WO1995029074A2

WO1995029074A2 - An engine emission restrictor

Info

Publication number: WO1995029074A2
Application number: PCT/NZ1995/000031
Authority: WO
Inventors: John Double Makavilitogia
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-04-15
Filing date: 1995-04-13
Publication date: 1995-11-02
Anticipated expiration: 1996-10-15
Also published as: AU2268895A; WO1995029074A3

Abstract

An engine emission restrictor (1) comprises a sleeve (3) and a stopper portion (4), the sleeve (3) being attached or attachable at or towards the end of an exhaust pipe (2) of or for the engine, the stopper portion (4) being releasably attachable to or within the sleeve (3) and serving, when fitted to, impede or prevent the flow of exhaust fumes out of the exhaust pipe (2). The engine emission restrictor may be particularly useful for securing a vehicle against theft, since when fitted to the exhaust pipe (2) of a vehicle the vehicle may not be easily driven away, if at all. A method of securing a vehicle utilising the engine emission restrictor (1) is also described.

Description

An Engine Emission Restrictor

TECHNICAL FIELD

This invention relates to an engine emission restrictor. In particular, this invention relates to an engine emission restrictor which may be fitted to the emission or exhaust pipe (herein: "exhaust pipe") of an engine. It is envisaged that the invention may be particularly suitable for fitting to the exhaust pipe of a vehicle to restrict or prevent engine emissions or exhaust fumes (herein: "exhaust fumes"), and thereby deter thieves from stealing the vehicle and/or for preventing the vehicle from being able to be stolen. However, it is to be understood and appreciated that the invention is not to be limited to such use. The prior art and possible applications of the invention as discussed below are therefore given by way of example only.

In this specification, the term "vehicle" is understood to include any engine operated vehicle such as a car, boat, motorcycle, tractor, motor mower, and so on.

BACKGROUND ART

Car theft is, unfortunately, a significant problem in most countries. As a result, numerous anti-theft devices for cars have been developed to deter would-be car thieves and/or prevent a car from being stolen.

There are two main types of anti-theft devices presently available. The first of these is warning devices such as electronic car alarms which are designed to emit a loud alarm or warning noise upon the car being broken into or otherwise interfered with. The activation of the alarm is usually sufficient for the would-be thief to be deterred from stealing the car and/or to compel them to quickly leave the scene.

However, one disadvantage associated with such car alarms is that the cost of purchasing and/or fitting same is usually substantial, and is therefore prohibitive for, or out of the price range of, many car owners. Another disadvantage is that car alarms are often activated or set off inadvertently either by the car owner, or by other means such as the wind or vibration. Not only is this of nuisance value to people in the vicinity of a car whose alarm has being inadvertently activated, but the continuous ringing of the alarm may eventually flatten the car battery.

The second type of anti-theft devices presently available are in the form of car immobilising devices. Examples of such devices are:

Devices which lock onto the steering wheel of a car and/or the brake pedal of a car.

Devices which lock onto the handbrake of a car.

Devices which, when engaged, can block the hydraulic brake lines of a car whereby the brakes are keep locked on until disengaged.

Advantages that such devices have over car alarms are that they are generally less expensive, less complicated, and not prone to false alarms. The present invention, in one embodiment or possible application, offers an alternative immobilising and/or anti-theft device for a vehicle such as a car, in the form of an engine emission restrictor which may be fitted to the exhaust pipe of the vehicle.

Accordingly, one object of the present invention is to address some or all of the foregoing problems or difficulties, or to at least provide the public with a useful choice.

It is a further object of the present invention to provide an engine emission restrictor.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided an engine emission restrictor comprising a sleeve and a stopper portion, said sleeve being attached or attachable at or towards the end of an exhaust pipe of or for the engine, said stopper portion being releasably attachable to or within said sleeve, the arrangement and construction of the engine emission restrictor being such that said stopper portion, when fitted to or within said sleeve, impedes or prevents the flow of exhaust fumes out of said exhaust pipe.

According to another aspect of the present invention there is provided an engine emission restrictor substantially as described above wherein the stopper portion is provided with engagement portions able to be releasably engaged with corresponding retention portions disposed upon or within said sleeve. According to another aspect of the present invention there is provided an engine emission restrictor substantially as described above wherein the stopper portion includes a locking mechanism operable to releasably lock said stopper portion with respect to said sleeve.

According to another aspect of the present invention there is provided an engine emission restrictor substantially as described above wherein said locking mechanism includes a biasing means operable to cause said engagement portions to engage and/or release said retention portions.

According to another aspect of the present invention there is provided an engine emission restrictor, substantially as described above, wherein said biasing means is rotatable to cause said engagement portions to engage said retention portions, said rotation of said biasing means resulting in the locking/unlocking of said stopper portion with respect to said sleeve.

According to another aspect of the present invention there is provided an engine, including an engine emission restrictor, substantially as described above.

According to another aspect of the present invention there is provided a method of securing a vehicle comprising the steps of:

a. fitting a sleeve at or towards the end of the exhaust pipe of the vehicle,

b. fitting a stopper portion to or within said sleeve, and c. locking said stopper portion to or with respect to said sleeve, the arrangement and construction being such that said stopper portion, when fitted, impedes or prevents the flow of exhaust fumes out of said exhaust pipe of said vehicle, thus adversely affecting the performance of the engine of the vehicle whereby the vehicle may not easily be driven, if at all.

According to another aspect of the present invention there is provided a method of securing a vehicle, substantially as described above, wherein said method includes the further step of orientating the stopper portion in a pre-defined way with respect to the sleeve or exhaust pipe prior to insertion of said stopper portion into said sleeve or exhaust pipe.

A preferred function of the engine emission restrictor may be to restrict, impede or prevent the flow of exhaust fumes out of the exhaust pipe of an engine, thus adversely affecting the performance of the engine, whereby the engine may not easily be run, if at all. Hence, the engine emission restrictor may be particularly suitable for securing a vehicle against theft, since when fitted to the exhaust pipe of a vehicle, the vehicle may not be easily driven away, if it is able to be driven at all. However, it is to be understood and appreciated that the engine emission restrictor is not to be limited to such use.

In one of its simplest forms, the stopper portion may comprise or consist of a bung or cover for the open end of an exhaust pipe of an engine. However it is preferable to have the stopper portion lockable with respect to the end of the exhaust pipe of an engine.

In one such embodiment the stopper portion may be fitted and locked directly to the end of the exhaust pipe of an engine. Any suitable means for locking or securing the stopper portion to or with respect to the end of the exhaust pipe may be utilised as required or as desired. For example, the stopper portion may be lockable to the end of the exhaust pipe by the use of a key and lock mechanism which is able to engage and disengage appropriate engagement portions disposed upon or within the stopper portion with corresponding retention portions disposed upon or within the exhaust pipe. Such a locking arrangement or mechanism may therefore be similar to a petrol cap type locking and unlocking mechanism.

In a second, and preferred embodiment of the present invention, the engine emission restrictor may comprise a sleeve which may be attached or attachable at or towards the end of the exhaust pipe of the engine, and a stopper portion which may be releasably attachable to or within the sleeve. The arrangement and construction of such an embodiment may be such that when the stopper portion is fitted or attached to or within the sleeve, the flow of exhaust fumes out of or from the exhaust pipe of the engine is impeded or prevented, substantially as described above. The sleeve may be of any suitable size shape or configuration as required or desired. Preferably, the sleeve may be substantially cylindrical in cross section, and of approximately the same diameter or section as the exhaust pipe. The sleeve may preferably be permanently attached or fitted to the exhaust pipe, and preferably by welding.

The sleeve may be fitted either within the exhaust pipe, or alternatively (and preferably) fitted over and/or around the end or towards the end of the exhaust pipe.

The stopper portion may preferably be adapted to be fitable within the sleeve, although an alternative would be to have the stopper portion adapted to be fitted over and/or around the sleeve.

If the stopper portion is adapted to be fitted or fittable within the sleeve, it may be of any suitable size shape or configuration as required or as desired, although it may preferably be of substantially the same diameter and/or section as the sleeve and/or exhaust pipe.

Preferably, the diameter or section of the sleeve may allow for or provide for a substantially snug fit between the sleeve and the stopper portion.

Any suitable means may be utilised for rendering the stopper portion lockable with respect to the sleeve. Such means may preferably utilise or incorporate a locking mechanism for activation by a key.

For example, the stopper portion may be provided with engagement portions which may be adapted to engage with or be engagable with and/or be retained by appropriate or corresponding retention portions disposed upon or within the sleeve. For example, the engagement portions of the stopper portion may comprise or consist of several flanges, and the retention portions may comprise slots cut into the sleeve to accommodate the flanges. When the engagement portions are engaged by the retention portions, the stopper may be retained within and/or by the sleeve.

In other preferred embodiments, the engagement portions may include a pin (or pins) and/or rod (or rods) which may be engaged by said retention portions to fix or hold the stopper portion in place with respect to the sleeve. Movement of said engaging portions to engage (or release) said retention portions may be controlled by activation (or de-activation) of the locking means by the user of the apparatus, or by any other means.

The engagement portions may preferably be spring loaded with respect to the stopper portion, such that the engagement portions are either urged away or towards the stopper portion, and against or into the retention portions disposed upon or within the sleeve, (until the engagement portions are disengaged, for example by the use of the key). In particular, preferred embodiments of the present invention may include springs which bias the ends of engagement portions in a position within or adjacent to the periphery of the stopper portion until it is desired to lock the stopper portion with respect to the sleeve.

The mouth of the sleeve may preferably be provided with an inwardly extending and/or tapering portion such as a tapering lip, and the stopper portion may be provided with a complimentary or matching portion(s), such that when the stopper portion is fitted to the sleeve a flush fit results, and whereby it may be difficult to forcibly remove the stopper portion from the sleeve, for example by prising with a screwdriver or similar means.

The stopper portion may also be provided with means for providing an air tight seal between itself and the sleeve and/or the exhaust pipe. Such means may, for example, be in the form of an 0-ring disposed around or within the stopper portion or a rubber sealing cap located at one end of the stopper portion, or any other means.

Alternatively, the fit between the stopper portion and the sleeve may allow for a minimal flow of exhaust fumes out of the exhaust pipe. This may ensure that the engine (or muffler) of or for the engine is not damaged if the engine is attempted to be started whilst the stopper portion is in place, since potentially destructive pressures may not be allowed to build up within the exhaust pipe or system of the engine, which may otherwise damage the engine. However, any flow of exhaust fumes which may be permitted to be expelled from the exhaust pipe should not be so great that the engine may still be ran for any significant length of time.

Moreover, the stopper portion may be provided with one or more apertures passing therethrough, the apertures being designed or being of a form whereby the starting of the engine to which the engine emission restrictor is fitted causes a loud, and preferably piercing, whistling noise by virtue of exhaust fumes being forced through the apertures under pressure. Such a whistling noise may attract attention if, for example, the engine has been started by an unauthorised person, for example a car thief.

Since the engine emission restrictor may preferably be attached or fitable to the exhaust pipe of an engine, the invention may be particularly suitable for use with engines which are powered by fossil fuels. The engine emission restrictor may therefore be fitted to the exhaust pipe of the engine to prevent the engine from being used or run by unauthorised people and/or to prevent the theft of or interference with the engine.

For example, the engine emission restrictor may be fitted to the exhaust pipe of a generator, so that the generator may only be run by people who have the authority to do so, and who therefore have the means, such as a key, to engage and disengage the stopper portion to the sleeve and/or the exhaust pipe of the generator.

It is envisaged however that the invention may be particularly useful for fitting to the exhaust pipe of a vehicle powered by an engine. Such use of the invention may deter would-be thieves from stealing the vehicle and/or for preventing the vehicle from being able to be stolen.

One possible way of utilising one embodiment of the engine emission restrictor to secure a vehicle is as follows. A driver of a vehicle may fit the stopper portion to the sleeve (which is fitted to the exhaust pipe of the vehicle), and ensure that it is secured or locked thereto. The driver may then leave the vehicle. Anyone attempting to steal the vehicle will be unable to drive the vehicle for any length of time, if at all, since the stopper portion will be impeding or preventing exhaust fumes from escaping from the exhaust pipe of the vehicle. As aforesaid, this has the effect of rendering the engine inoperable, and the vehicle therefore undriveable, either immediately or after a very short length of time.

The engine emission restrictor also has the advantage of being relatively unobtrusive and it is likely that a would-be vehicle thief, and in particular a car thief, would not see the engine emission restrictor attached to the exhaust pipe. When a vehicle therefore fails to start the thief may assume it is due to a mechanical fault, and look for a different vehicle to steal.

Further embodiments of the present invention may include a locking mechanism including a biasing means to control movement of the engagement portions in preferred embodiments of the present invention. Such biasing means may take the form of an elliptical washer or nut which may be positioned in such a way so that upon rotation of the biasing means (say, by turning of the key in the lock), the engagement portions engage the retention portions in the sleeve of the present invention, thus locking the stopper portion in position. Upon counter- rotation of the biasing means, springs (or other means) may cause the engagement portions to disengage from the retention portions of the sleeve, thus unlocking the stopper portion, and allowing the stopper portion to be removed from the sleeve, and the vehicle the apparatus is attached to, to be started. In further preferred embodiments of the present invention the stopper portion and/or sleeve may be provided with a guiding means to ensure correct alignment of the stopper portion when the stopper portion is inserted into the sleeve. For example, in preferred embodiments of the present invention there may be a number of raised ridges (or other protruding portions) on the stopper, which may fit into complementary grooves on the sleeve when the stopper portion is aligned correctly. Alternatively, a guiding means such as markings on the stopper portion or sleeve indicating correct alignment may be used. However, it is envisaged that a guiding means including grooves (or the like) may be preferable, as it allows the stopper portion to be inserted into the sleeve by feel, which is particularly advantageous in night-time (any many other) conditions.

Whilst the invention may be particularly suitable for securing a vehicle against theft, it may also be utilised by suitable authorities for rendering a vehicle immobile if required or desired. For example, Parking Wardens may fit such an engine emission restrictor to a vehicle, and only remove same once a parking fine had been paid.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 a cross sectional view of one possible embodiment of the present invention, and Figure 2 is a view along the line AA' of figure 1, and

Figure 3 is a perspective view of an alternative preferred embodiment of the present invention, and

Figure 4 is a cross-sectional view of the embodiment of the invention illustrated in Figure 3, and

Figure 5 is a view from beneath the stopper portion illustrated in Figures 3 and 4.

BEST MODES FOR CARRYING OUT THE INVENTION

Having regard to figures 1 and 2, there is shown an engine emission restrictor generally indicated by arrow 1, for an exhaust pipe 2 of a vehicle (vehicle not shown). The vehicle is a car.

The engine emission restrictor 1 comprises a sleeve 3 and a stopper portion 4.

The sleeve 3 is substantially cylindrical in cross section. The sleeve 3 is provided with a portion 5 which is of substantially the same diameter and section as the exhaust pipe 2. The portion 5 of the sleeve 3 is welded in the region 6 to the exhaust pipe 2, thus securing the sleeve 3 to the exhaust pipe 2.

A second portion 7 of the sleeve 3 is of a greater diameter than the first portion 5. The second portion 7 is provided with an inner diameter portion 8 of substantially the same diameter and section as the exhaust pipe 2.

The stopper portion 4 comprises or includes a body portion 9 which is of substantially the same diameter and section as the exhaust pipe 2 and inner portion 8.

The mouth 10 of the sleeve 3 is provided with an inwardly tapering lip portion generally indicated by arrow 11. The head 12 of the stopper portion 4 is of corresponding section whereby a snug and tight fit between the head 12 of the stopper portion 4 and the tapered lip portion 11 of the sleeve 3 results.

The stopper portion 4 is provided with a locking mechanism 13 which may be operated by a key (key not shown). The locking mechanism 13 operates engagement portions in the form of two outwardly extending flanges 14a,b. The flanges 14a,b are spring loaded with respect to the locking mechanism 13 and/or the body 9 of the stopper portion 4 (springs not shown).

The inner portion 8 of the second portion 7 of the sleeve 3 is provided with retention means in the form of two slots 15a,b. The slots 15a,b are adapted to receive and retain the flanges 14a,b when the stopper portion 4 is fitted within the sleeve 3. The engagement of the flanges 14a,b by the slots 15a,b secures the stopper portion 4 to and within the sleeve 3. The inner portion 8 of the second portion 7 of the sleeve 3 is also provided with two channels 16a,b which allow for easy fitting of the flanges 14a,b of the stopper portion 4 to and within the sleeve 3. The channels 16a,b act as guide channels for the flanges 14a,b. The tapered lip portion 11 also aids the fitting of the stopper portion 4 to the sleeve 3 since it allows for the flanges 14a,b to be pushed inwardly before they are engaged by the channels 16a,b, and ultimately the slots 15a,b. It may be appreciated therefore that the stopper portion 4 may be fitted to the sleeve 3 without the need for the use of the key. The key will however be required to disengage the flanges 14a,b from the slots 15a,b, thereby allowing for the removal of the stopper portion 4.

In use, a driver of the vehicle may fit the stopper portion 4 to the sleeve 3 when the vehicle is to be left unattended. Since the stopper portion 4, when fitted, has the effect of impeding or preventing the escape of exhaust fumes from the exhaust pipe 2 of the vehicle, the vehicle may not be driven very far by a would-be thief, or may not be able to be started at all by a would-be thief.

The stopper portion 4 may be fitted to a chain which itself may be fitted to the vehicle so that the stopper portion 4 need never be fully removed from the vehicle. Alternatively, there may be provided an appropriate storage means or compartment within or upon the vehicle to store the stopper portion 4 when it is not fitted to the sleeve 3.

With regard to Figure 3 there is illustrated an alternative embodiment of an engine emission restrictor 20. As in the previous embodiment, engine emission restrictor 20 comprises a sleeve 21 and a stopper portion 22. Sleeve 21 is envisaged to be connected to an exhaust pipe (not shown) of a vehicle (not shown). Usually this vehicle will be a car, although the engine emission restrictor may also be attached to other vehicles.

As in the previous embodiment sleeve 21 is substantially cylindrical in cross-section. Sleeve 21 includes an upper portion 23, which is designed for attachment of stopper portion 22, and a lower portion 24, which is designed to be used to attach to the exhaust pipe (not shown) of the vehicle. A suitable means of attachment may be by welding, although any other attachment means may also be used.

Upper portion 23 of sleeve 21 includes a number of ridges 25 and a groove 26. The groove is chosen to be of a suitable width and configuration to provide a guiding means for a complimentary protruding feature (such as "button" 27) of stopper portion 22. This allows stopper portion 22 to be inserted in sleeve 21 in an appropriate orientation.

Grooves 25 may be used to assist the retention of stopper portion 22 in sleeve 21, for example by providing a place where engagement portions (not shown) of stopper portion 22 may be retained. Alternatively, grooves 25 may serve a number of other purposes, for example to allow a small amount of exhaust fumes to flow past stopper portion 22, thus preventing damage to the engine when the vehicle is started. In addition to button 27, stopper portion 22 may also include a locking mechanism 28, which may be used to ensure that the stopper portion is able to be retained in sleeve 21. Details of the locking mechanism are discussed in relation to Figures 4 and 5.

Stopper portion 22 may also include a rubber cap 29 or seal of any sort, which may assist in providing a reasonably (or completely) air tight seal between stopper portion 22 and sleeve 21.

With regard to Figure 4 there is illustrated a cross-sectional view of stopper portion 22 and sleeve 21.

In this figure further details of locking mechanism 28 can be seen.

In particular, locking mechanism 28 includes a biasing means 30 (better shown in Figure 5), which is in contact with engagement portions 31 of stopper portion 22.

Engagement portions 31 include a rod, pin, or shaft which extends from within the periphery of stopper portion 22 to a position outside the usual width of stopper portion 22.

In Figure 4, the stopper portion 22 is shown in a configuration whereby the engagement portions may serve to lock the stopper portion in position with respect to sleeve 21 of the engine emission restrictor. In particular, springs 32 which are in contact with engagement portions 31 are compressed and engagement portions 31 are in a position whereby they may be engaged in complementary grooves 25 of sleeve 21. It should be understood that in use stopper portion 22 will be inserted into sleeve 21 with the engagement portions in an unlocked position, and subsequently locking mechanism 28 will be used to move engagement portions 31 into a position whereby they are housed within or retained by grooves 25. This prevents removal of the stopper portion from sleeve 21 and thus subsequently prevents the starting of the vehicle that the engine emission restrictor is attached to.

Figure 5 shows a view from beneath stopper portion 22. This view shows more clearly biasing means 30, and its connection with engagement portions 31 and spring 32.

As can be seen, biasing means 30 includes an elliptical washer which is housed on the lower end of a shaft 33, which forms the lower part of locking mechanism 28. When shaft 33 is rotated, the elliptical washer either pushes engagement means 31 towards the outside of the periphery of stopper portion 22, or allows springs 32 to bias the engagement portions 31 towards the centre of stopper portion 22, thus releasing the engagement portions 31 from grooves 25 of sleeve 21 (see Figure 4). Use of the elliptical washer thus serves either to lock or unlock the stopper portion 22 in place with respect to sleeve 21.

However, it should be appreciated that other biasing means, such as elliptical nuts, or any other similar means, may also be used to assist in the locking or unlocking of stopper portion 22 with respect to sleeve 21. In addition, although not shown in Figures 4 or 5, stopper portion 22 may also include a rubber cap or seal attached to the lower part of stopper portion 22, to ensure an appropriate seal is made between the stopper portion 22 and sleeve 21.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof, as defined in the appended claims.

Claims

THE CT-AIMS DEFINING THE INVENTION ARE:

1. An engine emission restrictor comprising a sleeve and a stopper portion, said sleeve being attached or attachable at or towards the end of an exhaust pipe of or for the engine, said stopper portion being releasably attachable to or within said sleeve, the arrangement and construction of the engine emission restrictor being such that said stopper portion, when fitted to or within said sleeve, impedes or prevents the flow of exhaust fumes out of said exhaust pipe.

2. An engine emission restrictor as claimed in claim 1, wherein the stopper portion is provided with engagement portions able to be releasably engaged with corresponding retention portions disposed upon or within said sleeve.

3. An engine emission restrictor as claimed in claim 1 or claim 2, wherein the stopper portion includes a locking mechanism operable to releasably lock said stopper portion with respect to said sleeve.

4. An engine emission restrictor as claimed in claim 3, wherein said locking mechanism includes a biasing means operable to cause said engagement portions to engage and/or release said retention portions.

5. An engine emission restrictor as claimed in claim 4, wherein said biasing means is rotatable to cause said engagement portions to engage said retention portions, said rotation of said biasing means resulting in the locking/unlocking of said stopper portion with respect to said sleeve.

6. An engine emission restrictor as claimed in either of claims 4 or 5 wherein said biasing means includes an elliptical washer or nut.

7. An engine emission restrictor as claimed in any of claims 2 to 6 wherein said engagement portions include at least one flange mounted on or within said stopper portion.

8. An engine emission restrictor as claimed in any of claims 2 to 6 wherein said engagement portions include at least one pin or rod mounted on or within said stopper portion.

9. An engine emission restrictor as claimed in claim 8 wherein said pin or rod is positioned between said biasing means and the periphery of said stopper portion, and extendable beyond said periphery of said stopper portion by movement or rotation of said biasing means.

10. An engine emission restrictor as claimed in claim 9 wherein said engagement portions are spring loaded to retain said pin or rod within the periphery of said stopper portion when not engaged by said biasing means.

11. An engine emission restrictor as claimed in any one of claims 1 to 10 wherein said sleeve is welded to said exhaust pipe.

12. An engine emission restrictor as claimed in any of claims 1 to 11 wherein said sleeve and/or stopper portion includes at least one guiding means for aligning said stopper portion with respect to said sleeve.

13. An engine emission restrictor as claimed in claim 12 wherein said guiding means includes at least one raised ridge and/or other protruding features on either said stopper portion or said sleeve.

14. An engine emission restrictor comprising a sleeve and a stopper portion, said sleeve being attached or attachable at or towards the end of an exhaust pipe at or for the engine, said stopper portion being releasably attachable to or within said sleeve, said stopper portion provided with at least one engagement portion positioned within said stopper portion and operable to extend therefrom, said sleeve being provided with at least one retention portion provided for engagement with or retaining of said engagement portion, said engagement portion, when engaged or retained within or by said retention portion, serving to lock said stopper portion in position with respect to said sleeve.

15. An engine emission restrictor as claimed in claim 14 wherein said engagement portion(s) includes at least one pin or rod mounted on or within said stopper portion.

16. An engine emission restrictor as claimed in claim 15 wherein said stopper portion includes a biasing means operable to extend said pin or rod beyond the periphery of said stopper portion.

17. An engine emission restrictor as claimed in claim 15 wherein said biasing means includes an elliptical washer or nut.

18. An engine emission restrictor as claimed in either of claims 16 or 17 wherein said engagement portion(s) are spring biased to be housed within the periphery of said stopper portion when not engaged by said biasing means.

19. An engine emission restrictor as claimed in any of claims 14 to 18 wherein said sleeve and/or stopper portion includes at least one guiding means for aligning said stopper portion with respect to said sleeve.

20. An engine emission restrictor as claimed in claim 19 wherein said guiding means includes at least one raised ridge and/or other protruding feature on either said stopper portion or said sleeve.

21. An engine emission restrictor as claimed in any of claims 14 to 20 wherein said sleeve is welded to said exhaust pipe.

22. An engine including an engine emission restrictor as claimed in any one of claims 1 to 21.

23. A vehicle engine including an engine emission restrictor as claimed in any one of claims 1 to 21.

24. A method of securing a vehicle comprising the steps of:

a. fitting a sleeve at or towards the end of the exhaust pipe of the vehicle,

b. fitting a stopper portion to or within said sleeve, and

c. locking said stopper portion to or with respect to said sleeve, the arrangement and construction being such that said stopper portion, when fitted, impedes or prevents the flow of exhaust fumes out of said exhaust pipe of said vehicle, thus adversely affecting the performance of the engine of the vehicle whereby the vehicle may not easily be driven, if at all.

25. A method of securing a vehicle as claimed in claim 24, the method including the step of orienting the stopper portion in a pre-defined way with respect to the sleeve or exhaust pipe prior to insertion of said stopper portion into said sleeve or exhaust pipe.