GB2261027A - Vehicle exhaust blocking - Google Patents

Abstract

A unit 1 to be fitted in or at an end of an exhaust pipe contains a mechanically, electrically, pneumatically or hydraulically remotely-operable blocking device 5. The device 5 may be a butterfly valve, a resilient flexible tube (9, Fig. 3) which is flattened, a disc (13, Fig. 4) operable by a magnet (14) subject to electromagnets (16) adjacent the exhaust pipe (15) or an inflatable bag (19, Fig.5) in the unit. <IMAGE>

Description

"ImProvements relations to Vehicle Security Devices" This invention relates to vehicle security devices. It is applicable not only to road vehicles such as cars, vans, buses and lorries, but also to boats, light aircraft and even rail locomotives. It will probably be of most interest to car owners and in the rest of this specification reference will just be made to cars.

Car thefts are running at a very high level and recent publicity suggests that it is increasing. Some locks are effective but others are relatively easily picked, and it is possible to start a car without an ignition key.

Various alarm systems have been proposed and are now in widespread use, but they are vulnerable to being tripped accidentally, and people are now tending to become blast and to ignore them. Many can be bypassed by the knowing thief.

It is the aim of this invention to provide a concealed way of incapacitating the car, which is easy to operate and which does not require a key.

According to the present invention there is provided a security device for vehicles driven by internal combustion engines, the device comprising a remotely controllable obstructor associated with the or each exhaust pipe, operable to open or block that pipe.

Some cars have two exhaust pipes, but from now on it will be assumed that there is just one. The invention works on the principle that if the exhaust pipe is blocked the engine will not work. It might very briefly cough into life, but it would very soon stall.

The obstructor can be fitted when the car is built.

Alternatively, it may be embodied in a unit fittable to the end of an exhaust pipe or intermediate of a pipe in replacement of a removed section or re-joining a severed pipe.

Preferably, it will be arranged upstream of any silencer and so will be concealed under the car and accessible only by jacking up the car. That is not the usual preliminary to theft.

The obstructor may be a member within the pipe movable from outside between blocking and unblocking positions. In one convenient form it resembles a butterfly valve.

Alternatively, the unit may have a resilient flexible portion and the obstructor is arranged to squeeze it for the blocking mode and to allow it to assume its natural shape for the unblocking mode.

The remote control may take various forms, but conveniently it will be mechanical and, because it may have to lead around various parts, it may include a Bowden cable. This may have a spring return so that the driver may simply have to release a catch to alter the state of the obstructor from one mode to another. In the reverse direction he would have to exert a mechanical pull.

With such a remote control, it can be led to almost anywhere within the car. For example, it could terminate in the boot, under one of the seats, in the glove compartment, or in the engine compartment. It does not have to be in a "standard" place. The important thing is that it should be concealed from sight to someone looking into the car from outside. From time to time its position could be altered.

Other forms of control are possible and may be preferred in certain circumstances. For example, the obstructor may be electro-mechanically operated, as by a solenoid. Or the obstructor could be electromagnetically operated, the exhaust pipe in that case at least locally being magnetically transparent and the obstructor being of, or carrying an element of, magnetically susceptible material within the influence of an external electromagnet. With these arrangements, the electrical energisation may be enabled or caused, not by a simple switch, but by a keypad or key operated means. The wiring for these embodiments can be hidden even more easily than a Bowden cable.

A further possibility is for the obstructor to be an expandible bag within the exhaust pipe. This could be filled with fluid or emptied, respectively to block or unblock the exhaust pipe. Again, a pneumatic or hydraulic line leading to a remote control can be easily concealed.

Alternatively, a small hydraulic or pneumatic ram could be actuated through such lines to operate a mechanical obstructor.

For extra security, it would be possible to have two or even more of these devices in tandem in the exhaust pipe, with the remote controls going to different positions within the vehicle.

For a better understanding of the invention some embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an obstructor unit for an exhaust pipe, Figure 2 is a side elevation, partly in longitudinal section, of the unit of Figure 1, Figure 3 is a diagrammatic side elevation of another mechanical obstructor unit, Figure 4 is a diagrammatic longitudinal section of an electromagnetically operated obstructor unit, and Figure 5 is a diagrammatic longitudinal section of a fluid operated obstructor unit.

The obstructor;device of Figures 1 and 2 has a hollow cylindrical body 1 with reduced ends 2, split and encircled by clamping collars 3 enabling them to be fitted over and tightened onto separate sections of an exhaust pipe.

