed position in which it bears against a face of the annular flange facing away from the inlet aperture, the second closure flap being movable against the spring biasing force into an open position to allow insertion of the nozzle of a fuel dispenser through said opening. In some embodiments when said closure flap and said second closure flap are in their closed positions, the closure flap and second closure flap abut one another. In some embodiments the closure flap and second closure flap have substantially the same configuration. In some embodiments the closure flap and second closure flap are generally semicircular. In other embodiments the closure flap and second closure flap are generally rectangular.

In some embodiments the spring bias force is provided by a helical torsion spring.

In some embodiments the closure flap and/or second closure flap is pivotably mounted to the annular flange. In other embodiments the closure flap and/or second closure flap is pivotably mounted to the tubular body.

In some embodiments the closure flap is pivotably mounted to a bracket which is in turn mounted to the annular flange or tubular body respectively. In some embodiments the closure flap is mounted on said bracket such that it has a degree of movement in an axial direction under said spring bias force to assist in correctly seating the closure flap against the annular flange.

In some embodiments the at least one closure flap and/or the annular flange is provided with a seal member to provide a fluid tight seal when the closure flap is in the closed position. In some embodiments the annular flange comprises a ring fabricated separately from the tubular body and secured therein. In some embodiments the ring is removably secured within the tubular body.

In some embodiments a float valve assembly is further provided and is supported by the tubular body and including a float member. In some embodiments the anti-siphon device further comprises an obstruction located within a housing disposed between the tubular body and the float valve assembly, wherein the obstruction blocks line of sight from the tubular body to the float member.

In some embodiments the anti-siphon device comprises a plurality of fuel flow apertures provided in the wall of the tubular body and wherein said means for inhibiting insertion of a siphon tube comprises a baffle. In some embodiments the baffle blocks the end of the tubular body remote from the inlet aperture and is optionally provided with one or more fuel flow apertures.

Other preferred features of the invention will become apparent from the description below.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic axial cross-section of a first known anti-siphon inlet device;

Figure 2 is a schematic axial cross-section of a second known anti-siphon inlet device;

Figure 3a is a side view of an anti-siphon device in accordance with an embodiment of the present invention;

Figure 3b is a plan view from below of the anti-siphon device of figure 3a;

Figure 3c is a plan view from above of the anti-siphon device of figure 3a; Figures 4a to 4c are views corresponding to figures 3 a to 3 c but showing a closure flap of the anti-siphon device in an open position;

Figures 5 a to 5 d show a splash guard/closure flap of the anti-siphon device of figures 3 and 4 with the closure flap in a closed position;

Figures 6a to 6d show the splash guard/closure flap of figures 5a to 5d with the closure flap in an open position;

Figure 7 shows a schematic cross-sectional view of a second embodiment of an anti-siphon device in accordance with the present invention with a closure flap in an open position;

Figure 8 shows the anti-siphon device of figure 7 with the closure flap in a closed position.

Figure 9 shows a schematic cross-sectional view of a third embodiment of an anti-siphon device in accordance with the present invention with a closure flap in a closed position;

Figure 10 shows the anti-siphon device of figure 9 with the closure flap in an open position;

Figure 11 shows a plan view from above of the anti-siphon device shown in figures 9 and 10 with the closure flap in a closed position;

Figure 12 shows a plan view from above of the anti-siphon device shown in figures 9, 10 and 11 with the closure flap in an open position;

Figure 13 shows a schematic cross-sectional view of a fourth embodiment of an anti- siphon device in accordance with the present invention with a pair of closure flap portions in a closed position;

Figure 14 shows the anti-siphon device of figure 13 with the pair of closure flap portions in an open position; Figure 15 shows a pian view from above of the anti-siphon device shown in figures 13 and 14 with the closure flap portions in a closed position;

Figure 16 shows a plan view from below of a splash guard arrangement, with the closure flap portions in a closed position, which forms part of the anti-siphon device shown in figures 13, 14 and 15;

Figure 17 shows a plan view from above of an alternative splash guard arrangement which may be used in the anti siphon device shown in figures 13, 14 and 15; and

Figure 18 shows a plan view from below of the splash guard arrangement shown in figure 17.

Figure 1 illustrates a first known anti-siphon device as for instance disclosed in WO2007/1 10640 mentioned above and incorporated herein by reference. The device 1 is adapted for fitting to a fluid tank 10 and comprises a substantially straight tubular body 5, an attachment means 2 at its inlet end and a grill or baffle 3 to permit the flow of liquid through the body 5, but block the passage of a siphon tube at its outlet end. The baffle 3 comprises a metal plate, provided with a plurality of fuel flow holes 3a, which is securely attached across the tubular body 5.

The anti-siphon inlet device 1 includes a float valve comprising a float ball 6 held within a float cage 7. The float ball is a spherical hollow plastics ball. The float valve is arranged to allow the float ball 6 to be move from an open position (as for instance shown in figure 1) to a closed position (blocking the outlet of the tubular body 5) when fuel rises above the float cage 7. It will be appreciated that when the float valve is "closed" it is still possible to fill the tank with further fuel as the fuel pressure entering the tank opens the valve against its buoyancy. The body 5 is provided with a plurality of vent outlets 9 spaced around its circumference adjacent to the attachment means 2. The vents 9 assist the filling of the tank by allowing gas to escape the tank as it is displaced by fuel.

In addition to the inlet body 5, and the float valve assembly 7, the inlet device also includes an anti-tamper means 11 disposed between the end of the tubular body 5 and the float valve cage 7. The anti -tamper means comprises an obstruction 12 located within a housing configured to prevent insertion of an elongate rigid member through the inlet body 5, through an aperture 3 a in the baffle 3, and into the float valve to displace the float member 6.

The tubular body 5 is provided with a splash guard comprising an internal annular flange 14 located towards the inlet end of the tubular body 5. The annular flange 14 extends radially inwardly from the internal wall of the tubular body 5 and defines a circular opening of sufficient size to receive a conventional fuel dispenser nozzle whilst leaving a small air gap between the dispenser and the radially inner edge of the flange 14. The flange 14 functions very effectively as a guard against splash back as fuel is dispensed into the tank through the inlet device. Any gap between the flange 14 and the dispenser nozzle ensures that sufficient gas can escape (e.g. via the vent apertures 9) to allow the fuel tank to fill effectively.

Figure 2 shows a second known anti-siphon device 20 disclosed in WO2007/110640. The device 20 comprises a tubular body 21 similar to the tubular body 5 of the device 1 of Fig. 1 , except that it is additionally provided with fuel flow holes 22 to allow sufficient flow of fuel through the inlet. An annular splash guard 14 is again provided adjacent the inlet end of the tubular body 21.

An embodiment of the present invention is illustrated in Figs. 3 to 6. Figs. 3a to 4c illustrate an anti-siphon inlet device 30 in accordance with the present invention which is similar in structure to the known anti-siphon device shown in Fig. 2. As such, the anti- siphon device 30 comprises a cylindrical body 31 depending from an attachment means or mounting structure 32 at its inlet end. The cylindrical body 31 defines an opening into which a fuel dispensing nozzle may be inserted such that fuel may pass through the tubular body 31. The cylindrical body 31 (or tubular body) defines an axis of the device 30. The outlet end of a tubular body 31 is closed by a baffle plate 33 (the detail of which is not visible in the drawings) which blocks insertion of a siphon tube but which may include apertures to which allow fuel flow therethrough. The wall of the cylindrical body 31 is provided with various apertures (slots and holes) 34 to permit fuel flow.

The mounting structure 32 comprises a collar 35 adapted to seat over the cylindrical neck of a conventional fuel tank inlet. Bayonet lugs 36 extend radially outwards from a radially thickened portion of the cylindrical body 31 towards the collar 34. The bayonet lugs 36 are adapted for engaging conventional bayonet fittings provided in a fuel tank inlet to receive a conventional fuel filler cap. The mounting structure 32 is provided with recesses 37 to receive the bayonet lugs of a conventional filler cap. Accordingly, the anti-siphon inlet device 30 according to the illustrated embodiment is designed to be fitted to the inlet neck of a conventional fuel tank inlet, and closed with a conventional fuel-filler cap. If necessary the collar 34 may be fixed to the inlet tank neck. Additionally, or alternatively, the inlet device 30 may be secured in the inlet tank neck by grub screws extending outwardly from the tubular body through holes 38 which will engage the internal surface of the tank inlet neck.

An anti siphon device according to the present invention comprises means for opening and closing the opening in the tubular body 31. In accordance with the embodiment of the present invention illustrated in figures 3 to 6, the means for opening and closing the opening in the tubular body 31 comprises a splash guard 40, provided internally to the tubular body 31 , which in accordance with the present invention supports a spring loaded closure flap 41. In Figs. 3a to 3c the closure flap 41 is shown in a "closed" position and in Figs. 4a to 4c the closure flap 41 is shown in an "open" position. In the illustrated embodiment of the invention the spring loaded closure flap 41 is mounted to the splash guard as shown in isolation in Figs. 5a to 6d. Figs. 5a to 5d show the closure flap in a closed position whereas in Figs. 6a to 6d the closure flap is shown in an open position. The splash guard 40 comprises an annular ring which may be secured in the tubular body 31 by screw thread engagement or any other suitable means (such as welding or otherwise bonding). Once fitted in position the ring 40 functions as a splash guard in essentially the same manner as the splash guard 14 of the known anti-siphon inlet devices shown in figures 1 and 2. However, in accordance with the present invention the spring loaded closure flap 41 will inhibit, or prevent, leakage of fuel from the fuel tank in the event that the tank is tilted, for instance if the vehicle rolls over as a result of an accident.

The splash guard 40/closure flap 41 according to the present invention is best viewed when removed from the anti-siphon inlet device as shown in Figs. 5a to 6d but is also visible in Figs 3a to 4c.

Referring to the figures, and in particular Figs. 5a to 6d, it can be seen that the closure flap 41 is a generally circular plate which is pivotally mounted on a spindle 42 which is supported between end posts 43 of a bracket 44 which is secured to the ring 40 by rivets 45. A helical torsion spring 46 is mounted to the spindle 42 so that one arm 46a of the spring bears against the ring 40 and the other arm 46b of the spring bears against the flap 41. The spring 46 acts to bias the closure flap 41 into the closed position illustrated in Figs. 5a to 5d. However, the spring force is easily overcome by pushing a conventional fuel dispensing nozzle into the inlet device and through the ring 40 to enable fuel to be dispensed into the fuel tank. When the dispensing nozzle (not shown) is removed, the spring will again act to the close the flap 41 and prevent fuel from flowing out of the tank through the anti-siphon inlet device 30.

It can be seen that the plate 41 is not exactly circular, but rather includes an arcuate cut away portion at its periphery which is provided to ensure that the flap will not be prevented from movement by the spring 46 (or mounting bracket 44). It will further be seen that portions of the material "cut-away" from the flap 41 are bent perpendicular to the flap 41 to define tabs 41a by which the flap 41 is mounted to the spindle 42. The cut-away portion does not however prevent the flap 41 from covering the entire central opening defined by the ring 40. The tabs 41a are provided with slots 47a to receive the spindle 42 which is supported in similar slots 47b defined by the bracket posts 43. The slots 47a/47b allow the plate 41 to pivot between the open and closed positions and also permit the flap 41 sufficient degree of movement in an axial direction (relative to the tubular body and ring 40) to ensure it sits well against the ring 40 when in the closed position.

Figures 7 and 8 show a further embodiment in accordance with the present invention comprising a ring 40 and single closure flap 41. Figure 7 shows the closure flap 41 in an "open" position, whereas figure 8 shows the closure flap 41 in a "closed" position in which the closure flap 41 abuts a radial face of the ring 40 which faces away from the anti-siphon device inlet aperture. The closure flap 41 of this embodiment is similar to that of the previous embodiment in that it is a generally circular plate. An elongate arm 41b depends from the side of the closure flap 41 facing away from the inlet aperture of the anti siphon device. The elongate arm 41b has a free end 41c remote to the closure flap 41. The elongate arm 41b and passes through an aperture (not shown) in the tubular body 31 and is pivotally mounted on a spindle 42a which is disposed upon the radially outer surface of the tubular body 31. The elongate arm 41b is pivotally mounted to the tubular body 31 by a portion of the elongate arm 41b which is intermediate the closure flap 41 and the free end 41c. The free end 41c of the elongate arm 41b is attached to a portion of a resilient biasing means 46a. In the shown embodiment, the free end 41c of the elongate arm 41b is attached to one end of a helical spring, however any appropriate resilient biasing means may be used. The helical spring extends outside the tubular body 31 , parallel to the axis of the tubular body 31 and is attached at a second end to an anchoring member 44a. In the case of the described embodiment the anchoring member is a protrusion which projects radially outwards from the radially outer surface of the tubular member 31 and is unitary in nature with the tubular member 31. However, the anchor member 31 may be of any appropriate construction.

The resilient biasing means 46a acts to bias the closure flap 41 into the closed position illustrated in Figure 8. However, the spring force is easily overcome by pushing a conventional fuel dispensing nozzle into the inlet device and through the ring 40 to move the closure flap 41 to an "open" position shown in figure 7 and thus enable fuel to be dispensed into the fuel tank. Whilst the closure flap 41 is in the "open position" it does not obstruct the apertures 34 in the tubular body 31 and therefore fuel flow thorough the tubular body 31 when the closure flap 41 is in the "open" position is substantially unaffected by the closure flap. When the dispensing nozzle (not shown) is removed, the resilient biasing means 46a will again act to the close the flap 41 and prevent fuel from flowing out of the tank through the anti-siphon inlet device 30.

Figures 9 to 12 show a yet further embodiment in accordance with the present invention comprising a ring 40 and single closure flap 41. Figures 9 and 11 show the closure flap 41 in a "closed" position in which the closure flap 41 abuts a radial surface of the ring 40 which faces towards the anti-siphon device inlet aperture, whereas figures 10 and 12 show the closure flap 41 in a "open" position. The closure flap 41 of this embodiment is generally D-shaped plate. The closure flap 41 of the present embodiment comprises a bracket (not shown) disposed near the edge of the closure flap 41, on the face of the closure flap 41 which faces away from the inlet aperture of the anti-siphon device. The closure flap 41 is pivotally mounted to the ring 40 by pivoting connection means 42b via the bracket. The closure flap 41 is mounted to the ring 40 such that when the closure flap 41 is in the "closed" position it abuts a radial surface of the ring which faces the inlet aperture of the anti-siphon device. One end of a resilient biasing means 46b in the form of a leaf spring engages the ring 40 (or may engage the tubular body 31) and the other end of the leaf spring is received by an opening (not shown) in a lug 41d which projects in a from approximately the centre of the side of the closure flap 41 which faces away from the anti- siphon device inlet aperture. The resilient biasing means 46b acts to bias the closure flap 41 into the "closed" position illustrated in Figures 9 and 11.

The closure flap 41 also defines an eyelet 41e which may receive one end of a flexible elongate member 44b. The flexible elongate member 44b may be a metal chain. The other end of the flexible elongate member 44b is attached to an underside portion of a conventional filler cap 36a. The use of a flexible elongate member 44b to link the filler cap 36a and closure flap 41 enables a degree of relative rotation between the filler cap 32 and the rest of the anti-siphon device 30 without affecting the closure flap 41. This is advantageous as conventional filler caps must be rotated relative to the rest of the anti- siphon device so as to secure the filler cap to or release the filler cap from the rest of the anti siphon device. When the anti siphon device 30 is closed by the filler cap 36a (as shown in figure 9) the flexible elongate member is slack and is received within the anti-siphon device 30. In order to enable fuel to be dispensed into the fuel tank via the anti siphon device, the filler cap 36a is removed (as shown in figure 10). The spring force of the leaf spring is easily overcome by moving the filler cap 36a a sufficient distance in a direction away from the ring 40 so that the flexible elongate member 44b moves the closure flap 41 to an "open" position (again shown in figure 10). In some embodiments of the invention, the weight of the filler cap 36a will be sufficient to maintain the closure flap 41 in an "open" position, whereas in other embodiments the filler cap 36a or flexible elongate member 44b may need to be held in position. Figure 12 shows a view of the anti-siphon device 30 from above with the closure flap 41 in another "open" position in which the closure flap 41 is substantially parallel to the axis of the anti- siphon device 30. With the closure flap 41 in an "open" position a conventional fuel dispensing nozzle may be inserted into the inlet device and through the ring 40 to enable fuel to be dispensed into the fuel tank.

In some embodiments of the invention, once the dispensing nozzle has been inserted into the anti-siphon device 30 it is no longer necessary to maintain the filler cap 36a at said sufficient distance from the ring 40 to maintain the closure flap 41 in an "open" position as the spring force of the resilient biasing means 46b causes the closure flap 41 to abut the dispensing nozzle.

Once the dispensing nozzle (not shown) has been removed, the resilient biasing means 46a will again act to try to close the flap 41 and prevent fuel from flowing out of the tank through the anti-siphon inlet device 30. In some embodiments the spring force of the resilient biasing means will be sufficient to overcome the weight of the filler cap 36a and as such the closure flap 41 will move to the "closed" position by itself. In other embodiments, it will be necessary to move the filler cap 36a closer to the ring 40 in order to enable the closure flap 41 to move towards the "closed" position.

It will be appreciated that modifications may be made to the details of the spring loaded closure flap 41 illustrated and described above. For instance, the flap 41 could be provided with a seal member on whichever surface of the flap otherwise abuts the ring when the closure flap is in a "closed" position. The seal member may improve the sealing engagement of the closure flap with the ring 40. Such a seal member could for instance be a simple disk or annular ring of an appropriate material, such as rubber, neoprene or a similar elastomeric material suitable to establish a seal and which is preferably resistant to fuel. Additionally, or alternatively, a seal member, such as a resilient annular ring could be provided on the splash guard ring 40 against which the closure plate 41 seats when in a closed position.

In other embodiments the means for opening and closing the opening may comprise two generally closure flaps (hereon in referred to as closure flap portions) which operate in a generally "trap-door" fashion. The flap portions may for instance be spring mounted to diametrically opposed sections of the ring 40 or tubular body 31.

An example of such an embodiment is shown in figures 13 to 16. Figures 13 and 14 show an anti-siphon device 30 having a splash guard arrangement 40a which comprises two similar closure flap portions 48, 49. The closure flap portions 48, 49 are generally semicircular in shape and are pivotally mounted to diametrically opposed sections of the splash guard arrangement 40. The closure flap portions 48, 49 are mounted to the splash guard arrangement 40a by spindles 50 and 51 respectively which are supported by a wall portion 52 of the splash guard arrangement 40 which extends generally axially in a direction away from the anti-siphon device inlet aperture. Figure 13 shows the closure flap portions 48, 49 in a "closed" position, whereas figure 14 shows the closure flap portions 48, 49 in an "open position". In the illustrated embodiment the flap portions 48, 49 do not overlap when they are in a "closed" position, but in other embodiments the flap portions may overlap to some degree.

Figures 15 and 16 show the splash guard arrangement 40a of the present embodiment from above and below respectively. It will be understood that the view from above corresponds to the view of the splash guard arrangement 40a through the anti-siphon device inlet aperture and that the view from below shows the reverse of the splash guard arrangement compared to the view from above. Figures 15 and 16 both show the closure flap portions 48, 49 in a "closed" position. Helical torsion springs (as shown in figure 16) are mounted to the spindles 50, 51 so that one arm 53a, 54a of each spring bears against the splash guard arrangement 40 and the other arm 53b, 54b of each spring bears against the respective flap portion 48, 49. The springs 53, 54 act to bias the closure flap portions 48, 49 into the closed position, illustrated in figures 13, 15 and 16, in which the closure flap portions 48, 49 abut the splash guard arrangement 40a. However, as with the previous embodiments, the spring force is easily overcome by pushing a conventional fuel dispensing nozzle into the inlet device and through the splash guard arrangement 40 to enable fuel to be dispensed into the fuel tank. When the dispensing nozzle (not shown) is removed, the springs will again act to the close the flap portions 48, 49 and prevent fuel from flowing out of the tank through the anti-siphon inlet device.

A splash guard arrangement 40a of a further embodiment of the invention which comprises a pair of generally rectangular shaped diametrically opposed closure flap portions 55, 56 is shown in figures 17 and 18. The closure flap portions 55, 56 are shown in a "closed" position. The closure flaps 55, 56 of the present embodiment are mounted and operated in the same manner as the previously described embodiment. However, the splash guard arrangement of the present embodiment comprises a generally square central opening 57 through which a dispensing nozzle can be inserted compared to the circular central opening of the previous embodiment. The dimensions of the rectangular closure flap portions 55, 56 are such that when they are in a "closed" position, they cover the central opening 57 and abut the splash flap arrangement 40a adjacent the opening 57. The extent of the closure flaps 55, 56 when there are in a "closed" position is marked with a dashed line 58 in figure 17.

