US2984695A - Electronic distributor - Google Patents

Description

May 16, 1961 B. W. BERDINE ETA]- ELECTRONIC DISTRIBUTOR ZSheetS-Sheet 1 INVENTORS $67 M Jawzd 63 aczzozu UZW g M J,

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Filed June 15, 1956 y 1961 B. w. BERDINE ETAL 2,984,695

ELECTRONIC DISTRIBUTOR 2 Sheets-Sheet 2 Filed June 15, 1956 AN IH INVENTORS R Q 3101 6 [fl- Zerarze jawd 6i Gocrzozw 64' mzzu United States Patent ELECTRONIC DISTRIBUTOR Blake W. Ber-dine, Fort Collins, and David C. Gochuour,

Boulder, Colo., assignors to Gochnour, Inc., a corporation of Colorado Filed June 15, 1956, Ser. No. 591,664

12 Claims. (Cl. 123-148) This invention is concerned generally with the automotive arts, and more particularly with a distributor for a spark ignited internal-combustion engine.

The present construction of automotive ignition systems is well known. In such systems, the primary of a spark coil is intermittently energized with six or twelve volt DC. current. Interruption of the current causes a high voltage on the order of several thousand volts to be generated in the secondary winding of the ignition coil, and this high voltage is applied to the spark plugs through the rotorand arcuately spaced contacts of a distributor. According to present day practice the primary is energized, and the circuit then is broken, through a pair of contact points which are opened and closed by a cam on the distributor shaft driven at a speed proportional to the engine speed. This present system has many drawbacks.

The spacing between:the contact points when fully opened must be controlled quite critically for satisfactory results to be obtained. Shifting or deformation of mechanical parts, wear of the rubbing block or cam follower (this part generally is made of fiber) on the cam, and erosion of the contact points through sparking thereof causes the spacing to vary in a relatively short time. Furthermore, the surfaces of the contact points become oxidized due to arcing between the points, and this increases the electrical resistance between the points, and leads to a relatively weak spark for igniting the fuel mixture in the cylinders of the engine. Furthermore, it is well recognized that the most intense (the hottest) spark for the spark plugs is obtained with extremely rapid closing and opening of the breaker points. Obviously, a finite time is necessary to separate the breaker points or contacts sufficiently for the arc therebetween to be extinguished. Conversely, a similar time is necessary to close the points.

If the core of the spark coil is not allowed to become completely saturated before the current through the primary is interrupted, the voltage induced in the secondary will be weaker than if the core had become saturated. in modern, high speed engines, the time available for core saturation through energization of the primary circuit is quite low. Furthermore, extremely high speed operation, such as is fairly common in modern engines, causes the cam to open the breaker points so rapidly that the cam follower or rubber block tends to fly outwardly away from the cam. Thus, the contacts do not reclose as soon as might be desired, and the primary energization period is reduced still further. If biasing springs are made stronger in order to hold the cam follower or rubber block against the cam, then wear of the cam and cam follower and of the distributor shaft bearings is increased unduly.

Accordingly, it is an object of this invention to provide an ignition system overcoming the shortcomings set forth above.

It is another object of this invention to provide an electronic ignition system overcoming the difficulties of the prior art, yet retaining the prior art ignition system as an auxiliary or safety factor.

Yet another object of this invention is to provide an electronic ignition system added to a conventional mechanical, or breaker point ignition system, without requiring removal of any of the prior parts, and retaining the prior parts in condition for operation as a safety measure.

Other and further objects and advantages of the present invention will be apparent from the following description when taken in connection with the accompanying drawings, wherein:

Fig.1 is a vertical sectional view through a distributor constructed or modified in accordance with the principles of this invention;

Fig. 2 is a horizontal sectional view through the distributor of Fig. l as taken along the line 2-2 therein;

Fig. 3 is a horizontal sectional view taken along the line 33 in Fig. 1;

Fig. 4 is a View partially in vertical or longitudinal section of a different type of distributor, but embodying the same principles;

Fig. 5 is a horizontal sectional view along the line 55 in Fig. 4;

Fig. 6 is a block diagram of the electronic portion of the invention; and

Fig. 7 is a schematic wiring diagram thereof.

Referring now in greater particularity to the drawings, and first to Figs. 13, there is shown a distributor indicated generally by the numeral it). Many of the parts of this distributor are of conventional configuration, and include a distributor body 12 of standard construction, having a distributor shaft 14 rotatable therein, and carrying a cam 16. This cam is provided with eight faces for an eight cylinder engine, and it will be understood that the number of cam faces would vary in accordance with the number of cylinders of the engine. The cam shaft 14 in this instance is of the two piece type well known in the art. Vacuum and centrifugal mechanism mounted in a housing extension part 18 are provided for advancing or retarding the upper portion of the shaft relative to the lower portion in accordance with engine speed and load to control spark advance or retardation. Details thereon are not set forth in this application. since such structure is well known in the prior art.

The distributor body or housing 12 includes an upstanding cylindrical wall 20. The upper edge of this wall is provided with a shoulder as at 22. A breaker point unit 2A is mounted within the housing 12 on a horizontal floor 26 therein. This breaker point construction is conventional, and includes relatively separable contacts or breaker points 23, one of the points being fixed and the other mounted on a movable arm 30, and a cam follower or rubber block 32 mounted on the arm 30. The precise construction of the breaker point unit may vary from one automotive manufacturer to another, and such constructions, as well as the wiring thereof, are well known in the art and need not be elaborated upon at this point. In this particular type of distributor construction, the condenser is mounted exteriorly of the distributor and is not shown.

The distributor also includes a generally cup-shaped cap 34 having a shouldered lower edge 36 complementary to the shouldered edge 22. Normally these edges would be in engagement, but are spaced apart as hereinafter will be explained. The cap includes a central, high tension contact 38 and a connector 40 therefor, and includes a plurality of arcuately arranged contacts 42 and complementary or cooperating connectors 44, the contacts 42 being equal in number to the cylinders of the engine. A rotor 46 of known construction is carried for rotation by the distributor shaft to effect contact between the central contact 38 and the arcuately spaced contacts 42 in succession.

The foregoing parts all are conventional. To them is added a cylinder or collar 48 made of the same material as the distributor body 12, or of some other suitable material, and having shouldered lower and upper edges 50 and 52, respectively cooperatively engaging the shouldered edges 22 and 36. Thus, the cylinder or collar 48 serves as an upward extension of the cylindrical wall 20 of the distributor .body, and spaces the distributor cap a short distance above its normal position.

An auxiliary or extension shaft 54 extends upwardly from the distributor shaft 14 and supports therotor 46 with the rotor in its normal position relative to the distributor cap. The extension shaft 54 is provided with a depending cylindrical skirt S6 encircling the upper end of the distributor shaft 14, and resting against the top of the cam 16. The upper end of the distributor shaft 14 is provided with a flat as at 58 for normally locking the rotor to the shaft. In this instance, a downwardly extending tongue 60 forming a part of the sleeve 56, or of the extension shaft 54 engages the flat 58 for insuring rotation of the extension shaft 54 with the distributor shaft '14. It will be understood that the upper end of the extension shaft 54 is provided with a similar flat to insure proper orientation and rotation of the rotor 46.

To the upper end of the cylinder or skirt 56 there is secured a normally disposed disc 62. Conveniently, the disc is provided with an upwardly directed, central, cylindrical skirt 64 fitting over the upper end of the depending skirt 56. The disc 62 extends to a position near the cylinder or collar 48 and the cylindrical distributor wall 20, and is provided with a plurality of arcuately spaced apertures or transparent areas 66. Such apertures or transparent areas are equal in number to the number of cylinders in the engine, eight in this illustrative example. A support 68 is secured to the inside of the wall 20, and this support carries a ray emitter 70. In a simple form of the device, the support 68 may include a bracket and socket, and the emitter 70 may comprise a light bulb for emitting light rays. Alternatively, other types of supports and emitters could be utilized, such as an emitter for gamma rays. It is even contemplated that a nuclear radiation product could be used, if suitably shielded. Above the disc 62 there is provided a receiver 72 secured to the cylinder or collar 48, and having a downwardly opening radiation sensitive element 74. In the case where the emitter 70 is a light bulb, this radiation sensitive device 74 conveniently could he a conventional photosensitive device, such as a selenium cell. Preferably, however, this radiation sensitive device 74 comprises a sodium crystal of the type known in the art, and sensitive to all types of radiation including visible light radiation and gamma rays.

Radiation is emitted constantly from the source 70, and preferably a shield 76 is provided about the emitter to prevent lateral scattering of rays. Each time one of the apertures or transparent areas 66 passes between the radiation source 70 and the radiation sensitive device 74, the device 74 is activated, and a circuit is completed as will be set out hereinfater for causing a spark plug to fire. In referring to the aperaure or area 66 as being transparent, it will be understood that the intended meaning of this is that the area is transparent to the type of radiation emitted from the emitter 70. Similarly, the shield 76 is substantially impervious to the type of radiation emitted.

A modification of the invention is shown in Figs. 4 and 5. Most of the parts in this modification are similar to, or identical with, those previously described. Ac-

cordingly, such parts are identified by similar numerals with the addition of the sufiix a. Repetition of the description of these parts therefore is believed to be unnecessary, and only the changed parts will be set forth.

More particularly, the distributor a is of the type having a breaker plate 78 therein mounted for pivoting motion about the axis of the distributor shaft 14a. A vacuum fitting 80 is provided on the outside of the distributor housing 12a, and includes a diaphragm (not shown) connected by means of a connecting rod 82 to the breaker plate 78 for pivoting the same about the distributor shaft relatively to advance or to retard the plate relative to the cam 16a for advancing or retarding the spark. In this instance the breaker point unit 2411 is mounted on the breaker plate 78. The condenser 84 generally is carried on the breaker plate as a matter of convenience in this type of construction. Further description of this portion of the distributor is believed unnecessary, since it is well known in the art.

The important distinction of the distributor of Figs. 4 and 5 relative to that of Figs. 1-3 is that the bracket or holder 68a supporting the ray emitter 70a is mounted on a breaker plate 78. Thus, whenever the breaker plate '78 is moved for advancing or retarding the spark, the

ray emitter 7011 also is moved. The distributor shaft in this instance is a one piece shaft, and hence the disc 62a and apertures or transparent areas 66a therein are relatively retarded or advanced in accordance with the movement of the breaker plate 78. The pickup 72a including the ray sensitive device 74a is mounted on the inside of the cylinder or collar 48a as before.

The electronic circuit usable in connection with the ray emitter, the radiation sensitive device, and the interrupter or timing disc is shown in Figs. 6 and 7. In accordance with the block diagram of Fig. 6, it will be seen that the electronic circuit comprises a pulse shaper 84, a pulse amplifier 86 and a triggering circuit 88 These three components are supplied by a common power supply 98. The details of these various components will be apparent upon reference to Fig. 7.

The automobile battery is shown at 92, connected through an ignition switch 94- and a fuse 96 to a junction point 98. A resistor 100 is connected to the junction point, and the other end of the resistor is connected to the light bulb or other ray emitter 70, the other side of the emitter being grounded as at 102. It will be understood that any other conventional connection or energize.- tion would be supplied for the ray emitter 70 were such ray emitter of a type requiring some different type of energization.

The junction point 98 also is connected to a bust 104 having various filament connections associated therewith as hereinafter will be set forth. The opposite end of the bus is connected to a fixed switch contact 106. The switch associated therewith will be set forth in greater detail hereinafter.

More specifically, the fixed contact 106 comprises part of a single pole, double throw switch 108 having a grounded fixed contact 110, and a movable switch arm or member 112. This movable switch arm or member is connected to one end of the primary winding 114 of the ignition coil 11 6. The movable switch arm 112 also is connected to a wire 118 leading to the vibrating reed or contact 120 of a conventional vibrator 122 forming a part of the power supply 90. The vibrator also includes the usual fixed contacts 124 connected to the opposite ends of the primary winding 126 of a vibrator transformer 128. The primary winding 126 is provided with a center tap at 130, and this is connected to a wire 132 leading to the bus 104. Thus, the six or twelve volt potential of the automobile battery 92 is connected to the vibrator 122 and vibrator transformer 128 when the ignition switch 94 is closed, and when the switch arm 112 is in engagement with the grounded contact 110.

The power supply also includes a secondary Winding 134 for the vibrator transformer, and a series connected capacitor 136 and rectifier 138 are connected across the secondary or output winding 134. The junction 140 between the capacitor and rectifier is connected to a grid biasing bus 142. The upper end of the winding 134 is connected to a capacitor 144 which is in turn connected to the junction 146 between a rectifier 148 and a rectifier 150. The lower end of the rectifier 148 is grounded along with the lower end of the capacitor 136 and of the secondary winding 134. The opposite end of the rectifier 150 is connected to a 8+ bus 152, and a capacitor 154 is connected between this bus and ground, as are series connected resistors 156 and 158. The junction 160 between the resistors 156 and 158 is connected to a Wire 162 leading through a resistor 164 to the anode of the radiation sensitive device or detector 74. The cathode is connected to ground, as will be understood. Obviously, other suitable connections could be made to the radiation sensitive device if it were desired to use some other type of device.

The ray emitter 70 and radiation sensitive device 74 together form the pulse shaper 84, and generate a negative pip or pulse 166 of fairly small magnitude, as is shown above the pulse shaper in Fig. 7. This pulse is applied to the pulse amplifier 86 to produce an amplified, positive pulse 168 approximating a square wave.

The pulse amplifier 86 includes a multigrid electron tube 176 having a filament 172' connected at one end to the bus 104, and grounded at the other end. The cathode 174 is grounded through a cathode resistor 1.76, and the suppressor grid is connected to the cathode. The control grid 178 is connected through a coupling capacitor 180 to the anode of the radiation sensitive device or pickup 74, and the control grid also is grounded through a grid resistor 182. The screen grid 184 is connected through a resistor 186 to the wire 162 of the power supply, while the plate 188 is connected through a plate load resistor 190 to the wire 162.

The triggering circuit comprises a pair of tubes 192 and 194. Preferably these tubes are of the gas discharge type known as thyratrons. The filaments 196 and 198 are connected to the filament bus 194, and to ground as will be apparent. The suppressor grids 200 and 202 are connected to the respective cathodes 204 and 206, and the cathodes are grounded.

The control grid 208 of the first triggering tube 192 is connected through a coupling capacitor 210 to the plate 188 of the pulse amplifier tube 170. The grid also is grounded through series connected resistors 212 and 214, the junction between these two resistors being connected to the grid biasing bus 142. The plate 216 of the first tube 192 is connected through a load resistor 218 to the B-lbus 152. The plate also is connected by a coupling capacitor 228 to the primary winding 222 of a triggering transformer 224. The secondary 226 of this transformer is connected to the control grid 228 of the second triggering tube 194, and also is connected to series connected, grid grounding resistors 230 and 232. The junction between these two resistors is connected to the grid biasing bus 142-.

The plate 234 of the tube 194 is connected to a rectifier 236 and to a choke 238, the latter being connected to the B+ bus 152. The plate also is connected to a grounded rectifier 240 which prevents the plate 234 from dropping below ground potential during discharge.

The plate 234 further is connected to a capacitor 242, and this capacitor is connected to a fixed contact 244 of a switch 246. This switch includes a movable switch arm 248 operable as a unit with the switch arm 1:12 of the switch 108. The switch arm 248 is connected to the primary 114 of the ignition coil 1'16.

The switch 246 additionally has a fixed contact 250 which is connected to the parallel combination of the breaker points and condenser 84, the combination being grounded at 252. The secondary winding 254 of the ignition coil is connected to the ground 252, and also is connected to a wire 256 leading to the distributor cap, specifically the center connector and accompanying contact 38.

The switches 108 and 246 preferably form part of a re lay. The switch arms 112 and 248 are biased so as normally to engage the fixed contacts 106 and 250. The winding of the relay, hereafter identified by the numeral 258, is positioned in proximity to the switch arms 112 and 248, the switch arms thereby forming an armature of the relay, so that when the relay coil or winding is energized the switch arms respectively will be moved to the fixed contacts and 244. The relay coil is arranged so as to be energized when the electronic circuit and distributor are operating properly. Upon failure thereof the relay coil is deenergized, and the switch arms 112 and 248 return to the fixed contacts 106 and 250 whereby the ignition coil 116, and the breaker points 30 and condenser 84 are connected into the circuit for operation in the normal manner. To this end the relay coil is connected between the wire 118 leading to the vibrator reed and the bus 104.

With the ignition switch 94 closed, and the relay energized so as to connect the switch arms 1:12 and 248 respectively to the fixed contacts 110 and 24-4, operation of the device is as follows. Each time one of the apertures or transparent areas of the timing disc passes between the light source or ray emitter 70 and the photo cell or radiation sensitive device 74, the device 74 conducts, thus causing an increased voltage drop across the resistor 164. This generates the negative pulse 166 previously referred to. The negative pulse is amplified and made positive in the pulse amplifier, and is applied to the first tube 192 of the triggering circuit. This causes the tube 192 to fire, thereby greatly reducing the voltage on the plate 216, and in fact dropping the plate voltage substantially to ground.

The capacitor 242 meanwhile charges from the B+ bus through the choke 238 and rectifier 236., and through the primary winding 114. Upon firing of the triggering tube 192, a positive pulse is applied to the grid 228 of the second triggering tube 194. This tube accordingly fires, and the plate potential thereon drops substantially to zero, it being understood that the choke 238 resists a sudden onrush of current. As a result, the capacitor 2-42 discharges through the tube 194 and the primary winding 114, and a high voltage of short duration is induced in the secondary winding 254. This high voltage is applied to the distributor cap, and is distributed in the normal manner.

It now will be apparent that there has been disclosed a superior ignition system providing a pulse of higher voltage than heretofore obtained, and of uniform quality irrespective of the engine speed. This allows operation of engines at higher speeds than heretofore possible, and by providing a hotter spark at all speeds, leads to improved performance and superior gasoline mileage. Engine longevity also is increased greatly by complete combustion, and therefore reduced carbon deposits. The conventional mechanical or breaker point ignition system is retained, and automatic means is provided for switch ing this system into operation should thereby any chance be failure or reduce deffectiveness of the electronic system. Since the breaker points are generally maintained out of the circuit, there is no arcing across the points, and they will last practically indefinitely in a standby status. Since there is nothing to arc, and no moving parts to wear in the electronic system, many thousands of miles of vehicle operation between adjustments can be expected.

The specific embodiments of the invention as herein shown and described are to be understood as being illustrative only. Various changes in structure will no doubt be apparent to those skilled in the art, and are to be understood as forming a part of this invention insofar as they fall within the spirit and scope of the appended claims.

The invention is hereby claimed as follows:

1. In a distributor having a body, a distributor shaft having a cam thereon, breaker points opened and closed by said cam, a cap having a central contact and a plurality of arcutely spaced contacts, and a rotor carried by said shaft and sequentially connecting said central contact with said arcuately spaced contacts, the combination comprising a radiation emitting device mounted in said body, a device sensitive to said radiation mounted in said body and adapted to receive radiation from said emitting device, means operated by said distributor shaft for intermittently exposing said sensitive device to said emitting device, and means including switch means for alternatively connecting said radiation sensitive device and said breaker points to the central contact of said cap.

2. In a distributor as set forth in claim 1, the combination wherein the exposing means comprises a disc carried by said shaft and interposed between said emitting and sensitive devices, said disc having a plurality of equally arcuately spaced areas therein transparent to the radiation emitted by said emitting device.

3. In a distributor as set forth in claim 1 and further including a spark coil, the combination as set forth wherein the switch means normally connect said sensitive device to said spark coil, and means automatically connecting said breaker points to said spark coil upon failure of any of said emitting device, sensitive device, and the previously-mentioned connecting means.

4. In a distributor having a body, a distributor shaft having a cam thereon, breaker points opened and closed by said cam, a cap having a central contact and a plurality of arcuately spaced contacts, and a rotor carried by said shaft and sequentially connecting said central contact with said arcuately spaced contacts, the combination comprising a ray emitting device carried within said body, a device sensitive to said rays carried within said body and in position to receive rays from said emitting device, means operated by said shaft for intermittently exposing said sensitive device to said emitting device and means including switch means alternatively connecting said sensitive device and said breaker points to said central contact of said cap.

5. In a distributor as set forth in claim 4, the combination wherein both the emitting device and the sensitive device are mounted on the body.

6. In a distributor as set forth in claim 4 and further including a breaker plate, the combination wherein one of said devices is mounted on said breaker plate and the other on said body.

7. In a distributor having a body, a distributor shaft having a cam thereon, breaker points opened and closed by said cam, a cap having a central contact and a plurality of arcuately spaced contacts, and a rotor carried by said shaft and sequentially connecting said central contact with said arcuately spaced contacts, the combination comprising a body extension interposed between said body and said cap, a shaft extension interposed between said shaft and said rotor, a ray emitting device carried from said body, a device sensitive to said rays carried from said body and in position to receive rays from said emitting device, at least one of said devices being mounted within said body extension, means operated by said shaft for intermittently exposing said sensitive device to said emitting device, and means including switch means selectively connecting said sensitive device and said breaker points to the central contact of said cap.

'8. in an ignition system, a ray emitting device, a ray sensitive device, means for intermittently exposing said sensitive device to said emitting device, a discharge tube, an ignition coil having a primary winding and a secondary winding, a capacitor, a voltage source, means con necting said voltage source, said tube, said capacitor, and said primary winding in circuit whereby said capacitor is charged during nonconducting of said tube, means for rendering said tube highly conductive upon exposure of said sensitive device to said emitting device, said capacitor thereupon discharging through said tube and said primary winding to generate a pulse of high voltage in said secondary winding, a set of breaker points and a condenser in parallel therewith, and switch means for alternatively connecting said breaker points and condenser and said discharge tube and capacitor in circuit with the primary winding of said ignition coil.

9. In an ignition system as set forth in claim 8, wherein the switch means comprises a relay.

10. In an ignition system, a ray emitting device, a ray sensitive device, means for intermittently exposing said sensitive device to said emitting device, an ignition coil having a primary winding and a secondary winding, a set of breaker points, a switch, means connecting said breaker points to said switch, means connecting said ray sensitive device to said switch, and means connecting said switch to said primary winding of said ignition coil, said switch being operable alternatively to connect the ray sensitive device or the breaker points to said primary winding for passing current therethrough to generate pulses of high voltage in the secondary winding.

11. In an ignition system as set forth in claim 10, wherein the switch comprises a relay.

12. In a distributor having a body, a distributor shaft having a cam thereon, breaker points opened and closed by said cam, a cap having a central contact and a plurality of arcuately spaced contacts, and a rotor carried by said shaft and sequentially connecting said central contact with said arcuately spaced contacts, the combination comprising a spark coil, a radiation emitting device carried from said body, a radiation sensitive device carried from said body and adapted to receive radiation from said emitting device, means operated by said distributor shaft for intermittently exposing said sensitive device to said emitting device, means normally connecting said sensitive device to said spark coil, and means automatically connecting said breaker points to said spark coil upon failure of any of said emitting device, sensitive device, and the previously-mentioned connecting means.

References Cited in the file of this patent UNITED STATES PATENTS 2,084,267 Hicks June 15, 1937 2,152,650 Kilborn Apr. 4, 1939 2,169,818 Scott Aug. 15, 1939

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