US3299875A

US3299875A - Ignition system

Info

Publication number: US3299875A
Application number: US403264A
Authority: US
Inventors: Skay Frank
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1964-10-12
Filing date: 1964-10-12
Publication date: 1967-01-24
Anticipated expiration: 1984-01-24
Also published as: GB1104957A

Description

F. SKAY IGNITION SYSTEM Jan. 24, 1967 4 Sheets-Sheet 1 Filed Oct. 12, 1964 MEI.

FRANK SKAY lNl/ENTOR ATTORNEYS Jan. 24, 1967 F. SKAY 3,299,875

IGNITION SYSTEM Filed Oct. 12, 1964 4 Sheets-Sheet 2 FRANK SKAY lNVENTO/P ATTDRNEVS F. SKAY IGNITION SYSTEM Jan. 24, 1967 4 Sheets-Sheet 3 Filed Oct. 12, 1964 FIG. 3 I

FRANK SKAY m/vs/v TOR c\./ 31%; ATTORNEYS Jan. 24, 1967 F. SKAY 3,299,875

IGNITION SYSTEM Filed Oct. 12, 1964 4 Sheets-Sheet i3 FRANK SKAY lNl ENTOP awfaywlm A T TORNEJ S FIC5.6

United States Patent 3,299,875 IGNITION SYSTEM Frank Skay, Detroit, Mich., assignor to Ford Motor Company, Dearborn, Mich., a corporation of Delaware Filed Oct. 12, 1964, Ser.'No. 403,264

9 Claims. (Cl. 123148) This invention relates to an ignition system for an internal combustion engine. More particularly, the invention relates to such an ignition system that employs av solid state switching device and a distributor that includes a new and novel electrical generator for generating electrical energy to control the switching of the solid state switching device.

In an ignition system of the invention, a solid state switching device is coupled to the source of electrical energy or battery of the automotive vehicle and to the primary winding of the ignition coil. The solid state switching device is under the control of an electrical generator which produces a periodically varying voltage, preferably of the alternating type. This periodically varying voltage alternately turns the solid state switching device to its conducting and nonconducting states thereby alternately energizing and de-energizing the primary winding of the ignition coil. As a result, ignition voltages are generated in the secondary winding of the ignition coil, and means are provided to sequentially apply these ignition voltages to the spark plugs of the internal combustion engine in synchronism with the generation of the periodically varying voltages by the electrical generator.

The electrical generator of the invention is positioned in a regular or conventional distributor housing, and it includes an annular permanent magnet positioned concentrically in the housing about the distributor shaft. An annular flux gate constructed of magnetic material and an annular output winding are positioned in radial spaced relationship with respect to the annular permanent magnet. Magnetic circuit means couple the annular permanent magnet and the annular flux gate, and magnetic circuit means also couple the annular permanent magnet and the annular output winding. This latter magnetic circuit means includes a means connected to the distributor shaft for varying the reluctance of the magnetic circuit between the annular permanent magnet and the annular output winding in synchronism with the operation of the engine to thereby generate output voltages in the output winding as the distributor shaft is rotated.

The annular flux gate serves to complete a fairly low reluctance magnetic circuit for the flux of the permanent magnet. The means connected to the distributor shaft alternately varies the air gap in the magnetic circuit coupling the permanent magnet and the output winding. As this means is rotated into the position where this air gap is small so that the reluctance of the path of the magnetic circuit coupling the annular permanent magnet and the output winding is low, a substantial amount of flux will be present in this magnetic circuit thereby linking the output winding with a substantial amount of flux. As this means attached to the distributor shaft rotates into position where the air gap is large, the flux linking the output winding is substantially reduced and this flux finds a path through the flux gate. Thus, as the distributor shaft is rotated, a periodically varying voltage of an alternating form is generated in the output winding.

The distributor shaft carries the standard rotor cap mechanism which is connected to the secondary winding of the ignition coil, and a cap is placed on the housing that includes spaced electrical contacts. The rotor cap sequentially connects the secondary winding of the igni- "ice tion coil to the spark plugs of the internal combustion engine as ignition voltages are generated in the secondary winding.

The distributor of the invention includes a centrifugally actuated advance mechanism that couples the distributor shaft and the means that varies the reluctance of the circuit coupling the annular permanent magnet and the output winding for providing spark advance in accordance with engine speed. The distributor also includes a standard vacuum advance mechanism that is coupled to the stator structure that includes the annular permanent magnet, the annular flux gate, and the annular output winding.

;This advance mechanism rotates the stator structure in accordance with engine vacuum and controls the advance or timing of the ignition voltages in accordance with engine vacuum.

An object of the present invention is the provision of an ignition system for an internal combustion engine that :of an internal combustion engine ignition distributor.

Other objects and attendant advantages of the present invention will be more readily apparent as the specification is considered in connection with the attached drawings, in which:

FIGURE 1 is a circuit diagram of the ignition system of the invention;

FIGURE 2 is a longitudinal sectional view of the distributor for the ignition system of FIGURE 1 including the electrical generator of the present invention;

FIGURE 3 is a top plan view of the electrical generator of the invention with a portion shown in section;

FIGURE 4 is a bottom plan view of the distributor shown in FIGURE 2;

FIGURE 5 is an enlarged sectional view of the electrical generator of the present invention taken along the lines 5-5 of FIGURE 6;

FIGURE 6 is a sectional view partially in elevation of the electrical generator of the present invention along the lines 66 of FIGURE 5, and

FIGURE 7 is a plot of the output voltage of the output winding of the electrical generator of the present invention.

Referring now to the drawings in which like reference numerals designate like parts throughout the several views thereof, there is shown in FIGURE 1 a circuit diagram of the ignition system of the present invention that includes an ignition coil 10 having a secondary winding 11. The secondary winding 11 is sequentially connected to spark plugs 12 through a distributor 13. The distributor 13 includes a rotating arm 14 for sequentially connecting the spark plugs 12 to the secondary winding 11 in synchronism with the operation of the engine in which the ignition system is mounted.

The primary winding 15 of the ignition coil 10 is energized from the source of electrical energy or storage battery 16 under the control of a transistor 17 that is connected in series with the primary winding 15 and the source of electrical energy 16. This is accomplished by connecting the positive terminal 21 of the source of electrical energy 16 to the emitter 22 of transistor 17 by means of lead 23, lead 24, movable arm 25 of ignition 3 switch 26, contact 27 of this switch, lead 28, ballast resistor 29, lead 30, resistor 31 and lead 32. The collector 33 of the transistor 17 is connected to the primary winding of ignition coil 10 through lead 34, winding 35 of a bistable electromagnetic switch 36, lead 37, lead 38 and resistor 41.

The control of transistor 17 is accomplished by means of a biasing circuit means 42 that includes a second transistor 43 having an emitter 44 connected to the base 45 of transistor 17 through diode 46. The collector 47 of transistor 43 is connected to ground through winding 48 of bistable electromagnetic switch 36 and a base current limiting resistor 49. The emitter 22 and the base 45 of transistor 17 are interconnected through output winding 50 of bistable electromagnetic switch 36 and a resistor 51.

The base 52 of transistor 43 is connected to collector 53 of transistor 54 by means of lead 55. The lead 55 and the collector 53 of transistor 54 are connected to ground through a resistor 56. The emitter 57 of transistor 54 is connected to lead 32 through resistor 58.

The base 60 of transistor 54 is connected through lead 61 to one terminal 62 of an annular output winding 63 of an electromechanical generator 64. The other terminal 65 of the output winding 63 is connected to a junction 66 between resistor 67 and the cathode 68 of diode 69. The anode 71 of the diode 69 is connected to junction 72 and this junction in turn is connected to one terminal of resistor 73. The other terminal of the resistor 73 is connected to lead 30. A resistor 74 has one terminal connected to junction 72 and the other terminal connected to junction 75, while a resistor 76 has one terminal connected to junction through lead 77 and the other terminal connected to the base 60 of transistor 54 by means of junction 78. The junction 78 is connected to lead 38 through a feedback resistor 81 and lead 82.

The ignition switch 26, in addition to having the movable arm 25, has a second movable arm 86 that moves in unison with the arm 25 and is connected to the positive terminal 21 of the source of electrical energy 16 through the lead 87 and the

leads

24 and 23. As shown in the drawing, movable arms 25 and 28 are in contact with off terminals 91 and 91' respectively. The ignition switch 26 is also provided with start terminals 92 and 92.

The start terminal 92 is connected to relay winding 93 of starting relay 94 through lead 95. The starting relay 94 has a movable armature 96 normally biased to the open position, but which will move into engagement with contacts 97 and 98 when relay winding 93 is energized. The contact 97 is directly connected to the positive terminal 21 of source of electrical energy 16 through lead 101 and lead 23. The other contact 98 of the starting relay 94 is connected to one terminal of starting motor 102 through a lead 103. The other terminal of the starting motor 102 is connected to ground through a lead 104.

A cold start relay 106 is provided that has a set of normally closed contacts 107 connected to armature 96 of the starting relay 94 and to lead 30. The winding 108 of the cold start relay 106 is connected to contact 98 of the starting relay 94 through lead 109. The other terminal of the winding 108 is connected to ground through a resistor 110. During cold weather starting operations, the terminal voltage of battery 16 will be low and thus when the starter relay 94 is energized during starting operations, the current fiow through the winding 108 will be insufficient to open contacts 107. Ballast resistor 29 will, therefore, be shorted out of the series circuit that includes source of electrical energy 16, transistor 17 and primary Winding 15 of coil 10. On the other hand, during starting operations of high temperatures, the terminal voltage of battery 16 will be sufficiently high that the current flow through winding 108 will be sufiicient to open contacts 107. This keeps the ballast resistor in the circuit during high temperature starting to effectively limit the current through the transistor 17 The junction 75 of the biasing circuit 42 is connected to the contact 98 of the starter relay 94 through a lead 111 thereby grounding the junction point 75 during normal running operations through the starter motor 102, by means of lead 111, contact 98 and lead 103.

The distributor 13 and the electromechanical generator 64 are shown in detail in FIGURES 2 through 6. The distributor 13 and electromechanical generator 64 include a housing 113 that may be suitably mounted in the internal combution engine by conventional methods or means. The housing 113 is a standard type and may be readily adapted for this use from a standard internal cornbustion engine distributor. An elongated bearing 114 is positioned within the housing 113 and it rotatably journals a distributor shaft 115. This shaft is also journaled directly within the housing 113 at 116. A gear 117 is fixed to the shaft by means of cross pins 118 and 121. This gear is adapted to be connected to a rotating part of an internal combustion engine so that the shaft 115 is rotated in synchronism with the operation of the engine.

The electromechanical generator 64 includes a stator 122 that has an annular permanent magnet 123 that may be constructed of barium titanite positioned concentrically about the distributor shaft 115. An annular magnetic flux gate element 124 is positioned in radially spaced relationship with respect to the permanent magnet 123. This magnetic flux gate element is constructed of any suitable ferromagnetic material. The annular output winding 63 is positioned radially outwardly from the magnetic flux gate element 124, and is enclosed in a bobbin 126 constructed of a plastic material that separates or spaces the magnetic flux gate element 124 from the annular output winding 63. The three annular elements, the annular permanent magnet 123, the annular flux gate 124, and the annular output winding 63 including the bobbin 126, are positioned between a lower plate 131 and an upper plate 132 constructed of magnetic material. The two

plates

131 and 132 are held between

shoulders

134 and 135 of a bushing 136. This bushing is rotatably mounted on the outer diameter of the bearing 114 for limited angular movement about this bearing.

As can be most readily seen by inspection of FIGURES 5 and 6, the lower plate 131 has an upstanding peripheral flange 138 that has a plurality of upstanding teeth 141 equally spaced about its periphery. The number of teeth 141 corresponds to the number of spark plugs employed in the engine, and as shown in FIGURE 5 and in FIG- URE l, the distributor 13 and electromechanical generator 64 are designed for an internal combustion engine of eight cylinders that employs eight spark plugs. The upper plate 132 also has a plurality of upstanding teeth 142 that correspond in number to the number of teeth 141 and to the number of cylinders and spark plugs of the engine. As shown in FIGURE 5, the teeth 142 are spaced radially inwardly from the teeth 141 and have one edge in approximate alignment with respect to one edge of the teeth 141.

The rotor 145 of the distributor 13 and the electromechanical generator 64 includes a rotatable plate member or armature 146 that has a number of depending shaped teeth 147 that correspond in number to the number of teeth 141 in the lower plate 131 and to the number of teeth 142 on the upper plate 132.

As can be seen by reference to FIGURES 3 and 5, rotor 145 including rotatable plate member or armature 146 rotates-in a counterclockwise direction as viewed in these figures. In FIGURE 5, the trailing edge of each tooth 147 is spaced only slightly from the trailing edge of each tooth 141 at the position shown, while the leading edge of each tooth 147 is spaced only slightly from the leading edge of each tooth 142. Thus, when the rotor 145 is in the position shown on the drawing, the air gap and the flux path that is seen on the right-hand portion of FIGURE 6 that links the annular permanent magnet 123 with the annular output winding 63- is quite small,

whereas when the rotor 145 is rotated so that the teeth 147 are positioned intermediate the

teeth

141 and 142 as shown in the dotted position, the air gap in this magnetic circuit is very large.

The annular permanent magnet 123 is polarized or magnetized in an axial direction as shown by the arrows in FIGURE 6 so that the flux path will be through the annular permanent magnet 123 and the two

plates

131 and 132 that are in contact with the permanent magnet. The annular magnetic flux gate 124 has a small clearance with respect to the upper plate 132 so that a small air gap 148, shown in exaggerated form for the purposes of clarity, exits between these two members. This air gap may be on the order of .050 of an inch. Thus, when the teeth 147 are in the position shown in the dotted line in FIGURE 5, the reluctance of the flux path through annular flux gate 124, the upper plate 131 and the lower plate 132, is quite small with respect to the parallel path through the bottom plate 132, the flange 138, the upstanding teeth 141, the teeth 147 of the armature or plate member 146, and the upstanding teeth 142 of the upper plate 132, and the plate 132.

On the other hand, when the teeth 147 are in the solid line position shown in FIGURE 5 and the right-hand side of FIGURE 6, the air gap in the magnetic circuit just previously described through the

teeth

141, 142 and 14] may be approximately equal to or smaller than the air gap between the magnetic flux gate 124 and the upper'plate 132 thereby providing an alternate path for the flux having a reluctance substantially equal to or less than the reluctance of the path through the annular flux gate 124. Thus, as the shaft 115 is rotated, the flux is alternately shifted from nearly 100% through the annular flux gate 124 to a substantial portion, which may be over 50%, through the parallel path comprising the

teeth

141, 142 and 147. Thus, the flux from the annular permanent magnet 123 linking the output winding 63 is alternately increased and decreased thereby generating an alternating output voltage in the annular output winding 63.

These flux paths can be seen by reference to FIGURE 6 where the lefthand portion shows the flux path through the annular flux gate 124 when the teeth 147 are in the position shown by the dotted lines in FIGURES, and the right-hand side of this view shows the flux paths when the teeth 147 are in the position shown by the solid lines in FIGURE 5 in which the teeth 147 are in substantial alignment with

teeth

141 and 142.

The distributor 13 and electromechanical generator 64 also include a centrifugally actuated advance mechanism that advances the timing of the ignition voltages applied to the spark plugs 12 in accordance with the speed of the engine. Referring to FIGURES 2 and 5, this centrifugally actuated advance mechanism includes a plate 151 rigidly attached to the

shaft

115 and 152. As shown in FIGUREB, this plate 151 has upstanding tangs 153 that extend through apertures 154 in the plate member or armature 146 of rotor 145. The plate member or armature 146 has a pair of upstanding posts 155, and the tangs 153 and the posts 155 are coupled by means of

springs

156 and 157. A post or sleeve 161 is affixed to the armature or plate member 146 and is mounted on shaft 115 for limited angular movement with respect thereto.

Apair of centrifugal weights 162 are mounted on upstanding posts 163 that are secured to the plate 151 as shown in FIGURE 2. The plate member or armature 146 has a pair of

upstanding flanges

164 and 165 struck therefrom to engage the cam surfaces of the centrifugal weights 162.

Upstanding pillar or post 161 also receives the rotor cap 171 that has an electrical contact 172 positioned thereon. This electrical contact includes a spring type termination 173 that engages a terminal 174 connected to the lead from the secondary winding 11 of ignition coil 10. This rotor cap 171 is designated in general terms by the numeral 14 and is designated as a rotatable arm 14 in describing the circuit of FIGURE 1. A cap 175 constructed of insulating material is positioned over the housing 113 and the rotor cap 171. This cap has a plurality of spaced contacts 176 that correspond to the number of spark plugs and cylinders of the engine and that are spaced equally around the perimeter of a circle so that as the rotor cap 171 is rotated by the shaft 115, the secondary winding 11 of ignition coil 10 will be sequentially connected to the spark plugs 12.

