US3634724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Auto theft prevention system
Assignee: CHAPMAN INDUSTRIES CORP A CORP OF
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Filing: 1969-09-16
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Granted: 1972-01-11
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Expires: 1989-09-16
Abstract
Abstract An auto theft prevention circuit in an ignition circuit, the theft prevention circuit including an impedance and switch means for connecting the impedance in parallel with one of the passive components of the ignition circuit, this theft prevention circuit downgrades the ignition capabilities and thus prevents or retards performance of the engine to a degree sufficient to prevent the vehicle from moving.
Inventors
- 👤 Gary W Vest
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:12
CPC Classifications
B; B60; B60R; B60R25/00; B60R25/01; B60R25/04; B60R25/045
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
In an ignition circuit including a distributor having a set of contacts, a plurality of spark plugs operatively connected to said distributor, a voltage supply source and at least one electrical component operatively connected between said voltage supply source and said distributor for causing a sparking voltage for said spark plugs sufficient to cause and maintain engine firing, the improvement which comprises: a theft prevention circuit including a reactive circuit component and switch means for connecting said reactive component in parallel with said ignition circuit whereby said theft prevention circuit is effective to limit the level of any transient surge of sparking voltage developed across said ignition circuit electrical component sufficiently to prevent said spark plugs from maintaining enginE firing.
Claim 2
Dependent Claim
120 words
In an ignition circuit including a distributor having a set of contacts, a plurality of spark plugs operatively connected to said distributor, a voltage supply source and at least one electrical component operatively connected between said voltage supply source and said distributor for causing a sparking voltage for said spark plugs sufficient to cause and maintain engine firing, the improvement which comprises: a theft prevention circuit including a reactive circuit component and switch means for connecting said reactive component in parallel with said ignition circuit whereby said theft prevention circuit is effective to limit the level of any transient surge of sparking voltage developed across said ignition circuit electrical component sufficiently to prevent said spark plugs from maintaining enginE firing.
Claim 3
Dependent Claim
16 words
A theft prevention circuit according to claim 1 wherein said reactive circuit component is a capacitor.
Claim 4
Dependent Claim
121 words
In an ignition circuit including a distributor having a set of contacts, a plurality of spark plugs operatively connected to said distributor, a voltage supply source and at least one electrical component operatively connected between said voltage supply source and said distributor for causing a sparking voltage for said spark plugs sufficient to cause and maintain engine firing, the improvement which comprises: a theft prevention circuit including a unilateral impedance component and switch means for connecting said unilateral impedance component in parallel with said ignition circuit whereby said theft prevention circuit is effective to limit the level of any transient surge of sparking voltage developed across said ignition circuit electrical component sufficiently to prevent said spark plugs from maintaining engine firing.
Claim 5
Dependent Claim
121 words
In an ignition circuit including a distributor having a set of contacts, a plurality of spark plugs operatively connected to said distributor, a voltage supply source and at least one electrical component operatively connected between said voltage supply source and said distributor for causing a sparking voltage for said spark plugs sufficient to cause and maintain engine firing, the improvement which comprises: a theft prevention circuit including a unilateral impedance component and switch means for connecting said unilateral impedance component in parallel with said ignition circuit whereby said theft prevention circuit is effective to limit the level of any transient surge of sparking voltage developed across said ignition circuit electrical component sufficiently to prevent said spark plugs from maintaining engine firing.
Claim 6
Dependent Claim
16 words
A theft prevention circuit according to claim 3 wherein said unilateral impedance is a semiconductor device.
Claim 7
Dependent Claim
19 words
A theft prevention circuit according to claim 3 wherein said unilateral impedance is a threshold voltage level conducting device.
Claim 8
Dependent Claim
16 words
A theft prevention circuit according to claim 3 wherein said unilateral impedance is a threshhold-biased semiconductor.
Claim 9
Dependent Claim
14 words
A theft prevention circuit according to claim 6 wherein said semiconductor is a transistor.
Claim 10
Dependent Claim
15 words
A theft prevention circuit according to claim 6 wherein said semiconductor is a silicon-controlled rectifier.
Claim 11
Dependent Claim
119 words
In an ignition circuit including a distributor having a set of contacts, a plurality of spark plugs operatively connected to said distributor, a voltage supply source and at least one electrical component operatively connected between said voltage supply source and said distributor for causing a sparking voltage for said spark plugs sufficient to cause and maintain engine firing, the improvement which comprises: a theft prevention circuit including a diode and switch means for connecting said diode in parallel with said ignition circuit component whereby said theft prevention circuit is effective to limit the level of any negative transient surge of sparking voltage developed across said ignition circuit electrical component sufficiently to prevent said spark plugs from maintaining engine firing.
Claim 12
Dependent Claim
119 words
In an ignition circuit including a distributor having a set of contacts, a plurality of spark plugs operatively connected to said distributor, a voltage supply source and at least one electrical component operatively connected between said voltage supply source and said distributor for causing a sparking voltage for said spark plugs sufficient to cause and maintain engine firing, the improvement which comprises: a theft prevention circuit including a diode and switch means for connecting said diode in parallel with said ignition circuit component whereby said theft prevention circuit is effective to limit the level of any negative transient surge of sparking voltage developed across said ignition circuit electrical component sufficiently to prevent said spark plugs from maintaining engine firing.
References Cited (Backward Citations)
US3439771A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |