WO1999050131A2

WO1999050131A2 - Motor vehicle immobilising system

Info

Publication number: WO1999050131A2
Application number: PCT/ZA1999/000011
Authority: WO
Inventors: Reginald John Gibbs
Original assignee: Reginald John Gibbs
Priority date: 1998-04-01
Filing date: 1999-04-01
Publication date: 1999-10-07
Also published as: AU3674199A; WO1999050131A3

Abstract

A sealed battery having exposed positive (16) and negative (18) terminals connectable to the appropriate battery electrodes, wherein at least one terminal (16) comprises an internal terminal (16.1) that is connected to the appropriate battery electrodes and a spaced external terminal (16.2) and an immobilising device (11) is provided within the casing for selectively connecting the internal and external terminals to each other. The invention also comprises a battery cap securable to a battery casing for forming a battery as above. The battery is used to immobilise a vehicle.

Description

MOTOR VEHICLE IMMOBILISING SYSTEM

FIELD OF THE INVENTION:

This invention relates to a system for immobilising a motor vehicle as a deterrent to theft or unauthorised use and has application, particularly, but not exclusively, for motor vehicles having simple add-on immobilisers rather than circuits built into electronic engine management systems.

BACKGROUND OF THE INVENTION: Add-on immobilisers that disable the starter motor or ignition circuit of a motor vehicle have been a relatively effective deterrent to theft over the years. However, that effectiveness is on the wane as thieves have learned how to bypass or defeat most systems, usually by attacking the over-ride switch, the control unit itself or rewiring the ignition and shorting across the starter solenoid . In other words, the problem is not with the design of the immobiliser, but with the way it is attached to the electrical system.

This invention seeks to provide a system for immobilising a motor vehicle that defeats attacking the electrical system. The invention also seeks to provide a battery cap for a battery casing to form a battery that can be selectively disabled. SUMMARY OF THE INVENTION:

One aspect of the invention provides a battery cap connectable to a battery casing to form a sealed battery, the battery cap having exposed positive and negative terminals connectable to the appropriate battery electrodes, wherein:

-- at least one of the terminals comprises an internal terminal that is connected to the appropriate battery electrodes and a spaced apart external terminal;

- an immobilising device is provided within the casing; - first conductor means is electrically connected between the immobilising device and the internal terminal; -- second conductor means is electrically connected between the immobilising device and the external terminal; and

- actuating means is provided for actuating the immobilising device to connect the first and second conductor means to each other to form an electrical path between the internal and external terminals that can carry the full current capacity of the battery.

The actuating means may be selected from electronic key means, such as a coded plug, magnetically encoded card, an electronic keypad and the like means, and a wireless system with a receiver in the battery cap that is responsive to a remote transmitter.

Preferably the immobilising device includes relay means and means for actuating the relay means to connect the first and second conductor means to each other such that the full current capacity of the battery can flow from the internal to the external terminal. Preferably the immobilising device permits a predetermined low current to flow internally between the internal and external terminals when the internal and external terminals are not connected by an electrical path capable of carrying the full current capacity of the battery. This limited current is normally less than 2.5 Amps, which is the minimum required to energise an ignition coil for a spark ignition engine, but may be any desired value as technology changes. A current above about 2.5 enables the ignition coil to be active, so that a vehicle fitted with an immobilising battery of the invention can be "push" or "jump" started. The limited current need be sufficient only to permit motor vehicle accessories, such as a clock, radio, computer, vehicle alarm, central locking and the like to function.

Preferably the immobilising device permits a trickle charge to be applied to the battery for charging it when required, ie. so that the battery can be used in the normally expected manner other than its immobilising function.

Preferably the immobilising device includes interlock means that acts to prevent disconnecting the first and second conductor means from each other, unless the immobilising device is suitably activated to disconnect the conductor means. This is to protect the alternator from being burnt out.

Alternatively sensing means may be provided for the alternator to disconnect its supply voltage, which can be an internally redirected supply, in the event that such supply exceeds a predetermined value, say

14.5 volts for an alternator that normally provides charging output at 14.2 volts. Preferably the immobilising device includes sensing means to sense whether a current is being applied to charge the battery and switch means responsive to the sensing means to disconnect the first and second conductor means from each other at a predetermined time after the engine is switched off. A suitable time delay ranged from 30 to 60 seconds, which is sufficient to enable the engine to be restarted in the event of it stalling or cutting out inadvertently.

The immobilising device may include signal generating means for indicating when it changes between active and inactive states. The signal generating means may include an audible or visual indicator on the battery cap and/or may include signal terminals connectable to the hooter/horn and/or suitable lights of a vehicle, such as the turn indicator lights.

At least one of the conductor means may comprise a plurality of stranded wires constructed and arranged such that piercing the conductor means breaks some of the strands and limits the current carrying capacity of the conductor means to below a predetermined value, such as that required to start a motor vehicle engine.

Preferably diverting means is provided between the internal and external terminals to cause a drill and the like piercing means passing through the external terminal to be diverted away from the internal terminal to defeat an attempt to connect the terminals mechanically.

The invention also includes a battery comprising a battery cap as described above connected in a sealed manner to a battery electrode casing containing electrodes and a suitable electrolyte. Further features, variants and/or advantages of the invention will emerge from the following non-limiting description of an example of the invention made with reference to the accompanying schematic drawings.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 shows a schematic partly sectioned side view of a battery of the invention; Figure 2 shows a plan view of the battery of Figure 1 ;

Figure 3 shows a schematic plan view of another example of a battery cap of the invention;

Figure 4 shows a schematic side view of the battery cap of Figure 3, partly exploded; and Figure 5 shows a circuit diagram of a cut out protector device for use with a battery of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS:

Figures 1 and 2 of the drawings show a vehicle immobiliser battery 10 comprising a battery electrode casing 12 and a terminal housing 14, both of which are of plastics and are sealed to each other via a flange 14.1 of the terminal housing. While not shown, the casing and electrode construction is conventional and is formed with compartments, positive and negative battery electrodes being provided in the compartments and being connected in series to each other by lead bridges. The battery includes an exposed positive terminal 1 6, an exposed negative terminal 18 connected to the negative electrodes and an immobilising device 1 1 for selectively connecting the positive electrodes to the positive terminal. The negative terminal is conventional. It is sealed to the housing by filler material 18.2 and has a foot portion 18.1 that is connected to the final negative lead bridge, not shown.

The positive terminal comprises an external terminal 16.2 and an internal terminal or foot 1 6.1 that is connected to the final positive lead bridge, not shown, the terminals being spaced from each other. The external terminal 1 6.2 is connected to an output terminal 20 of the immobilising device by a strap 22 capable of carrying current sufficient to start a vehicle, ie. about 400 Amps, and a connecting ring 24 that mates with the base of the terminal. The internal terminal 1 6.1 is sealed to and connected to the terminal housing by filler material 1 6.3 in the known manner. A strap 26 and connection ring 28 connect the internal terminal to an output terminal 30 of the immobilising device. A ball bearing 1 6.5 rests on top of the internal terminal in a cylindrical cavity formed by the filler material.

The immobilising device 1 1 comprises a circuit board 32 to which are fitted a low current relay 34, a starting current relay 36, a receiver circuit 38 and further components for actuating the relays in response to signals received by the transmitter from a remote wireless transmitter, eg. a hand held transmitter, not shown. The circuit of the immobilising device is not described in detail, as it is within the scope of any skilled technician to design or build up a suitable circuit using known components. The negative terminal 18 is connected by a light wire 42 that can carry a current of about 2 Amps only to a negative input terminal of the immobilising device.

The immobilising device is completely encased in a suitable hard epoxy resin that prevents access to the components without damaging them. In use, the immobilising device circuit functions as follows. Operating voltage is provided to the immobilising device through the strap 26 and wire 42. The low current relay 34 is normally closed and permits only sufficient current to flow to the external positive terminal to run motor vehicle accessories, but not enough to operate an engine management system or to prevent the diodes of an alternator connected to the battery from burning out if the vehicle is "jump started", ie. started using another battery in parallel. It also allows a trickle charge to be fed to the battery to recharge it when desired. The starting current relay 36 is normally open, but is switchable to closed when actuated by a actuating signal from the receiver 38. Closing the relay 36 allows sufficient current for starting and operating an engine to flow between the internal and external terminals via the straps 22 and 26. The relay 36 latches in the closed position, provided current is supplied to it. When the engine of a vehicle is switched off, then, after a preset time delay of say 10 to 60 seconds, the immobilising device removes latching current from the relay or resets the relay to an open position.

Attempts to defeat the system are prevented as follows. The straps are of fine strand wires that break easily if a nail or the like is passed through them to connect them to each other, sufficient strand being broken that the remaining strands burn out in the manner of a fuse when required to carry a current sufficient to start an engine, eg. about 400 Amps. Connecting the external terminal to the internal terminal is inhibited by the ball bearing 1 6.5. Jump starting the vehicle using another battery is foiled in two ways. First the immobilising device circuit including the low current relay is caused to burn out. Second the alternator diodes burn out as soon as the engine is started, because there is no battery in the circuit. Also shorting the straps 22 and 26 causes the immobilising device circuit to burn out.

Figures 3 and 4 show a battery cap 50 that can be fitted to a standard battery casing, not shown, to form an immobilising battery. The cap comprises a body 52 of an appropriate plastics, the body having a peripheral lip 52.1 by means of which it can be sealingly secured to a casing. The cap is formed with six filling openings, each of which has a screw in closure 54 in the known manner. The cap has a bulge 56 forming an internal compartment for accommodating an immobilising device comprising a control board 58 including a coded signal responsive wireless receiver, a time delay circuit and a current limiting regulator and a heavy duty relay 60 capable of carrying about 400 Amps when closed. As with the previous embodiment the cap is fitted with a negative terminal 64 of lead that has a base connecting shaft 66 that can be press fitted to an end bridge, not shown, of an array of battery electrodes. The terminal carries a conductor 68 that extends towards the control circuit 58. The conductor is connected to the control circuit by a fusible link 70 that can carry a maximum of 2.5 Amps. The cap is also fitted with a lead positive terminal 72 to which a conductor post 74 is secured by press fitting the upper end of the post into a cavity in the terminal. A conductor 76 is connected between the post 74 and an output terminal 78 of the relay 60. A second connecting shaft 80, securable to the positive end bridge of an array of battery electrodes is spaced from the post 74 by a non-conductive sphere 82, eg. of granite or ceramic, and is connected by a conductor 84 to a second output terminal 86 of the relay 60. As best seen in Figure 3 the conductors 76 and 84 are laterally offset from each other, so that drilling through the cap does not enable one to form or insert a conductive link between the two conductors.

In use, the control board through the relay supplies a limited current, of about 2.0 Amps to the positive battery terminal 72 regardless of whether the immobiliser is armed/active or disabled to run motor vehicle accessories. When the immobiliser is disabled, ie. does not interrupt the current flow, then the relay 60 is switched in response to voltage received from the control circuit to a closed position to connect conductors 76 and 84 to each other so that the battery operates in the normal way and the vehicle can be started, etc.

At least in theory one can remove the cap 50 from a dead or dysfunctional battery and install it on a new casing. This has not been tested in practice, but should be effective provided none of the parts corrodes in use and the connections between the terminal posts and the bridges are separated carefully.

Figure 5 shows a cut out protector device 90 for use with a battery of the invention in order to protect the alternator diodes in the event that the battery is disconnected. The device 90 comprises a circuit board 92, a 100 Amp relay 94 mounted on the board and a three terminal connector 96 also mounted on the board. The relay 92 has high current terminals 98.1 and 98.2 and low current or trigger terminals 100.1 and 100.2. Terminal 98.1 is connected to the alternator voltage-in supply and terminal 98.2 connected to the battery. Terminal 98.1 is also connected to terminal 100.1 and a voltage supply 102 on the connector 96. Terminal 100.2 is connected to a relay trigger terminal 104 that is connected to the output of the alternator. Terminal 106 of the connector is connected to ground . A high voltage sensitive diode 108 that switches at about 14.5 volts, ie. in the range 14.4 to 14.6 volts, is connected between terminals 104 and 106. A low voltage sensitive diode 1 10 that switches at about 14.2 volts is connected between terminals 104 and 102.

In use, an alternator normally generates current at 14.2 volts which is supplied to the battery and motor vehicle electrics. If the alternator is still being driven by an engine when the battery is switched off, then it would normally, ie. but for this device 90, run on an open circuit and cause the output voltage to climb to 20 volts causing the diodes on the alternator to burn out. However, as soon as the voltage rises above 14.5 volts, then this is sensed by diode 108, which provides a path from the output of the alternator through terminal 100.2 opens and the relay cuts off current from the alternator, ie. between terminals 98.1 and 98.2. There is now not enough current from the battery, ie. 2.0 Amps, to energise the ignition coil and the engine stops. Low voltage diode 1 10 limits the maximum voltage supplied to the battery during normal use to 14.2 volts.

The invention is not limited to the precise details described above and shown in the drawings. Modifications may be made and other embodiments developed without departing from the scope of the invention as defined in the claims. The claims form an integral part of this disclosure.

Claims

CLAIMS:

1 . A battery cap (10, 50) connectable to a battery casing (12) having battery electrodes to form a sealed battery, the battery cap having exposed positive (1 6) and negative ( 18) terminals connectable to the appropriate battery electrodes, wherein: -- at least one of the terminals (1 6) comprises an internal terminal

(16.1 ) that is connectable to the appropriate battery electrodes and a spaced apart external terminal (1 6.2); - an immobilising device (1 1 ) is provided within the cap ( 10, 50); - first conductor means (26) is electrically connected between the immobilising device and the internal terminal; -- second conductor means (22) is electrically connected between the immobilising device and the external terminal; and ΓÇö actuating means (38, 58) is provided for actuating the immobilising device to connect the first and second conductor means to each other to form an electrical path between the internal and external terminals that can carry the full current capacity of the battery.

2. The battery cap of claim 1 , wherein the actuating means (38, 58) is selected from electronic key means, such as a coded plug, magnetically encoded card, an electronic keypad and the like means, and a wireless system with a receiver in the battery cap that is responsive to a remote transmitter.

3. The battery cap of either one of claims 1 or 2, wherein the immobilising device (11 ) includes relay means (34, 36, 60) and means for actuating (38, 58) the relay means to connect the first and second conductor means to each other such that the full current capacity of the battery can flow from the internal to the external terminal.

4. The battery cap of any one of claims 1 to 3, wherein the immobilising device (1 1 ) permits a predetermined low current to flow between the internal and external terminals when the internal and external terminals are not connected by an electrical path capable of carrying the full current capacity of the battery.

5. The battery cap of claim 4, wherein the predetermined current is less than 2.5 Amps.

6. The battery cap of either one of claims 4 or 5, wherein the predetermined current is sufficient only to permit motor vehicle accessories, such as a clock, radio, computer, vehicle alarm, central locking and the like to function, but insufficient to enable the ignition coil of a motor vehicle to be energised enough to enable the engine of the vehicle to be started or to operate.

7. The battery cap of any one of the preceding claims, wherein the immobilising device permits a trickle charge to be applied to the battery for charging it when required.

8. The battery cap of any one of the preceding claims, wherein the immobilising device includes interlock means that acts to prevent disconnecting the first and second conductor means from each other, unless the immobilising device is suitably activated to disconnect the conductor means.

9. The battery cap of any one of the preceding claims, wherein the immobilising device includes sensing means to sense whether a current is being applied to charge the battery and switch means responsive to the sensing means to disconnect the first and second conductor means from each other at predetermined time after the engine is switched off.

10. The battery cap of any one of the preceding claims, wherein the immobilising device includes signal generating means for indicating when it changes between active and inactive states.

1 1 . The battery cap of any one of the preceding claims, wherein at least one of the conductor means (22, 26) comprises a plurality of stranded wires constructed and arranged such that piercing the conductor means breaks some of the strands and limits the current carrying capacity of the conductor means to below a predetermined value, such as that required to start a motor vehicle engine.

12. The battery cap of any one of the preceding claims, wherein diverting means (16.5, 82) is provided between the terminals to cause a drill and the like piercing means passing through the external terminal to be diverted away from the second terminal to defeat an attempt to connect the terminals mechanically.