US3776204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speed limiting systems for internal combustion engines
Assignee: ZF International UK Ltd
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Filing: 1971-06-28
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Granted: 1973-12-04
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Expires: 1991-06-28
Abstract
Abstract A speed limiting system for an internal combustion engine has a switching device in series with the primary winding of an ignition coil, a spark being produced when the switching device is turned off. The speed limiting system comprises a thyristor connected in a circuit across the primary winding and a transistor which is coupled to the switching device and is turned on as a result of opening of the switching device. Current flow is initiated to the gate of the thyristor at a predtermined instant of time after the transistor has been turned on, and is maintained for a predetermined period of time. The thyristor prevents production of a further spark if the switching device is turned off during the predetermined period of time.
Inventors
- 👤 P Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:54
CPC Classifications
F; F02; F02P; F02P9/00; F02P9/002; F02P9/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
215 words
A speed limiting system for an internal combustion engine having an ignition coil with a primary winding and a secondary winding, means connecting said secondary winding to the plugs of the engine in turn, and an engine driven switching device through which the primary winding is connected to a d.c. source, the engine driven switching device being turned on and off in timed relationship to the engine and a spark being produced when said switching device is turned off to break current flow in said primary winding, said system comprising a thyristor connected in a circuit across said primary winding, a transistor which is coupled to the switching device and is turned on as a result of opening of said switching device, means For initiating flow of gate current to the thyristor at a predetermined instant of time after the transistor has been turned on, and allowing gate current for a predetermined period of time, and means for holding said transistor on until gate current is supplied to the thyristor, said thyristor preventing production of a further spark if said switching device is turned off during said predetermined period of time, and said predetermined instant of time being chosen so that the switching device is never turned off before said predetermined period of time commences.
Claim 2
Dependent Claim
215 words
A speed limiting system for an internal combustion engine having an ignition coil with a primary winding and a secondary winding, means connecting said secondary winding to the plugs of the engine in turn, and an engine driven switching device through which the primary winding is connected to a d.c. source, the engine driven switching device being turned on and off in timed relationship to the engine and a spark being produced when said switching device is turned off to break current flow in said primary winding, said system comprising a thyristor connected in a circuit across said primary winding, a transistor which is coupled to the switching device and is turned on as a result of opening of said switching device, means For initiating flow of gate current to the thyristor at a predetermined instant of time after the transistor has been turned on, and allowing gate current for a predetermined period of time, and means for holding said transistor on until gate current is supplied to the thyristor, said thyristor preventing production of a further spark if said switching device is turned off during said predetermined period of time, and said predetermined instant of time being chosen so that the switching device is never turned off before said predetermined period of time commences.
Claim 3
Dependent Claim
151 words
A system as claimed in claim 1 including a first capacitor which charges when the first-mentioned transistor is turned on, a second transistor which is held off while the first capacitor charges and is then turned on again, a feedback circuit from the second transistor to the first transistor, a second capacitor which charges when the second transistor turns on, a third transistor which is turned off when the second capacitor is charging and then turns on again, a feedback circuit from the third transistor to the first transistor, said feedback circuit providing the required means for holding the first transistor on, a third capacitor which charges when the third transistor turns on again, and a fourth transistor which is turned off while the third capacitor is charging and then turns on again, the fourth transistor serving when it is off to allow gate current to be supplied to the thyristor.
Claim 4
Dependent Claim
31 words
A system as claimed in claim 2 including a feedback circuit from the second transistor to the first transistor for holding the first transistor on when the second transistor is off.
Claim 5
Dependent Claim
18 words
A system as claimed in claim 2 including means for varying the charging rate of the first capacitor.
Claim 6
Dependent Claim
18 words
A system as claimed in claim 2 including means for varying the charging rate of the second capacitor.
Claim 7
Independent Claim
17 words
A system as claimed in 2 including means for varying the charging rate of the third capacitor.
Claim 8
Dependent Claim
18 words
A system as claimed in claim 2 in which the engine driven switching device is a contact breaker.
References Cited (Backward Citations)
US3153746A
Cited
US3356082A
Cited
US3581720A
Cited
DE2004464A1
Cited
US3563219A
Cited
US3601103A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |