WO1994018038A1

WO1994018038A1 - Vehicle security device

Info

Publication number: WO1994018038A1
Application number: PCT/GB1994/000212
Authority: WO
Inventors: William Kenneth Divers
Original assignee: William Kenneth Divers
Priority date: 1993-02-04
Filing date: 1994-02-04
Publication date: 1994-08-18
Also published as: GB9302208D0

Abstract

A vehicle security device for selectively passing or blocking exhaust fumes from an internal combustion engine, comprising an inlet manifold pipe section (1a) for receiving exhaust fumes from said engine, and juxtaposed therewith an outlet exhaust pipe section (1b) for venting exhaust fumes; a gas-tight housing (2) provided between both sections and completing an exhaust flow path therebetween; a slidable barrier (12) located within the housing and movable between a first position obstructing the flow path between the sections and a second position wherein exhaust flow is permitted between the sections; and actuator means (14) such as electro-mechanical means, or a working fluid system for selectively moving the barrier between the first position and the second position.

Description

VEHICLE SECURITY DEVICE This invention relates to a vehicle security device and in particular provides a concealed vehicle immobilisation device. Crime involving theft of motor vehicles, especially private cars is increasing annually. Statistical analysis of vehicle theft crimes indicates that a vehicle is stolen or broken into every two minutes. Sophisticated alarm systems which add significantly to the cost of a vehicle are proving unequal to the task and criminals are often able to overcome such alarm systems and still make off with the vehicle within a few minutes.

A further problem is that public reaction to an alarm sounding is to tend to ignore it because there are so many alarm systems which may be triggered by passing traffic, underground trains and even high winds. Therefore an audible alarm is not the best solution to prevent vehicle theft.

In order to gain entry to a vehicle a thief may either break the door lock or pick the lock with an appropriate tool and an alarm, if fitted, can be shorted out or otherwise disabled. Once inside the vehicle, the ignition lock can be by-passed and the ignition system activated fairly quickly so that the vehicle can then be removed within a matter of minutes.

There are many precautionary measures which may be taken to prevent theft of a vehicle. These include removing a small but vital component such as the distributor rotor arm from the engine, fitting electronic disabling devices to the ignition system of more expensive breakerless ignition systems or attaching lockable physical barriers to prevent normal use of the steering wheel, handbrake or gear lever of the vehicle. However these measures frequently become a nuisance to the vehicle owner who may not wish to spend time dismantling parts of the engine, or fitting any such security device every time the vehicle is to be left unattended.

It is also known to provide manually operated means for shutting off the exhaust fumes of a vehicle, for example, by _ means of a butterfly valve located within the exhaust pipe and operated by cables to prevent or pass exhaust fumes from the engine in order to allow or prevent running o'f the engine. However these known security devices may be breached by disconnecting or severing the cable or by accidental damage to the cable.

It is an object of the present invention to overcome or at least mitigate the above disadvantages with known security devices.

Accordingly this invention provides a vehicle security device for selectively passing or blocking exhaust fumes from an internal combustion engine, the said device comprising an inlet pipe section for receiving exhaust fumes from said engine, and juxtaposed therewith an outlet pipe section for venting exhaust fumes; a gas-tight housing provided between both sections and completing an exhaust flow path therebetween; a slidable barrier located within the housing and movable between a first position obstructing the flow path between the sections and a second position wherein exhaust flow is permitted between the sections; and actuator means for selectively moving the barrier between the first position and the second position.

Advantageously, the device further comprises means for sensing and indicating the position of the barrier within the housing. The sensing means may be a limit switch activating an audible or visible signal to indicate the status of the device. The status may be indicated only upon activation and deactivation or may permanently show whether the device is in activated or deactivated mode. Conveniently the status may be shown by an optional audible 5 tone and a visual display device such as a light emitting diode on the vehicle dashboard. The device may be used in isolation or optionally linked to an alarm system including, infra red detectors, tilt or gas pressure switches without affecting its performance. When used in isolation a thief may not be able to determine why the vehicle engine will not start and will be forced to give up the attempted theft of the vehicle. When linked to a conventional alarm the thief may be deterred from remaining to cause damage to the vehicle or steal auxiliary equipment in the vehicle. The barrier may be actuated by a working fluid system, or more preferably by an electro-mechanical system.

Conveniently, the actuator means is an electro¬ mechanical means for moving the barrier between the first position and the second position and comprises a combination switch connected to the main battery of the vehicle and either a solenoid or electric motor with a suitable mechanical coupling, which may include a flexi-drive coupling, which moves the barrier within the housing. Preferably a solenoid is used to move the barrier within the housing, but alternatively a remotely controlled permanent magnet may be used.

In its preferred form the barrier traverses the exhaust flow path and engages positively in a portion of the housing beyond the juxtaposed sections to provide optimum resistance to overcome pressure of the exhaust fumes. Means may be provided for ensuring that the barrier is "deadlocked" in the flow-obstructing position should any attempt be made to by-pass the switch electrically. This may be achieved by providing a concealed resistor in the switch circuits together with a concealed fuse or the like current overload breaker in the circuitry activating the device.

Preferably, the device is provided with a key for disabling the security device to allow authorised use of the vehicle. However an electronic touch pad allowing input of a security code is envisaged as a possible alternative though it may increase the cost of the device.

The device may be conveniently substituted for a length of exhaust pipe or may be built into an exhaust system. In the latter case the opportunity may be taken to disguise it as a typical silencer or muffler box.

Embodiments of the present invention will now be described by way of illustration with reference to the drawings in which: - Figure 1 is a perspective view of a vehicle security device according to one aspect of the present invention, and Figure 2 is a plan view of the device of Figure 1; Figure 3 is a section through a vehicle security device in accordance with the invention; Figures 4a, 4b, 4c and 4d show in plan, a partially exploded view of the device shown in Figure 3 , whilst Fig. 4e shows an end view of the mating end plate shown in Fig. 4d into which the exhaust is fitted;

Figure 5 shows in plan the assembly of parts shown in Figures 4a-4e; and

Figure 6 shows a section through a further embodiment of the invention for use with twin exhaust pipe systems.

Referring to the drawings, Figure 1 shows a perspective view of a vehicle security device according to one aspect of the present invention.

The exhaust conduit 1 is provided by two sections of exhaust pipe la, lb. The two sections are placed end to end and a hollow, substantially rectangular housing 2 is located between the sections. The housing may be located by welding or any other suitable means.

The housing comprises a front face 3, a rear face 4 and surrounding side walls 5 therebetween. The housing extends beyond the outer periphery of the exhaust pipe sections la, lb and is provided with a corresponding aperture 6 in each of the front and rear faces which communicate with the exhaust conduit 1.

A barrier (not shown) such as a slidable gate is provided within the housing 2 and is movable between a first position between the exhaust pipe sections and a second position remote from the conduit.

A second housing 7 may be located adjacent the exhaust pipe sections for housing control means such as a motor or solenoid for moving the gate into and out of engagement with the conduit. The prime mover for the control means may be the vehicle battery or alternatively may be a separate stored charge device connectable to the solenoid for electromagnetic actuation of the slide gate.

The security device also comprises a sensor (not shown) for sensing the position of the slide gate within the housing.

An alarm means such as an audible signal is linked to the sensor. The alarm means may alternatively be in the form of a light emitting diode on the dashboard of the vehicle.

Switch means (not shown) are provided, for example on the dashboard of the vehicle or alternatively adjacent the engine of the vehicle for activating the control means of the device. The switch means may comprise a detachable multi-pin key locatable in a corresponding multi-pole socket wired to the control means through appropriate circuitry.

The use of the device will now be described. When the vehicle ignition is off the device will be activated such that the slidable gate will be in the first position in the exhaust conduit preventing fluid communication between the two sections of the exhaust pipe. Upon actuation of the vehicle ignition, the sensor senses the position of the slide gate and passes a signal to the alarm means. This will produce an alarm signal such as an audible or visual signal depending upon the system provided. Activation of the switch means by the location of the multi-pin key in the socket operates the control means which moves the slide gate into the second position within the housing thereby allowing fluid communication between the two sections of the exhaust pipe. The sensor senses the position of the slide gate and passes a signal to the alarm means thereby disarming the alarm.

