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US 4,071,007 AGranted
Stop auto theft
AssigneeNone recorded
InventorRobert J. Arix
Life of this patent
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AssigneeNone recorded
InventorRobert J. Arix
Estimating the term…
An anti-theft device for a motor vehicle includes a starter-connected ignition switch which has a first accessible terminal, and a second substantially non-accessible terminal connected to a third substantially non-accessible terminal of a voltage dropping means, such as a resistor. A relay has a coil and at least a pair contacts closable by operating the ignition switch, and is connected in series with a circuit breaker, the voltage dropping means, the ignition switch and a voltage source. The circuit breaker trips at a predetermined current setting, and the coil is designed to burn out at a current just exceeding the predetermined current. Periodically openable contact-means actuate the motor vehicle's engine and are energizable by the pair of contacts. The circuit breaker trips upon a thief shorting the accessible terminals, and the relay coil burns out upon the thief shorting the circuit breaker.
An anti-theft device in combination with motor vehicle having an internal combustion engine and an ignition system, said device comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
No related US applications are recorded in the indexed filing history.
Operating on vehicle systems or fittings, e.g. on doors, seats or windscreens: operating on the propulsion system, e.g. engine or drive motor
Vehicle fittings and parts
Term ended 31 Jan 1995 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The field of the present invention relates to an anti-theft device for a motor vehicle.
2. Description of the Prior Art
My invention will be better understood by means of the accompanying drawing, the sole FIGURE of which illustrates a schematic circuit diagram of the anti-theft device, according to my invention.
The anti-theft device for a motor vehicle which has an internal combustion engine 11 and an ignition system, includes a transformer 10 which has a primary winding 12 and a stepped-up secondary winding 14, a distributor 36 connected to a starter 17 for starting the engine 11. A switch 16 has a first accessible terminal 21, a second substantially non-accessible terminal 19, and a battery 18 supplying a voltage is connected to the ignition switch 16. Voltage-dropping means 20 are provided for dropping the voltage of the voltage source 18; the voltage-dropping means 20 are provided with a third substantially non-accessible terminal 22 connected to the second terminal 19, and with a fourth accessible terminal 24. A circuit breaker 26 is connected to the ignition switch 16, and is set to trip at the predetermined current. A relay 28 has a coil 30 energizable by the ignition switch 16, and at least a pair of contacts 32 closable by operating the ignition switch 16. The coil 30 is designed to burn out at a current just exceeding the predetermined current, and the ignition switch 16, the voltage dropping means 20, the circuit breaker 26 and the relay 28 are connected in series across the voltage source 18. Periodically openable contact means 34 are actuable by closure of the pair of contacts 32, and the latter, the contact means 34 and the voltage source 18 are connected in series with the primary transformer winding 12; the voltage-dropping means 20 is preferably a resistor. The circuit breaker 26, upon a thief shorting the accessible terminals 21 and 24, trips, and the relay coil 30 burns out upon the thief shorting the circuit breaker 26, so that the thief cannot start the engine of the motor vehicle.
Although the invention has been described with respect to a preferred version thereof, it is to be understood that it is not to be so limited since changes can be made therein which are within the full intended scope of the appended claims.