FUEL-PICK-UP DEVICE

Abstract

A fuel pick-up device (11) for a fuel tank (10) comprises a float (17) arranged for rising and falling with the level of fuel (F) in the tank (10) and a plurality of elongate flexible tubes (16a, 16b) extending helically from the float (17) to a fuel outlet (15) of the device (11), the float (17) being arranged for generally vertical movement within an apertured sleeve (13). The flexible tubes (16a, 16b) are sufficiently thin to allow the float (17) to freely rise and fall with the level of the fuel (F). However, the combined cross-sectional area of the ducts provided by the plurality of flexible tubes (16a, 16b) is sufficient to allow fuel to be drawn from the tank at a high flow rate sufficient for large engines.

Claims

1. A fuel pick-up device comprising a float arranged for rising and falling with the level of fuel in a tank and a plurality of elongate flexible tubes extending from the float to a fuel outlet of the device, the float being arranged for generally vertical movement within a constraint which encloses the float and the elongate flexible tubes.

2. A fuel pick-up device as claimed in claim 1, in which solely two of said elongate flexible tube extending between the float and the outlet.

3. A fuel pick-up device as claimed in claim 1, in which the elongate flexible tubes extend independently of each other between the float and the outlet.

4. A fuel pick-up device as claimed in claim 1, in which the plurality of elongate flexible tubes extend helically between the float and the outlet about a longitudinal axis along which the float rises and falls in use.

5. A fuel pick-up device as claimed in claim 4, in which the helical turns of each elongate flexible tube are circumferentially offset about said axis by an angle of 360/n, where n is the number of flexible tubes.

6. A fuel pick-up device as claimed in claim 1, in which the elongate flexible tubes comprise open ends at the float.

7. A fuel pick-up device as claimed in claim 1, in which each elongate flexible tube is connected to a filter provided on the float.

8. A fuel pick-up device as claimed in claim 1, in which the elongate flexible tubes are recessed into a tubular side wall of the float.

9. A fuel pick-up device as claimed in claim 8, in which the elongate flexible tubes are recessed in respective channels which extend helically of the side wall of the float.

10. A fuel pick-up device as claimed in claim 1, in which the outlet comprises a single outlet having a manifold which fluidly interconnects connects each elongate flexible tube.

11. A fuel pick-up device as claimed in claim 1, in which each elongate flexible tube has a respective outlet.

12. A fuel pick-up device as claimed in claim 1, in which the tubes are engaged with an upper end of the filter.

Description

[0018] An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:

[0019] FIG. 1 is a perspective view, from one side and below, of internal components of a fuel pick-up in device accordance with the present invention; and

[0020] FIG. 2 is a schematic sectional view through a fuel tank to which the fuel pick-up device of FIG. 1 is fitted.

[0021] Referring to the drawings, there is shown a fuel tank 10 containing fuel F to which a fuel pick-up device 11 in accordance with the present invention is fitted. The device 11 is fitted to a circular aperture formed in the top wall of the tank 10. The device 11 comprises an elongate circular-section filter 13 in the form of a metal sleeve provided with an array of apertures 14. The sleeve 13 is open at its lower end and closed at its upper end by a flanged end cap 12, which is secured around its periphery to the edges of the aperture in the tank 10. A tubular fuel outlet duct 21 extends from the flanged end cap 12 for connecting to the engine of a machine.

[0022] The lower end of the outlet duct 21 is connected to a manifold 15 having two tubular arms, which are respectively connected to a pair of elongate helically-coiled flexible tubes 16a, 16b of plastics material. It is envisaged that the elongate helically-coiled flexible tubes 16a, 16b may be formed by wrapping straight tubes around a mandrel and then applying heat to the tube. The turns of the elongate helically-coiled flexible tubes 16a, 16b are offset from each other by an angle of 180 relative to the longitudinal axis of the sleeve 13.

[0023] A hollow tubular float 17 of plastics material is disposed inside the sleeve 13 and is connected to the lower ends of the elongate helically-coiled flexible tubes 16a, 16b. The float 17 has a tubular side wall of a diameter which is slightly less than the internal diameter of the sleeve 13, so that the float 17 can freely rise and fall inside the sleeve 13. The lower ends of the elongate helically-coiled flexible tubes 16a, 16b are attached to the upper ends of the float 17 by extending the tubes through respective apertured formations e.g. 18b on the upper end of the float 17. elongate helically-coiled flexible tubes 16a, 16b then extend helically down towards the lower end of the float in respective recessed channels e.g. 19b formed in the side of the float 17. The lower ends of the elongate helically-coiled flexible tubes 16a, 16b open into a bottom filter chamber 20 having side walls which are provided with apertures.

[0024] In use, the float 17 floats on the surface of the fuel F and fuel is drawn into the filter chamber 20 through the apertured side walls thereof and along the elongate helically-coiled flexible tube 16a, 16b. The apertures in the side walls of the filter chamber 20 serve to filter the fuel and prevent sediment and other contaminants from being drawn up the elongate helically-coiled flexible tubes 16a, 16b. The apertures 14 in the sleeve 13 also serve to prevent suspended sediment and other contaminants from entering the device. The fuel then flows out of the elongate helically-coiled flexible tubes 16a, 16b to the outlet 21 via the manifold 15.

[0025] The elongate helically-coiled flexible tubes 16a, 16b are sufficiently flexible to allow the float 17 to freely rise and fall inside the sleeve 13 according to the level of fuel F in the tank 10. However, the combined cross-sectional area of the ducts provided by the elongate helically-coiled flexible tubes 16a, 16b is sufficient to allow fuel F to be drawn from the tank 10 at a high flow rate.