Electrical transmission or interconnection systems – Vehicle mounted systems – Automobile
Reexamination Certificate
1999-05-21
2001-01-30
Paladini, Albert W. (Department: 2836)
Electrical transmission or interconnection systems
Vehicle mounted systems
Automobile
C070S277000, C070S278100, C340S870030, C340S870030
Reexamination Certificate
active
06181025
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an interrogator circuit for a lock and, more particularly, to an interrogator-coil circuit integrated on a circuit board.
2. Description of Related Art
A simple lock-and-key arrangement in some circumstances is deemed insufficiently secure to protect valuable or dangerous items. Unauthorized persons with enough expertise can often open a lock by somehow duplicating the key. This is especially true for automobiles, in which a traditional key-lock ignition can be defeated by an experienced car thief. However, it is equally true for other items.
One approach to this problem has been to use an “interrogator” circuit, which in an automobile is incorporated into the ignition circuitry. The interrogator circuit, mounted in the vehicle, activates the ignition circuit to permit the vehicle engine to be started. The interrogator circuit has a decoder programmed to activate the ignition only when it receives from the key the particular coded signal preprogrammed into the interrogator for that vehicle. By matching the interrogator and the key, a different key, even one that fits the vehicle ignition lock, will not start the engine.
The system is implemented by providing an electromagnetic coil in the vehicle. The coil is typically a wire wound around a bezel surrounding the key opening in the vehicle ignition lock. The vehicle coil in the bezel cooperates with a corresponding coil embedded in the handle of the vehicle ignition key. When the ignition key is inserted into the ignition lock, the vehicle coil, which is always energized, is brought into proximity with a coil in the key handle to induce a current in it. The induced current in turn activates an RF transmitter in the key handle. The transmitter emits a signal with a signature (say a particular frequency) recognized by the interrogator circuit's decoder, and the interrogator circuit activates the ignition and starts the vehicle engine. This type of system requires no independent source of electrical power in the key.
This is a very effective approach, and has application beyond vehicle ignition locks. However, the mere fact that the system comprises multiple components makes it more expensive both to manufacture and install. As presently implemented the vehicle coil consists of copper wire wound on a spool in the bezel, which makes it expensive to manufacture. In addition, the interrogator circuit is typically located remote from the ignition lock, necessitating separate wiring for the different system components, adding further to the expense attributable to system installation.
SUMMARY OF THE INVENTION
It is an object of the present invention to avoid these shortcomings of prior art interrogator systems.
It is another object of the invention to provide an integrated interrogator-coil circuit for use with a lock capable of being opened by a key, which circuit comprises a flexible circuit board having a coil portion and a base portion, an electrical coil on the coil portion for inducing an electric current in a coil in the key when the key is placed in position to open the lock, and an interrogator circuit on the base portion for decoding a coded signal transmitted by the key in response to the electric current induced therein.
In accordance with one aspect of the invention, an interrogator-coil assembly for use with a lock capable of being opened by a key comprises an integrated interrogator-coil circuit on a flexible circuit board having a coil portion with a central opening and a base portion, the circuit including an electrical coil on the coil portion, and an interrogator circuit on the base portion for decoding a coded signal transmitted by the key in response to an electric current induced in a coil in the key, and a housing for accepting the lock, the circuit board being mounted to the housing for permitting access to the lock by the key, wherein the housing includes a coil-mounting portion to which the coil is mounted at a location for inducing an electric current in a coil in the key when the key is placed in position to open the lock and a circuit-holding portion to which the base portion is mounted.
In accordance with a more specific embodiment of the invention, a vehicle ignition lock assembly comprises an integrated interrogator-coil circuit on a flexible circuit board having a coil portion with a central opening and a base portion, the circuit including an electrical coil formed on the coil portion by etching a spiral pattern from a metallic foil adhered to a surface of the circuit board, and an interrogator circuit for decoding a coded signal transmitted by a vehicle ignition key in response to an electric current induced in a coil in the ignition key, the interrogator circuit providing a signal to circuitry in the vehicle to enable the engine thereof to be started only if the interrogator circuit can decode the signal from the key, wherein the interrogator circuit includes circuit components electrically connected by an electrically conductive circuit pattern formed by etching a metallic foil adhered on a surface of the base portion, and a housing for mounting the assembly on a vehicle ignition lock tumbler, the circuit board being mounted to the housing for permitting access to the lock tumbler by the ignition key, wherein the housing includes a coil-mounting portion to which the coil is mounted at a location for inducing an electric current in a coil in the key when the key is placed in the ignition lock tumbler and a circuit-holding portion to which the base portion is mounted.
In such a vehicle ignition lock assembly, the present invention further provides that the flexible circuit board is substantially planar and T-shaped in planform, with the cross portion of the T comprising the base portion and the upright portion of the T terminating in a generally circular loop comprising the coil portion, the interrogator-coil circuit includes connectors on the circuit board for connecting the coil and the interrogator circuit to associated circuitry in the vehicle, the housing is generally circularly cylindrical with a front recess comprising the loop-holding portion and a rear recess for accepting the ignition lock tumbler, wherein the circuit-holding portion comprises an outside surface of the rear recess and the base portion is wrapped around the outside surface, a bezel secured to a front edge of the housing to hold the loop in place in the front recess, and a rear cover fitting around the base portion to secure the vehicle lock tumbler within the rear recess and holding the base portion in place on the outside surface, the rear cover including an access opening for permitting vehicle electrical connectors to be connected to said interrogator-coil circuit connectors.
In such a vehicle ignition lock assembly, the present invention also provides that the flexible circuit board is substantially planar and has a base portion substantially rectangular in planform with a stem extending from a side of the rectangle and terminating in a generally circular loop comprising the coil portion, the interrogator-coil circuit includes connectors on the circuit board for connecting the coil and the interrogator circuit to associated circuitry in the vehicle, the housing includes a generally circularly cylindrical portion with a front recess comprising the loop-holding portion and a rear recess for accepting the vehicle lock tumbler, wherein said circuit-holding portion comprises an enclosure holding the rectangular portion in a plane at an angle to a plane of the loop, the enclosure including an access opening for permitting vehicle electrical connectors to be connected to the interrogator-coil circuit connectors, and a bezel secured to a front edge of the housing to hold the loop in place in the front recess.
REFERENCES:
patent: 5532522 (1996-07-01), Dietz et al.
patent: 5724028 (1998-03-01), Prokup
patent: 5889603 (1999-03-01), Roddy et al.
patent: 6035677 (2000-03-01), Janssen et al.
Krupp Eric
McConnell John E.
Lear Corporation
Niro Scavone Haller & Niro
Paladini Albert W.
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