US3942501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Timing circuit for flywheel ignition system
Assignee: Motorola Solutions Inc
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Filing: 1974-11-14
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Granted: 1976-03-09
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Expires: 1994-11-14
Abstract
Abstract A flywheel alternator for use with an electronic ignition system of an internal combustion engine. The flywheel has a rotor with an odd number of circumferentially located permanent magnets each of substantially the same size and shape. The radially inward pole faces of adjoining pairs of the magnets are of opposite polarity except for one pair which is of the same polarity. At least one stationary trigger coil is positioned to form magnetic circuits with the rotor magnets by bridging alternate ones of the magnets as the rotor rotates. A unique trigger pulse suitable for activating an electronic ignition system is generated only once each flywheel revolution. A stationary power coil has a length to bridge consecutive ones of the magnets to provide power to run other electrical appliances.
Inventors
- 👤 Theodore A. Byles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:57
CPC Classifications
F; F02; F02P; F02P1/00; H; H02; H02K; H02K21/00; H02K21/12; H02K21/22; H02K21/222; H02K21/225; H02K21/48
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
228 words
An arrangement in a flywheel alternator for use with an electronic ignition system of an internal combustion engine having: a rotor provided with a plurality of circumferentially located radially polarized permanent magnets; at least one stationary power coil oriented in magnetic circuit relationship to the rotor magnets; at least one stationary trigger coil oriented in magnetic circuit relationship to the rotor magnets; and means for electrically coupling the coils to an electronic ignition system wherein the improvement comprises the rotor having an odd number of magnets with an adjoining pair of the magnets of the same radial polarity, the remaining adjoining pairs of the magnets of opposite polarity, the trigger coil having a dimension with respect to the permanent magnets to bridge two of the magnets each of which adjoins a common third one of the magnets, the power coil having a dimension with respect to the magnets to bridge magnets having a North-South or South-North orientation of their radially inward pole faces a number of times equal to one less than the total number of magnets, whereby in the sequence of magnetic circuits formed by the magnets bridging the trigger coil a unique pulse suitable for firing an electronic ignition system is generated exactly once each flywheel revolution and in the sequence of magnetic circuits formed by the magnets bridging the power coil substantial power is generated.
Claim 2
Dependent Claim
228 words
An arrangement in a flywheel alternator for use with an electronic ignition system of an internal combustion engine having: a rotor provided with a plurality of circumferentially located radially polarized permanent magnets; at least one stationary power coil oriented in magnetic circuit relationship to the rotor magnets; at least one stationary trigger coil oriented in magnetic circuit relationship to the rotor magnets; and means for electrically coupling the coils to an electronic ignition system wherein the improvement comprises the rotor having an odd number of magnets with an adjoining pair of the magnets of the same radial polarity, the remaining adjoining pairs of the magnets of opposite polarity, the trigger coil having a dimension with respect to the permanent magnets to bridge two of the magnets each of which adjoins a common third one of the magnets, the power coil having a dimension with respect to the magnets to bridge magnets having a North-South or South-North orientation of their radially inward pole faces a number of times equal to one less than the total number of magnets, whereby in the sequence of magnetic circuits formed by the magnets bridging the trigger coil a unique pulse suitable for firing an electronic ignition system is generated exactly once each flywheel revolution and in the sequence of magnetic circuits formed by the magnets bridging the power coil substantial power is generated.
Claim 3
Dependent Claim
17 words
The arrangement of claim 1 wherein each of the magnets has substantially the same size and shape.
Claim 4
Dependent Claim
15 words
The arrangement of claim 1 in which there are at least five rotor permanent magnets.
Claim 5
Dependent Claim
13 words
The arrangement of claim 1 in which there are seven rotor permanent magnets.
Claim 6
Dependent Claim
94 words
The arrangement of claim 1 wherein the magnetic orientation of the radially inward pole faces of the pairs of magnets sequentially bridged by the trigger coil is North-South once during one revolution and South-North once during one revolution, a trigger pulse of one polarity being generated during one of the orientations and a trigger pulse of opposite polarity being generated during the other of the orientations, further comprisng means for blocking the trigger pulse created during one of the orientations, the other of the trigger pulses being useable for firing an electronic ignition system.
Claim 7
Dependent Claim
43 words
The arrangement of claim 4 in which the power coil has a dimension with respect to the magnets to bridge an adjoining pair of the magnets having a North-South or South-North orientation of their radially inward pole faces six times per flywheel revolution.
Claim 8
Dependent Claim
47 words
The arrangement of claim 1 wherein two stationary trigger coils are stationed one half flywheel revolution apart, each trigger coil creating a single pulse per revolution suitable for firing an electronic ignition system, one pulse occurring 180° of a flywheel revolution with respect to the second pulse.
Claim 9
Dependent Claim
78 words
The arrangement of claim 1 wherein the trigger and power coils are each comprised of an armature plate made of a permeable material and having pole shoes formed thereon, the pole shoes designed to conform the magnets face leaving a small air gap therebetween, and a winding thereon formed of a continuous length of conductive wire wound to form a cylindrical coil the longitudinal axis of which is substantially parallel to the longitudinal axis of the armature plate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |