US3705573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic timing system for internal combustion engine
Assignee: Fiat SpA
•
Filing: 1970-12-18
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Granted: 1972-12-12
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Expires: 1990-12-18
Abstract
Abstract An electronic timing system for an internal combustion engine provides an angle of advance which increases linearly with the engine speed up to a maximum angle of advance, at which it remains despite any increase in engine speed.
Inventors
- 👤 Mario Palazzetti
- 👤 Bruno Cavallarin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:43
CPC Classifications
F; F02; F02P; F02P5/00; F02P5/04; F02P5/145; F02P5/155; F02P5/1553; F02P5/1555; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
396 words
A method of generating a signal for controlling the angle of advance in an ignition circuit comprising the steps of: a. detecting the rotation of a drive shaft past a first predetermined point, said first predetermined point being a first predetermined angle from the top dead point of said drive shaft; b. detecting the rotation of said drive shaft past a second predetermined point, said second predetermined point being a second predetermined angle from said dead point wherein said first predetermined angle is greater than said second predetermined angle; c. generating a first signal which varies in a first predetermined manner as a function of time, wherein the generation of said first signal is initiated by the detection of the rotation of said drive shaft past said first predetermined point; d. stopping the generation of said first signal by the detection of the rotation of said drive shaft past said second predetermined point; e. generating a pulse signaL having a minimum amplitude equal to the maximum amplitude of said first signal, wherein said pulse signal is generated by the detection of the rotation of said drive shaft past said second predetermined point; f. generating a second predetermined signal which varies in a second predetermined manner as a function of time, wherein the generation of said second predetermined signal is initiated when said pulse signal reaches its minimum value, and wherein said second predetermined signal decreases to zero when said drive shaft rotates past a third predetermined point which is in advance of or at the dead point of said drive shaft; g. generating a threshold signal having an amplitude equal to the minimum value of said pulse signal when the drive shaft is rotating at a predetermined maximum speed; h. determining the point at which said threshold signal intersects said second signal; i. generating a command signal in accordance with the intersection of said threshold signal and said second signal when said drive shaft is rotating at a speed less than said predetermined maximum speed; j. using said command signal to advance the ignition timing wherein the advance of said ignition timing increases as the speed of said drive shaft increase until the speed of said drive shaft reaches the predetermined maximum speed and the advance of said ignition timing is constant when said drive shaft rotates at a speed greater than said predetermined maximum speed.
Claim 2
Independent Claim
396 words
A method of generating a signal for controlling the angle of advance in an ignition circuit comprising the steps of: a. detecting the rotation of a drive shaft past a first predetermined point, said first predetermined point being a first predetermined angle from the top dead point of said drive shaft; b. detecting the rotation of said drive shaft past a second predetermined point, said second predetermined point being a second predetermined angle from said dead point wherein said first predetermined angle is greater than said second predetermined angle; c. generating a first signal which varies in a first predetermined manner as a function of time, wherein the generation of said first signal is initiated by the detection of the rotation of said drive shaft past said first predetermined point; d. stopping the generation of said first signal by the detection of the rotation of said drive shaft past said second predetermined point; e. generating a pulse signaL having a minimum amplitude equal to the maximum amplitude of said first signal, wherein said pulse signal is generated by the detection of the rotation of said drive shaft past said second predetermined point; f. generating a second predetermined signal which varies in a second predetermined manner as a function of time, wherein the generation of said second predetermined signal is initiated when said pulse signal reaches its minimum value, and wherein said second predetermined signal decreases to zero when said drive shaft rotates past a third predetermined point which is in advance of or at the dead point of said drive shaft; g. generating a threshold signal having an amplitude equal to the minimum value of said pulse signal when the drive shaft is rotating at a predetermined maximum speed; h. determining the point at which said threshold signal intersects said second signal; i. generating a command signal in accordance with the intersection of said threshold signal and said second signal when said drive shaft is rotating at a speed less than said predetermined maximum speed; j. using said command signal to advance the ignition timing wherein the advance of said ignition timing increases as the speed of said drive shaft increase until the speed of said drive shaft reaches the predetermined maximum speed and the advance of said ignition timing is constant when said drive shaft rotates at a speed greater than said predetermined maximum speed.
Claim 3
Dependent Claim
108 words
The method as set forth in claim 1, further comprising: a. detecting the rotation of said drive shaft past a fourth predetermined point, said fourth predetermined point being a fourth predetermined angle from said dead point wherein said fourth predetermined angle is less than said second predetermined angle; b. stopping the generation of said second signal upon the detection of said fourth predetermined point if said second signal is greater than zero, wherein said fourth predetermined point corresponds to the minimum angle of advance of said ignition circuit wherein said minimum angle of advance is the angle of advance for all engine speeds below a predetermined minimum speed.
Claim 4
Dependent Claim
31 words
The method as set forth in claim 1, further including varying said first and second signals and/or said threshold signal as a function of a physical condition and/or an engine parameter.
Claim 5
Dependent Claim
16 words
The method as set forth in claim 1, wherein said first and second signals are linear.
Claim 6
Dependent Claim
205 words
An ignition timing system for advancing the timing in an ignition system in accordance with an increase in speed of an engine, said system comprising: a. first detecting means for detecting the rotation past a first predetermined point of a mark on the engine drive shaft, and for producing an output upon the occurrence thereof; b. second detecting means for detecting the rotation of said mark past a second predetermined point and for producing an output upon the occurrence thereof; c. signal processing and generating means coupled to said first and second detecting means, for producing a first increasing signal upon the receipt of the output of said first detecting means, a pulse signal having a minimum amplitude equal to the amplitude of said first increasing signal upon the receipt of the output of said second detecting means, and a second decreasing signal upon the return of said pulse signal to its minimum value. d. threshold generating means for generating a threshold signal; e. comparator means for comparing said second decreasing signal with said threshold signal and for producing a command signal upon the coincidence of said second decreasing signal and said threshold signal, wherein said command signal initiates the firing of said ignition system.
Claim 7
Dependent Claim
205 words
An ignition timing system for advancing the timing in an ignition system in accordance with an increase in speed of an engine, said system comprising: a. first detecting means for detecting the rotation past a first predetermined point of a mark on the engine drive shaft, and for producing an output upon the occurrence thereof; b. second detecting means for detecting the rotation of said mark past a second predetermined point and for producing an output upon the occurrence thereof; c. signal processing and generating means coupled to said first and second detecting means, for producing a first increasing signal upon the receipt of the output of said first detecting means, a pulse signal having a minimum amplitude equal to the amplitude of said first increasing signal upon the receipt of the output of said second detecting means, and a second decreasing signal upon the return of said pulse signal to its minimum value. d. threshold generating means for generating a threshold signal; e. comparator means for comparing said second decreasing signal with said threshold signal and for producing a command signal upon the coincidence of said second decreasing signal and said threshold signal, wherein said command signal initiates the firing of said ignition system.
Claim 8
Dependent Claim
34 words
The system as set forth in claim 5, further comprising means for varying the output of said threshold generating means and/or said comparator means in accordance with variations in physical conditions and/or engine conditions.
Claim 9
Dependent Claim
25 words
The system as set fOrth in claim 6, wherein said first increasing signal comprises a square wave component and a linearly increasing component superimposed thereon.
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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) | 1975-12-12 | 1976-06-12 | 1976-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-12 | 1980-06-12 | 1980-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-12 | 1984-06-12 | 1984-12-12 | $7700.00 | Window Closed / Lapsed |