US4549090A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for preventing theft of motor vehicles
Assignee: Individual
•
Filing: 1984-04-26
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Granted: 1985-10-22
•
Expires: 2004-04-26
Abstract
Abstract Apparatus is disclosed for preventing theft or unauthorized use of motor vehicles. An auxiliary electrical switch is mounted on the housing of the ignition or starter key cylinder, and is connected to a fuse in the main electrical circuit. When the key cylinder is removed and the ignition or starter switch is shorted, this auxiliary switch causes the fuse to blow out and disable the electrical system in the vehicle. The ignition or starter switch actuates a relay, which in turn is connected to a valve mechanism in the fuel line and the ignition coil or starter through independent circuits. Actuation of the relay causes electrical power to be delivered to the fuel valve and ignition coil or starter. When the relay is de-actuated, the ignition coil is grounded, and the vehicle cannot be started with a jumper wire. A further switch is disclosed for disabling the relay.
Inventors
- 👤 William A. Read
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:49
CPC Classifications
B; B60; B60R; B60R25/00; B60R25/20; B60R25/21; B60R25/01; B60R25/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
153 words
An anti-theft circuit for a key-operated electrical system in a moror vehicle, said system having a power source and an electrical circuit connected between the electric load in the system and the power source, and further having a key cylinder switch in said circuit which is operated by insertion of a key into a rotatable key cylinder and rotation of said key cylinder in its housing support, such that said key cylinder switch connects the electrical power source to the electric load of the system, comprising: switching means actuatable by the removal of the key cylinder from said system; fuse means in the electrical circuit of said system; and circuit means connecting said switching means to said fuse means, such that said electric load is connected to ground upon removal of said key cylinder and said power source is disconnected by said fuse means upon subsequent connection of the key cylinder switch contacts.
Claim 2
Dependent Claim
153 words
An anti-theft circuit for a key-operated electrical system in a moror vehicle, said system having a power source and an electrical circuit connected between the electric load in the system and the power source, and further having a key cylinder switch in said circuit which is operated by insertion of a key into a rotatable key cylinder and rotation of said key cylinder in its housing support, such that said key cylinder switch connects the electrical power source to the electric load of the system, comprising: switching means actuatable by the removal of the key cylinder from said system; fuse means in the electrical circuit of said system; and circuit means connecting said switching means to said fuse means, such that said electric load is connected to ground upon removal of said key cylinder and said power source is disconnected by said fuse means upon subsequent connection of the key cylinder switch contacts.
Claim 3
Dependent Claim
27 words
A circuit as recited in claim 1, wherein a switching means, upon removal of said key cylinder, provides a mechanical obstruction preventing replacement of said key cylinder
Claim 4
Dependent Claim
63 words
A circuit as recited in claim 2, wherein said switching means comprises an electrical switch attached to the housing support for said key cylinder, having a spring-actuated plunger pressing against said key cylinder, such that when said key cylinder is removed said plunger is urged into the space occupied by said key cylinder and said switch attached to said housing support is closed.
Claim 5
Dependent Claim
60 words
A circuit as recited in claim 1, wherein said fuse means comprise a fuse connected in series between said electrical power source and the electric load of said system, and wherein the terminal of said fuse connected to the electric load is also connected to one terminal of said switching means, the opposite terminal of said switching means being grounded.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-21 | 1989-04-22 | 1989-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-21 | 1993-04-22 | 1993-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-21 | 1997-04-22 | 1997-10-22 | $7700.00 | Window Closed / Lapsed |