WO2025133557A1

WO2025133557A1 - A liquid level sender and liquid pick-up device

Info

Publication number: WO2025133557A1
Application number: PCT/GB2023/053295
Authority: WO
Inventors: Curtis JOHNS; Nicholas James Andrew MASSEY; Jack STODDART; Rhys Howard Arthur DAVIES; Neal David SILVERWOOD
Original assignee: Fuel Active Ltd
Current assignee: Fuel Active Ltd
Priority date: 2023-12-18
Filing date: 2023-12-18
Publication date: 2025-06-26
Anticipated expiration: 2026-06-18

Abstract

A liquid level sender and liquid pick-up device 101,201,301 for fitting to a liquid reservoir 1 through an industry standard ancillary aperture 5. It comprises a body 103,203,303 having a fitment for fitting the device 101,201,301 to a liquid reservoir and a connector head 107,207,307 attached to the body. It also comprises a liquid level sensor 135,235,335 that is attached to the body 103,203,303 and has a moveable liquid level sensor float 141,251,341, a liquid pick-up conduit 149,275,375 having at one end a liquid pick-up inlet that is moveable with and adjacent to a buoyant element 151,251,341 and at another end a liquid pick-up outlet that is fluidly connected to the connector head 107,207,307, wherein the buoyant element 151,251,341 is guided by a guiding arrangement, such that, in use, the moveable liquid pick- up inlet moves along a pre-defined pathway.

Description

A LIQUID LEVEL SENDER AND LIQUID PICK-UP DEVICE

The present invention relates to a combined liquid level sender and liquid pick-up device for installation in a liquid tank. In particular, the present invention relates to a fuel level sender and fuel pick-up device for installation into a fuel tank through an industry standard ancillary aperture.

Fuel contamination is a common problem experienced by operators of vehicles powered by internal combustion engines, such as diesel powered on-road heavy goods vehicles or offroad haul trucks. The contamination is usually in the form of particulates, water and microbial growth (known in diesel fuel as ‘diesel bug’). Particulate material in fuel can cause problems such as reduced service intervals and increased fuel consumption. Apparatus for improving the cleanliness of fuel that is picked up from a fuel tank is known. However, such apparatus is typically retrofitted and therefore needs to be installed into a fuel tank through an aperture that has to be cut into the tank. Installation in this way poses various challenges. It is important that any swarf from the cutting operation doesn’t remain in the tank, because if swarf does enter the tank that would necessitate draining of the tank so that the debris can be removed and a high standard of cleanliness restored. Also, it may be difficult to find a part of the fuel tank that is suitable for installation of the apparatus, because it is often the case that the packaging envelope into which the fuel tank is fitted is small. Furthermore, internal baffles within the fuel tank limit the number of potential positions for the apparatus. Fuel tanks are typically already provided with an industry standard sized aperture for the fitment of ancillary equipment in the form of a fuel level sender, which is a device for detecting the amount of fuel in the fuel tank and drawing fuel from the bottom of the tank. It would be advantageous if both a fuel level sender and a dynamic floating fuel pick-up device could be fitted through that preexisting aperture and therefore there is a need for a combination device that is small enough to be accommodated within the space that is available.

A liquid level sender and liquid pick-up device for fitting to a liquid reservoir through an industry standard ancillary aperture and comprising, a body having a fitment for fitting the device to a liquid reservoir, a connector head attached to the body, a liquid level sensor attached to the body and comprising a moveable liquid level sensor float, a liquid pick-up conduit having at one end a liquid pick-up inlet that is moveable with and adjacent to a buoyant element and at another end a liquid pick-up outlet that is fluidly connected to the connector head, wherein the buoyant element is guided by a guiding arrangement, such that, in use, the moveable liquid pick-up inlet moves along a pre-defined pathway. This arrangement is advantageous, for example when used in a fuel system for a heavy goods vehicle, because the claimed features facilitate combination of the fuel level sender and the fuel pick-up in a device with a packaging envelope that enables it to be fitted through an industry standard ancillary aperture of a fuel tank. In addition, the device is suitable for fitment as original equipment, or as an aftermarket part.

Preferably, the buoyant element is guided by a guiding arrangement that is attached to the body. The present invention envisages other variants of the guiding arrangement for the buoyant element. For example, the guiding arrangement may be provided on the fuel tank by means of a channel into which the buoyant element can be located during installation of the device and within which the buoyant element can slide as the level of fuel within the tank changes.

Preferably, the moveable liquid level sensor float is guided by a guiding arrangement such that, in use, the moveable liquid level sensor float moves along a pre-defined pathway. Controlling movement of the liquid level sensor float means that it can always be placed in an area of the tank in which there is relatively clean fuel.

Preferably, the moveable liquid level sensor float is guided by a guiding arrangement that is attached to the body.

Preferably, the pre-defined pathway along which the liquid pick-up inlet moves and the predefined pathway along which the moveable liquid level sensor float moves have at least a section which is a common pre-defined pathway. This facilitates a particularly compact arrangement of the device.

Preferably, the device further comprises a liquid return line that is attached to the body, that has an inlet end fluidly connected to the connector head and that has an outlet end that, in use, is located within the liquid reservoir, wherein a liquid directing means is provided at the outlet end, such that, in use, at least some of the liquid exiting the liquid return line through its outlet end is directed by the liquid directing means. In a fuel system this facilitates creation of a clean fuel zone from which contaminants such as particulates (for example fine steel fragments introduced with the fuel, degraded surface coating chips and rust from the walls of the tank itself and dirt and dust introduced through the breather pipe), water and microbial growth. It is envisaged that the return line could also be provided separately, i.e. passing into the fuel tank via an aperture other than the ancillary aperture. Preferably, the liquid directing means is a nozzle provided with a plurality of nozzle ports. It is further envisaged that other physical arrangements, including mechanical arrangements, can be employed for directing the liquid and/or for increasing the flow velocity of that liquid.

Preferably, the liquid pick-up inlet of the liquid pick-up conduit is fluidly connected with a moveable liquid pick-up receptacle, the liquid pick-up receptacle having an internal volume with at least one flooding aperture, wherein, in use, at least some of the liquid picked up from the reservoir flows through the flooding aperture into the pick-up receptacle and then into the liquid pick-up inlet.

More preferably, the liquid pick-up receptacle comprises a diffuser and the at least one flooding aperture forms part of that diffuser. The diffuser slows down the velocity and reduces the pressure of the liquid being drawn up by the device which is advantageous because it reduces the ability for the liquid pick-up inlet to draw in any contaminants from the fuel in the tank.

In one embodiment of the present invention, the device may further comprise a float tube that is perpendicularly attached to the body, that contains the liquid level sensor and that is orientated vertically in use, wherein the moveable liquid level sensor float is slideably moveable within an internal bore of the float tube and, in use, is moveable up and down in a vertical direction and relative to a static component of the liquid level sensor, wherein the buoyant element is a liquid pick-up float engaged with the external surface of the float tube and slideable relative to that external surface such that the float tube provides the guiding arrangement for the buoyant element and wherein the liquid pick-up conduit is extendable in length and the end of the liquid pick-up conduit that is provided with a liquid pick-up inlet is attached to the liquid pick-up float. These features facilitate a particularly compact arrangement of the device.

Preferably, the liquid pick-up float has a free-flooding internal volume to which the liquid pickup inlet is attached.

Preferably, the static component of the liquid level sensor is an array of reed switches.

Preferably, the liquid pick-up conduit is a helically coiled pipe. This arrangement facilitates a change in the distance between the inlet and outlet ends of the liquid pick-up conduit by moving the coils closer together, or by moving them further apart. Preferably, the liquid level sensor float and buoyant element move along a common pathway and the liquid level sensor float can pass through the buoyant element.

Preferably, the device further comprises a liquid return line that is attached to the body, that has an inlet end fluidly connected to the connector head and to one end of the internal bore of the float tube and that has an outlet end at the other end of the internal bore of the float tube, wherein, in use, the outlet end is located within the liquid reservoir.

Preferably, a liquid directing means is provided at the outlet end of the liquid return line, such that, in use, at least some of the liquid exiting the liquid return line through its outlet end is directed by the liquid directing means.

Preferably, the buoyant element is provided by the moveable liquid level sensor float and the moveable liquid level sensor float is attached to a swing arm which is pivotably attached to a pivot provided on the device, wherein the swing arm provides the guiding arrangement for the buoyant element, such that, in use, the liquid level sensor float moves in an arced pathway around the pivot.

Preferably, the liquid pick-up conduit has a rigid part and a flexible part. In an alternative, the liquid pick-up can be made up from a rigid pipe or pipes. For example, the liquid pick-up could have a rigid pipe articulated so that it can travel with the arc of the swing arm.

Preferably, the device further comprises a rigid liquid return pipe that has an inlet end fluidly connected to the connector head and that has an outlet end which, in use, is located within the liquid reservoir.

In another embodiment of the present invention, the device may further comprise a float tube that is perpendicularly attached to the body, that contains the liquid level sensor and that is orientated vertically in use, wherein the moveable liquid level sensor float is slideably moveable within the float tube and, in use, is moveable up and down in a vertical direction and relative to a static component of the liquid level sensor, wherein the buoyant element is a liquid pick-up float attached to a swing arm which is pivotably attached to a pivot provided on the device, wherein the swing arm provides the guiding arrangement for the buoyant element, such that, in use, the liquid pick-up float moves in an arced pathway around the pivot.

Preferably, the fitment is for fitting the device to an industry standard ancillary aperture. For example, in the case of utilising the device for a fuel system of a heavy goods vehicle it can be fitted through the industry standard ancillary aperture provided in the fuel tank.

A liquid level sender and liquid pick up device for fitting to a liquid reservoir through an industry standard ancillary aperture and comprising a body having a fitment for fitting the device to a liquid reservoir, a connector head attached to the body, a liquid level sensor, a liquid return conduit with an outlet end and with an inlet end that is fluidly connected to the connector head, a moveable liquid level sensor float guided by a guiding arrangement that is attached to the body, a moveable liquid pick-up receptacle guided by a guiding arrangement that is attached to the body, such that, in use, the moveable liquid level sensor float and the moveable liquid pick-up receptacle each move along a common pre-defined pathway, the moveable pick-up receptacle having an internal volume with at least one flooding aperture, wherein there is provided a liquid pick-up conduit that has an inlet end that is fluidly connected to the internal volume of the moveable pick-up receptacle, and that has an outlet end that is fluidly connected to the connector head.

The various aspects of the present invention will be described below, with reference to the following figures:

Figure 1 is a cross-sectional view of a half full fuel tank fitted with a coaxial float device according to a first embodiment of the present invention;

Figure 2 is a close-up perspective view of the body, connector head and fitting plate of the coaxial float device of Figure 1 ;

Figure 3 is a close-up cross-sectional perspective view of an upper portion of the coaxial float device of Figure 1 , showing the float tube and part of the reed switch sensor;

Figure 4 is a close-up view of the nozzle that caps the bottom of the float tube;

Figure 5 is a close-up cross-sectional perspective view of the reed switch float and the fuel pick-up float;

Figure 6 is a perspective view of the coaxial float device of Figure 1 showing the fuel exit from the fuel pick-up float;

Figure 7 is a cross-sectional view of a nearly full fuel tank fitted with the coaxial float device of the first embodiment of the present invention;

Figure 8 is a close-up cross-sectional perspective view of the reed switch float and the fuel pick-up float when the fuel tank is nearly full, as shown in Figure 7;

Figure 9 is a cross-sectional view of a nearly empty fuel tank fitted with the coaxial float device of the first embodiment of the present invention;

Figure 10 is a cross-sectional view of a half full fuel tank fitted with a common float device according to a second embodiment of the present invention;

Figure 11 is a close-up perspective view of the body, connector head and fitting plate of the common float device of Figure 10; Figure 12 is a close-up cross-sectional view of the pick-up float of the common float device of Figure 10;

Figure 13 is a cross-sectional view of a half full fuel tank fitted with a separate float device according to a third embodiment of the present invention;

Figure 14 is a close-up perspective view of the body, connector head and fitting plate of the separate float device of Figure 13;

Figure 15 is a cross-section view of the separate float device of Figure 13 showing the reed switch fuel level sensor; and

Figure 16 is a close-up cross-sectional view of the pick-up float of the separate float device of Figure 13.

Figure 1 illustrates a first embodiment of the present invention, which is a coaxial float liquid level sender and liquid pick-up device 101 . It is shown fitted to a fuel tank 1 that is half full of fuel 3. The coaxial float device 101 is inserted into the fuel tank 1 through an industry standard ancillary aperture 5 provided in the fuel tank 1. In this specific embodiment the aperture 5 is a 55mm diameter female bayonet fitting 7, which is used as an industry standard for the fuel tanks of heavy goods vehicles. The coaxial float device 101 has a flat cylindrical body 103 which comprises as an upper part a connector head 105 and as a lower part a circular fitting plate 107. The fitting plate 107 is provided with a male bayonet fitting 109 which is complementary to the female bayonet fitting 7 on the fuel tank 1. The following description of the coaxial float device 101 of the first embodiment (and also the descriptions below of the second and third embodiments) describes various components with reference to their use with fuel, but those components are suitable for use with other liquids, for example water.

The connector head 105 comprises a fuel pick-up pipe connector 111 , a fuel return pipe connector 113 and a fuel sender electrical connector 115, as shown in Figure 2. One end of the fuel pick-up pipe connector 111 is attached to the connector head 105 in line with a pickup passageway 117 that passes through the body 103. The other end of the fuel pick-up pipe connector 111 is spaced away from the body 103 and, in use, is connected to a fuel supply line (not shown) of an internal combustion engine. Similarly, one end of the fuel return pipe connector 113 is attached to the connector head 105 in line with a fuel return passageway 119 that passes through the body 103, as shown in Figure 3. The other end of the fuel return pipe connector 113 is spaced away from the body 103 and, in use, is connected to a fuel return line (not shown) of an internal combustion engine. The fuel sender electrical connector 115 is aligned with an electrical passageway 121 that passes through the body 103 and passes through that electrical passageway 121 and is connected to a fuel sender 123, as will be explained in further detail below.

The underside of the fitting plate 107 of the body 103 has a float tube 125 attached to it so that there is a liquid tight interface between an upper end of the float tube 125 and the fitting plate 107. The float tube 125 is rigid, straight, cylindrical and hollow, with a solid wall 127 and a constant cross-sectional profile. A semi-circular vent 128 is provided through the wall 127 towards the top of the tube 125 such that is adjacent to the fitting plate 107, as shown in Figure 2. It is orientated perpendicularly to the connector head 105 and, in use, it is orientated vertically within the fuel tank 1 . The wall 127 is located around the fuel return passageway 119 and around the electrical passageway 121 , so that the fuel return passageway 119 and the electrical passageway 121 open out into the bore 129 of the float tube 125. A lower end of the float tube 125 is provided with a nozzle 131 which caps the float tube 125, but which allows fuel to flow out of the float tube 125 through nozzle ports 133 that pass through the nozzle 131 , as shown in Figure 4.

The fuel sender 123 is located within the bore 129 of the float tube 125. The fuel sender 123 comprises a reed switch sensor 135 that has a vertically orientated printed circuit board 137 provided with a number of reed switches 139 and a reed switch float 141 that is provided with a magnet 143 and that is slideably moveable relative to the printed circuit board 137 within the bore 129. The printed circuit board 137 is attached to the underside of the fitting plate 107 of the body 103, as shown in Figure 3. It is located within the bore 129 of the float tube 125 and extends along the length of the float tube 125, with its lower end being adjacent to the nozzle 131 , as shown in Figure 4. The printed circuit board 137 is in the form of a thin strip along which the reed switches 139 are located, spaced at regular intervals.

Figure 5 is a close-up cross-sectional view of a middle section of the reed switch sensor 135 showing the reed switch float 141 located around the printed circuit board 137. The reed switch float 141 is cylindrical, hollow and sealed, so that a sealed internal volume provides it with a buoyancy that is sufficient for it to float at the surface of the fuel and move up and down as the fuel level within the fuel tank 1 changes. A pathway 145 is provided through the reed switch float 141 , so that, in use, the reed switch float 141 is slideably moveable over, and guided by, the printed circuit board 137. The external diameter of the reed switch float 141 is slightly less than the diameter of the bore 129 of the float tube 125, so that the reed switch float 141 is slideably moveable within, and guided by, the bore 129. The magnet 143 is located within the reed switch float 141 in a position such that, in use, when it is adjacent to a reed switch 139 it causes that reed switch 139 to activate and when it moves past that reed switch 139, that reed switch 139 will open or close.

The other element of the coaxial float liquid level sender and liquid pick-up device 101 of the present invention is a fuel pick-up 147. The fuel pick-up 147 comprises a coiled fuel pick-up pipe 149 that is attached at an upper end to the pick-up passageway 117 in the body 103 and at a lower end to a fuel pick-up float 151.

The coiled fuel pick-up pipe 149 is flexible and extendable in length and is helically coiled around the float tube 125. Figure 1 shows the coiled fuel pick-up pipe 149 in a partially extended position in a fuel tank 1 that is half full of fuel 3. The coiled fuel pick-up pipe 149 is, for example, made from a flexible polymer tubing.

The fuel pick-up float 151 is shown in Figure 1 and, in a close-up cross-sectional view, in Figure 5. It is cylindrical and is provided with a cylindrical internal duct 153 that has a longitudinal axis that is coaxial with the longitudinal axis of the pick-up float 151 , such that an annular cylindrical volume is created within the pick-up float 151. The volume is divided into a centrally located sealed buoyancy chamber 155, around which is provided an open pick-up chamber 157. The sealed buoyancy chamber 155 is sized so that the volume enclosed by it provides the fuel pick-up float 151 with a buoyancy that is sufficient for it to float at the surface of the fuel and move up and down as the fuel level within the fuel tank 1 changes. The open pick-up chamber 157 is formed between an external wall 159 of the fuel pick-up float 151 and an external wall 161 of the buoyancy chamber 155. The pick-up chamber 157 comprises at its lower end a fuel entrance 163 and at its upper end a fuel exit 165. The fuel entrance 163 is provided through the external wall 159 of the pick-up float 151 and is formed from a number of vertical and parallel slots 167. The slots 167 form a diffuser, i.e. a device which reduces the velocity and reduces the pressure of the fuel 3 within the pick-up chamber 157. The fuel exit 165 is an aperture through a top surface of the external wall 159 to which the lower end of the coiled fuel pick-up pipe 149 is connected, as shown in Figure 6.

The coaxial float device 101 is typically used to supply fuel 3 from the fuel tank 1 to a fuel system of an internal combustion engine of a vehicle (not shown). It also provides to that vehicle an electrical signal that enables the vehicle to display on a dashboard the level of fuel 3 within the fuel tank 1. In addition, fuel 3 that is not consumed by the internal combustion engine is returned back to the fuel tank 1 via the fuel return pipe connector 113. In order to supply fuel 3 to the internal combustion engine it is first drawn into the bottom of the fuel pick-up float 151 through the slots 167 that form the fuel entrance 163 into the fuel pick-up chamber 157. This is done under the action of a fuel pump (not shown) that is located outside of the fuel tank 1. The fuel 3 passes upwardly through the pick-up chamber 157 and then flows out of the fuel pick-up float 151 through the fuel exit 165 and into the coiled fuel pick-up pipe 149. The fuel then travels along the length of the coiled fuel pick-up pipe 149, passes through the fuel pick-up passageway 117 provided in the body 103 and out to a fuel supply line (not shown) which is connected to the fuel pick-up pipe connector 111.

Fuel 3 returning to the fuel tank 1 from the fuel system of the internal combustion engine passes into the fuel return pipe connector 113, through the fuel return passageway 119 and into the bore 129 of the float tube 125. The fuel then flows downwardly through the bore 129 until it reaches the nozzle 131 that caps the bottom end of the float tube 125. It then exits the bore 129 via the nozzle ports 133 and re-joins the other fuel 3 in the fuel tank 1. The bore 129 of the float tube 125 is free-flooding, due to the presence of the vent 128.

