GB2240331A

GB2240331A - Mounting a sleeve in the neck of a filler pipe

Info

Publication number: GB2240331A
Application number: GB9002040A
Authority: GB
Inventors: David Thomas Bowles
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1990-01-30
Filing date: 1990-01-30
Publication date: 1991-07-31
Also published as: GB9002040D0

Abstract

In a fuel filler pipe arrangement comprising a sleeve 12 having an external diameter to be a snug fit inside a fuel filler pipe terminal 10 and an internal diameter of a size to refuse access to a leaded-fuel filler nozzle, the sleeve is formed as a plastics moulding and the sleeve exterior and terminal interior carry cooperating formations 26-34; 20, 22 respectively which allow the sleeve to be pushed into the terminal and be locked in place by engagement of the formations. <IMAGE>

Description

MOUNTING A SLEEVE IN THE NECK OF A FILLER PIPE This invention relates to an arrangement for mounting a sleeve in the neck of a fuel filler pipe. In particular, the sleeve may be a diameter reducing sleeve to convert the filler pipe from one which can be filled with any grade of fuel to one which can be filled only with unleaded fuel.

Vehicles which are fitted with catalytic converters in order to minimise exhaust emissions must run on unleaded fuel. The introduction of leaded fuel will lead to poisoning of the of the catalyst. In order to provide a clear differentiation between leaded fuel supply and unleaded fuel supply, the two different types of fuel are generally supplied through filler nozzles of different diameters, with the filler nozzle for unleaded fuel being smaller than that for leaded fuel. In order to adapt a conventional (leaded) fuel tank to allow the tank to be filled only with unleaded fuel, it is desirable to place an adapter in the mouth of the tank which will deny access to the (larger) leaded fuel filler nozzle.

According to the invention there is provided an arrangement for mounting a sleeve in the neck of a fuel filler pipe, the arrangement comprising a filler pipe terminal and a sleeve having an external diameter to be a snug fit inside the filler pipe terminal and an internal diameter of a size to refuse access to a filler nozzle used for leaded fuel but to allow access to a filler nozzle used for unleaded fuel, the sleeve being formed as a plastics moulding and the sleeve exterior and the interior of the filler pipe terminal carrying cooperating formations which allow the sleeve to be pushed into the terminal and then locked in place by engagement of the formations.

Preferably the sleeve is a single plastics moulding, and the cooperating formations on the sleeve include resilient tongues which can be pushed aside when they pass the formations on the terminal and spring back behind the formations to lock the sleeve in place.

Preferably the filler pipe terminal itself is also moulded from plastics material, and is designed so that it can be manufactured as a single injection moulding. Where the filler pipe for the tank is also plastics, the terminal may then be welded to the end of the filler pipe, and the invention extends to a fuel tank with a filler pipe terminal as set forth above welded to the end of the filler pipe.

The internal diameter of the sleeve may taper from one end to the other.

The sleeve may also include a hinged flap which is spring loaded into a position where it normally closes the internal diameter of the sleeve but can be pushed open by an unleaded fuel filler nozzle when the nozzle is pushed through the sleeve.

The flap may be a separate component snap-fitted onto the sleeve (which can be form as a single injection moulding), and the spring biasing the flap to its closed position may be an integral part of the sleeve moulding.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a sleeve and a filler pipe terminal in accordance with the invention; Figure 2 is an end view of the filler pipe terminal, omitting the sleeve; Figure 3 is a sectional view of the terminal of Figure 2; Figure 4 is an end view of the sleeve alone; Figure 5 is a cross section through the sleeve; and Figure 6 is a perspective view of an alternative filler pipe terminal.

Figure 1 shows a filler pipe terminal 10 and a sleeve 12.

The terminal is welded to the end of a plastics fuel filler pipe 10a and is constructed so that it both retains a filler cap and locates the sleeve. It has a peripheral flange 16 at its free end which forms one part of a bayonet fastening for a filler cap (not shown). The axial dimension of the flange 16 varies around the circumference to form the cam surface necessary for the cap to be tightened onto the neck as the cap is done up on the bayonet fastening. The flange also has two diametrically opposite slots 18 which allow entry of the bayonet lugs on the cap. The remainder of the terminal has a cylindrical wall 14, the thickness of which is indicated by a dotted line. The internal bore 14 of the terminal also includes lugs 20 and 22 which are in line with the slots 18. These lugs have a tapered leading end facing the mouth of the terminal, and a squared off trailing end.

The design of the terminal in this way allows it to be manufactured in a single injection moulding process. The mould tools can be withdrawn from the completed moulding along the axis of the terminal.

The sleeve 12 has an internal bore 24 and external formations at 26 and 28. The overall dimensions of these formations 26,18 match those of the slots 18. The construction of these formations will be clearest when considering the uppermost formation, 26, in Figure 1. It is to be understood however that the lowermost formation 28 will have the same features.

The formation 26 includes a slot 30 which will accommodate the lug 20 in the filler terminal. To the right of the slot 30 is an entry neck which has two wings 32,34. The wings are just connected to the rest of the sleeve at one end, and are otherwise separated from the sleeve by a slit 36. The wings form an access opening to the slot 30 which is narrower than the slot. When the sleeve is pushed into the filler neck 10, the lugs 20 initially enter the passage between the wings 32,34. As the sleeve is pushed in, the wings spread apart to allow the lug 20 to pass, and when the lug is fully received in the slot 30, then the wings snap back behind the lug to prevent removal. In this way, the sleeve 12 can be simply and permanently fitted in the neck 10 through the slots 18 which also function as part of the bayonet fastening for the filler cap.

Most of these features can be seen also in Figures 2 to 5.

It is common to construct the fuel tanks of motor vehicles from plastics by a blow moulding process. However blow moulding does not allow the production of accurately shaped internal components as are required at the neck of a fuel tank, and therefore a separately formed, injection moulded terminal 10 is welded to the blow moulded part 10a of the neck. This can be seen in Figures 1 and 3.

Figures 4 and 5 show how the internal bore 24 in the sleeve tapers from a large diameter at one end to a relatively small diameter at the other end. At the small diameter end, a hinged flap 38 is fitted and is normally held in a closed position by a spring 40 which is moulded in one piece with the sleeve.

In order to fill the fuel tank, the flap 38 has to be opened and this will be done by pushing the end of the fuel filler nozzle through the bore 24 so that the end of the nozzle pushes aside the flap 38. This will however only be possible with a nozzle which has a diameter smaller than that of the narrow end of the bore 24, and this narrow end will be of a dimension such that only a fuel filler nozzle for unleaded fuel will pass through.

Figure 6 shows an alternative terminal design where an internal thread is formed by two thread portions 50, 52 to allow a filler cap to be screwed on. Other features of this terminal are unchanged from those shown in Figures 1, 2 and 3. The terminal can still be formed as a single injection moulding.

The arrangement disclosed can be simply constructed and allows the option of either fitting a leaded fuel inhibitor or not to a standard fuel tank. If the leaded fuel inhibitor in the form of a sleeve 12 is to be fitted, then the fitting operation is a simple push in action.

Claims

1. An arrangement for mounting a sleeve in the neck of a fuel filler pipe, the arrangement comprising a filler pipe terminal and a sleeve having an external diameter to be a snug fit inside the filler pipe terminal and an internal diameter of a size to refuse access to a filler nozzle used for leaded fuel but to allow access to a filler nozzle used for unleaded fuel, the sleeve being formed as a plastics moulding and the sleeve exterior and the interior of the filler pipe terminal carrying cooperating formations which allow the sleeve to be pushed into the terminal and then locked in place by engagement of the formations.

2. An arrangement as claimed in Claim 1, wherein the sleeve is a single plastics moulding, and the cooperating formations on the sleeve include resilient tongues which can be pushed aside when they pass the formations on the terminal and spring back behind the formations to lock the sleeve in place.

3. An arrangement as claimed in Claim 1 or Claim 2, wherein the filler pipe terminal itself is also moulded from plastics material, and is designed so that it can be manufactured as a single injection moulding.

4. An arrangement as claimed in Claim 3, wherein the filler pipe for the tank is also plastics and the terminal is welded to the end of the filler pipe.

5. An arrangement as claimed in any preceding claim, wherein the internal diameter of the sleeve tapers from one end to the other.

6. An arrangement as claimed in any preceding claim, wherein the sleeve includes a hinged flap which is spring loaded into a position where it normally closes the internal diameter of the sleeve but can be pushed open by an unleaded fuel filler nozzle when the nozzle is pushed through the sleeve.

7. An arrangement as claimed in Claim 6, wherein the flap is a separate component snap-fitted onto the sleeve (which can be form as a single injection moulding), and the spring biasing the flap to its closed position may be an integral part of the sleeve moulding.

8. An arrangement for mounting a sleeve in the neck of a fuel filler pipe, substantially as herein described with reference to the accompanying drawings.

9. A fuel tank with a sleeve mounting arrangement as claimed in any preceding claim welded to the end of the filler pipe.