Ignition circuit with automatic spark advance

Claim 2

An ignition system for igniting a combustible charge in an internal combustion engine having at least one cylinder, a piston operable in said cylinder, a crankshaft rotated by said piston, a spark device for said cylinder and a source of electrical energy, said ignition system comprising circuit means adapted to transfer energy from said source to said spark device at substantially a first crankshaft angle in a timing cycle of said engine when said engine is running at a predetermined running speed and at substantially a second predetermined crankshaft angle when said engine is cranked at a lower speed during starting, said energy transferring circuit means comprising electronic switch means responsive to an electrical triggering signal having a predetermined value to switch from a first state to a second state and thereby cause electrical energy to be transferred to said spark device, and trigger means for providing triggering signals to actuate said control device, said triggering means comprising coil means coupled to said switch means, permanent magnet means movable relative to said coil means and having first and second poles displaced along the direction of travel relative to said coil means so that said first pole leads said second pole relative to said coil means, said poles having a magnetic gap therebetween, core means having two core legs of magnetic material displaced from each other along the direction of magnet travel, said coil means being mounted on One of said legs, and wherein said poles of said magnet means and said displacement between said core legs are correlated to each other so that during relative motion therebetween the magnetic flux in said one leg undergoes at least two changes in the same predetermined direction but at different rates with the first occuring flux change generating a first pulsation in said coil means that occurs substantially at said first crankshaft angle and has a value below said predetermined value at said low engine speed and above said predetermined value at said running speed and the second occurring flux change generating a second pulsation in said coil means that occurs at said second crankshaft angle and has a value above said predetermined value at both said low engine speed and said running speed.

Claim 3

The ignition system set forth in claim 1 wherein said core means comprises a generally U-shaped core of magnetic material so that said core legs are magnetically coupled together.

Claim 4

The ignition system set forth in claim 2 wherein said leading pole has an effective length along its path of travel relative to said coil means that is greater than the displacement between said core legs, and said one core leg leads said other core leg along the path of travel of said magnet means so that said leading pole first encounters said one leg and then said other leg to shunt flux from said one leg to said other leg and cause a first flux change in said one leg at said first crankshaft angle, said second flux change occurring in said one core when said magnetic gap passes said one leg at said second crankshaft angle.

Claim 5

The ignition system set forth in claim 2 wherein said first and said second poles each have an effective length along the path of travel relative to said core means that is less than the displacement between said core legs, said other leg of said core leads said one leg along the path of travel of said magnet means so that magnetic flux first encounters said other leg and then said one leg, and wherein the effective lengths of said first and said second poles along the path of travel of said magnet means are correlated to the displacement between said legs so that the trailing edge of said second pole breaks from said other leg to cause a first flux change at said first crankshaft angle and then said magnetic gap passes said one leg to cause a second flux change at said second crankshaft angle.

Claim 6

In an ignition system for igniting a combustible charge in an internal combustion engine having at least one cylinder, a piston operable in said cylinder, a crankshaft rotated by said piston, a spark device for said cylinder and a source of electrical energy, wherein said ignition system comprises circuit means adapted to transfer energy from said source to said spark device at substantially a first crankshaft angle in a timing cycle of said engine when said engine is running at a predetermined running speed and at substantially a second predetermined crankshaft angle when said engine is cranked at a lower speed during starting, said energy transferring circuit means comprising electronic switch means responsive to an electrical triggering signal having a predetermined value to switch from a first state to a second state and thereby cause electrical energy to be transferred to said spark device, and trigger means for providing triggering signals to actuate said control device, that improvement wherein said trigger means comprises coil means coupled to said switch means, magnetic flux source means movable relative to said coil means and adapted to supply flux to said coil means during relative rotation therebetween, magnetic core means having two core legs displaced from each other along the direction of travel of said flux source means, said coil means being mounted on one of said legs, and wherein said displacement between said legs and the configuration of said flux source means are correlated to each other so that during relative motion therebetween flux in said one lEg undergoes a first change at a first rate and then a second change at a higher rate, said first change occurs substantially at said first crankshaft angle at both said cranking speed and said running speed and said second change occurs substantially at said second crankshaft angle at both said cranking speed and said running speed.

Claim 7

In an ignition system for igniting a combustible charge in an internal combustion engine having at least one cylinder, a piston operable in said cylinder, a crankshaft rotated by said piston, a spark device for said cylinder and a source of electrical energy, wherein said ignition system comprises circuit means adapted to transfer energy from said source to said spark device at substantially a first crankshaft angle in a timing cycle of said engine when said engine is running at a predetermined running speed and at substantially a second predetermined crankshaft angle when said engine is cranked at a lower speed during starting, said energy transferring circuit means comprising electronic switch means responsive to an electrical triggering signal having a predetermined value to switch from a first state to a second state and thereby cause electrical energy to be transferred to said spark device, and trigger means for providing triggering signals to actuate said control device, that improvement wherein said trigger means comprises coil means coupled to said switch means, magnetic flux source means movable relative to said coil means and adapted to supply flux to said coil means during relative rotation therebetween, magnetic core means having two core legs displaced from each other along the direction of travel of said flux source means, said coil means being mounted on one of said legs, and wherein said displacement between said legs and the configuration of said flux source means are correlated to each other so that during relative motion therebetween flux in said one lEg undergoes a first change at a first rate and then a second change at a higher rate, said first change occurs substantially at said first crankshaft angle at both said cranking speed and said running speed and said second change occurs substantially at said second crankshaft angle at both said cranking speed and said running speed.

Claim 8

In an ignition system for igniting a combustible charge in an internal combustion engine having at least one cylinder, a piston operable in said cylinder, a crankshaft rotated by said piston and a spark device for said cylinder wherein said ignition system comprises energy storage means adapted to store electrical energy from a source of electrical energy, electronic switch means responsive to a trigger signal of predetermined value for transferring energy from said storage means to said spark device at predetermined crankshaft angles according to the speed of the engine and means coupled to said switch means and operable in synchronism with said engine to generate said trigger signal, said trigger signal generating means comprises pulse generating means for generating first and second pulses having a predetermined timing displacement therebetween, said first pulse having an amplitude less than a predetermined value at a predetermined low cranking speed of said engine and an amplitude exceeding said predetermined value at a predetermined running speed, and said second pulse having an amplitude that exceeds said predetermined value at said cranking speed so that discharge of said energy storage means is initiated in response to said second pulse at said cranking speed and in response to said first pulse at said running speed, that improvement wherein said pulse generating means comprises a rotor member and a stator member, said rotor member being adapted to be driven in synchronism with said engine, magnet means carried on one of said members and having a leading pole face and a trailing pole face separated by a magnetic gap, a generally U-shaped core mounted on said other member and having first and second legs the outer ends of which face said pole faces on said magnet means to form respective air gaps therebetween when said magnet means travels past said legs, said outer ends of said legs having a predetermined displacement therebetween along the path of travel of said magnet means according to said predetermined crankshaft angles, and a coil mounted on one of said core legs and coupled to said switch means and wherein the lengths of said pole faces are correlated to said displacement between said leg ends to generate a flux in said one leg having at least two separate changes in the same polarity direction with a timing separation therebetween corresponding to said predetermined timing displacement.

Claim 9

In an ignition system for igniting a combustible charge in an internal combustion engine having at least one cylinder, a piston operable in said cylinder, a crankshaft rotated by said piston and a spark device for said cylinder wherein said ignition system comprises energy storage means adapted to store electrical energy from a source of electrical energy, electronic switch means responsive to a trigger signal of predetermined value for transferring energy from said storage means to said spark device at predetermined crankshaft angles according to the speed of the engine and means coupled to said switch means and operable in synchronism with said engine to generate said trigger signal, said trigger signal generating means comprises pulse generating means for generating first and second pulses having a predetermined timing displacement therebetween, said first pulse having an amplitude less than a predetermined value at a predetermined low cranking speed of said engine and an amplitude exceeding said predetermined value at a predetermined running speed, and said second pulse having an amplitude that exceeds said predetermined value at said cranking speed so that discharge of said energy storage means is initiated in response to said second pulse at said cranking speed and in response to said first pulse at said running speed, that improvement wherein said pulse generating means comprises a rotor member and a stator member, said rotor member being adapted to be driven in synchronism with said engine, magnet means carried on one of said members and having a leading pole face and a trailing pole face separated by a magnetic gap, a generally U-shaped core mounted on said other member and having first and second legs the outer ends of which face said pole faces on said magnet means to form respective air gaps therebetween when said magnet means travels past said legs, said outer ends of said legs having a predetermined displacement therebetween along the path of travel of said magnet means according to said predetermined crankshaft angles, and a coil mounted on one of said core legs and coupled to said switch means and wherein the lengths of said pole faces are correlated to said displacement between said leg ends to generate a flux in said one leg having at least two separate changes in the same polarity direction with a timing separation therebetween corresponding to said predetermined timing displacement.

Claim 10

The ignition system set forth in claim 6 wherein the displacement between said first and said second core leg ends is less than the dimension between leading and trailing edges of said leading pole face, said core being mounted on said other member so that said one core leg leads said other core leg and said magnet means travels past said one core leg and then said other core leg, and wherein the displacement between said core leg ends is correlated to said dimension between leading and trailing edges of said leading pole face so that during each revolution of said rotor said leading edge of said leading pole passes said one leg and then said other leg to provide said first flux change at a crankshaft angle corresponding to ignition timing for said running speed.