The fuel 3 returning to the fuel tank 1 can be used to create a clean fuel zone 169 around the nozzle 131 , so that the fuel 3 being drawn into the coaxial float device 101 is always relatively clean, for example containing less contaminants. The clean fuel zone 169 is created by expelling fuel 3 from the nozzle ports 133 of nozzle 131 at a relatively high velocity. This relatively high velocity fuel flushes contaminants away from the nozzle 131 and out of the clean fuel zone 169, but without agitating the contaminant layer 170. It is important not to agitate the contaminant layer 170 in order to avoid contaminants within that layer, for example particulate matter or water, being pushed upwards into the fuel 3 above it. The degree of contamination within a region of the fuel 3 is generally proportional to the distance of that region of the fuel 3 from the bottom of the fuel tank 1. Consequently, when the fuel pick-up 147 is at a mid-position in the fuel tank 1 , as shown in Figure 1 , or at a high-position in the fuel tank 1 , as shown in Figure 7, the fuel 3 that is being picked up is relatively clean. However, when the fuel pick-up 147 is at a low-position in the fuel tank 1 , as shown in Figure 9, there is a risk that the fuel 3 being picked-up will be contaminated, because of the proximity of the fuel pick-up 147 to the contaminant layer 170. The provision of the clean fuel zone 169 around the nozzle 131 means that even when the pick-up float 151 is near to the bottom of the fuel tank 1 the fuel 3 being picked up can be relatively free of contaminants because the fuel entrance 163 into the pick-up chamber 157 is located within the clean fuel zone 169 within which the degree of contamination has been reduced as a result of at least some of the contaminants having been flushed from the clean fuel zone 169 by the fuel returning to the fuel tank 1. A fuel pick-up float stop (not shown) can be provided on the float tube 125 to ensure that the fuel-pick up 147 does not drop below the level of the clean fuel zone 169.

Figure 1 shows the fuel tank 1 half full of fuel 3. Figures 7 and 9 shows the fuel tank 1 nearly full of fuel 3 and nearly empty of fuel 3 respectively. Figures 1 , 7 and 9 illustrate the positions of various components of the coaxial float device 101 in each of those three scenarios, and in particular illustrate the positions of the reed switch float 141 and the fuel pick-up float 151.

The reed switch float 141 and the pick-up float 151 can move independently of each other, the reed switch float 141 slides up and down within the float tube 125 and the fuel pick-up float 151 slides up and down the outside of float tube 125.

In Figure 1 , the reed switch float 141 and the fuel pick-up float 151 sit at the same level within the fuel 3, i.e. adjacent to the surface, as shown in the cross-sectional close-up view of Figure 5. This is because at this fuel level, there is no constraint on the vertical movement of the fuel pick-up float 151.

Figure 8 is a close-up cross-sectional view of the coaxial float device 101 of Figure 7 and shows the pick-up float 151 below the surface of the fuel 3 and the reed switch float 141 above it, at the surface of the fuel 3. The pick-up float 151 is positioned lower than the reed switch float 141 because the coiled fuel pick-up pipe 149 has been compressed to such a degree that the buoyancy of the pick-up float 151 is no longer sufficient to compress it any further to facilitate upwards movement of the pick-up float 151 (or it may be the case that the coils of the coiled fuel pick-up pipe 149 are touching each other). The reed switch float 141 has no such constraint on its movement, so it can follow the level of the surface of the fuel 3, right up to the top wall of the fuel tank 1 . The fuel level sender 123 will thus always give an accurate indication of the level of the fuel 3 within the fuel tank 1 , when the fuel tank 1 is full or nearly full.

Figure 9 shows a nearly empty fuel tank 1 , with the reed switch float 141 and the fuel pick-up float 151 sitting at the same level within the fuel 3, i.e. adjacent to the surface, as is the case with the half full fuel tank situation illustrated in Figure 1. The fuel level sender 123 will thus always give an accurate indication of the level of the fuel 3 within the fuel tank 1 , when the fuel tank 1 is empty or nearly empty. Figure 10 illustrates a second embodiment of the present invention, which is a common float liquid level sender and liquid pick-up device 201 , shown fitted to a fuel tank 1 that is half full of fuel 3. The common float device 201 is inserted into the fuel tank 1 through an industry standard ancillary aperture 5 provided in the fuel tank 1. In this specific embodiment the aperture 5 is a 55mm diameter female bayonet fitting 7, which is used as an industry standard for the fuel tanks of heavy goods vehicles. The common float device 201 has a flat cylindrical body 203 which comprises as an upper part a connector head 205 and as a lower part a circular fitting plate 207. The fitting plate 207 is provided with a male bayonet fitting 209 which is complementary to the female bayonet fitting 7 on the fuel tank 1.

The connector head 205 comprises a fuel pick-up pipe connector 211 , a fuel return pipe connector 213 and a fuel sender electrical connector 215, as shown in Figure 11. One end of the fuel pick-up pipe connector 211 is attached to the connector head 205 in line with a pickup passageway 217 that passes through the body 203. The other end of the fuel pick-up pipe connector 211 is spaced away from the body 203 and, in use, is connected to a fuel supply line (not shown) of an internal combustion engine. Similarly, one end of the fuel return pipe connector 213 is attached to the connector head 205 in line with a fuel return passageway 219 that passes through the body 203, as shown in Figure 3. The other end of the fuel return pipe connector 213 is spaced away from the body 203 and, in use, is connected to a fuel return line (not shown) of an internal combustion engine. The fuel sender electrical connector 215 is aligned with an electrical passageway 221 that passes through the body 203 and passes through that electrical passageway 221 and is connected to a fuel sender 223, as will be explained in further detail below.

The underside of the fitting plate 207 of the body 203 has a fuel return pipe 271 attached to it so that there is a liquid tight interface between an upper end of the fuel return pipe 271 and the fuel return passageway 219. The fuel return pipe 271 is rigid, straight, cylindrical and hollow, with a solid wall and a constant cross-sectional profile. It is orientated perpendicularly to the fitting plate 207 and, in use, it is orientated vertically within the fuel tank 1 . A lower end of the fuel return pipe 271 is provided with a nozzle 231 which caps the fuel return pipe 271 , but which allows fuel to flow out of the fuel return pipe 271 through nozzle ports that pass through the nozzle 231 . The nozzle ports are not shown in Figure 10, but are of a similar form to the nozzle ports 133 of the first embodiment.

The underside of the fitting plate 207 also has a rigid fuel pick-up pipe 273 attached to it so that there is a liquid tight interface between an upper end of the rigid fuel pick-up pipe 273 and the fuel pick-up passageway 217. The rigid fuel pick-up pipe 273 is rigid, straight, cylindrical and hollow, with a solid wall and a constant cross-sectional profile. It is orientated perpendicularly to the fitting plate 207 and, in use, it is orientated vertically within the fuel tank 1 . A lower end of the rigid fuel pick-up pipe 273 is connected to one end of flexible fuel pickup pipe 275 in a liquid-tight manner which forms part of a fuel pick-up 247. The other end of the flexible fuel pick-up pipe 275 is attached to a fuel pick-up float 251 , which is another component of the fuel pick-up 247.

The fuel pick-up float 251 is shown in a close-up cross-sectional view in Figure 12. It has an external wall 259 that defines a generally cylindrical shape with closed ends and having an internal volume. A sealed buoyancy chamber 255 is located within the fuel pick-up float 251 and attached to it. The sealed buoyancy chamber 255 is sized so that the volume enclosed by it provides the fuel pick-up float 251 with a buoyancy that is sufficient for it to float at the surface of the fuel and move up and down as the fuel level within the fuel tank 1 changes. It has an internal volume that is smaller than the internal volume of the fuel pick-up float 251 , such that an open pick-up chamber 257 is created between the external wall 261 of the buoyancy chamber 255 and the internal wall of the fuel pick-up float 251. The pick-up chamber 257 comprises at one end a fuel entrance 263 and at the other end a fuel exit 265. The fuel entrance 263 is provided through the external wall 259 of the pick-up float 251 and is formed from a number of vertical and parallel slots 267. The slots 267 form a diffuser, i.e. a device which reduces the velocity and increases the pressure of the fuel 3 within the pick-up chamber 257. The fuel exit 265 is an aperture through the external wall 259 to which an end of the flexible fuel pick-up pipe 275 is connected, as described above.

The common float device 201 also comprises a fuel sender 223 in the form of a swing arm sensor 235. The swing arm sensor 235 comprises a rigid swing arm 277 which is pivotably attached at one end to a pivot 279 fixed to the bottom of the rigid fuel pick-up pipe 273 and attached at its other end to the fuel pick-up float 251 . The swing arm 277 is straight and made from a stiff rod. The swing arm sensor 235 also comprises a variable resistor 281 attached to the rigid fuel pick-up pipe 273 and an electrical mechanism in the form of wiper arm contacts 283 attached to the swing arm 277. The wiper arm contacts 283 contact the variable resistor 281 and, as the swing arm 277 moves with a change in the fuel level, the length of the resistive path between the wiper arm contacts 283 and the variable resistor 281 changes, thus the resistance of the swing arm sensor 235 changes.

The common float device 201 is typically used to supply fuel 3 from the fuel tank 1 to a fuel system of an internal combustion engine of a vehicle (not shown). It also provides to that vehicle an electrical signal that enables the vehicle to display on a dashboard the level of fuel 3 within the fuel tank 1. In addition, fuel 3 that is not consumed by the internal combustion engine is returned back to the fuel tank 1 via the fuel return pipe 271.

In order to supply fuel 3 to the internal combustion engine it is first drawn into the fuel pick-up float 251 through the slots 267 that form the fuel entrance 263 into the fuel pick-up chamber 257. This is done under the action of a fuel pump (not shown) that is located outside of the fuel tank 1. The fuel 3 passes through the fuel pick-up chamber 257 and then flows out of the fuel pick-up float 251 through the fuel exit 265 and into the flexible fuel pick-up pipe 275. The fuel then travels along the length of the flexible fuel pick-up pipe 275, along the length of the rigid fuel pick-up pipe 273, passes through the fuel pick-up passageway 217 provided in the body 203 and out to a fuel supply line (not shown) which is connected to the fuel pick-up pipe connector 211.

Fuel 3 returning to the fuel tank 1 from the fuel system of the internal combustion engine passes into the fuel return pipe connector 213, through the fuel return passageway 219, through the fuel return pipe 271 until it reaches the nozzle 231 that caps the bottom end of the fuel return pipe 271. It then exits the fuel return pipe 231 via the nozzle ports (not shown) and rejoins the other fuel 3 in the fuel tank 1 .

The fuel 3 returning to the fuel tank 1 can be used to create a clean fuel zone 269 around the nozzle 231 , as illustrated in Figure 10, so that the fuel 3 being drawn into the common float device 201 is always relatively clean, for example containing less contaminants. The clean fuel zone 269 is created by expelling fuel 3 from the nozzle ports of nozzle 231 at a relatively high velocity. Figure 10 shows that the clean fuel zone 269 extends further to the left of the nozzle 231 than to the right. This is achieved by arranging the nozzle ports so that there is a bias towards the left hand side, i.e. the side of the fuel tank 1 in which the fuel pick-up 247 is located. This relatively high velocity fuel flushes contaminants away from the nozzle 231 and out of the clean fuel zone 269, but without agitating a contaminant layer 270. It is important not to agitate the contaminant layer 270 in order to avoid contaminants within that layer, e.g. particulate matter or water, being pushed upwards into the fuel 3 above it. The degree of contamination within a region of the fuel 3 is generally proportional to the distance of that region of the fuel 3 from the bottom of the fuel tank 1. Consequently, when the fuel pick-up 247 is at a mid-position in the fuel tank 1 , as shown in Figure 10, or at a high-position in the fuel tank 1 (not shown), the fuel 3 that is being picked up is relatively clean. However, when the fuel pick-up 247 is at a low-position in the fuel tank 1 (not shown - but at the bottom of the dotted arc 272 shown in Figure 10) there is a risk that the fuel 3 being picked-up will be contaminated, because of the proximity of the fuel pick-up 247 to the contaminant layer 170. The provision of the clean fuel zone 269 around the nozzle 231 means that even when the pick-up float 251 is near to the bottom of the fuel tank 1 the fuel 3 being picked up can be relatively free of contaminants because the fuel entrance 263 into the pick-up chamber 257 is located within the clean fuel zone 269 within which the degree of contamination has been reduced as a result of at least some of the contaminants having been flushed from the clean fuel zone 269 by the fuel returning to the fuel tank 1. A fuel pick-up float stop (not shown) can be provided to constrain movement of the swing arm 277 to ensure that the fuel-pick up 247 does not drop below the level of the clean fuel zone 269.

Figure 10 shows the fuel tank 1 half full of fuel 3 and illustrates the position of various components of the common float device 201 at that fuel fill level and in particular illustrates the position of the fuel pick-up float 251. The fuel pick-up float 251 moves with the level of the fuel 3 in the fuel tank 1 , for example along the dotted arc 272. When the fuel tank 1 is being filled with fuel 3 the fuel pick-up float 251 , which is located at the surface of the fuel 3, moves upwards. As it does so, the swing arm 277 rotates around the pivot 279 and moves the wiper arm contacts 283 across the surface of the variable resistor 281. The swing arm sensor 235 with then facilitate the fuel sender 235 to provide an electrical signal to the vehicle in which the fuel tank 1 is fitted that enables the vehicle to display on a dashboard the level of fuel 3 within the fuel tank. When the fuel tank 1 is being emptied of fuel 3 the fuel pick-up float 251 moves downwards, the swing arm 277 rotates around the pivot 279 in the opposite direction and the electrical signal from the fuel level sender 235 changes accordingly.

Figure 13 illustrates a third embodiment of the present invention, which is a separate float liquid level sender and liquid pick-up device 301, shown fitted to a fuel tank 1 that is half full of fuel 3. The separate float device 301 is inserted into the fuel tank 1 through an industry standard ancillary aperture 5 provided in the fuel tank 1. In this specific embodiment the aperture 5 is a 55mm diameter female bayonet fitting 7, which is used as an industry standard for the fuel tanks of heavy goods vehicles. The separate float device 301 has a flat cylindrical body 303 which comprises as an upper part a connector head 305 and as a lower part a circular fitting plate 307. The fitting plate 307 is provided with a male bayonet fitting 309 which is complementary to the female bayonet fitting 7 on the fuel tank 1.

The connector head 305 comprises a fuel pick-up pipe connector 311 , a fuel return pipe connector 313 and a fuel sender electrical connector 315, as shown in Figure 14. One end of the fuel pick-up pipe connector 311 is attached to the connector head 305 in line with a pickup passageway 317 that passes through the body 303. The other end of the fuel pick-up pipe connector 311 is spaced away from the body 303 and, in use, is connected to a fuel supply line (not shown) of an internal combustion engine. Similarly, one end of the fuel return pipe connector 313 is attached to the connector head 305 in line with a fuel return passageway 319 that passes through the body 303. The other end of the fuel return pipe connector 313 is spaced away from the body 303 and, in use, is connected to a fuel return line (not shown) of an internal combustion engine. The fuel sender electrical connector 315 is aligned with an electrical passageway 321 that passes through the body 303 and passes through that electrical passageway 321 and is connected to a fuel sender 323, as will be explained in further detail below.

The underside of the fitting plate 307 of the body 303 has a float tube 325 attached to it so that there is a liquid tight interface between an upper end of the float tube 325 and the fitting plate 307. The float tube 325 is rigid, straight, cylindrical and hollow, with a solid wall 327 and a constant cross-sectional profile. A semi-circular vent 328 is provided through the wall 327 towards the top of the tube 325 such that is adjacent to the fitting plate 307, as shown in Figure 13. It is orientated perpendicularly to the fitting 305 and, in use, it is orientated vertically within the fuel tank 1. The wall 327 is located around the fuel return passageway 319 and around the electrical passageway 321 , so that the fuel return passageway 319 and the electrical passageway 321 open out into the bore 329 of the float tube 325. A lower end of the float tube 325 is provided with a nozzle 331 which caps the float tube 325, but which allows fuel to flow out of the float tube 325 through nozzle ports (not shown, but of the type described in relation to the first embodiment) that pass through the nozzle 331 .

The fuel sender 323 is located within the bore 329 of the float tube 325. The fuel sender 323 comprises a reed switch sensor 335 that has a vertically orientated printed circuit board 337 provided with a number of reed switches 339 and a reed switch float 341 that is provided with a magnet 343 and that is slideably moveable relative to the printed circuit board 337 within the bore 329. The printed circuit board 337 is attached to the underside of the fitting plate 307 of the body 303, as shown in Figure 14. It is located centrally within the bore 329 of the float tube 325 and extends along the length of the float tube 325, with its lower end being adjacent to the nozzle 331 , as shown in Figure 15. The printed circuit board 337 is in the form of a thin strip along which the reed switches 339 are located, typically spaced at regular intervals.

Figure 15 shows the reed switch float 341 located around the printed circuit board 337. The reed switch float 341 is cylindrical, hollow and sealed, so that a sealed internal volume provides it with a buoyancy that is sufficient for it to float at the surface of the fuel and move up and down as the fuel level within the fuel tank 1 changes. A pathway 345 is provided through the reed switch float 341 , so that, in use, the reed switch float 341 is slideably moveable over, and guided by, the printed circuit board 337. The external diameter of the reed switch float 341 is slightly less than the diameter of the bore 329 of the float tube 325, so that the reed switch float 341 is slideably moveable within, and guided by, the bore 329. The magnet 343 is located within the reed switch float 341 in a position such that, in use, when it is adjacent to a reed switch 339 it causes that reed switch 339 to activate and when it moves past that reed switch 339, that reed switch 339 will open or close.

The other element of the separate float liquid level sender and liquid pick-up device 301 of the third embodiment of the present invention is a fuel pick-up 347. The underside of the fitting plate 307 also has a rigid fuel pick-up pipe 373 attached to it so that there is a liquid tight interface between an upper end of the rigid fuel pick-up pipe 373 and the fuel pick-up passageway 317. The rigid fuel pick-up pipe 373 is rigid, straight, cylindrical and hollow, with a solid wall and a constant cross-sectional profile. It is orientated perpendicularly to the fitting plate 307 and, in use, it is orientated vertically within the fuel tank 1 . A lower end of the rigid fuel pick-up pipe 373 is connected to one end of flexible fuel pick-up pipe 375 in a liquid-tight manner which forms part of a fuel pick-up 347. The other end of the flexible fuel pick-up pipe 375 is attached to a fuel pick-up float 351 , which is another component of the fuel pick-up 347.

The fuel pick-up float 351 is shown in a close-up cross-sectional view in Figure 16. It has an external wall 359 that defines a generally cylindrical shape with closed ends and having an internal volume. A sealed buoyancy chamber 355 is located within the fuel pick-up float 351 and attached to it. The sealed buoyancy chamber 355 is sized so that the volume enclosed by it provides the fuel pick-up float 351 with a buoyancy that is sufficient for it to float at the surface of the fuel and move up and down as the fuel level within the fuel tank 1 changes. It is also generally cylindrical and it has an internal volume that is smaller than the internal volume of the fuel pick-up float 351 , such that an open pick-up chamber 357 is created between the external wall 361 of the buoyancy chamber 355 and the internal wall of the fuel pick-up float 351. The pick-up chamber 357 comprises at one end a fuel entrance 363 and at the other end a fuel exit 365. The fuel entrance 363 is provided through the external wall 359 of the pick-up float 351 and is formed from a number of vertical and parallel slots 367. The slots 367 form a diffuser, i.e. a device which reduces the velocity and increases the pressure of the fuel 3 within the pick-up chamber 357. The fuel exit 365 is an aperture through the external wall 359 to which an end of the flexible fuel pick-up pipe 375 is connected, as described above. The fuel pick-up float 351 is attached to a rigid swing arm 377 which is pivotably attached at one end to a pivot 379 fixed to the bottom of the rigid fuel pick-up pipe 373 and rigidly attached at its other end to the fuel pick-up float 351. The swing arm 377 is straight and made from a stiff rod. The separate float device 301 is typically used to supply fuel 3 from the fuel tank 1 to a fuel system of an internal combustion engine of a vehicle (not shown). It also provides to that vehicle an electrical signal that enables the vehicle to display on a dashboard the level of fuel 3 within the fuel tank 1. In addition, fuel 3 that is not consumed by the internal combustion engine is returned back to the fuel tank 1 via the fuel return pipe connector 313.

In order to supply fuel 3 to the internal combustion engine it is first drawn into the fuel pick-up float 351 through the slots 367 that form the fuel entrance 363 into the fuel pick-up chamber 257. This is done under the action of a fuel pump (not shown) that is located outside of the fuel tank 1. The fuel 3 passes through the fuel pick-up chamber 357 and then flows out of the fuel pick-up float 351 through the fuel exit 365 and into the flexible fuel pick-up pipe 375. The fuel then travels along the length of the flexible fuel pick-up pipe 375, along the length of the rigid fuel pick-up pipe 373, passes through the fuel pick-up passageway 317 provided in the body 303 and out to a fuel supply line (not shown) which is connected to the fuel pick-up pipe connector 311.

Fuel 3 returning to the fuel tank 1 from the fuel system of the internal combustion engine passes into the fuel return pipe connector 313, through the fuel return passageway 319 and into the bore 329 of the float tube 325. The fuel then flows downwardly through the bore 329 until it reaches the nozzle 331 that caps the bottom end of the float tube 325. It then exits the bore 329 via the nozzle ports and rejoins the other fuel 3 in the fuel tank 1. The bore 329 of the float tube 325 is free-flooding, due to the presence of the vent 328.

The fuel 3 returning to the fuel tank 1 can be used to create a clean fuel zone 369 around the nozzle 331 , so that the fuel 3 being drawn into the separate float device 301 is always relatively clean, for example containing less contaminants. The clean fuel zone 369 is created by expelling fuel 3 from the nozzle ports of nozzle 331 at a relatively high velocity. Figure 13 shows that the clean fuel zone 369 extends further to the left of the nozzle 331 than to the right. This is achieved by arranging the nozzle ports so that there is bias towards the left hand side, i.e. the side of the fuel tank 1 in which the fuel pick-up 347 is located. This relatively high velocity fuel flushes contaminants away from the nozzle 331 and out of the clean fuel zone 369, but without agitating a contaminant layer 270. It is important not to agitate the contaminant layer 170 in order to avoid contaminants within that layer, e.g. particulate matter or water, being pushed upwards into the fuel 3 above it. The degree of contamination within a a region of the fuel 3 is generally proportional to the distance of that region of the fuel 3 from the bottom of the fuel tank 1 . Consequently, when the fuel pick-up 347 is at a mid-position in the fuel tank 1 , as shown in Figure 13, or at a high-position in the fuel tank 1 (not shown), the fuel 3 that is being picked up is relatively clean. However, when the fuel pick-up 347 is at a low-position in the fuel tank 1 (not shown - but at the bottom of the dotted arc 372 shown in Figure 13), there is a risk that the fuel 3 being picked-up will be contaminated, because of the proximity of the fuel pick-up 347 to the contaminant layer 170. The provision of the clean fuel zone 369 around the nozzle 331 means that even when the pick-up float 351 is near to the bottom of the fuel tank 1 the fuel 3 being picked up can be relatively free of contaminants because the fuel entrance 363 into the pick-up chamber 357 is located within the clean fuel zone 369 within which the degree of contaminants has been reduced as a result of at least some of the contaminants having been flushed from the clean fuel zone 369 by the fuel returning to the fuel tank 1 . A fuel pick-up float stop (not shown) can be provided to constrain movement of the swing arm 377 to ensure that the fuel-pick up 347 does not drop below the level of the clean fuel zone 369.

Prior art fuel level sender and fuel pick up devices are typically provided with primary fuel supply and return lines and also with auxiliary fuel supply and return lines. The auxiliary fuel supply and return lines might be connected to an auxiliary device such as a heater for the sleeping compartment of a vehicle. The input end of the auxiliary fuel supply line is typically located within the fuel tank at a level above the lowest position for the primary fuel supply line, so that, in use, it is not possible for the auxiliary device to drain the tank to a level such that fuel cannot be drawn up through the primary fuel supply line. It is envisaged that devices according to the present invention, for example the three specific embodiments described above, could be fitted with auxiliary fuel supply and return lines, if that is required by the application to which they are applied.

Claims

1. A liquid level sender and liquid pick-up device (101 ,201 ,301) for fitting to a liquid reservoir (1) through an industry standard ancillary aperture (5) and comprising, a body (103,203,303) having a fitment (109,209,309) for fitting the device (101 ,201 ,301) to a liquid reservoir (1), a connector head (105,205,305) attached to the body (103,203,303), a liquid level sensor (135,235,335) attached to the body (103,203,303) and comprising a moveable liquid level sensor float (141 ,251 ,341), a liquid pick-up conduit (149,275,375) having at one end a liquid pick-up inlet that is moveable with and adjacent to a buoyant element (151 ,251 ,351) and at another end a liquid pick-up outlet that is fluidly connected to the connector head

(105.205.305), wherein the buoyant element (151 ,251 ,351) is guided by a guiding arrangement, such that, in use, the moveable liquid pick-up inlet moves along a pre-defined pathway.

2. A liquid level sender and liquid pick-up device (101 ,201 ,301) as claimed in claim 1 , wherein the buoyant element (151 ,251 ,351) is guided by a guiding arrangement that is attached to the body (103,203,303).

3. A liquid level sender and liquid pick-up device (101 ,201 ,301) as claimed in claim 1 or claim 2, wherein the moveable liquid level sensor float (141 ,251 ,341) is guided by a guiding arrangement such that, in use, the moveable liquid level sensor float (141 ,251 ,341) moves along a pre-defined pathway.

4. A liquid level sender and liquid pick-up device (101 ,201 ,301) as claimed in claim 3, wherein the moveable liquid level sensor float (141 ,251 ,341) is guided by a guiding arrangement that is attached to the body (103,203,303).

5. A liquid level sender and liquid pick-up device (101 ,201 ,301) as claimed in any one of the preceding claims, wherein the pre-defined pathway along which the liquid pick-up inlet moves and the pre-defined pathway along which the moveable liquid level sensor float (141 ,251 ,341) moves have at least a section which is a common pre-defined pathway.

6. A liquid level sender and liquid pick-up device (101 ,201 ,301) as claimed in any one of the preceding claims, further comprising a liquid return line (125, 271 ,325) that is attached to the body (103,203,303), that has an inlet end fluidly connected to the connector head

(105.205.305) and that has an outlet end that, in use, is located within the liquid reservoir (1), wherein a liquid directing means (131 ,231 ,331) is provided at the outlet end, such that, in use, at least some of the liquid exiting the liquid return line through its outlet end is directed by the liquid directing means.

7. A liquid level sender and liquid pick-up device (101 ,201 ,301) as claimed in claim 6, wherein the liquid directing means is a nozzle provided with a plurality of nozzle ports.

8. A liquid level sender and liquid pick up device (101 ,201 ,301) as claimed in any of the preceding claims, wherein the liquid pick-up inlet of the liquid pick-up conduit (149,275,375) is fluidly connected with a moveable liquid pick-up receptacle (157,257,357), the liquid pick-up receptacle (157,257,357) having an internal volume with at least one flooding aperture (167,267,367), wherein, in use, at least some of the liquid picked up from the reservoir (1) flows through the flooding aperture (167,267,367) into the pick-up receptacle (157,257,357) and then into the liquid pick-up inlet.

9. A liquid level sender and liquid pick up device (101 ,201 ,301) as claimed in claim 8, wherein the liquid pick-up receptacle (157,257,357) comprises a diffuser and the at least one flooding aperture (167,267,367) forms part of that diffuser.

10. A liquid level sender and liquid pick up device (101) as claimed in claim 1 , further comprising a float tube (125) that is perpendicularly attached to the body (103), that contains the liquid level sensor (135) and that is orientated vertically in use, wherein the moveable liquid level sensor float (141) is slideably moveable within an internal bore (129) of the float tube (125) and, in use, is moveable up and down in a vertical direction and relative to a static component of the liquid level sensor (135), wherein the buoyant element (151) is a liquid pickup float (151) engaged with the external surface of the float tube (125) and slideable relative to that external surface such that the float tube (125) provides the guiding arrangement for the buoyant element (151) and wherein the liquid pick-up conduit (149) is extendable in length and the end of the liquid pick-up conduit (149) that is provided with a liquid pick-up inlet is attached to the liquid pick-up float (151).

11. A liquid level sender and liquid pick up device (101) as claimed in claim 10, wherein the liquid pick-up float (151) has a free-flooding internal volume (157) to which the liquid pick-up inlet is attached.

12. A liquid level sender and liquid pick up device (101) as claimed in claim 10 or claim 11 , wherein the static component of the liquid level sensor (135) is an array of reed switches (139).

13. A liquid level sender and liquid pick up device (101) as claimed in any one of claims 10, 11 and 12, wherein the liquid pick-up conduit (149) is a helically coiled pipe.

14. A liquid level sender and liquid pick up device (101) as claimed in any one of claims 10 to

13, wherein the liquid level sensor float (141) and buoyant element (151) move along a common pathway and the liquid level sensor float (141) can pass through the buoyant element (151).

15. A liquid level sender and liquid pick up device (101) as claimed in any one of claims 10 to

14, further comprising a liquid return line (125) that is attached to the body (103), that has an inlet end fluidly connected to the connector head (105) and to one end of the internal bore (129) of the float tube (125) and that has an outlet end at the other end of the internal bore (129) of the float tube (125), wherein, in use, the outlet end is located within the liquid reservoir (1).

16. A liquid level sender and liquid pick up device (101) as claimed in claim 15, wherein a liquid directing means (131) is provided at the outlet end of the liquid return line (125), such that, in use, at least some of the liquid exiting the liquid return line (125) through its outlet end is directed by the liquid directing means (131).

17. A liquid level sender and liquid pick up device (201) as claimed in claim 1 , wherein the buoyant element (251) is provided by the moveable liquid level sensor float (251) and the moveable liquid level sensor float (251) is attached to a swing arm (277) which is pivotably attached to a pivot (279) provided on the device (201), wherein the swing arm (277) provides the guiding arrangement for the buoyant element (251), such that, in use, the liquid level sensor float (251) moves in an arced pathway around the pivot (279).

18. A liquid level sender and liquid pick up device (201) as claimed in claim 17, wherein the liquid pick-up float (251) has a free-flooding internal volume (257) to which the liquid pick-up inlet is attached.

19. A liquid level sender and liquid pick up device (201) as claimed in claim 17 or claim 18, wherein the liquid pick-up conduit has a rigid part (273) and a flexible part (275).

20. A liquid level sender and liquid pick up device (201) as claimed in any one of claims 17, 18 or 19, further comprising a rigid liquid return pipe (271) that has an inlet end fluidly connected to the connector head (205) and that has an outlet end which, in use, is located within the liquid reservoir (1).

21. A liquid level sender and liquid pick up device (201) as claimed in claim 20, wherein a liquid directing means (231) is provided at the outlet end of the liquid return line (271), such that, in use, at least some of the liquid exiting the liquid return line (271) through its outlet end is directed by the liquid directing means (231).

22. A liquid level sender and liquid pick up device (301) as claimed in claim 1 , further comprising a float tube (325) that is perpendicularly attached to the body (303), that contains the liquid level sensor (335) and that is orientated vertically in use, wherein the moveable liquid level sensor float (341) is slideably moveable within the float tube (325) and, in use, is moveable up and down in a vertical direction and relative to a static component of the liquid level sensor (335), wherein the buoyant element (351) is a liquid pick-up float (351) attached to a swing arm (377)which is pivotably attached to a pivot (379) provided on the device (301), wherein the swing arm (377) provides the guiding arrangement for the buoyant element (351), such that, in use, the liquid pick-up float (351) moves in an arced pathway around the pivot (379).

23. A liquid level sender and liquid pick up device (301) as claimed in claim 22, wherein the liquid pick-up float (351) has a free-flooding internal volume (357) to which the liquid pick-up inlet is attached.

24. A liquid level sender and liquid pick up device (301) as claimed in claim 22 or claim 23, wherein the static component of the liquid level sensor (335) is an array of reed switches (339).

25. A liquid level sender and liquid pick up device (301) as claimed in any one of claims 22 to 24, further comprising a liquid return line (325) that is attached to the body (303), that has an inlet end fluidly connected to the connector head (305) and to one end of the internal bore (329) of the float tube (325) and that has an outlet end at the other end of the internal bore (329) of the float tube (325), wherein, in use, the outlet end is located within the liquid reservoir (1).

26. A liquid level sender and liquid pick up device (301) as claimed in claim 25, wherein a liquid directing means (331) is provided at the outlet end of the liquid return line (325), such that, in use, at least some of the liquid exiting the liquid return line (325)_through its outlet end is directed by the liquid directing means (331).

27. A liquid level sender and liquid pick up device (301) as claimed in any one of claims 22 to

26, wherein the liquid pick-up conduit has a rigid part (373) and a flexible part (375).

28. A liquid level sender and liquid pick up device (301) as claimed in any preceding claim, wherein the fitment is for fitting the device to an industry standard ancillary aperture (5).

29. A liquid level sender and liquid pick up device (101 ,201) for fitting to a liquid reservoir (1) through an industry standard ancillary aperture (5) and comprising a body (103,203) having a fitment for fitting the device (101 ,201) to a liquid reservoir (1), a connector head (105,205) attached to the body (103,203), a liquid level sensor (135,235), a liquid return conduit (125,271) with an outlet end and with an inlet end that is fluidly connected to the connector head (105,205), a moveable liquid level sensor float (141 ,251) guided by a guiding arrangement that is attached to the body (103,203), a moveable liquid pick-up receptacle (157,257) guided by a guiding arrangement that is attached to the body (103,203), such that, in use, the moveable liquid level sensor float (141 ,251) and the moveable liquid pick-up receptacle (157,257) each move along a common pre-defined pathway, the moveable pickup receptacle (157,257) having an internal volume with at least one flooding aperture (167,267), wherein there is provided a liquid pick-up conduit that has an inlet end that is fluidly connected to the internal volume of the moveable pick-up receptacle (157,257), and that has an outlet end that is fluidly connected to the connector head (105,205).