The distributor 13 including the electromechanical generator 64 also includes a standard vacuum advance mechanism 177 as shown in FIGURE 3. This mechanism has an arm 178 connected to the lower plate 131 of stator 122 that includes the annular permanent magnet 123, the annular flux gate 124, the annular output winding 63, and the upper and

lower plates

131 and 132 with spaced

teeth

141 and 142. This arm rotates the stator 122 including the bushing 136 about the bearing 114 in accordance with engine vacuum. This changes the position of the

teeth

141 and 142 relative to the teeth 147 thereby advancing or retarding the timing of the spark applied to the spark plugs 12 of the internal combustion engine in accordance with engine vacuum.

The output winding 63 is connected to the remainder of the circuit shown in FIGURE 1 by means of

leads

179 and 180 as shown in FIGURES 2 and 4.

In the operation of the electrical generator and distributor, the rotor 145 including the armature or plate member 146, the stationary plate 151, the shaft 115, the pillar 161, and the rotor cap 171, are rotated in a counterclockwise direction when using FIGURE 3 as a reference. It can readly be appreciated that the teeth 147 of the armature or plate member 146 come into alignment with the

teeth

141 and 142 once during each eighth of a revolution of the rotor including the shaft and the armature or plate member 146. Thus, during each revolution of the armature or plate member 146 and the shaft 115, eight cycles of alternating electrical energy will 40 be produced in the output Winding 63. The eight sets of

teeth

141, 142 and 147 when in alignment, act as a parallel magnetic circuit for the flux from the permanent magnet 123.

As discussed previously, the centrifugal advance mechanism couples the plate 151 that is aflixed to the shaft 115 to the armature or plate member 146 and the post to which the rotor cap 171 is attached through

spring mechanisms

156 and 157, the centrifugal weights 162 and

upstanding flanges

164 and 165 of the armature or plate member 146. The higher the speed of the shaft 115 and the plate 151, the greater will be the centrifugal force on the plates 162. This will force the weight outwardly against the

flanges

164 and 165, and rotate the armature or plate member 146, post 161 and rotor cap 171 counterclockwise with respect to the shaft 115 and the plate 151. Since the direction of rotation of the whole rotor mechanism is counterclockwise, this will advance the generation of the alternating voltages in the output winding 63 with respect to the rotation of the shaft 115 and the rotation of the engine, thus advancing the timing of the spark as engine speed increases.

It can be appreciated from an inspection of FIGURE 3 that as engine vacuum increases, the stator including the permanent magnet 123, the output winding 63 and the

upstanding teeth

141 and 142 on the stator structure will be rotated clockwise with respect to the rotor including the armature or plate member 146. This also has the effect of advancing the spark or advancing the timing of ignition voltages that are applied to the spark plugs, in accordance with the vacuum present in the engine manifold.

The alternating voltage output of the output winding 63 is shown in FIGURE 7, and this voltage is applied to the base 60 of the transistor 54. This transistor is normally conducting or, stated differently, is in a con- 7 ducting state when the circuit is in a steady state condition.

In normal operation, when the internal combustion engine is running, the movable arms 25 and 86 of the ignition switch 26 are in engagement with the

ignition contacts

27 and 27 of ignition switch 26 respectively.

This connects the source of electrical energy 16 in series with the emitter 22 and collector 33 of transistor 17 and the primary winding 15 of ignition coil 10. At this time, and if it is assumed that the annular output winding 63 is not producing any output voltage, the transistor 54 is biased to a steady state conducting state. This is done by the connection of the emitter 57 of transistor 54 to the positive terminal 21 of the source of electrical energy 16 through the resistor 58, lead 32, and the circuit previously described. The base 60 of this transistor isconnected to ground or the negative terminal of the source of electrical energy 16 through resistor 76, lead 77, lead 111, contact 98 of starting relay 94, lead 103, the armature of the starting motor 102, and lead 104. This provides the proper negative bias on the base 60 with respect to the emitter 57 to bias the transistor 54 into its conducting state. The current fiow through the base circuit of this transistor, including the resistor 76 and the circuit previously described, will provide approximately a 0.4 volt negative voltage bias on the base 60 with respect to emitter 57.

With transistor 54 conducting, the transistor 43 will be in a nonconducting state, since the voltage drop across the transistor 54 is so small that the base current of transistor 43, flowing out of base 52, is zero. It can be appreciated that when transistor 43 is in a nonconducting state, transistor 17 will also be in a nonconducting state since no current can flow out of the base 45 of transistor 17.

In order to turn transistor 54 off and to turn

transistors

43 and 17 on, it is necessary to overcome the negative bias on the base 60 of transistor 54, and this is done by means of the output voltage from .the output winding 63 of the electromechanical generator 64. The output voltage waveform 181 appearing at the terminal 62 that is connected to the base 60 through lead 61 is shown in FIGURE 7., The bias on the transistor 54 that must be overcome by this voltage waveform in order to turn the transistor 54 off, is shown in the dotted line. The voltage waveform 181 is the normal output voltage that occurs when the rotor 145 of the electromechanical generator 64 is driven at normal operating speeds.

When the voltage rises to the cross 182 where the waveform 181 intersects the dotted line, the bia on the base 60 of transistor 54 is overcome and the positive potential applied to the base 60 from the output winding 63 blocks current flow from the base thereby turning off transistor 54. This action permits current flow from the :base 52 of transistor 43 thereby turning on both transistor 52 and transistor 17.

When the voltage appearing at the terminal 62 drops to the point of the cross 183, the base current from transistor 54 is no longer blocked and, therefore, this transistor will turn on and

transistors

43 and 17 will turn off. During the dwell period that transistor 17 is conducting, the time between the two crosses, designated by the

numerals

182 and 183, current flows from the source of electrical energy 16 through the emitter 22, collector 33 circuit of the transistor 17, and the primary winding 15 of the ignition coil 10. This current also flows through lead 34, Winding 35 of bistable electromagnetic switch 36, and lead 37. When the point of the cross 183 is reached, the transistor 54 turns on and

transistors

43 and 17 turn off. This interrupts current flow in the primary winding 15 of ignition coil 10, and ignition voltages are generated in the secondary winding 11.

The output voltage of the winding 63 appearing at terminal 62 represented by the voltage waveform 181 then goe negative, and after a ti;me reverses and comes, back 8 to the same level that it Was at the cross 182. At this time, the transistor 54 will again be turned off and

transistors

43 and 17 will be turned on to initiate another ignition cycle.

The electromagnetic switch 36 and its action is identical to that described in copending application S.N. 170,055, filed January 31, 1962 in the name of Laurence F. Mieras and assigned to the assignee of this invention. It furnishes a means for rapidly switching the transistor 17 from a conducting to a nonconducting state at the time the voltage waveform 181 falls to the point of the cross 183.

The electrical circuit and its operation is disclosed in Patent Number 3,270,731 and also in copending application S.N. 387,003, both filed August 3, 1964, in the name of Laurence F. Mieras, and assigned to the assignee of this invention. 7

The present invention provides an ignition system including a distributor and electromechanical generator that is reliable, efficient, and that uses solid state switching components to accomplish the switching operation of the ignition system. It also provides a reliable and inexpensive electrical generator and distributor for controlling the switching of the solid state switching circuits that requires only a minimum of change from a standard distributor that uses contact breaker points. This can readily be appreciated by an inspection of FIGURE 2 in which it is seen that the stator structure, including the annular permanent magnet 123, annular flux gate 124, and the annular output winding 63 with the two upper and

lower plates

131 and 132, can be readily substituted for the contact breaker plates of the standard ignition distributor.

It is to be understood that this invention is not to be limited to the exact construction shown and described, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. An electrical generator for use in an ignition system of an automotive vehicle comprising, a housing, a shaft rotatably mounted in said housing, a rotor mounted on said shaft and having an annular flange wit-h a plurality of spaced teeth positioned therein, a stator positioned in said housing about said shaft, said stator comprising a bottom plate having a flange with a plurality of spaced teeth positioned therein, a top plate having a flange with a plurality of spaced teeth positioned therein, an annular permanent magnet positioned in said housing about said shaft between and in engagement with said top and bottom plates, an annular output winding positioned in spaced relationship radially outwardly of and about said annular permanent magnet and between said top and bottom plates, said annular flange of said rotor positioned between said flange of said top plate and said flange of said bottom plate whereby rotation of said rotor induces a periodically varying voltage in said output Winding.

2. An electrical generator for use in an ignition system of an automotive vehicle comprising, a housing, a shaft rotatably mounted in said housing, a stator positioned about said shaft and comprising a first plate and a second plate constructed of ferromagnetic material, an annular permanent magnet positioned between and in engagement with said first plate and said second plate, an annular output Winding positioned between said first plate and said second plate radially outwardly of said annular permanent magnet, an annular flux gate element constructed of ferromagnetic material positioned between said annular permanent magnet and said annular output winding and between said first and said second plate for providing a flux path for the flux from said permanent magnet, said first and said second plates each having a plurality of teeth, the teeth of said first plate being separated from the teeth of said second plate by a substantial air gap positioned radially outwardly from said annular output winding, and ferromagnetic means mounted on said shaft for periodically reducing the air gap between the teeth of said first plate and the teeth of the second plate to an extent that a substantial portion of the flux from said annular permanent magnet is diverted periodically from said annular flux gate through the teeth of said first and second plates and said ferromagnetic means mounted on said shaft.

3. An electrical generator for use in an ignition system comprising, a housing, a shaft rotatably mounted in said housing, a permanent magnet, a flux gate and an output winding fixedly, nonrotatably and concentrically positioned in spaced radial relationship in said housing about said shaft, means supported in said housing for magnetically coupling said flux gate and said permanent magnet, and means coupled to said shaft and cooperating with said last mentioned means for magnetically coupling said permanent magnet and said output winding, said means coupled to said shaft including means for varying the reluctance of the magnetic coupling between said permanent magnet and said output winding whereby an output voltage is generated in said output winding.

4. An electrical generator for use in an ignition system comprising, a housing, a shaft rotatably mounted in said housing, an annular permanent magnet, an annular magnet flux gate and an annular output winding concentrically mounted in radial spaced relationship in said housing about said output shaft, said annular permanent magnet, said annular magnetic flux gate and said annular output winding being fixedly and nonrotatably mounted in said housing with respect to said housing and to each other, said annular magnetic flux gate being positioned radially between said annular permanent magnet and said annular output winding, ferromagnetic circuit means coupling said annular permanent magnet and said annular magnetic flux gate and coupling said annular permanent magnet and said annular output winding, said ferromagnetic circuit means including means coupled to said shaft for varying the reluctance of said ferromagnetic circuit means coupling said annular permanent magnet and said annular output winding when said shaft is rotated whereby a periodically varying output voltage is generated in said output winding when said shaft is rotated.

5. A distributor for use in an ignition system of an internal combustion engine comprising, a housing, a shaft rotatably mounted in said housing, an annular permanent magnet, an annular magnetic flux gate and an annular output winding fixedly, nonrotatably and concentrically mounted in radial spaced relationship in said housing about said output shaft, said annular magnetic flux gate being positioned radially between said annular permanent magnet and said annular output winding, magnetic circuit means coupling said annular permanent magnet and said annular flux gate and coupling said annular permanent magnet and said annular output winding, said magnetic circuit means including means coupled to said shaft for varying the reluctance of said magnetic circuit means coupling said annular permanent magnet and said annular output winding when said shaft is rotated whereby a periodically varying output voltage is generated in said output winding when said shaft is rotated, means connected to said last mentioned means and including an electrical contact mounted for limited angular movement on said output shaft, a cap mounted on said housing and including a plurality of spaced contacts, said electrical contact adapted to sequentially contact said spaced contacts when said shaft is rotated, and centrifugally actuated means coupling said shaft and said means for varying the reluctance of said magnetic circuit means coupling said annular permanent magnet and said annular output winding for varying the angular relationship between said shaft and said last mentioned magnetic circuit means in accordance with the speed of said shaft.

6. In an ignition system for an internal combustion engine, an ignition coil including a primary and a secondary winding, a source of electrical energy, a solid state switching device coupled to said source of electrical energy and said primary winding for controlling the energization of said primary winding from said source of electrical energy, said solid state switching device including a control electrode, a distributor including a housing, a shaft rotatably mounted in said housing, an annular permanent magnet, an annular flux gate and an annular output winding fixedly and nonrotatably positioned in radially spaced relationship in said housing and about said output shaft, magnetic circuit means coupling said permanent magnet and said flux gate and coupling said permanent magnet and said output winding, said magnetic circuit means including means mounted on said shaft for varying the reluctance of said magnetic circuit means coupling said annular permanent magnet and said annular output winding, whereby a periodically varying voltage is generated in said output winding when said shaft is rotated, and circuit means coupling said output winding and the control electrode of said solid state switching device.

7. In an ignition system for an internal combustion engine, an ignition coil including a primary and a secondary winding, a source of electrical energy, a solid state switching device coupled to said source of electrical energy and said primary winding for controlling the energization of said primary Winding from said source of electrical energy, said solid state switching device including a control electrode, a distributor including a housing, a shaft rotatably mounted in said housing, an annular permanent magnet, an annular flux gate and an annular output winding fixedly and nonrotatably positioned in radially spaced relationship in said housing and about said output shaft, magnetic circuit means coupling said permanent magnet and said flux gate and coupling said permanent magnet and said output winding, said magnetic circuit means including means mounted on said shaft for varying the reluctance of said magnetic circuit means coupling said annular permanent magnet and said annular output winding, whereby a periodically varying voltage is generated in said output winding when said shaft is rotated, and circuit means coupling said output winding and the control electrode of said solid state switching device, a plurality of spark plugs, said distributor including means operable by said shaft for sequentially coupling said secondary winding of said ignition coil to said spark plugs.

8. An ignition distributor for an internal combustion engine comprising, a housing, a distributor shaft rotatably supported in said housing, a stator mounted in said housing including an annular permanent magnet, an annular output winding positioned radially outwardly of said annular permanent magnet, an annular flux gate positioned radially between said annular permanent magnet and said annular output winding, a first plate, a second plate, said annular permanent magnet, said annular flux gate and said annular output winding being positioned and held between said first plate and said second plate, said first and said second plates each having a plurality of spaced teeth extending substantially perpendicularly with respect to the planes of said plates, said teeth of said first plate being spaced radially inwardly of the teeth of said second plate, and the teeth of said second plate being positioned radially outwardly of said annular output winding, said distributor shaft having an armature positioned thereon with a plurality of spaced teeth positioned radially between said teeth of said first plate and said teeth of said second plate, said first plate, said second plate and said armature being constructed of ferromagnetic material, the reluctance of the flux path through said teeth of said first and second plates and the teeth of said armature being such that when the air gap between said teeth is a maximum substantially all 11 of the flux of said permanent magnet goes through said annular flux gate and being such that when the air gap between said teeth is a minimum that a substantial amount of the flux from said annular permanent magnet goes through said teeth and links said annular output winding 5 whereby a periodically varying voltage is induced in said annular output winding as said distributor shaft and said armature are rotated.

9. The combination of claim 8 in which said stator is mounted in said housing for limited angular movement and a vacuum motor adapted to be actuated in accordance with the load on the engine aflixed to said stator.

References Cited by the Examiner UNITED STATES PATENTS 2,537,093 1/1951 Schlenker et al 310164 3,073,879 1/1963 Straub 123148 3,139,081 6/1964 Tyzack 123148 MARK NEWMAN, Primary Examiner.

LAWRENCE M. GOODRIDGE, Examiner.

Claims

1. AN ELECTRICAL GENERATOR FOR USE IN AN IGNITION SYSTEM OF AN AUTOMOTIVE VEHICLE COMPRISING, A HOUSING, A SHAFT ROTATABLY MOUNTED IN SAID HOUSING, A ROTOR MOUNTED ON SAID SHAFT AND HAVING AN ANNULAR FLANGE WITH A PLURALITY OF SPACED TEETH POSITIONED THEREIN, A STATOR POSITIONED IN SAID HOUSING ABOUT SAID SHAFT, SAID STATOR COMPRISING A BOTTOM PLATE HAVING A FLANGE WITH A PLURALITY OF SPACED TEETH POSITIONED THEREIN, A TOP PLATE HAVING A FLANGE WITH A PLURALITY OF SPACED TEETH POSITIONED THEREIN, A ANNULAR PERMANENT MAGNET POSITIONED IN SAID HOUSING ABOUT SAID SHAFT BETWEEN AND IN ENGAGEMENT WITH SAID TOP AND BOTTOM PLATES, AN ANNULAR OUTPUT WINDING POSITIONED IN SPACED RELATIONSHIP RADIALLY OUTWARDLY OF AND ABOUT SAID ANNULAR PERMANENT MAGNET AND BETWEEN SAID TOP AND BOTTOM PLATES, SAID ANNULAR FLANGE OF SAID ROTOR POSITIONED BETWEEN SAID FLANGE OF SAID TOP PLATE AND SAID FLANGE OF SAID BOTTOM PLATE WHEREBY ROTATION OF SAID ROTOR INDUCES A PERIODICALLY VARYING VOLTAGE IN SAID OUTPUT WINDING.