Spanning the centre of the body 1 there is a spindle 4 carrying a disc 5. This can be rotated through 900 between a non-obstructing position in which its diameter transverse to the spindle 4 is aligned with the axis of the body 1, and an obstructing position in which it provides a complete barrier across the passage through the body 1. In this position, it abuts opposed stops 6. There can also be stops to define the non-obstructing position.

The spindle 4 is extended through one journal outside the body 1 to carry a pinion 7 which engages a rack 8.

Almost any linear actuator can be coupled to the rack to operate it, mechanical (particularly a Bowden cable), electro-mechanical, hydraulic or pneumatic, and the control will be remote and through easily concealable lines. A rack and pinion is not the only way of operating the obstructor disc 5, of course, and there can be other types of shutter.

Where appropriate, a spring return from one or other position may be provided.

In Figure 3 a resiliently flexible tube 9 spans two sections of exhaust pipe 10. An external member 11 engages one side of the tube 9 and is movable by any of the means suitable for the previous embodiment between the full line position, allowing the tube 9 to assume its natural shape, and the dotted line position where it squeezes the tube 9 flat against an anvi;l 12.

Alternatively, there could be two opposed members 11 which are brought together to pinch the tube 9 or which are rotated about an intermediate axis transverse to the tube to force the latter into a flattened S configuration.

In Figure 4, the obstructor is a pivoted disc 13 similar to the disc 4, but with an elongated magnet 4 coaxial with it and projecting equally to opposite sides. The body 15 in which this is journalled is non magnetic so that electromagnetic coils 16 set at positions diametrically opposed to the centre of the disc can influence the magnet 14. The disc 14 will have a bias through spring means and/or weighting (not shown) so that it normally adopts an obstructing attitude. But when the coils 16 are energised, acting through the magnet 14, they pull the disc to a non-obstructing attitude. While a powerful current may be needed to initiate this, because the respective magnetic poles are adjacent in the non-obstructing mode the "holding" current can be small. Since the engine will then be running anyway, this is easily assimilated.

In Figure 5, a tubular body 17 similar to the body 1 is inserted in an exhaust pipe 18 and contains an inflatable bag 19. When expanded, as shown in full lines, the bag completely blocks the exhaust, while when exhausted it collapses to the dotted line position and allows free passage of exhaust gases. Since the body 17 is enlarged compared with the pipe 18, the deflated bag 19 is out of the main stream and will not be flogged to bits. The bag may be air or liquid filled.

Claims (1)

1. A security device for vehicles driven by internal combustion engines, the device comprising a remotely controllable obstructor associated with the or each exhaust pipe, operable to open or block that pipe.

2. A device as claimed in Claim 1, wherein it is embodied in a unit fittable to the end of an exhaust pipe or intermediate of a pipe in replacement of a removed section or re-joining a severed pipe.

3. A device a claimed in Claim 1 or 2, wherein the obstructor is a member within the pipe movable from outside between blocking and unblocking positions.

3. A device as claimed in Claim 3, wherein said member is in the form of a butterfly valve.

5. A device as claimed in Claim 2, wherein the unit has a resilient flexible portion and the obstructor is arranged to squeeze it for the blocking mode and to allow it to assume its natural shape for the unblocking mode.

6. A device as claimed in any preceding Claim, wherein the obstructor is mechanically operated.

7. A device as claimed in Claim 7, wherein the remote control includes a Bowden cable.

8. A device as claimed in any one of Claims 1 to 5, wherein the obstructor is electro-mechanically operated.

9. A device as claimed in Claim 3 or 4, wherein the obstructor is electro-magnetically operated, the exhaust pipe at least locally being magnetically transparent and the obstructor being of, or carrying an element of, magnetically susceptible material within the influence of an external electromagnet.

10. A device as claimed in Claim 8 or 9, wherein the electrical energisation is enabled or caused by a keypad or key operated means.

11. A device as claimed in any one of Claims 1 to 5, wherein the obstructor is pressure fluid operated.

12. A device as claimed in Claim 3, wherein the obstructor is an expandible bag, there being remote by controllable means to fill the bag with fluid or to empty it, respectively to block or unblock the exhaust pipe.

13. A security device for vehicles driven by internal combustion engines, the device being substantially as hereinbefore described with reference to the accompanying drawing.

14. A vehicle driven by an internal combustion engine and having an exhaust pipe fitted with at least one security device as claimed in any preceding Claim.