GB2157662A - Drainage arrangement - Google Patents

Abstract

A drainage arrangement for a liquid container such as a vehicle fuel tank 10 includes a cylindrical member 15 which is mounted in the base wall 11 of the container. A drainage path 17 is defined between the member 15 and the container and is arranged to be closed by a seal member carried by an annular member 18 movable on the cylindrical member towards and away from the base wall. The annular member has a flange 19 having a wall 20 extending upwardly and outwardly to define a trough 21 from which extends a tubular outlet 22. The trough receives liquid from the container which flows through the drainage path when the latter is opened. <IMAGE>

Description

SPECIFICATION Drainage arrangement This invention relates to a drainage arrangement for a liquid container.

A number of forms of drainage arrangement are known for containers for example containers used in the fuel system of a vehicle engine. Such a container may be the fuel tank of the vehicle or the container of a fuel treatment device such as sedimentation unit. The most common form of drainage arrangement comprises a plug which is screwed into a boss defined by the base wali of the container. When the plug is removed the contents of the container will drain through the aperture in the boss. The removal of the plug inevitably means that the hands of the operator will be covered in the liquid and the same will apply if it should be required to insert the plug before all the contents of the container have been drained. This may well be the case when all that is required is to drain water which has collected in the tank. The advantage of the drain plug is that it is cheap.A more expensive arrangement is a tap and this has the advantage that it is possible for the operator to avoid the liquid in the tank flowing onto his hands.

The tap usually projects from the base of the tank where it can be knocked and damaged and also it usually incorporates co-operating sealing surfaces which are expensive to manufacture.

The object of the invention is to provide a drainage arrangement for a liquid container in a simple and convenient form.

According to the invention a drainage arrangement for a liquid container comprises a cylindrical member adapted to be secured in the base wall of the container, an annular member slidable on said cylindrical member, a drainage path from the interior of the container, sealing means carried by said annular member, said sealing means acting to close said drainage path when the annular member is moved into close proximity to the base wall of the container and opening said drainage path as the annular member is moved away from the base wall, means operable to effect movement of said annular member towards said container and a trough defined in said annular member to receive liquid drainage through said drainage path.

Examples of drainage arrangement in accordance with the invention will now be described with reference to the accompanying drawings in which Figure 1 is a part sectional side elevation of a container with one example of the drainage arrangement, Figure 2 is a view similar to Figure 1 showing part of the drainage arrangement in an alternative position, FIgure 3 is a view similar to Figure 1 showing another form of drainage arrangement, Figure 4 is a view similar to Figure 1 showing a drainage arrangement similar to that of Figure 1 but showing a different actuation arrangement, Figure 5 is a sectional side elevation of another form of drainage arrangement, and Figure 6 is a perspective view of a part of the drainage arrangement shown in Figure 5 removed from the assembly.

Referring to Figures 1 and 2 of the drawings there is illustrated at 10 a container which forms a sedimentation unit in a fuel system for a compression ignition engine. The fuel is passed into the container and large particles of dirt and also water will collect at the bottom of the container. The container has a base wall 11 in which is formed a first boss 12 to receive a bolt not shown, serving to secure the container to a mounting. The base wall is also provided with a threaded aperture 13 in which is engaged a threaded cylindrical member 14. The member 14 has an integral right cylindrical portion 15 exterior of the container which is connected to an enlarged portion 16 spaced from the exterior of the base wall of the container. The portion of the cylindrical member 14 within the container forms the body of an electrical probe for detecting the presence of water in the container.The aperture 13 is provided with an axial slot which is indicated at 17, the slot serving to define a drainage path from the interior of the container.

Mounted about the right cylindrical portion 15 is an annular member 18 having an outwardly directed flange portion 19 integral with a wall 20 extending upwardly and outwardly, the wall 20 defining a trough 21 from which extends a tubular outlet 22. The member 18 is movable axially on the right cylindrical portion 15 and as will be seen in Figure 2, at its end adjacent the container it mounts a sealing ring 23 and further sealing members 24 are provided between the surface of the cylindrical portion and the internal surface of the member 18.

The member is movable axially so as to cause the sealing member 23 to engage with the base wall of the container at a position outwardly of the slot 17. In this position, which is shown in Figure 1, no flow of liquid can take place through the slot but if the annular member is moved downwardly to the position shown in Figure 2, liquid in the base of the container can flow through the slot and will flow into the trough 21. It can then discharge through the outlet 22 which may receive a drainage pipe.

In order to achieve axial movement of the member 18, the enlarged portion incorporates balls 25 which upon angular movement from the position shown in Figure 1, can locate within recesses 26 formed in the flange 19. The downward movement of the annular member may be effected by utilising resilient means in the form of a coiled spring and conveniently the exterior of the wall 20 is provided with ribs to enable an operator to grip the wall so as to be able to effect the required angular movement. It is desirable to provide a number of sets of recesses into which the balls can locate since this enables the general angular position of the annular member to be set.

In the arrangement shown in Figure 3 the annular member 18 is substantially identical with the member 18 of Figure 1 but instead of moving the member 18 angularly to allow its downward move ment, there is provided an annular plate member 27 movable angularly about the portion 15 and interposed between the annular member and the enlarged portion 16. The plate member 27 is provided with projections 28 on its peripheral surface to enable it to be moved angularly and it accommodates the balls 25.

The arrangement shown in Figure 4 shows the use of a special shaped bolt 29 instead of the probe unit 14 which is shown in Figures 1 and 2.

Moreover, the head 30 of the bolt has its undersurface shaped to provide ramps 31 which upon movement of the annular member 32 co-operate with ramp surfaces formed on the annular member 32 to effect the axial movement of the annular member towards the base wall of the container. It will also be noted that in this example the drainage path is constituted by a slot 33 formed in the bolt.

Turning now to Figure 5, this shows an alternative way of actuating the annular member. Moreover, it shows in greater detail the probe unit and wherever possible, the reference numerals of Figures 1 and 2 are utilised. It will be observed that the enlarged portion 16 is in fact hollow and defines a recess 34 in which is located an electrical circuit board 35 which mounts electrical components forming a circuit which is able to provide an indication of the level of water in the base wall of the container. The arrangement of Figure 5 differs from that of Figure 1 in the way in which the member 18 is moved axially. In the example of Figure 5 there is provided a camming arrangement which includes a pair of angularly movable cam elements 36 which are interposed between the presented surfaces of the annular member 18 and the enlarged portion 16.The cam elements are diametrically disposed and at their outer ends are connected to arms 37 respectively which are interconnected by a hoop portion 38. Each cam element is provided at its inner end, with a cylindrical guide portion 39 which is located within a complementarily shaped recess 40 in the cylindrical portion 15.

Moreover, at a position removed from the portion 39 there is defined a further guide portion 39A which is engageable with the surface of the enlarged portion 16. The curvature of the surface of the cylindrical guide portion and also the further guide portion 39A is substantially the same. intermediate the portions 39 and 39A is an actuating portion 41 which is of cylindrical form and which has its axis offset from the axes of the surfaces of the portions 39 and 39A. The cam elements 36 together with the arms 37 and the hoop portion 38 can be formed as a moulding from "Nylon" or other synthetic resin material or from a metal such as aluminium.

As shown in Figures 5 and 6 the annular member 18 is urged upwardly against the base wall of the container thereby sealing the drainage path. If now the cam elements are moved through approximately 90 by appropriate movement of the hoop portion 38, the annular member 18 can move downwardly to open the drainage path. The cam elements are retained in the position shown by means of a clip action which is provided by surfaces 42 defined at the ends of the arms 37 remote from the elements 36, the surfaces 42 engaging with complementary surfaces defined on the enlarged portion 16.

In all the examples described it is possible for an operator to open the drainage path without water or fuel flowing onto his hands and the sealing of the drainage path is achieved using simple elastomeric seals which engage surfaces which do not have to be machined to a high degree of accuracy.

It is also possible to actuate the annular member 18 using air or electrically operated servo mechanisms which can be brought into operation when the water sensing probe senses that the level of the water in the bottom of the container has risen to a level such that there is a risk that it might be drawin into the remaining portion of the fuel system. It is also possible to use instead of the ramps, ball mechanisms and cam elements illustrated, screw threads to effect the required movement although the use of such threads may require more than the ideal amount of rotational movement to be applied to the annular member.

Claims (15)

1. A drainage arrangement for a liquid container comprising a cylindrical member adapted to be secured in the base wall of the container, an annular member slidable on said cylindrical member, a drainage path from the interior of the container, sealing means carried by said annular member, said sealing means acting to close said drainage path when the annular member is moved into close proximity to the base wall of the container and opening said drainage path as the annular member is moved away from the base wall, means operable to effect movement of said annular member towards said container and a trough defined in said annular member to receive liquid drainage through said drainage path.

2. An arrangement according to Claim 1 in which said sealing means includes an annular sealing ring mounted on said annular member and arranged to engage with the exterior of the base wall of the container.

3. An arrangement according to Claim 2 in which said sealing means further includes a seal member or members interposed between the cylindrical member and the annular member.

4. An arrangement according to Claim 1 in which said drainage path is defined by a slot defined between said cylindrical member and the base wall of the container.

5. An arrangement according to Claim 1 in which said cylindrical portion mounts an enlarged portion at its end remote from the container, the means operable to effect movement of the annular member being located intermediate the enlarged portion and said annular member.

6. An arrangement according to Claim 5 in which said means includes recesses formed in the face of the annular member presented to the enlarged portion, and balls carried by said enlarged portion or a part angularly moveable relative thereto, said balls and the recesses being aligned with each other to permit movement of the annular member away from the container to open said drainage path.

7. An arrangement according to Claim 5 in which said means comprises ramps defined on said enlarged portion and ramp surfaces on said annular member.

8. An arrangement according to Claim 5 in which said means comprises a pair of angularly movable cam elements which are diametrically disposed on opposite sides of the cylindrical portion, arms connected to the outer ends of the camele- ments respectively, a hoop interconnecting said arms whereby the cam elements can be moved angularly together and clip means for retaining the cam elements in an operative position in which said drainage path is closed.

9. An arrangement according to Claim 8 in which each cam element comprises an intermediate actuating portion and outer guide portions, said portions being of cylindrical form, the axis of the actuating portion being offset from the axes of the guide portions.

10. An arrangement according to Claim 9 in which the inner one of the outer guide portions are located in recesses respectively formed in the cylindrical member.

11. An arrangement according to any one of the preceding claims in which said enlarged portion is hollow the interior of said enlarged portion serving to accommodate the electrical components of a sensing probe, the probe being constituted by a part of the cylindrical member within the container.

12. An arrangement according to any one of the preceding claims in which the cylindrical member is in screw thread engagement with the container.

13. An arrangement according to any one of the preceding claims including a tubular outlet communicating with the trough.

14. An arrangement according to any one of the preceding claims including resilient means acting to urge the annular member to a position to open the drainage path.

15. A drainage arrangement for a liquid container substantially as hereinbefore described with reference to the accompanying drawings.