GB2230765A

GB2230765A - Insert for restricting access to fuel tank

Info

Publication number: GB2230765A
Application number: GB8908602A
Authority: GB
Inventors: David Thomas Bowles
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1989-04-15
Filing date: 1989-04-15
Publication date: 1990-10-31
Anticipated expiration: 2009-04-15
Also published as: GB2230765B; GB8908602D0

Abstract

An insert for the filler neck of a fuel tank is made in one piece as a plastics article. It has an access portion 22 which is of a size such that only the nozzle of an unleaded fuel pump can pass into it, a larger nozzle such as used for leaded fuel being unable to enter. After the unleaded fuel nozzle has passed through the access portion, it enters a tapered passage 26 and movement of the nozzle along the tapered passage cause radially arranged fingers 28 of a valve portion 24 to open. The access portion preferably includes a tapered portion 20 which is clipped or bonded to the neck of a filler pipe of the tank. <IMAGE>

Description

Fuel Tank Filler Pipe Insert This invention relates to a fuel tank filler pipe insert.

The invention is particularly intended to restrict access to the fuel tank so that the tank can only be filled with unleaded petrol.

Regulations require that petrol pumps for leaded fuel have a larger diameter nozzle than those for unleaded fuel.

Because engines intended to run on unleaded fuel only can be damaged if leaded fuel is inadvertently used, it is known to put some form of restriction into the fuel tank filler pipe to prevent the nozzle of a leaded petrol pump being used to fill the tank of an unleaded engine. Such restrictions use the difference in nozzle diameter to determine whether the fuel is leaded or unleaded and therefore whether the fuel will be allowed in.

Known restrictions have a gate in the filler pipe which can be pushed aside by the small diameter unleaded nozzle, but cannot be moved by the large diameter leaded nozzle. Because the larger nozzle cannot open the gate, an attempt to fill the tank with the larger nozzle will result in an immediate back pressure which will trigger the closing of the nozzle before any appreciable amount of fuel has been dispensed.

These known restrictions however have the disadvantage that they are made up of a number of components and are difficult to secure in the filler pipe.

According to the present invention, there is provided a fuel tank filler pipe insert comprising a generally tubular body moulded in one piece of a plastics material, the body having a tapering entry portion at one end, a resiliently closing valve portion at the other end and an access portion between the ends, the access portion being non-elastic and having an open circular cross-section dimensioned to receive a first fuel filler nozzle of a first predetermined size and to deny access to a fuel filler nozzle larger than said first nozzle, and the valve portion being normally closed but capable of being opened by insertion of a first fuel filler nozzle through the access portion into the valve portion.

The entry portion is preferably in the form of a tapered passage connected to the access portion, and the access portion is preferably connected to the valve portion by a second tapered passage. All the passages and all the portions are preferably concentric. The access portion preferably has a constant cross-section over its length.

The valve portion may be a parallel-sided cylinder with a closed end, with the walls and the end being formed by a series of fingers which emanate from the access portion. The fingers are constructed so that they normally form a substantially closed cylinder. However when the correct sized nozzle is pushed through the access portion, the fingers are opened out to leave the end of the nozzle in direct communication with the tank.

The insert can suitably be moulded in an acetal material.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic view of part of a car showing the fuel tank filler pipe with an insert in accordance with the invention; Figure 2 is a cross-section through an insert in accordance with the invention; Figure 3 shows the insert with a fuel filler nozzle inserted; and Figure 4 is an external perspective view of the insert.

Figure 1 shows part 10 of the external surface of the bodywork of a car, with a fuel filler recess 12. Normally this recess would be closed by a door which is not shown here. In the recess is the mouth 14 of a fuel filler pipe. 16 which leads to the car's fuel tank (also not shown). At the mouth 14, there will also be a socket for receiving a fuel cap. Neither the socket nor the fuel cap are shown here because they form no part of the present invention.

Located in the filler pipe, at the top of the pipe, is an insert 18. The insert is made of a plastics material which is unaffected by contact with motor fuel, and will be secured in place in the neck by any convenient fastening method. The neck itself may be of plastics, and the fastening of the insert in the neck can be through a clipping arrangement or through some form of bonding.

The insert itself has an entry portion 20, an access portion 22 and a valve portion 24. The access portion and the valve portion are parallel-sided and are connected by a tapered passage 26.

Figure 4 shows how the valve portion 24 is made up of fingers 28. The fingers are separated from one another by longitudinal slits 30. The slits start in the access portion 22 and end in segment shaped tongues 32 which together make up a continuous base for the valve portion.

Figure 3 shows what happens when a fuel filler nozzle 34 is pushed into the insert. The nozzle 34 is an unleaded fuel nozzle, and it fits inside the access portion of the insert.

The act of pushing the nozzle through the tapered passage spreads the fingers 28 so that the valve portion is opened wide and offers no obstruction to the incoming fuel. The figure also shows the relative size of a leaded petrol nozzle at 36. This larger diameter nozzle cannot enter the access portion 22 and consequently it cannot open the valve portion.

If this nozzle is used with just its tip in the insert, the automatic shut off mechanism of the nozzle will be immediately triggered because of the closed valve portion.

Although this valve portion does not provide a complete fluid tight seal, it does provide sufficient resistance to flow to operate the automatic shut-off feature of the nozzle.

Claims

1. A fuel tank filler pipe insert comprising a generally tubular body moulded in one piece of a plastics material, the body having a tapering entry portion at one end, a resiliently closing valve portion at the other end and an access portion between the ends, the access portion being non-elastic and having an open circular cross-section dimensioned to receive a first fuel filler nozzle of a first predetermined size and to deny access to a fuel filler nozzle larger than said first nozzle, and the valve portion being normally closed but capable of being opened by insertion of a first fuel filler nozzle through the access portion into the valve portion.

2. An insert as claimed in Claim 1, wherein the entry portion comprises a first tapered passage connected to the access portion, and the access portion is connected to the valve portion by a second tapered passage.

3. An insert as claimed in Claim 2, wherein all the passages and all the portions are concentric.

4. An insert as claimed in any preceding claim, wherein the valve portion is a parallel-sided cylinder with a closed end, with the walls and the end being formed by a series of fingers which emanate from the access portion.

5. An insert as claimed in Claim 4, wherein the fingers are constructed so that they normally form a substantially closed cylinder but when the correct sized nozzle is pushed through the access portion, the fingers are opened out to leave the end of the nozzle in direct communication with the tank.

6. An insert as claimed in any preceding claim, wherein the access portion has a cross-section which is substantially constant along its length.

7. An insert substantially as herein described, with reference to the accompanying drawings.