GB2417239A

GB2417239A - Preventing the theft of liquids from tanks

Info

Publication number: GB2417239A
Application number: GB0418509A
Authority: GB
Inventors: Paul Millard
Original assignee: P & C Fabrications
Current assignee: P & C Fabrications
Priority date: 2004-08-19
Filing date: 2004-08-19
Publication date: 2006-02-22
Also published as: GB0418509D0

Abstract

Existing devices for preventing theft of fuel from tanks rely on the principle of placing an obstruction inside a pipe leading to the tank so as to prevent insertion of a siphon tube. A problem is that these obstructions cannot be used in lorry fuel tanks where the inlet to the tank is a simple hole provided with a lip for retaining a removable fuel-cap; without any tube or only a short tube leading from the opening to the main body of the tank. The problem is solved using a device that is designed to attach to the aforementioned lip at the tank inlet. The device includes a substitute lip 3 onto which the fuel-cap can fit and has a cylindrical barrel 10 which receives a pump nozzle during refuelling. This barrel has a perforated tube 11, wherein the apertures are sufficiently large to allow free flow of fuel but sufficiently small to prevent passage of a siphon tube. Screws 20 can serve to clamp the tank-inlet lip 3 firmly between annular flanges 12 and 18, to hold the anti-theft assembly permanently onto the tank.

Description

24 1 7239

PREVENTING THE THEFT OF LIQUID FROM TANKS

This invention relates to a device for preventing the theft of liquid from tanks. It was particularly devised for preventing theft of fuel from large vehicles such as trucks and lorries but it could also be used on tanks installed at fixed locations.

Diesel tanks on lorries are normally equipped with lockable fuel caps which are effective as a deterrent against unplanned casual theft. However, these lockable caps can easily be wrenched off, using a suitable tool, whereupon the diesel can be siphoned or pumped away. Another problem is that lorry drivers may themselves be tempted to steal fuel in a sufficient quantity to have a significant value but not so much as to raise the suspicion of their employers.

Many proposals have previously been made for preventing the theft of fuel from motor cars. These have usually involved placing an obstruction inside a pipe leading to the tank so as to prevent insertion of a siphon tube. However these previous proposals have also hindered the flow of fuel into the tank and cannot be used in the type of tank, such as used on lorries, where there is no tube, or only a very short tube, leading to the tank. Also, many of the previous proposals have required some form of interference with the integrity of the tank or the tube leading to it, eg by drilling holes, and this can have safety implications as well as requiring the services of a specialist fitter equipped with specialist - 2 tooling. The invention was made in an endeavour to overcome the above problems.

According to this invention there is provided a device for preventing the theft of liquid from a tank, the tank having a tank-inlet lip designed to receive a removable closure cap: the device being designed to attach to the tank-inlet lip; and including a substitute lip which performs the function of the tank-inlet lip when the device is fitted.

There are many ways in which the device can be attached permanently in position. A clamping arrangement which clamps onto the tank-inlet lip is preferred because it can be designed in a way which is simple to construct and to fit, whilst providing a very strong connection which cannot easily be wrenched off. However other arrangements would be possible. For example, a spring-action retainer could be included, allowing easy insertion of the device into the tank but preventing removal. Whatever form of attachment is used, it is preferably permanent; though it may be feasible to employ some form of locking device which could be released using a key kept by someone other than the vehicle driver.

One way in which the invention may be performed will now be described with reference to the accompanying drawing which shows an exploded perspective view of an antitheft device constructed in accordance with the invention. - 3

Referring to the drawing, a diesel tank (not shown) for a lorry has a short inlet sleeve 1 defined by a cylindrical body 2 welded to the main body of the tank.

The top of the cylindrical body 2 is rolled over to form a tank-inlet lip 3 having diametrically opposite slots 4. This tank-inlet lip 3 extends circumferentially at and then axially downwards at 6. The downwardly extending part 6 has two ramped surfaces 7 (only one shown) which terminate at abutments 8 (also only one shown). In normal use, a lockable bayonet-type retaining bar within a conventional fuel cap 9, passes through the slots 4 and is turned, using a key, so that it slides over the ramped surfaces, tightening into position, until further rotational movement is prevented by the abutments 8.

A steel receptacle 10 is formed from a perforated tube 11 closed at its bottom end and welded at its upper end to an annular flange 12. This flange has two projecting tabs 13 and four threaded bushes 14 as shown. Each tab has a slot 15 for a purpose which will become apparent later.

A retaining member 16 is formed from a cylindrical wall 17, to the lower end of which is welded an annular flange 18. This flange has four holes 19 (only one shown), in positions corresponding to the threaded bushes 14, to receive respective tamperproof screws 20. - 4

The top end of the cylindrical wall 17 is rolled over in exactly the same way as the cylindrical body 22 to form a substitute tank-inlet lip 21 having diametrically opposite slots 22. This substitute tank-inlet lip 21 extends circumferentially at 23 and then axially downwards at 24. The downwardly extending part 24 has two ramped surfaces 25 (only one shown) which terminate at abutments 26 (also only one shown).

To fit the illustrated device to a fuel tank, the screws 20 are threaded through the holes 19 and screwed loosely into the threaded bushes 14 to form an antitheft assembly. The perforated receptacle 10 is then inserted into the tank so that the tabs 13 pass through the slots 4. The assembly is then rotated and lifted so that the abutments 8 enter the slots 15. The screws 20 are now tightened, this serving to clamp the tank-inlet lip 3 firmly between the annular flanges 12 and 18, holding the antitheft assembly permanently onto the tank. Many different designs of tamperproof screw are available. For example, some have a head which allows engagement of a screwdriver for turning in one but not the other direction. Others have an area of weakness allowing the head to break off after tightening above a predetermined torque. A thread- locking adhesive can be used as an alternative or supplementary method of preventing removal of the screws.

In use it will be seen that the substitute tank inlet lip 21 acts in exactly the same way as the original action of the lip 3, whilst the new function of the latter is to hold the antitheft assembly in position. The receptacle 10 prevents intrusion of a - s - tube into the tank for the theft of fuel whilst comfortably accommodating a fuel nozzle and permitting rapid flow of fuel into the tank.

In an alternative construction the tabs 13, instead of having slots 15 to receive abutments 26, could have upwardly extending extremities to engage the underside of the circumferential part 5 of the tank-inlet lip 3, providing sufficient frictional grip to prevent reverse rotation and removal of the antitheft assembly after it has been fitted.

It will be appreciated that many other alternative constructions are possible without departing from the scope of the invention as defined by the accompanying Claims. However it is believed that an assembly, constructed on similar principles to the illustrated example, has the potential to provide a simple and highly effective solution to the growing problem of fuel theft from lorries and trucks. Furthermore, in contrast with previous proposals, the system can be fitted by anybody without the need for any special tooling. - 6

Claims

1. A device for preventing the theft of liquid from a tank, the tank having a tank-inlet lip designed to receive a removable closure cap: the device being designed to attach to the tank-inlet lip; and including a substitute lip which performs the function of the tank-inlet lip when the device is fitted.

2. A device according to Claim 1 including means for clamping the device onto the tank-inlet lip.

3. A device according to claim 2 in which the device has projections which fit through slots in the tank-inlet lip, at least one of these projections having an opening designed to receive an abutment defined by the tank-inlet lip.

4. A device according to any preceding Claim comprising a receptacle which is designed to fit into the tank, to receive a filling nozzle, to allow free passage of liquid fuel into the tank and to prevent passage of a tube into the tank; and a retaining member which is designed to fit outside the tank and

5. A device according to Claim 5 in which the receptacle and the retaining member each has an annular flange, these flanges being adapted to be clamped together with the interposition of the tank-inlet lip. - 7

6. A device according to Claim 5 including means for clamping the tankinlet lip between the receptacle and the retaining member.

7. A device according to Claim 5 or 6 in which the retaining member has a

S tubular wall connected at one end to the annular flange and at the other end to 8. A device according to Claim 5, 6 or 7 in which the flanges are adapted to be clamped together by screws and wherein means is provided for preventing removal of the screws.

9. An antitheft device according to Claim 1 and substantially as described with reference to and as illustrated in the accompanying drawings.