WO1993002897A1

WO1993002897A1 - Vehicle security system

Info

Publication number: WO1993002897A1
Application number: PCT/AU1992/000391
Authority: WO
Inventors: Adrian Christopher Joseph Harris; Michael Robert Frank Hammer; Jack Chatziyakoumis; Andrew Simon Conlon
Original assignee: General Motors-Holden's Automotive Limited
Priority date: 1991-07-30
Filing date: 1992-07-30
Publication date: 1993-02-18

Abstract

A vehicle security system (11) of the kind which is armed or disarmed by means of a radio frequency signal generated by a portable device (1) located remote from the vehicle (8). The portable device (1) includes a transmitter (4), a battery (6) capable of providing a power source for the transmitter (4), and a switch (7) which is operable to connect the transmitter (4) and battery (6) and thereby cause generation of a coded signal. The system includes a secondary signal path (21) which is completed by cooperative engagement between two contacts (15, 16), one (15) of which is provided on the portable device (1) and the other (16) is provided on the vehicle (8). Engagement of the contacts (15, 16) also has the effect of connecting the device transmitter (4) to the vehicle battery (20) which then provides a power source for the transmitter (4) so that a coded signal is generated and transmitted along the secondary signal path (21). A signal so generated will cause the security system (11) to be disarmed. The portable device (1)may form part of the vehicle ignition key.

Description

VEHICLESECURITYSYSTEM

This invention relates to vehicle security systems, and is particularly concerned with such systems as used to protect motor vehicles against improper use and which are able to be controlled from a remote location.

Security systems of the kind to which the invention relates, generally include an alarm mounted in the vehicle and which, when armed, will emit a signal if the associated vehicle is tampered with. The alarm can be armed and disarmed from a remote location by means of a transmitter which is operable to emit a coded radio frequency (RF) signal. The security system in the vehicle responds to that (RF) signal by arming or disarming, as appropriate, the alarm. Some security systems also control the effective operation of the vehicle engine start system. The relevant control means is generally switchable between two conditions in which operation of the start system is enabled and disabled respectively. Any suitable means may be utilised to effect switching between those conditions, including receipt of a signal from the aforementioned transmitter.

The transmitter usually forms part of a portable (RF) signal generating device and is contained within a housing of that device which also contains a small battery arranged to provide the transmitter power source. A press button switch is selectively operable to connect the battery and transmitter so as to cause generation of the coded signal. Effective operation of the signal generating device may be hinderded or prevented in a variety of ways. By way of example, the battery may have lost its charge, or may have insufficient charge to effectively operate the transmitter. Location of the transmitter in close proximity to radio towers or the like can also render the signal generating device ineffective. The consequence of such a malfunction can be quite dramatic. The alarm may continue to operate and/or it will not be possible to start the vehicle engine. One proposal for meeting the foregoing problem is to provide a special by-pass key which is usable to disarm the security system, but that has the disadvantage of diminishing the overall level of security of the system. It is an object of the present invention to provide a relatively simple and effective solution to the aforementioned problem.

According to one aspect of the present invention, there is provided a vehicle security system including, detection means operable to adopt either an armed condition or a disarmed condition in which it indicates proper and improper use respectively of the vehicle with which the system is associated, a portable signal generating device having a transmitter, a battery and switch means which is selectively operable to connect said transmitter and battery, said transmitter being responsive to connection with a power source to transmit a coded signal and said battery forming a said power source, said detection means being responsive to receipt of a said signal to adopt either one of said conditions thereof, and an auxiliary power source separate from said device and being operable to enable operation of said transmitter independent of or through said battery.

The detection means may take any of a variety of forms. In many cases it will include or comprise an alarm which is operative to produce an audible signal, which if sounded will be an indication of (attempted) improper use of the associated vehicle. Absence of the alarm signal is by corollary an indication of proper use. The detection means may also include or comprise means which controls the vehicle engine start system, in which event disabling of that system is an indication of improper use and enabling of the system is an indication of proper use. It will be appreciated from the foregoing that an "indication" as referred to in the preceding paragraph of the specification need not be a visible or audible indication, but could be a result or absence of a result of performance of a certain activity such as use of a vehicle ignition key. -3- In many applications of the invention the auxiliary power source will be the battery of the associated vehicle, and connection of that battery to the signal generating device can have a number of consequences. If the battery of the device is rechargeable, such connection may result in that battery being charged. Alternatively or additionally such connection may activate the transmitter so that a signal is generated.

The signal generating device may be of the conventional kind which is a stand-alone unit adapted to be carried to and from the vehicle. Quite often such devices are connected to the key ring to which the vehicle ignition key is connected. In a preferred embodiment of the invention, the signal generating device forms part of the head of the vehicle ignition key.

According to a further aspect of the present invention, there is provided a portable signal generating device having a transmitter, a battery and switch means which is selectively operable to connect and disconnect respectively the transmitter and battery, said transmitter being responsive to connection with a power source to transmit a coded signal and said battery providing a said power source, and contact means connected to said transmitter or said battery and being connectable to a power source separate from said device.

In one particular form, the signal generating device is built into the head of a vehicle ignition key.

An embodiment of the invention is described in detail in the following passages of the specification which refer to the accompanying drawings. The drawings, however, are merely illustrative of how the invention might be put into effect, so that the specific form and arrangement of the various features as shown is not to be understood as limiting on the invention. In the drawings:

Figure 1 is a block diagram showing one embodiment of the invention.

A security system according to the invention is characterized in that it includes back-up means which -4- enables transmission of the required coded signal in circumstances where the signal generating device is ineffective for any reason such as the transmitter battery having inadequate charge or being inoperable. The back-up means can operate in any one of a variety of ways. It may for example operate to charge the transmitter battery, or it may operate to provide an independent or auxiliary power source for the transmitter. It will be convenient to hereinafter particularly describe an embodiment of the invention in which the back-up means provides an auxiliary power source for the transmitter.

The signal generating device or actuator is usually a relatively small device which is often either built into the ignition key head or is attached to the key ring which carries the ignition key for the relevant vehicle. The actuator will therefore be located adjacent the ignition switch of the vehicle when the vehicle is in use, and the present invention makes use of that relationship.

In the particular embodiment of the invention shown in the drawings, the signal generating device or actuator

1 forms part of an ignition key 2. The actuator 1 is conveniently provided in the head 3 of the key 2, and is of conventional form in that it includes a transmitter 4,

.an encoder 5, and a battery 6 which provides a power source for the transmitter 4. A switch 7 is selectively operable to connect the transmitter 4 and battery 6 and thereby result in generation of a coded signal. In

•^■accordance with conventional practice, the signal generated in the illustrated example is a radio frequency (RF) signal.

A vehicle, which is represented by the block 8, will have a receiver 9 which receives the RF signal and transmits that signal to a decoder 10 which forms part of the vehicle security system 11. That security system 11 may be alarm base or it may be based on some other function such as control of the vehicle start system. A combination arrangement which is both alarm based and vehicle operation based may be employed, and such an arrangement will be hereinafter described. -5- Assuming the signal received by the decoder 10 is the correct signal, the decoder 10 passes a consequent signal onto the critical aspects of the security system

11, and in the illustrated arrangement they include an alarm 12 and a control unit 13 for the vehicle engine start system. The consequent signal operates in a known manner to disarm, or arm, the alarm 12, and to enable or disable the vehicle start system through the unit 13.

In normal operation of the actuator 1, the operator presses the switch 7 to connect the battery 6 and transmitter 5. A coded signal is then generated which is sent by the transmitter 4 along a path 14 to the receiver 9 of the vehicle 8. The received signal then conditions the security system 11 as required in a known manner. Assuming the actuator 1 is operated from a remote location to disarm the alarm 12 and enable the engine start system through the unit 13, it is preferred that the enabling function is limited to a period of time - for example, 30 seconds. If the correct ignition key is not inserted into the ignition keyway of the vehicle within that time, the security system preferably operates to automatically disable the engine start system. The by-pass facility hereinafter described operates to sense whether or not a correct key has been inserted into the ignition keyway. The arrangement shown in the drawings has a by-pass facility which comes into operation in the event of malfunction of the actuator 1. That facility includes a contact 15 provided on the key head 3, or at any other suitable location, so as to be engageable with a cooperable contact 16 located within the vehicle 8. In the particular arrangement shown, the contact 16 is in the form of an annulus, or part thereof, which is disposed around the vehicle ignition keyway 17. The arrangement is such that the two contacts 15 and 16 engage when the key blade 18 is fully inserted into the keyway 17 and the key 2 is turned towards the vehicle start position.

There are two consequences of operation of the key 2 as described above. First, the key 2 causes operation of a switch 19 which connects the vehicle battery 20 to the decoder 10 and to the contact 16. Second, because of engagement between the contacts 15 and 16 and the connection of the latter contact to the vehicle battery

20, the battery 20 is connected to the transmitter 4 and provides a power source for that transmitter.

The second consequence results in the generation of a coded signal by the actuator 1, and that signal is transmitted to the decoder 10 along the path 21. The received signal then functions in the same manner as it would if received through the receiver 9. In particular, the alarm 12 is disarmed, and the unit 13 operates to enable the engine start system. A timer 22, or other suitable means, may operate to cease transmission of a signal along the path 21 after the intended purpose of that signal has been accomplished.

When the ignition system of the vehicle is de-energised by the reverse rotation of the key 2 and subsequent withdrawal of the key 2 from the keyway 17, the actuator 1 may be operated to return the security system to a secure condition. It is preferred however, that means is provided to prevent such rearming for a predetermined period of time - e.g., to allow the vehicle occupant to leave the vehicle. Any suitable electronic circuitry may be employed for that purpose, and the block 23 is representative of that circuitry. Preferably, the relevant circuitry 23 forms part of the decoder logic.

If the actuator battery 6 is of the rechargeable kind, engagement between the contacts 15 and 16 may cause that battery to be recharged through the resulting connection with the vehicle battery 20.

An arrangement as described makes it unnecessary to operate the actuator 1 through use of the switch 7, since all necessary functions can be performed through normal operation of the ignition key 2. In the event of failure of the communication path through the contacts 15 and 16, the arrangement preferably provides for the decoder 10 to change its mode of operation. For example, the system may sense movement of the key 2 towards the vehicle start position, an if data is not received along the path 21 -7- after a predetermined period of time (say two seconds), the system may respond by causing the decoder 10 to switch to monitor incoming data received through the receiver 9. Any suitable means may be adopted for that purpose. Thus, if there is no response to placement of the key 2 at the vehicle start position, the user can disarm the alarm 12 and enable the vehicle start system by pressing the switch 7 and thereby causing a coded signal to be transmitted along the path 14. It will be apparent that the invention may be applied in a variety of ways. By way of example, the actuator 1 could be formed separate from the key head 3 and connected to the contact 15 through an appropriate conductive path. If the vehicle is provided with charging means which is operable to charge the transmitter battery, the charging operation may occur automatically or in response to specific circumstances such as doing something to cause the charging means to be active or operable on the relevant battery. By way of example, the actuator may be exposed to an energy field when located adjacent the vehicle ignition switch. The field may be electronic, magnetic, or electromagnetic, and could be activated in any appropriate manner, such as by operation of the ignition switch, or by insertion of the ignition key into the ignition key slot. Simple exposure to the energy field may be sufficient to provide adequate energy for the transmitter to be able to generate the coded signal. Alternatively, or additionally, ^' the energy field may function to automatically charge the transmitter battery during use of the relevant vehicle.

In another arrangement, the vehicle may be provided with a device which physically mates with the actuator in such a way as to enable effective operation of the actuator. By way of example, the actuator housing may have a contact which is engageable with a contact of the aforementioned device so as to enable passage of energy through the device to the transmitter. The contacts may be of any suitable form such as cooperable plug and socket -8- contacts. In the latter event, one or both of the contacts may be provided on an end of a flexible conductor lead.

According to another possible arrangement, the actuator housing, or part of that housing, may be located within a recess or cavity provided within the vehicle, and by that location causes the two contacts, whatever their form, to engage. Passage of energy through the engaging contacts may occur automatically, or in response to operation of an associated control switch.

It will be apparent from the foregoing description that a system according to the present invention provides a simple yet effective solution to the problem of a depleted energy source for the system transmitter. Various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention as defined by the appended claims.

Claims

-9- CLAIMS :

1. A vehicle security system including, detection means operable to adopt either an armed condition or a disarmed condition in which it indicates proper and improper use respectively of the vehicle with which the system is associated, a portable signal generating device having a transmitter, a battery capable of providing a power source for said battery and switch means which is selectively operable to connect said transmitter and battery, said transmitter being responsive to connection with a power source to transmit a coded signal and said detection means being responsive to receipt of a said signal to adopt either one of said conditions, and an auxiliary power source separate from, said device and being operable to enable operation of said transmitter independent of or through said battery.

2. A vehicle security system according to claim 1, wherein connection of said auxiliary power source and said transmitter results in generation of a said coded signal which is transmitted to said detection means along a secondary signal path, and said detection means responds to that signal by adopting said disarmed condition.

3. A vehicle security system according to claim 1 or 2, wherein said auxiliary power source is the battery of said associated vehicle.

4. A vehicle security system according to any preceding claim, wherein said secondary signal path includes cooperable contacts provided on said device and said associated vehicle respectively, and that path is interrupted when the said contacts are not in engagement.

5. A vehicle security system according to claim 4, wherein one said contact is provided on an ignition key for the said associated vehicle, said device is connected to said one contact, and the other said contact is provided on the said vehicle and is connected to the vehicle battery.

6. A vehicle security system according to claim 5, wherein said device is attached to or forms part of the head of said ignition key.

-10- 7. A vehicle security system according to claim 5 or 6, wherein said tranmistter operates automatically to transmit a said signal along said secondary signal path while the two said contacts are in engagement.

8. A vehicle security system according to any one of claims 5 to 7, wherein means is responsive to disengagement of said contacts to cause said detection means to adopt said armed condition.

9. A vehicle security system according to any preceding claim, wherein said detection means includes a decoder which responds to receipt of ^"a correct said signal so as to cause adoption of either of said conditions.

'

10. A vehicle security system according to any preceding claim, including an alarm which is operative to emit an audible signal indicating said improper use, and said alarm is operative in said armed condition and is inoperative in said disarmed condition.

11. A vehicle security system according to any preceding claim, including control means which is connected to the engine start system of said associated vehicle, and said control means is operative to disable said start system in said armed condition and to enable said start system in said disarmed condition so as to thereby indicate said improper and proper use respectively.

12. A portable signal generating device having a transmitter, a battery capable of providing a power source for said battery, switch means which is selectively operable to connect and disconnect respectively said transmitter and battery, said transmitter being responsive to connection with a power source to transmit a coded signal, and contact means connected to said transmitter or said battery and being connectable to an auxiliary power source separate from said device.

13. A device according to claim 12, wherein said device forms part of a vehicle ignition key.

14. A vehicle security system substantially as herein particularly described with reference to what is shown in the accompanying drawings.

15. A portable signal generating device substantially as herein particularly described with reference to what is shown in the accompanying drawings.