Claim 11

The ignition system set forth in claim 6 wherein said displacement between said first and said second core leg ends is less than the dimension between a leading edge of said leading pole and a trailing edge of said trailing pole, said core is mounted on said other member so that said other leg leads said one leg relative to said magnet so that said magnet passes said other leg and then said one leg during each revolution of said rotor and wherein said displacement between saiD core leg ends is correlated to the leading and trailing edges of said leading and said trailing poles so that during each revolution of said rotor said trailing edge of said trailing pole moves past said other core leg while the leading pole is passing said one core leg to thereby provide said first flux change at a crankshaft angle corresponding to ignition timing at said running speed and then said magnetic gap passes said one leg of said core at a crankshaft angle corresponding to ignition timing at said cranking speed.

Claim 12

The ignition system set forth in claim 6 wherein said pole faces and said core leg ends are so spaced and related to each other that successively during each revolution of said rotor a leading edge of said leading pole sweeps said one leg and then sweeps said other leg to generate said first pulse in said coil and then said magnetic gap overlies said one leg to generate said second pulse in said coil.

Claim 13

The ignition system set forth in claim 6 wherein said pole faces and said core leg ends are so spaced and related to each other that successively during each revolution of said rotor said leading pole overlies said one leg while said trailing pole overlies said other leg, then said trailing edge of said trailing pole moves past said other core leg while said leading pole overlies said one core leg to generate said first pulse in said coil, and then said magnetic gap overlies said one leg of said core to generate said second pulse in said coil.

Claim 14

In a breakerless ignition system for a spark ignition engine, the combination comprising a part rotated in synchronism with the operation of said engine, a spark gap device, means including an electronic switching device for causing the occurrence of a spark at said spark gap device as said switching device is switched from a first state to a second state, a triggering coil located adjacent said part and coupled with said switching device and operable to switch said switching device from said first state to said second state when a triggering signal in said triggering coil reaches a predetermined level, a source of magnetic flux, and means for providing a circuit for said magnetic flux which circuit passes through said triggering coil, said flux circuit providing means including first and second angularly spaced core members, magnetic material means arranged on said part so as to travel sequentially past said core members, said core members being arranged to be brought into said flux circuit at two different angular positions of said part in response to rotation of said part so that flux in said first core member changes in one direction at one angular position of said part and changes in the opposite direction at the other position of said part with said second core member being operable to shunt flux from said first core member to thereby cause one of said flux changes and with said coil being coupled to said first core member so that said flux changes induce a first triggering signal with both positive and negative peaks one of which is adapted to reach said predetermined level and actuate said switching device.

Claim 15

In a breakerless ignition system for a spark ignition engine, the combination comprising a part rotated in synchronism with the operation of said engine, a spark gap device, means including an electronic switching device for causing the occurrence of a spark at said spark gap device as said switching device is switched from a first state to a second state, a triggering coil located adjacent said part and coupled with said switching device and operable to switch said switching device from said first state to said second state when a triggering signal in said triggering coil reaches a predetermined level, a source of magnetic flux, and means for providing a circuit for said magnetic flux which circuit passes through said triggering coil, said flux circuit providing means including first and second angularly spaced core members, magnetic material means arranged on said part so as to travel sequentially past said core members, said core members being arranged to be brought into said flux circuit at two different angular positions of said part in response to rotation of said part so that flux in said first core member changes in one direction at one angular position of said part and changes in the opposite direction at the other position of said part with said second core member being operable to shunt flux from said first core member to thereby cause one of said flux changes and with said coil being coupled to said first core member so that said flux changes induce a first triggering signal with both positive and negative peaks one of which is adapted to reach said predetermined level and actuate said switching device.

Claim 16

The combination set forth in claim 11 wherein said flux circuit providing means includes means operable at a third angular position of said part to cause a further flux change in said one core member to thereby induce a second triggering signal in said coil, said second triggering signal having a higher magnitude than the magnitude of said first triggering signal so that at low engine speeds said switching device is switched from said first state to said second state at one time in the engine cycle in response to said second triggering signal and at higher engine speeds at a different time in the engine cycle in response to said first triggering signal.

Claim 17

The combination set forth in claim 12 wherein said magnetic material means has a surface adapted to sequentially sweep past said core members and having a circumferential length sufficient to simultaneously bridge said core Members.

Claim 18

The combination set forth in claim 13 wherein said magnetic material member has a second surface adapted to sequentially sweep past said core members, said second surface being spaced from said first surface so as to generate said second triggering signal in said coil.

Claim 19

The combination set forth in claim 13 wherein said second core member is swept by said surface subsequent to said first core member being swept by said surface.