It is within the scope of the present invention that the closure flap portions 48, 49 and/or the splash guard arrangement 40a may additionally comprise at least one additional seal member of different material which increases the effectiveness of the seal between the closure flap portions 48, 49 and the splash guard assembly 40, when said closure flap portions are in a "closed" position. Such an at least one seal member could for instance be an annular ring mounted to the splash guard arrangement 40a or arcuate part-annular members mounted to a surface of the flap portions 48, 49 which would otherwise abut the splash guard assembly 40a when the closure flap portions 48, 49 are in a "closed" position. Appropriate materials for the at least one seal member include rubber, neoprene or a similar elastomeric material suitable to establish a seal and which is preferably resistant to fuel. It is further within the scope of the invention to provide at least one additional seal member between the edges of the flap portions 48, 49 which oppose each other when the flap portions 48, 49 are in the closed position. Such an at least one seal member may comprise a single seal member mounted to one of the closure flap portions 48, 49 or a pair of seal members, one seal member being mounted to each closure flap portion 48, 49.

As mentioned above, the anti-siphon inlet device according to the present invention has the functionality of a splash guard as known from the prior art, but includes at least one closure flap which can seal, or substantially seal, the inlet device against fuel spillage. For instance diesel spillage on public roads (e.g. from trucks and other commercial vehicles) is often the cause of other road accidents. The closure flap(s) may also prevent fuel spillage in the event that the fuel tank is tipped, for instance if a vehicle rolls over during an accident. This enhances safety since fuel leakage from the fuel tank in the event of an accident can present a fire hazard. Accordingly, the anti-siphon fuel inlet device according to the present invention improves upon known designs.

It will be appreciated that known anti-siphon devices could be modified to include a closure flap 41 or flap portions 48, 49 according to the present invention. For instance, the known anti-siphon devices illustrated in figures 1 and 2 could be modified to incorporate the present invention by mounting a spring loaded closure flap 41 or flap portions 48, 49 to the existing splash guard 14. Alternatively, in place of the existing splash guard 14 a removable splash guard as for instance shown in Figs. 5 and 6; and Figs. 7 to 10 could be substituted. Sirnilarly, a splash guard and closure flap according to the present invention may be added to an anti-siphon device which does not already have a splash guard. A removable splash guard is preferably as it simplifies assembly of the spring loaded flap 41 or flap portions 48, 49.

Accordingly, the skilled person will appreciate that details of the anti-siphon device (such as details of the tubular body 31, the mounting structure 32, and baffle amongst other features) may vary significantly from those illustrated without having any impact on operation of the spring loaded closure flap 41 or flap portions 48, 49.

It will also be appreciated that details of the way in which flap or flap portions are mounted and the spring arrangement may vary from that illustrated. For instance, in some embodiments the flap 41 or flap portions 48, 49 may be mounted to the internal wall of the tubular body 31 rather than mounted directly to the splash guard ring 40. For example, a bracket very similar to the bracket 44 may be readily modified for mounting to the wall of the tubular member. It will also be appreciated that different forms of spring, and different mounting arrangements for the spring, may be employed to bias the flap 41 or flap portions 48, 49 to the closed position.

It will be understood that other modifications could be made to the closure flap mechanism. For instance, the flap and/or splash guard may be magnetised so that when closed the magnetic force will help provide good fluid tight connection between the two and may help prevent the flap from being dislodged unintentionally. Although the closure flap and flap portions of the described embodiments are generally planar, it will be appreciated that it is within the scope of the present invention to provide closure flap or flap portions which is/are non planar.

It will also be appreciated that although the embodiments described above relate to means of opening and closing the opening in the tubular member which comprise either a single flap or a pair of flaps portions, it is also within the scope of the invention to provide a greater number than two flap portions. For example, any number of segment-shaped closure flap portions may be used as long as they are moveable between a "closed" position in which the flap portions cooperate to close the opening in the tubular body and an "open" position in which a fuel dispensing nozzle and/or fuel can pass through the tubular body.

Other possible arrangements will be readily apparent to the appropriately skilled person.

Claims

1. An anti-siphon fuel tank inlet device comprising: a generally tubular body defining an inlet aperture at one end and one or more fuel flow apertures remote from said inlet aperture; means supported by the tubular body for inhibiting the passage of a siphon tube through the tubular body; an internal annular flange extending radially inwards into the tubular body and defining a central opening for receiving the nozzle of a fuel dispenser; and means for opening and closing said opening, said means comprising a closure flap which is spring biased into a closed position in which it bears against a face of the annular flange, the closure flap being movable against the spring biasing force into an open position to allow insertion of the nozzle of a fuel dispenser through said opening.

2. A device according to claim 1, wherein the face of the annular flange which the closure flap bears against when in said closed position faces away from the inlet aperture.

3. A device according to claim 1, wherein the face of the annular flange which the closure flap bears against when in said closed position faces towards the inlet aperture.

4. A device according to any of the preceding claims, wherein the means for opening and closing said opening comprises a single closure flap.

5. A device according to claim 4, wherein the closure flap is generally circular.

6. A device according to any of claims 1 to 4, wherein the closure flap is generally D- shaped.

7. A device according to any preceding claim, wherein an arm with a free end depends from the closure flap, the arm being pivotally mounted to the tubular body, by a portion intermediate its free end and the closure flap; and wherein the free end of the arm is linked to an anchor portion of the tubular member by a resilient biasing means.

8. A device according to claim 7, wherein the arm passes though an aperture in the tubular body such that the free end of the arm is outside the tubular member.

9. A device according to any of the preceding claims, wherein the closure flap comprises an engagement portion which may be pulled to move the closure flap from the closed position to the open position.

10. A device according to claim 8, wherein the engagement portion of the closure flap is linked to a filler cap via a flexible elongate member.

11. A device according to either claim 1 or claim 2, wherein the means for opening and closing said opening includes a second closure flap.

12. A device according to claim 11 wherein said second closure flap is spring biased into a closed position in which it bears against a face of the annular flange facing away from the inlet aperture, the second closure flap being movable against the spring biasing force into an open position to allow insertion of the nozzle of a fuel dispenser through said opening.

13. A device according to claim 12, wherein when said closure flap and said second closure flap are in their closed positions, the closure flap and second closure flap abut one another.

14. A device according to any of claims 11 to 13, wherein the closure flap and second closure flap have substantially the same configuration.

15. A device according to claim 14, wherein the closure flap and second closure flap are generally semicircular.

16. A device according to claim 14 wherein the closure flap and second closure flap are generally rectangular.

17. A device according to any of the preceding claims, wherein the spring bias force is provided by a helical torsion spring.

18. A device according to any of the preceding claims, wherein the closure flap and/or second closure flap is pivotably mounted to the annular flange.

19. A device according to any of the preceding claims, wherein the closure flap and/or second closure flap is pivotably mounted to the tubular body.

20. A device according to claim 18 or claim 19 when dependant on claim 4, wherein the closure flap is pivotably mounted to a bracket which is in turn mounted to the annular flange or tubular body respectively.

21. A device according to claim 20, wherein the closure flap is mounted on said bracket such that it has a degree of movement in an axial direction under said spring bias force to assist in correctly seating the closure flap against the annular flange.

22. A device according to any preceding claim, wherein the at least one closure flap and/or the annular flange is provided with a seal member to provide a fluid tight seal when the closure flap is in the closed position.

23. A device according to any preceding claim, wherein the annular flange comprises a ring fabricated separately from the tubular body and secured therein.

24. A device according to claim 23, wherein the ring is removably secured within the tubular body.

25. A device according to any preceding claim, further providing a float valve assembly supported by the tubular body and including a float member.

26. A device according to claim 25, further comprising an obstruction located within a housing disposed between the tubular body and the float valve assembly, wherein the obstruction blocks line of sight from the tubular body to the float member.

27. A device according to any preceding claim, comprising a plurality of fuel flow apertures provided in the wall of the tubular body and wherein said means for inhibiting insertion of a siphon tube comprises a baffle.

28. A device according to claim 27, wherein the baffle blocks the end of the tubular body remote from the inlet aperture and is optionally provided with one or more fuel flow apertures.