AU614301B2 - Coded security device - Google Patents

Description

AUSTRALIA 4 3 Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Application Number: Lodged: Int. Class t 4.

4. 4.4 e t 4. I .999.9 9# 9 9 4. 4.

9r 4.

Complete Specification Lodged: Accepted: Published: Priority Related Art: APPLICANT'S REF.: CAP of PI4195 ROBB FARM INDUSTRIES PTY. LTD. Name(s) of Applicant(s): Address(es) of Applicant(s): Actual Inventor(s): Address for Service is: 15-19 Govan Street, Seaford, Victoria 3198, Australia.

MARTIN, Anthony George PHILLIPS, ORMONDE AND FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne, Australia, 3000 Complete Specification for the invention entitled: "CODED SECURITY DEVICE" The following statement is a full description of this invention, including the best method of performing it known to applicant(s): P19/3/84 CODED SECURITY DEVICE This invention relates generally to a security device for securing apparatus against unauthorised access or operation and, in particular to an electrically coded security device connectable to an operating system of the apparatus for selectively enabling and disabling the system to respectively permit and prevent apparatus operation.

The security device of the present invention is suitable for installation in an electrical system of a vehicle for securing the system against unauthorised vehicle engine ignition, and it will be convenient to hereinafter describe S the invention in relation to that exemplary application.

0000 J However it is to be appreciated, that the present invention is ap not thereby limited to that application.

A variety of arrangements have been developed for o disabling normal operation of vehicle electrical systems, particularly that part providing engine ignition, in order to secure the vehicle against theft or unauthorised use.

~Typically, these arrangements involve "grounding" some critical component of the system, such as the high tension lead connected between the ignition coil and distributor, or depriving a critical component, such as an electronic management device of the system, of electrical power. Thus, normal operation of the system through use of an ignition key or "hot wiring" the system is inhibited.

Some of these prior arrangements, once identified, are readily circumvented by a thief or unauthorised person. That may be achieved with force. Alternatively, a part or component of the electrical system that is critical to operation of the security device, usually a part or component common to all systems, may be isolated, inserted or replaced.

More sophisticated approaches involve integration of the security arrangement into the electrical system or components thereof. However, such arrangements can be expensive because of the need for alternative components. Moreover, some of these arrangements may only be readily incorporated into new electrical systems during manufacture, and therefore may not be appropriate for existing electrical systems of vehicles.

39 It is an object of the present invention to alleviate l-_llil:.- CI these disadvantages of prior arrangements through the provision of a relatively simple security device suitable for use with vehicle operating systems.

With this in mind, the present invention provides an electrically coded security device for providing combined mechanical and electrical security against unauthorised operation of an operating system of a vehicle ignition system, the security device including: a lock having a keyway; (ii) a portable actuating key insertable into the keyway and, following insertion, actuable from an inoperative position in which the lock disables the operating system from operation to an operative position of the operating system and thereby provide mechanical locking security against unauthorised operation of the operating system; (iii) an actuating module carried by the actuating Skey, and having encoder means operable to transmit coded rto serial data signals in response to supply of electrical "200 power thereto; and (iv) a control module connectable to the operating system, and being connectable to the actuating module upon insertion of the key into the keyway, the control module having decoder means operable to receive and validate the transmitted serial data signals during connection with the actuating module, and having operating means enabling the operating system to operate upon validation of the data signals and thereby provide electrical locking security against unauthorised operation of the operating system.

2a I ~PZP~s~nWC imalan~ g C~p .tho disadvantages of prior OdUi' -r h- -o r provision of a relatively simple security devic suitable for use with vehicle operating systems.

With that object in mind, the pr ent invention provides an electrically coded security devi .efor an operating system, including: an actuating modul ,-having encoder means operable to transmit coded data si s; and, a control module connectable to an ope ,ting system, the control module and actuating module J.'terconnectable, the control module having decoder mean operable to receive and validate the transmitted data siq s, during connection with the actuating module, and 0000 havj operating means enabling said operating system to -perate upon validatien of the dafteignal.

Preferably, the encoder means is operable to transmit data signals to the decoder means when they are 00 interconnected. That interconnection is preferably electrical to enable data transmission to occur. The encoder means may be adapted to transmit data in the form of serial data bits.

In turn, the decoder means is operable to receive the data bits transmitted by the encoder means and to compare, for validation, the received data with data bits stored in the o decoder means. If the bits match then a valid output transmission is generated. That valid output transmission is preferably a logical high output, relative to a logical low output corresponding to an invalid output transmission of unmatched bits.

In one preferred form, the encoder means includes an encoder integrated circuit (IC) chip, and the decoder means includes a decoder IC. One example encoder IC is MOTOROLA device MC 145026, and example decoder ICs are MOTOROLA devices MC 145027 and MC 145028. This 16 pin encoder IC will encode 9 bits of data for serial transmission. Pins 1 to 7, 9 and may be encoded with trinary data 1, open) providing approximately 20,000 different data codes. The 16 pin decoder ICs may accept up to approximately 13,000 data codes from the encoding IC. Thus, the encoder and decoder ICs can be selected so that a valid output transmission is generated only if one in approximately 13,000 data codes match when the 39 encoder and decoder means are interconnected.

In this example, pin 15 (Data Out) of the encoder IC is used to transmit the data bits, whilst pin 9 (Data In) of the decoder IC is used to receive those bits and pin 11 (Valid Transmission) is used for the valid output transmission.

In a preferred form, the encoder and decoder means include support components for the respective ICs in order to facilitate correct operation, generation and transmission of the data bits, and examination of those data bits.

Thus, in one example the encoder means includes components for supporting an internal oscillator for the encoder IC. The components may include first and second resistors connected in series between pins 11 and 13, and a capacitor connected between pin 12 and the junction of the Sfirst and second resistors.

In the example the decoder IC of the decoding means e includes components to detect the format of the encoded data i from the encoder IC, for example narrow or wide pulse data bits. The components may include a resistor connected between I. pins 6 and 7, and a capacitor connected between pin 7 and S 20 ground.

i Components may also be provided to detect the end of the encoded data transmission. Those components may include a resistor and capacitor connected in parallel between pin 10 of KI the decoder IC and ground.

U In a preferred form, the encoder and decoder means are electrically powered from the operating system in which the control module is installed, although it is to be appreciated that alternative power supplies may be provided. Power to the encoder IC may be provided upon electrical interconnection of the encoder and decoder means, or it may be provided prior to such interconnection. Power to the encoder IC may be provided on a continuous basis or it may be provided temporarily, e.g.

during starting of a vehicle only.

Upon interconnection, in the exemplary application, active and ground terminals of a suitable power supply may be respectively connected to pins 16 (VDD) and 14 (Transmit Enable) of the encoder IC. A diode may be inserted between pin 14 of the encoder IC and the ground terminal to avoid 39 positive spikes at pin 14.

-4- In one form the actuating module is mechanically connectable with the control module, the electrical connection being arranged to be associated with such mechanical connection via suitable terminals. Alternatively the actuating and control modules are physically separated. At least one electrical connection may be provided between the actuating and control modules for transfer of data.

The actuating module may include a base member on which the encoder means is carried. The base member may be adapted to directly or indirectly connect with the control module.

The nature of the base member may determine the manner of interconnection.

Thus, in one preferred form, the base member comprises an actuating key insertable into a key way. This key carries the encoder means with electrical terminals located so as to a interconnect with corresponding terminals of the decoder means/power supply upon insertion df the key into the key way. The key may be of a conventional type with a head and blade which may have bittings cut therealong. Thus, the key may form part of a mechanical security arrangement as well as part of an electrically coded operated security device according to the present invention. This may be particularly advantageous in the exemplary application where the key may be used in a conventional manner with locks installed within the vehicle but also forms part of the present security device.

It will be appreciated that alternative base members may be provided. In that regard, the base member may comprise a carry card.

The control module may include operating means responsive to valid output transmissions of the decoder means and adapted to enable and disable operation of the operating system. That operating means preferably includes a switching device switchable between a condition disabling the system when an invalid output transmission is received, and a condition enabling the system when a valid output transmission is received. Enabling and disabling may be conveniently achieved by respective connection and disconnection of an electrical power source of the operating system or one or more S 2 components thereof.

In a preferred form, the switching device comprises a buffer transistor and/or one or more relays. The base of the transistor may be connected to receive output transmissions from the decoder means and so as to be turned "ON" during a valid output transmission.

The security device of the present invention may include means for indicating its operating condition during use, i.e.

whether the device is enabling or disabling the operating system to which it is connected. The means for indicating may be audible and/or visual. Thus, for example the control module may include one or more light emitters, such as light f emitting diodes, connected so as to respond directly or ft* c indirectly to output transmissions from the decoder means.

The light emitters may respond to the condition of the S switching device.

Q

In a preferred form, the control module is constructed for ready connection to an operating system. In the exemplary application, that facilitates installation of the device I within a vehicle ignition system. If the security device is 2 0 incorporated into the system during manufacture then the control module may be incorporated into the electronic management module.

The security device of the present invention may provide a simple yet effective arrangement for securing electrical operating systems against unauthorised use. In particular, the large number of uniquely coded signals available allows relatively unique devices to be produced.

The security device of the present invention is equally suitable for connection to existing operating systems as well as new systems at the time of manufacture. The device may be relatively easy to install in existing systems. That is important in the exemplary application where the security device may form an important and inexpensive "after market" vehicle accessory.

For assistance in arriving at an understanding of the present invention a preferred embodiment of the invention will now be described with reference to the accompanying drawings wherein: 39 Figure 1 shows a block diagram of a preferred embodiment security device incorporating the present invention; Figure 2 shows a schematic diagram of an actuating module of the security device of Fig. 1; and Figure 3 shows a schematic diagram of a control module of the security device of Fig. i.

The security device shown in Figure 1 includes actuating module 10 connected to respective power supply terminals.

Power supply to actuating module 10 is provided from the 12 Volt "START" terminal of a vehicle ignition switch and the ground terminal of the vehicle respectively.

The security device includes control module 11 also connected to respective power supply terminals. Power supply aana oa o to control module 11 is provided from the 12 Volt "IGNITION" o o terminal of the vehicle ignition switch and the ground terminal of the vehicle respectively. Modules 10 and 11 are 6a o, interconnected via a data line 12 for transfer of data from module 10 to module 11. Control module 11 enables operating system 13 to be secured via line 14.

°oa Referring to Figure 2, actuating module 10 includes a 00 a 20 encoder 20. Encoder 20 comprises IC device MC 145026.

*0 Encoder 20 serially transmits from its Data Out terminal (pin 15) nine bits of trinary data as defined by the state of its input terminals (pins 1-7, 9 and 10). These input terminals 9 can be in either of three states 1, open) allowing 3 19683 possible codes. The transmit sequence is initiated by a low level to the Transmit Enable (TE) terminal (pin 14). The TE terminal initiates transmission when low. The TE input is connected to ground via diode D1 to avoid positive spikes at pin 14.

The oscillator of encoder 20 is set up via terminals

R

S (pin 11), CTC (pin 12) and RTC (pin 13). Resistors RTC and R S are connected in series between terminals RTC and R S of encoder 20 as shown. Capacitor CTC is connected between the junction of resistors RTC, R S and terminal CTC of encoder 20. The frequency of the oscillator is approximately equal to: f 1 Hz 2.3 RTC

CTC

39 The value of R S should be chosen to be approximately 2 KW -7- -rrx~ r*rpn*-crr~~~nr times RTC. Power to encoder 20 is provided via terminals VDD (pin 16) and VSS (pin 8) from the 12 Volt "START" terminal of the vehicle ignition switch and the vehicle ground terminal respectively.

Actuating module 10 is assembled on a key printed circuit board (PCB). The PCB includes an earth track around 3 sides thereof to facilitate attachment to the key.

Referring to Figure 3 control module 11 includes decoder Decoder 30 comprises IC device MC 145028. Decoder receives at its Data In terminal (pin 9) serial data from encoder 20. Decoder 30 checks the data for errors and compares it with data encoded at address input terminals A1-A9

POO*

(pins 1-5 and 12-15). Because the ninth address bit (A9) must D, 8 be a 1 or 0, decoder 30 can accept only 2 x 3 13122 o s different codes. A trinary (open) A9 will be interpreted as S Logic 1. If the data matches the Valid Transmission (VT) terminal (pin 11) of decoder 30 goes high.

Resistor R 1 is connected between terminal R 1 (pin 6) o and terminal C 1 (pin 7) of decoder 30 and capacitor C 1 is 1 1p connected between terminal C 1 of decoder 30 and ground.

0° Resistor R 1 and capacitor C 1 match decoder 30 to the pulse o, width of transmitted data. The time constant R x C 1 1 Sshould be set to approximately 1.72 transmit clock periods

(R

1 3.95 RTC CTC).

r Terminal R 2

/C

2 (pin 10) of decoder 30 accepts a B resistor R 2 and parallel capacitor C 2 to ground. The Svalues of R 2

C

2 are used to determine the end of an encoded word and the end of a transmission. The time constant

R

2 x C 2 should be approximately 33.5 transmit clock S 30 periods (4 data bit periods). This time constant is used to determine that the Data In terminal has remained low for four data bit periods (end of transmission). A separate comparator looks at a voltage equivalent to two data bit periods (0.4

R

2

C

2 to detect the dead time between transmitted words

(R

2

C

2 77 RTC CTC).

Power to decoder 30 is provided via terminals VDD (pin 16) and VSS (pin 8) from a regulated power supply comprising series resistor R4, Zener diode Z1 and smoothing capacitor 39 C3. Power is provided from the 12 Volt "IGNITION" terminal of T- the vehicle ignition switch and the vehicle ground terminal respectively. The decoder 30 is connected to ground via diode to avoid positive spikes.

When decoder 30 receives a valid transmission its output terminal VT (pin 11) goes high. This output is buffered by transistor T 1 which in turn switches relay RL 1 to the position shown. Latching diode D 3 latches relay RL 1 in the position shown until power is disconnected from relay

RL

1 i.e. when vehicle ignition is turned off.

Relay RL 1 connects power to operating system 13 (refer Fig 1) being secured by the security device of the present invention. In the example shown operating system 13 incorporates a fuel supply control valve (not shown).

o" Operating system 13 also includes a starter solenoid relay (not shown) adapted to enable the vehicle starter solenoid 04 0 prior to starting the vehicle. The starter solenoid relay and fuel valve are isolated via isolating diode D 4 Finally, it is to be understood that various 0, modifications and/or additions may be made to the security 4,0 device without departing from the ambit of the present co invention described herein.

Claims (8)

1. 2. A security device as claimed in claim 1, wherein the encoder means is operable to transmit a serial data stream of trinary data bits and the actuating module and control module- -are electrically interconnectable to enable data bit transmission, the decoder means providing reference bits against which the data bits received from the actuating module are compared for validation, a valid output transmission being generated from the decoder means to operate the operating means when the data bits are validated. 10 I-li -~currrr rr*rissl~lUI~DI~ i~l-- S3. A security device as claimed in claim 2, wherein the valid output transmission is a high voltage output from the decoder means, the decoder means generating an invalid output transmission comprising a low voltage output when the received data signals are not validated.
2. 4. A security device as claimed in any preceding claim, wherein the actuating module has at least one terminal for exposure to the keyway when the key is inserted therein and the encoder means is operable to transmit the data signals to the terminal, and the control module has at least one terminal mounted for exposure to the keyway so that connection can be made between the actuating module and the control module through the terminals thereof when the key is in the keyway. A security device as claimed in claim 4, wherein the terminals of the actuating and control modules interconnect and power is connected to the actuating module upon insertion of the key into the keyway in the So o inoperative position and subsequent actuation of the key 44,4 to the operative position. 0 o o 6. A security device as claimed in any preceding claim, wherein the operating means includes a switching device switchable between a condition disabling the system when an invalid output transmission is received, and a condition enabling the system when a valid output transmission is received.
3. 7. A security device as claimed in claim 6, wherein the switching device includes a buffer transistor.
4. 8. A 3 security device as claimed in claim 6 or 7, wherein-the switching device includes a latching relay.
5. 9. A security device as claimed in any one of claims 2 to 8, wherein said data comprises 9 bits of trinary data. An electrically coded security device substantially as hereinbefore described with reference to the accompanying drawings.
6. 11. A vehicle ignition system including a security device as claimed in any preceding claim incorporated into an operating system of the ignition system. 11 -I
7. 12. An' ignition system as claimed in claim 11, wherein the operating system includes a fuel supply control valve.
8. 13. An ignition system as claimed in claim 11 or 12, wherein the operating system includes a starter solenoid. DATED: 13 June, 1991 PHILLIPS ORMONDE FITZPATRICK Attorneys for: ROBB FARM INDUSTRIES PTY LTD -L tr !1 27571 t t n 4 t I 49i t tr 12