Vehicle

The present invention relates to the filling of a vehicle fuel tank and in particular, though not exclusively, to the filling of a road vehicle fuel tank.

Referring firstly to figure 1 there is shown a simplified schematic representation of a vehicle fuel tank arrangement generally designated 10. The arrangement 10 includes a tank 12 having an inlet conduit 14 and an outlet conduit 16. The tank 12 can be filled by the introduction of liquid fuel through the inlet conduit 14, while the outlet conduit 16 permits fuel to be supplied to the engine of the vehicle. The arrangement 10 further includes a pressure relief valve 18 and a level control valve 20.

The level control valve 20 includes a buoyant member 22 which is moveable by the free surface 24 of fuel within the tank 12. For the sake of simplicity a single buoyant member 22 is shown, however multiple buoyant members may be provided. The buoyant member 22 is provided within a breather conduit 26 which extends through the upper wall 28 of the tank 12 and extends a calibrated distance into the upper region of the tank 12. The breather conduit 26 is provided with a seat 30 against which the buoyant member 22 rests when the free surface 24 of the fuel within the tank 12 reaches a predetermined height. During the initial filing of the tank 12 the level control valve 20 acts as a breather and allows air and fuel vapour displaced by liquid fuel entering via the inlet conduit 14 to leave the tank 12. As the free surface 24 of fuel within the tank 12 rises it eventually reaches the buoyant member 22 and subsequently raises it in the breather conduit 26. The buoyant member 22, upon reaching the seat 30, closes the breather and thereby a back pressure is applied to liquid fuel in the inlet conduit 14. This back pressure can be sensed by a fuel delivery means supplying fuel to the inlet conduit and used to cease the flow of fuel.

The pressure relief valve 18 comprises a valve member 32 which is biased by a spring 34 against a seat 36. The valve member 32, spring 34 and seat 36 are provided in a conduit 38 extending through the upper wall 28 of the tank 12. In the event that the pressure within the tank 12 exceeds a predetermined limit, the valve member 32 is moveable from the seat 36 against the spring 34 to open a pressure relief path through the conduit 38 to the exterior of the tank 12.

The level control valve 20 may typically also be configured to seal the breather conduit 26 in the event that the fuel tank 12 is tipped onto one side or inverted, for example in the event of an accident involving the vehicle to which the tank 12 is fitted. The level control valve 20 may further function to permit air to enter the tank 12 as fuel is removed through the outlet conduit 16.

Level control and pressure relief valves 18,20 of the type described above may be fitted to a fuel tank 12 prior to its initial fitment to a vehicle. The retrofitting of such valves to a fuel tank already fitted to a vehicle may however be problematic. Access to the tank may be restricted and apertures may thus need to be cut into the vehicle body. The procedure may be time consuming and result in the vehicle being out of service for an extended period of time.

According to a first aspect of the present invention there is provided a combined vehicle fuel filler mouth assembly and level control valve, wherein the vehicle fuel filler mouth assembly has a filler mouth body including a fuel inlet aperture, a fuel outlet aperture and a fuel conduit extending therebetween, a valve member positioned within the fuel conduit to selectively open and close the fuel conduit, the filler mouth body further having a breather inlet aperture, a breather outlet aperture and breather conduit extending therebetween, wherein the filler mouth body is further provided with pressure relief inlet, a pressure relief outlet and a pressure relief conduit extending therebetween, the pressure relief outlet having a pressure relief valve connected thereto, wherein the level control valve is connected to a conduit which extends from fuel outlet aperture and breather inlet aperture of the filler mouth assembly.

The combined assembly provides both pressure relief and level control functions and can be inserted into the filler neck of a fuel tank. The filler mouth assembly fits to the outer end of the filler neck and the level control valve is suspended at a desired location within the fuel tank.

The filler mouth assembly may further include a cap which is fittable to the filler mouth body to cover the fuel inlet aperture. The cap may be provided with a sealing member which seals against an external surface of the filler mouth body. The cap may further cover the breather outlet aperture when fitted to the filler mouth body.

The pressure relief valve may be provided with an anti-vacuum valve which is operable to permit ambient air to enter the pressure relief conduit when the pressure within the pressure relief conduit is reduced by a predetermined amount relative to the external ambient pressure.

The filler mouth body may be provided with a rib which extends at least partially around the fuel outlet aperture, which rib may retain a fuel delivery hose connected to the fuel outlet aperture. The filler mouth body may be provided with a rib which extends at least partially around the breather inlet aperture, which rib may retain a breather hose connected to the breather inlet aperture. In a preferred embodiment, the filler mouth body may be provided with a rib which extends at least partially around both the fuel outlet aperture and the breather inlet aperture, which rib may retain a combined fuel delivery and breather hose to the valve body.

The pressure relief inlet may partially surround the fuel outlet aperture and the breather inlet aperture. The pressure relief inlet may be separated from the fuel outlet aperture and the breather inlet aperture by a wall surrounding both the fuel outlet aperture and the breather inlet aperture. In such an embodiment the aforementioned rib extending around the fuel outlet aperture and the breather inlet aperture may be provided on the wall. The pressure relief inlet may be substantially crescent shaped. The level control valve preferably has a valve body including a fuel inlet aperture, a fuel outlet aperture and a fuel conduit extending therebetween, the valve body further having a breather inlet aperture, a breather outlet aperture and a breather conduit extending therebetween, wherein the valve body is provided with a valve chamber containing a buoyant valve element, the valve chamber having an inlet aperture and an outlet aperture, the outlet aperture being in communication with the breather conduit, wherein further the breather inlet aperture is in communication with breather outlet aperture via the valve chamber, the buoyant valve element being movable in the valve chamber between a position where communication between the breather inlet aperture and the breather outlet aperture, and communication between the valve chamber inlet and the breather outlet aperture is enabled, and a position where communication between the breather inlet aperture and the breather outlet aperture, and communication between the valve chamber inlet and the breather outlet aperture is prevented.

In one embodiment the valve chamber is inclined relative to an axis normal to a centreline axis of the valve body. The valve chamber is inclined so as to take into account the anticipated inclination of the valve body, in use, and thus orientate the valve chamber in a generally vertical manner. Alternatively, the valve chamber may be aligned so as to be substantially parallel to the a centreline axis of the valve body. The fuel conduit of the valve body may also be aligned so as to be substantially parallel to the centreline axis of the valve body. The buoyant element is preferably spherical and is movable into contact with a seat portion of the valve chamber to prevent communication between the breather inlet aperture and the breather outlet aperture, and between the valve chamber inlet and the breather outlet aperture. The seat portion of the valve chamber may comprise a seal member fitted to the valve chamber. The seal member may comprise an annular seal member such as, for example, an elastomeric o-ring.

The valve chamber may contain two buoyant elements, both of which may be spherical. In an alternative embodiment the valve chamber may be further provided with a non buoyant element. Such an element may be used to urge the buoyant element or elements against the seal member in the event that the level control valve is inverted. The element or elements may be retained in the valve chamber by a snap ring fitted to a recess extending around the valve chamber inlet aperture. The valve body may be provided with a rib which extends at least partially around the fuel inlet aperture, which rib may retain a fuel supply hose connected to the fuel inlet aperture. The valve body may be provided with a rib which extends at least partially around the breather outlet aperture, which rib may retain a breather hose connected to the breather outlet aperture. In a preferred embodiment, the valve body may be provided with a rib which extends at least partially around both the fuel inlet aperture and the breather outlet aperture, which rib may retain a combined fuel supply and breather hose to the valve body. The valve body may further be provided with a rib which extends at least partially around the fuel outlet aperture, which rib may retain a fuel delivery hose connected to the fuel outlet aperture.

The valve chamber may preferably extend across the fuel conduit of the valve body. In such an embodiment, the valve body may be provided with a flow diverter member which, in use, diverts the flow of fuel passing through the fuel conduit around the valve chamber. The flow diverter member extends across the fuel conduit and is positioned between the fuel inlet aperture and the valve chamber.

The conduit connecting the fuel filler mouth assembly to the fill level control valve may comprise a fuel conduit and a breather conduit which are contained within a common conduit body.

According to a further aspect of the present invention there is provided a method of providing a vehicle fuel tank with a fill level control valve and a pressure relief valve, the method comprising the steps of providing a combined assembly as described with reference to the first aspect, and fitting said assembly to the filler neck of a vehicle fuel tank such that the fuel filler mouth assembly extends from the filler neck and the fill level control valve is disposed within the filler neck.

An embodiment of the present invention will now be described with reference to the accompanying drawings in which:

Figure 1 shows a schematic representation of a prior art vehicle fuel tank having a level control valve and a pressure relief valve; Figure 2 shows an exploded isometric view of a fuel filler mouth subassembly according to a first embodiment of the present invention;

Figure 3 shows an exploded side view of the fuel filler mouth a subassembly of figure 2;

Figure 4 shows an assembled cross sectional view of the fuel filler mouth subassembly with the filler cap removed;

Figure 5 shows a rear view of the body of the fuel filler mouth subassembly; Figure 6 shows a further assembled cross-sectional view of the fuel filler mouth subassembly and including a pressure relief valve;

Figure 7 shows an exploded isometric view of the fuel filler mouth subassembly of figure 6;

Figure 8 shows a cross-sectional view of the fuel filler mouth subassembly as indicated by arrows A- A on figure 6;

Figure 9 shows an exploded cross-sectional side view of a fill level control valve according to an embodiment of the present invention;

Figure 10 shows an exploded isometric view of the level control valve of figure 9;

Figure 11 shows an assembled cross-sectional view of the level control valve;

Figure 12 shows an isometric view of a hose for connecting the fuel filler mouth assembly to the level control valve;

Figure 13 shows a cross-sectional view of the hose of figure 12;

Figure 14 shows an exploded isometric view of a fuel filler mouth subassembly according to a further embodiment of the present invention;

Figure 15 shows an exploded side view of the fuel filler mouth a subassembly of figure 14;

Figure 16 shows an assembled cross sectional view of the fuel filler mouth subassembly;

Figure 17 shows a rear view of the body of the fuel filler mouth subassembly; Figure 18 shows a further assembled cross-sectional view of the fuel filler mouth subassembly and including a pressure relief valve;

Figure 19 shows an exploded isometric view of the fuel filler mouth subassembly of figure 18; Figure 20 shows a cross-sectional view of the fuel filler mouth subassembly as indicated by arrows A- A on figure 18;

Figure 21 shows an exploded cross-sectional side view of a fill level control valve according to a further embodiment of the present invention;

Figure 22 shows an exploded isometric view of the level control valve of figure 21;

Figure 23 shows an assembled cross-sectional view of the level control valve; Figure 24 shows an isometric view of an assembly comprising a fuel filler mouth subassembly, level control valve and connecting hose;

Figure 25 shows an exploded view of the assembly of figure 24;

Figure 26 shows an isometric view of an alternative assembly comprising a fuel filler mouth subassembly, level control valve and connecting hose; and

Figure 27 shows an exploded view of the assembly of figure 26

Referring firstly to figures 2 to 8 there is shown a filler mouth subassembly according to a first aspect of the present invention and generally designated 40. The filler mouth subassembly 40, in use, is fitted to the end of a fuel tank inlet conduit which is distal to the fuel tank and provides a location to which the nozzle of a fuel dispensing apparatus can be attached. The filler mouth subassembly 40 includes a cap 42, a filler mouth body 44, a mounting plate 46 and a gasket 48. The mounting plate 46 is adapted to fit to the fuel tank inlet conduit and enables the filler mouth body 44 to be fixed to the fuel tank inlet conduit. The gasket 48 ensures that a fluid tight seal is made between the filler mouth body 44 and mounting plate 46. In the embodiment shown both the gasket 48 and mounting plate 46 are provided with a substantially central aperture 50,52 which, in use, aligns with the fuel tank inlet conduit and the outlet of the filler mouth body 44 to define a conduit therebetween.

The filler mouth body 44 is provided with a fuel inlet aperture 54 and a fuel outlet aperture 56 and defines a fuel conduit 58 therebetween. To assist with the further description of the filler mouth body 44, the fuel inlet aperture 54 may be considered to be positioned at the front of the body 44 and the fuel outlet aperture 56 to the rear of the body 44. Within the filler mouth body 44 there is provided a poppet valve 60. The stem 62 of the poppet valve 60 is slidably received in a sleeve 64 of the fuel conduit 58 of the filler mouth body 44. The sleeve 64 is supported by three arms 66 extending from the wall of the fuel conduit 58. The spring 68 of the poppet valve 60 is provided between an annular seat 70 surrounding the sleeve 64 and an annular recess 72 provided on the underside 74 of the head 76 of the poppet valve 60. The poppet valve head 76 is provided with an annular elastomeric sealing member 78. The sealing member 78, in use, engages an annular insert 80 provided in the fuel conduit 58. The outer periphery of the insert 80 is threaded 82 and a complementarily thread form 84 is provided on the wall of fuel conduit 58. The sealing member 78 is urged against the insert 80 by the spring 68 to close the fuel conduit 58. The sealing member 78 is displaced from the insert 80 by the action of a similar poppet valve provided in the nozzle of a fuel dispensing apparatus attached, in use, to the filler mouth body 44. Figure 4 shows the poppet valve 60 in the displaced position. The fuel inlet aperture 54 is surrounded by a segmented flange 86. The segmented flange 86 enables both a fuel dispensing nozzle and the cap 42 to be positively engaged to the filler mouth body 44. The cap 42 and fuel dispensing nozzle are provided with three spaced projections, one of which 88 can be seen on the cap 42 shown in figure 6, which are sized and spaced so as to be able pass between the spaces 90 between the flange segments 92. The cap 42 or fuel dispensing nozzle can then be rotated to position the projections 88 behind the flange segments 92. The cap 42 shown in figure 6 is further provided with an o-ring type elastomeric seal 94 which provides a fluid tight seal between the cap 42 and a substantially cylindrical portion 96 of the exterior of the filler mouth body 44 when the cap 42 is fitted.

The filler mouth body 44 is further provided with a breather conduit 98 and a pressure relief conduit 100. The breather conduit 98 is provided with an inlet aperture 102 to the rear of the filler mouth body 44 and an outlet aperture 104 to the front of the filler mouth body 44. The breather conduit 98 provides a path, as indicated by arrow 106, for air and fuel vapour to leave the fuel tank as liquid fuel is introduced to the tank. The breather conduit 98 is, in use, connected to a level control valve situated within either the fuel tank or fuel tank filler neck as will be described in greater detail below. The breather conduit inlet aperture 102 and the fuel conduit outlet aperture 56 are surrounded by a wall 59 having a rib 61. As can be seen from figure 6, the breather outlet aperture 104 is covered by the cap 42 when the cap 42 is fitted to the filler mouth body. The presence of the elastomeric seal 94 on the cap 42 and its interaction with the cylindrical portion 96 of the filler mouth body 44 means that the breather conduit 98 is prevented from venting to atmosphere when the cap 42 is fitted. This prevents the escape of fuel through breather conduit in the event of tipping or inversion of the vehicle to which the filler mouth body 44 is fitted. The breather conduit 98 may be used to enable fuel vapour recovery during filling of the tank by providing vapour recovery means at the breather conduit outlet aperture 104.

The pressure relief conduit 100 is provided with an inlet 108 to the rear of the filler mouth body 44 and an outlet 110 to the underside of the filler mouth body 44. The pressure relief conduit 100 provides a path, as indicated by arrow 112, for pressurised fluid, for example, air and fuel vapour, to exit the fuel tank in the event that the tank is over pressurised. As can be seen from figure 5, the pressure relief conduit inlet 108 surrounds both the fuel outlet aperture 56 and the breather conduit inlet 102 and is positioned outside of the wall 59 surrounding the breather conduit inlet aperture 102 and the fuel conduit outlet aperture 56. The pressure relief conduit inlet 108 is substantially crescent shaped

The filler mouth body 44 is further provided with a pressure relief valve generally designated 114 which is shown in figures 6 to 8. The pressure relief valve 114 includes a shroud 116 and a valve seat member 118 which are connected to the filler mouth body 44 around the pressure relief conduit outlet 1 10 by two threaded fasteners 120. The fasteners 120 extend through aligned holes 122,124 of the shroud 116 and valve seat member 118 and into blind threaded holes 126 of the filler mouth body 44. The shroud 116 and valve seat member 118 each have an aperture 128,130 which aligns with the pressure relief conduit outlet 110. The valve seat member 118 is provided with a raised seating surface 132 which surrounds the aperture 130 in the member 118.

The pressure relief valve 114 further includes a movable valve plate 134 having a compressible gasket 136 attached thereto. The valve plate 134 is retained in association with the valve seat member 118 by two threaded fasteners 138 which are received in complementarily threaded holes 140 of the valve plate 134. The threaded fasteners 138 extend through holes 142 provided in the valve seat member 118. The holes 142 are of a greater diameter than the threaded fasteners 138. A spring 144 is held in compression between the head 146 of each threaded fastener 138 and the valve seat member 118 such that the valve plate 134 is urged against the valve seat member 118. The valve plate 134 is maintained against the valve seat member 118 until the force applied to the valve plate 134 by pressure within the pressure relief conduit 100 exceeds the force of the springs 144. Typically the rate of the springs 144 is such that the valve plate 134 is moved from the valve seat member 118 when the pressure within the pressure relief conduit exceeds 2.2 to 5 psi.

The pressure relief valve 114 is further provided with an anti- vacuum valve arrangement generally designated 148. The arrangement 148 comprises a recess 150 of the valve plate 134 within which there is provided a ball element 152. The recess 150 is provided with an internal aperture 154 and an external aperture 156. The internal aperture 154 is covered by the compressible gasket 136 of the valve plate 134 which acts to retain the ball element 152 within the recess 150. The gasket 136 is provided with a plurality of apertures 158 which overlie the internal aperture 154. The external aperture 156 is circular and of a diameter which is less than the diameter of the ball element 152. The ball element 152 is thus able to seal the external aperture 156 either under its own weight or as the result of elevated pressure, i.e. above external ambient pressure, within the pressure relief conduit 100. The anti- vacuum valve arrangement 148 permits air to enter the pressure relief conduit 100 and hence the filler neck and fuel tank as fuel is removed from the tank. The removal of fuel from the tank results in a drop in pressure with in the tank. When the pressure within the tank is reduced below the external ambient pressure by a sufficient amount to overcome the weight of the ball element 152, the ball element 152 will be lifted from its seated position in the external aperture 156 and thereby permit air to enter the tank. The ball element 152 is buoyant. In the event that the vehicle is tipped or inverted such that fuel is able to flow into the pressure relief conduit 100 and hence reach the pressure relief valve 114, the buoyancy of the ball element 152 urges it against the external aperture to prevent the flow of fuel therethrough.

Figures 9 to 11 show a fill level control valve generally designated 160. The valve 160 has a generally cylindrical body 162 having a fuel inlet 164, a fuel outlet 166 and a fuel conduit 168 therebetween. The body 162 is further provided with an inclined valve chamber 170 having an inlet 172 in the wall of the body 162 and an outlet 174. The valve chamber extends across the fuel conduit 168. The valve chamber 170 is inclined by an angle a relative to an axis N which is normal to the longitudinal centreline axis CL of the body 162. In the embodiment shown the angle a is in the region of 15 degrees. The valve chamber 170 may be provided at alternative inclinations. The inclination of the valve chamber 170 is dependent upon the anticipated inclination angle of the valve 160, in use, and is chosen such that the valve chamber 170 has a generally vertical orientation, in use. The valve chamber outlet 174 is in communication with a breather outlet conduit 176 of the body 162 which extends to a breather outlet 178 provided above the fuel inlet 164. In use, the breather outlet 178 is connected to the breather conduit inlet 102 of the filler mouth body 44. The body 162 is further provided with a pair of breather inlet conduits 175 each of which extends between an aperture 177 in the exterior of the body 162 and an aperture 179 in the wall of the valve chamber 170.

The fuel inlet 164 and breather outlet 178 are surrounded by a rib 181 provided on the body 162 which permits the secure connection of a hose to the body 162 around the fuel inlet 164 and breather outlet 178. A further rib 183 is provided on the body 162 around the fuel outlet 166. This rib 183 permits the optional fitment of a hose to the fuel outlet 166. Depending upon the nature of the fuel which passes through the valve 160, it may be advantageous to fit a hose which extends into a lower region of the tank. Such a hose permits fuel to enter the tank below the surface of fuel already present in the tank. Sub surface filling of the tank can prevent foam forming on the fuel surface and thus provides a laminar fuel surface for the ball elements, which are described below, to interact with. The body 162 is further provided with a flow diverter member 185 extending across the fuel conduit 168. The diverter member 185 is provided between the valve chamber 170 and the fuel inlet 164 and is aligned with the valve chamber 170. The diverter member 185, in use, guides incoming fuel flow around the valve chamber 170.

Within the valve chamber 170 there are provided upper and lower ball elements 180,182. The lower ball element 182 is a buoyant ball element manufactured from a buoyant material such as, for example, cork. The upper ball element 180 is a sealing ball element and may comprise, for example, a hollow alloy sphere. The ball elements 180,182 are retained in the valve chamber 170 by a snap ring 184 which is received in a recess 186 provided within the valve chamber inlet 172. The valve chamber 170 is further provided in an upper region thereof with an elastomeric o-ring seal 188 which is received in an annular recess 190 of the chamber 170. The breather inlet apertures 179 in the wall of the valve chamber 174 are at a position below the level of the o-ring seal 188.

During initial filling of the tank to which the level control valve 160 is fitted, the weight of the ball elements 180,182 ensures they are spaced from the o-ring seal 188. Air and fuel vapour displaced by the incoming fuel is able to pass though the breather inlet conduits 175 to the valve chamber 170 and then into the breather outlet conduit 176. There is sufficient clearance between the ball elements 180,182 and the valve chamber 170 to permit some air and fuel vapour displaced by liquid fuel entering the tank to pass through the valve chamber 170 and into the breather outlet conduit 176. The free surface of fuel within the tank will eventually reach the buoyant lower ball element 182 and subsequently raise both ball elements 180,182 towards the o-ring seal 188. The upper ball element 182 will eventually contact and seal against the o-ring seal 188 thereby preventing the further flow of air and fuel vapour through the valve chamber 170 and into the breather outlet conduit 176.

Figure 12 shows a hose, generally designated 192, for connecting the level control valve 160 to the filler mouth body. The hose 192 has a teardrop-like cross-sectional shape and includes a fuel conduit 194 and a separate breather conduit 196. At each end of the hose 192 there is provided a wall 198 which, in use, enables the hose 192 to be fitted to the ribs 61, 181 provided respectively on the filler mouth body 44 and the level control valve 160. The hose 192 is manufactured from a resiliently deformable material and, as such, the walls 198 deform and grip the ribs 61,181. The hose 192 serves to both mechanically connect the filler mouth body 44 to the level control valve 160 and provide fuel and breather conduits 194,196.

In use, the level control valve 160 is connected to the filler mouth subassembly 40 by the hose 192 to provide a combined assembly having a filler mouth, level control valve and pressure relief valve. The combined assembly is fittable to the filler neck of a fuel tank such that the filler mouth subassembly 40 extends from the outer end of the filler neck and the level control valve 160 is situated below the inner end of the filler neck and within the fuel tank of a vehicle. The diameter of the level control valve 160 and hose 192 are such that they have sufficient clearance with respect to the filler neck to allow their movement therethrough. It will be appreciated that the length of the hose 192 will depend upon the length of the filler neck and the desired fill level of the tank. It will further be appreciated that the hose 192 may need to be curved so as to complement the path of the filler neck if this is not straight. As noted above, the valve chamber 170 is inclined to take into account the anticipated inclination of the level control valve 160 when it is situated, in use, within a fuel tank.

The combined assembly can be fitted to a vehicle having a fuel tank which does not have a level control valve or a pressure relief valve so as to provide the fuel tank with these functions. It will be appreciated that access to the filler neck only is required in order to fit the combined assembly and that draining and/or removal of the tank is not required.

Referring now to figures 14 to 20 there is shown an alternative embodiment of a filler mouth subassembly generally designated 240. Features common to the subassembly 40 described with reference to figures 2 to 8 are identified with like reference numerals prefixed with either 2 or 3. Looking firstly at figures 14 to 16, the filler mouth sub-assembly 240 differs in that the filler mouth body is split into two parts, namely a front part 244a and a rear part 244b. The body parts 244a,244b are connectable to one another by threaded fasteners 245. A gasket 247 is provided between the body parts 244a,244b to ensure that the parts 244a,244b are connected to one another in a fluid tight manner. The splitting of the body into two parts 244a,244b further enables the poppet valve 260 and spring 268 to be encapsulated between the parts 244a, 244b. The poppet valve 260 and spring 268 thus no longer need to be inserted through the inlet aperture 254 and retained by a threaded annular insert 80 as in the embodiment of figures 2 to 8. Instead, the poppet valve 260 acts against an annular seat 280 formed integrally with the front part 244a.

The filler mouth assembly 240 further differs in the configuration of the pressure relief conduit 300. The pressure relief conduit inlet 308 remains to the rear of the filler mouth body, however the outlet 310 is provided to the upper side of the filler mouth body as opposed to the underside. The pressure relief conduit inlet 308 is split into two parts, each of which is positioned above and to one side of the fuel outlet aperture 256 and the breather conduit inlet 302.

The repositioning of the pressure relief conduit outlet 310 requires the pressure relief valve 314 to be provided on the upper side of the filler mouth body. The components of the pressure relief valve 314 are the same as that described with reference to figures 2 to 8 with the exception of the shroud 316. The shroud 316 substantially encloses the pressure relief valve 314 and is provided with laterally positioned outlets 317 which are provided on opposing sides of the filler mouth assembly 240. Figures 21 to 23 show an alternative embodiment of a level control valve generally designated 360. Features common to the embodiment described with reference to figures 9 to 11 are identified with like reference numerals but prefixed with 3 as opposed to 1. The level control valve 360 differs in that the valve chamber 370 is no longer inclined relative to the fuel conduit 368, but is instead aligned with the fuel conduit 368 so as to be substantially parallel thereto. This eliminates the need for the diverter member 185 of the previous embodiment. The parallel alignment of the valve chamber 370 and fuel conduit 368 further eliminates the need for breather inlet conduits extending between apertures in the wall of the valve chamber and corresponding apertures in the exterior of the body 362 of the level control valve 360. Instead, apertures 377 in the exterior of the body 362 of the level control valve 360 communicate directly with the interior of the valve chamber 370. The level control valve 360 is further provided with three ball elements 380,382 and 387. The upper ball element 380, that is to say the ball element 38 closest to the valve chamber outlet 374, is a sealing ball element and may comprise, for example, a hollow alloy sphere. The intermediate ball element 382 is a buoyant ball element manufactured from a buoyant material such as, for example, cork. The lower ball element 387 is a weight ball element and may comprise, for example a solid metal sphere. The lower element 387, in use, acts to ensure that the buoyant ball elements 380, 382 are urged against the o-ring seal 388 in the event that the level control valve 360 is inverted.

Figure 24 shows the combination of the filler mouth assembly 240 of figures 14 to 20 and the level control valve 360 of figures 21 to 23 connected by a combined conduit 392. Figure 25 shows an exploded view of the combination. It will be noted that the longitudinal centreline axes of the filler mouth assembly 240, level control valve 360 and conduit 392 are aligned.

Figure 26 shows an alternative combination of a filler mouth assembly 240, level control valve 360 and combined conduit 392. In this embodiment the longitudinal centreline axes of the level control valve 360 and combined conduit are aligned but are inclined relative to the longitudinal centreline axis of the filler mouth assembly 240. The inclination is achieved by the provision of an elbow-like rear body part 244b of the filler mouth body. It will be understood that a range of different elbow-like rear body parts 244b may be provided in order to provide a range of inclination angles. The appropriate rear body part 244b may be chosen for a given installation in order to ensure that the conduit 392 and level control valve 360 are correctly aligned with the filler neck within which they are situated, in use.