In order to further prevent unauthorised use of the vehicle, a resistor may be provided in the switch means to reduce the current from the switch means which then flows through a fuse to the control means when the key is inserted into the socket. In the event that the switch means is by¬ passed and it is attempted to activate the ignition of the vehicle without the multi-pin key, the resistor is by-passed and the unaltered current flows through the fuse which overloads, the circuit is broken and the slide gate remains within the conduit. The position of the slide gate is sensed and an audible alarm activated.

The sensor, resistor and fuse may be replaced by a microprocessor which senses the position of the slide gate, monitors the current from the switch means and activates the alarm signal in response to the information received.

Referring to Figures 3 to 5, a vehicle immobilisation device of this invention comprises a housing 2 for a slidable barrier 12, which housing is located in a vehicle exhaust conduit 1 including a manifold pipe section la, and an exhaust pipe section lb. The two sections engage the housing and are secured by inter-engaging clamping means 10, 11 or any other suitable fastening means. A sealing member 13 is provided downstream of the barrier.

The barrier is slidable between a first position in which it obstructs exhaust flow to immobilise a vehicle and a retracted second position within the housing in which exhaust fumes may by-pass the barrier to allow normal use of the vehicle. The housing extends beyond the outer periphery of the exhaust pipe sections la, lb as before to provide for penetration of the barrier into the extended portion to thereby positively obstruct the flow of exhaust. The barrier is actuated in this instance by a flexible drive mechanism in which the initial drive input may be provided by an electric motor, a solenoid, a hydraulics system or even manual activation. Electrical energy when necessary for the selected system may be obtained from the standard vehicle battery or alternatively may be a separate stored charge device.

The same principle may be applied with appropriate modifications to a multiple exhaust pipe system e.g. a twin exhaust system as shown in Figure 6.

Naturally, the variants just described with reference to Figures 3 to 6 may be linked to control switches, sensors, conventional alarm and status indicating means as described hereinbefore.

It is to be appreciated that the security device may be sold as a post-manufacture accessory "add-on feature" or may be alternatively fitted to vehicles at the production line stage.

Claims

1. A vehicle security device for selectively passing or blocking exhaust fumes from an internal combustion engine, the said device comprising an inlet pipe section for

Ξ receiving exhaust fumes from said engine, and juxtaposed therewith an outlet pipe section for venting exhaust fumes; a gas-tight housing provided between both sections and completing an exhaust flow path therebetween; a slidable barrier located within the housing and movable between a 0 first position obstructing the flow path between the sections and a second position wherein exhaust flow is permitted between the sections; and actuator means for selectively moving the barrier between the first position and the second position. 5

2. A device according to claim 1 which further comprises means for sensing and indicating the position of the barrier within the housing.

0 3. A device according to claim 2 wherein the sensing means is a limit switch activating an audible or visible signal to indicate the status of the device.

4. A device according to claim 3 wherein the status is 5 selectively indicated (a) only upon activation and deactivation or (b) permanently.

5. A deveice according to claim 3 or claim 4 wherein the status is indicated by an audible tone and a visual display 0 device such as a light emitting diode on the vehicle dashboard.

6. A device according to claim 1 wherein the actuator means for moving the barrier comprises an electro-mechanical 5 system or a system using a working fluid.

7. A device according to claim 7 wherein the electro¬ mechanical means for moving the barrier between the first position and the second position comprises a combination switch connected to the main battery of the vehicle and either a solenoid or electric motor with a suitable mechanical coupling which moves the barrier within the housing.

8. A device according to claim 6 wherein the means for moving the barrier within the housing comprises a solenoid or a remotely controlled permanent magnet .

9. A device according to claim 1 wherein the barrier traverses the exhaust flow path and engages positively in a portion of the housing beyond the juxtaposed sections to provide optimum resistance to overcome pressure of the exhaust fumes.

10. A device according to claim 1 wherein locking means is provided for ensuring that the barrier is "deadlocked" in the flow-obstructing position.