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US5222468A Expired / Lapsed US ⏱️ 0.0 years remaining

Anti-theft ignition control apparatus

Assignee: Mitsubishi Electric Corp
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Filing: 1992-04-22
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Granted: 1993-06-29
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Expires: 2012-04-22
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Abstract

Abstract An ignition apparatus for an engine includes an ignition switch and a monitor switch connected to a battery. A power supply circuit generates a reset signal for a microcomputer in response to closing of the ignition switch. A monitor signal generating circuit generates a monitor signal for the microcomputer in response to closing of the monitor switch. The microcomputer enables ignition to take place only if the monitor signal has a prescribed value when the reset signal is generated. The timing of the reset signal and the timing of the monitor signal are chosen so that the microcomputer will enable ignition only if the ignition switch and the monitor switch are closed substantially simultaneously and will prevent ignition when the switches are closed sequentially, such as when the switches are hot-wired.

Inventors

  • 👤 Takaharu Korenaga

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 20:25
CPC Classifications
B; B60; B60R; B60R25/00; B60R25/01; B60R25/04; B60R25/045

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 97 words
An ignition control apparatus for an engine comprising: an ignition switch; a monitor switch coupled to the ignition switch for switching movement therewith; an ignition coil; reset signal generating means for generating a reset signal in response to closing of the ignition switch; monitor signal generating means for generating a monitor signal in response to closing of the monitor switch; and control means responsive to the reset signal and the monitor signal for enabling the ignition coil to fire a spark plug only if the monitor signal has a prescribed level when the reset signal is generated.
Claim 2
Dependent Claim 97 words
An ignition control apparatus for an engine comprising: an ignition switch; a monitor switch coupled to the ignition switch for switching movement therewith; an ignition coil; reset signal generating means for generating a reset signal in response to closing of the ignition switch; monitor signal generating means for generating a monitor signal in response to closing of the monitor switch; and control means responsive to the reset signal and the monitor signal for enabling the ignition coil to fire a spark plug only if the monitor signal has a prescribed level when the reset signal is generated.
Claim 3
Dependent Claim 48 words
A control apparatus as claimed in claim 1 wherein: the monitor signal generating means generates the monitor signal substantially simultaneously with closing of the monitor switch; and the reset signal generating means generates the reset signal a prescribed length of time TR after closing of the ignition signal.
Claim 4
Dependent Claim 30 words
A control apparatus as claimed in claim 2 wherein TR is shorter than the length of time T1 required to sequentially short circuit the ignition switch and the monitor switch.
Claim 5
Dependent Claim 52 words
A control apparatus as claimed in claim 2 wherein the monitor signal generating means generates the monitor signal for at most a period TM from the closing of the monitor switch, wherein TR>TM-T1 and T1 is the length of time required to sequentially short circuit the ignition switch and the monitor switch.
Claim 6
Dependent Claim 21 words
A control apparatus as claimed in claim 1 further comprising holding means for maintaining the monitor signal at the prescribed level.
Claim 7
Dependent Claim 55 words
An ignition control apparatus for an engine comprising: an ignition switch; a monitor switch; an ignition coil; and control means connected to the ignition switch, the monitor switch, and the ignition coil for allowing the ignition coil to ignite a spark plug only when the ignition switch and the monitor switch are closed substantially simultaneously.
Claim 8
Dependent Claim 55 words
An ignition control apparatus for an engine comprising: an ignition switch; a monitor switch; an ignition coil; and control means connected to the ignition switch, the monitor switch, and the ignition coil for allowing the ignition coil to ignite a spark plug only when the ignition switch and the monitor switch are closed substantially simultaneously.

References Cited (Backward Citations)

US4842093A Cited
JPH0241958A Cited
JPH0372067A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-06-28 1996-12-28 1997-06-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-06-28 2000-12-28 2001-06-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-06-28 2004-12-28 2005-06-29 $7700.00 Window Closed / Lapsed

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