US3738340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internal combustion engine limiter
Assignee: IKON ENG Inc
•
Filing: 1972-01-10
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Granted: 1973-06-12
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Expires: 1992-01-10
Abstract
Abstract An RPM limiter for an internal combustion engine employs a silicon-controlled rectifier (SCR) as a switch to shunt the ignition system in response to an RPM limiting pulse from an RC timing circuit which is reset to initiate the pulse immediately upon the ignition breaker points opening. A monostable multivibrator is also set at that time to initiate the generation of a spark timing pulse of sufficient duration to allow the magnetic field of the ignition coil to break down, and thereby fire a spark plug. An inhibit gate receives both pulses and allows the SCR to be fired during the period of the RPM limiting pulse after the period of the spark timing pulse. A switch connects a second capacitor in parallel with the capacitor of the RC timing circuit to permit a potentiometer of the timing circuit to be set and tested for the desired RPM limit while operating the engine at only half of that limit when the two capacitors are of equal size.
Inventors
- 👤 J Olson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:52
CPC Classifications
F; F02; F02P; F02P9/00; F02P9/002; F02P9/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
200 words
An RPM limiter for an internal combustion engine of the spark ignition type having an ignition system including a breaker with points which open to produce a transient electrical signal in the primary winding of an ignition coil to fire a spark plug comprised of an electronic switch connected in parallel with said ignition system, said switch having a control terminal for receiving an electrical pulse in response to which current flows through said switch to shunt said ignition system, and means for producing said control pulse for a selected period after a predetermined delay period following the opening of said breaker points, said means including an RC timing circuit comprised of a first capacitor and a resistor for RPM limiting operation by shunting said ignition system for a period of time following breaker point opening set by said RC timing circuit, and a second capacitor in series with a test switch, said series circuit of said capacitor and said test switch being in parallel with said first capacitor, whereby upon closing said test switch, the period of said control pulses set by said RC timing circuit is increased to permit testing proper RPM limiting operation at a lower RPM.
Claim 2
Dependent Claim
200 words
An RPM limiter for an internal combustion engine of the spark ignition type having an ignition system including a breaker with points which open to produce a transient electrical signal in the primary winding of an ignition coil to fire a spark plug comprised of an electronic switch connected in parallel with said ignition system, said switch having a control terminal for receiving an electrical pulse in response to which current flows through said switch to shunt said ignition system, and means for producing said control pulse for a selected period after a predetermined delay period following the opening of said breaker points, said means including an RC timing circuit comprised of a first capacitor and a resistor for RPM limiting operation by shunting said ignition system for a period of time following breaker point opening set by said RC timing circuit, and a second capacitor in series with a test switch, said series circuit of said capacitor and said test switch being in parallel with said first capacitor, whereby upon closing said test switch, the period of said control pulses set by said RC timing circuit is increased to permit testing proper RPM limiting operation at a lower RPM.
Claim 3
Dependent Claim
126 words
An RPM limiter as defined in claim 1 wherein a given control pulse is initiated by said means immediately upon said breaker points opening, said means further including a spark timing means for producing a pulse of a predetermined period sufficient for a spark plug to be responsive to said spark timing pulse, and means responsive to said spark timing means for inhibiting said control pulse from being applied to said electronic switch to shunt said ignition system, thereby enhancing ignition system performance while providing for RPM limiting by shunting said ignition system for an RPM limiting period only after a spark plug has been fired, whereby another spark plug may be fired upon said breaker points opening again only after said control pulse has terminated.
Claim 4
Dependent Claim
31 words
An RPM limiter as defined in claim 2 wherein said second capacitor is equal to said first capacitor, whereby test RPM limiting may be conducted at half the desired RPM limit.
Claim 5
Dependent Claim
31 words
An RPM limiter is defined in claim 3 wherein said resistor is comprised of a potentiometer for setting said desired RPM limit while operating said engine at half the desired RPM.
Claim 6
Dependent Claim
35 words
An RPM limiter as defined in claim 1 wherein said electronic switch is a silicon controlled rectifier having an anode, a cathode and a gate, and said control terminal of said switch is said gate.
Claim 7
Dependent Claim
19 words
An RPM limiter as defined in claim 2 wherein said spark timing means is comprised of a monostable multivibrator.
Claim 8
Dependent Claim
51 words
A RPM limiter as defined in claim 1 wherein said ignition system includes a DC battery and power supply for said control pulse means is derived from said battery through a decoupling circuit comprising an isolating resistor, a filter capacitor, and voltage stabilizing zener diode in parallel with said filter capacitor.
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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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |