US3886923A

US3886923A - Inductive discharge ignition system

Info

Publication number: US3886923A
Application number: US378273A
Authority: US
Inventors: Martin E Gerry
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-07-11
Filing date: 1973-07-11
Publication date: 1975-06-03
Anticipated expiration: 1992-06-03

Abstract

This system provides means for storing electrical energy in a plurality of inductors during the period when no demand for the stored energy is made and having means for discharging the stored energy from each particular inductor to fire a particular igniter, one igniter at a time. Circuits included involve individual inductors for each ignition, wherein the primaries are connected to the charging means and the secondaries of the inductors to the discharging means in order to provide the requisite energy needed to fire the igniter substantially instantaneously.

Description

United States Patent Gerry June 3, 1975 [54] INDUCTIVE DISCHARGE IGNITION 2,527,211 10/1950 Brinson 123/148 DS SYSTEM SDtotto 2110/12/ 1;

. s evens [76] Inventor: Martin E. Gerry, 13452 Winthrope Santa Cahf' 92705 Primary Examiner-Charles .1. Myhre [22] Filed; July 11, 1973 Assistant E.\'aminerRonald E. Cox

[21] Appl. No.: 378,273

[57] ABSTRACT This system provides means for storing electrical en- [52] us Cl Sf ergy in a plurality of inductors during the period when 200/24. 200726 200/8 no demand for the stored energy is made and having [51] Int Cl Fozp Holh 39/00 means for discharging the stored energy from each 58 Field of Search 123/148 E, 148 DC, 148 D, pfmcular l Q F i g g l f v f v 123/148 200/24 26 8 R niter at a time. IICUIS inc u e mvo ve1n 1v1 ua 1nductors for each 1gn1t10n, wherein the prlmaries are I connected to the charging means and the secondaries [56] References cued of the inductors to the discharging means in order to UNITED STATES PATENTS provide the requisite energy needed to fire the igniter 333,1? llguschka 123/148 D substantially instantaneously. l, ,2 1 3 itzsimmons 123/148 DC U 2,163,843 6/1939 Lansing 123/148 D sclalmsdDrawmg Flgures I INDUCTIVE DISCHARGE IGNITION SYSTEM ignition transformer and points to provide periodic .ond.,plurality of stationary members. In other configurations of each of the transformers, one end of the primary winding is at ground potential, and one end of the "secondary winding is connected to the ungrounded portion of, its respective igniter, the other end of the ,primary winding is connected to its corresponding ,jrnemb erof the first plurality of stationary members,

pulses to the primary of the tranformer, Setunattainable demands upon the system to deliver energy to igularly at higher engine speeds. Various artifices, such' as vacuum advance mechanism, was used to advance the pulsing of the transformer, or operation of the points, in anticipation of delayed build up of energy in the transformer, which in fact actually never occurred to the fullest extent possible. The results, including engine inefficiency are also plagued with hydrocarbon and unburned gaseous wastes that contaminate the atmosphere as well as provide high cost of operation of the engine due to unneccessary fuel consumption.

SUMMARY OF THE INVENTION An apparatus and method for an ignition system having igniters, a plurality of inductive means, and ignition selection means responsive to a driven shaft, for enabling the firing said igniters, is provided in the disclosed invention. Means are provided for charging said inductive means during the non-firing period of all but one of said igniters, and means for discharging said inductive means, synchronized with the means for charging, is provided during the firing period of any one of said igniters.

The means for charging comprises first means having an aperture at its periphery and insulated from and coupled to the driven shaft, a first plurality of stationary members disposed about the periphery and spaced from each other and from the first means, and means for providing electrical energy coupled to the first means. The means for discharging comprises, second means attached to said driven shaft, and a second plurality of stationary members disposed about the locus of the free end of said second means and spaced from each other and from the second means, each one of the second plurality of stationary members having associated therewith one of the first plurality of stationary members.

The inductive means constitutes a plurality of transformers, each transformer having a primary winding, and a secondary winding with a larger number of turns than the primary winding, each transformer having one of the ingiters associated therewith. In each of the transformers one end of the primary winding is connected to one end of the secondary winding and to the ungrounded portion of its respective igniter, the other end of the primary winding is connected to its corresponding member of the first plurality of stationary members, and the other end of the secondary winding is connected to its corresponding member of the secand thelother end of the secondary winding is connected to its corresponding member of the second plurality of stationary members.

In such configurations powered by RF energy, a diode is connected between each of the plurality of stationary members and its corresponding primary winding in series with the wire connecting such members and winding, in one configuration.

In configurations employing DC power, the means for charging includes a first plurality of member pairs disposed about a driven circular member at the periphery thereof and spaced from each other, and includes the means for discharging as hereinabove described.

In another configuration employing DC power, the means for charging comprises first means, having a multiplicity of protrusions which contactors at each of the protrusions, and coupled to said driven shaft, and a first plurality of stationary members disposed about the contactors and spaced from each other, each of the contactors providing intermittent electrical connection with the first plurality of secondary members, and includes the means for discharging as above described.

In all configurations, when the primaries of the ignition transformers have obtained their full charge, maximum voltage across the secondary will be encountered by transformer action in readiness for discharge and firing of the igniter. It should be remembered that energy will be constantly fed to the primary until the particular transformer is ready to discharge its energy into the igniter, so that the maximum amount of energy will also be available when needed.

It should also be kept in mind that when energy is stored in the primary of any of the transformers it is also available at the secondary by transformer action, and hence is available on demand by the means for discharging to fire the particular igniter related to that particular transformer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view partially in cross section of a four cylinder ignition system having a radio frequency energy power source in accordance with the invention.

FIG. 2 is a plan view partially in perspective of a modification upon FIG. 1 providing isolation between the primary and secondary windings of each ignition transformer.

EXEMPLARY EMBODIMENT Structural Relationships Referring to FIG. 1, an ignition system utilizing radio frequency energy to power same is illustrated, in accordance with the invention.

Cam shaft 10 normally extends from the internal combustion engine, and normally drives a distributor arm. This arm, in the ordinary Kettering type ignition system, is used. to switch power to the several ignition coils. Such cam shaft is generally at potential of the engine casing. This shaft is used for driving the inventive devices hereinbelow described.

Insulating bushing 12 is circumjacent portion of shaft 10, and metallic sleeve 13 is circumjacent bushing 12. Sleeve 13 is attached to or integral with metallic circular member 14, which may be of aluminum or may be of thin metal, hollow on the inside. Both bushing 12 and sleeve 13 are attached to each other and to member 14, and all of them to shaft by means of nylon screw 15, which extends through the bushing, sleeve and partially through the shaft. In this way when shaft 10 is driven, member 14 will be rotated in the direction of drive. The invention illustrates an ignition system suitable for powering for ignitors or spark plugs. However, it may be appreciated that any number of spark plugs or ignitors ranging from one upward, may be used by appropriate design.

Accordingly,

metallic members

17, 18, 19 and are equally spaced apart from and about the periphery of member 14. Cut-out portion 16 at the periphery of member 14, is shown in the figure as representing capacitance C between

members

14 and 17, such capacitance having a lower value when capacitance C, due to the cut-out portion 16, than capacitance C, which is present between

members

18, 19 or 20 and rotatable member 14. Of course, when member 14 is rotated so that cut-out portion 16 is opposite stationary member 18, then the value of the capacitance thereat will be valued as C and so on.

Another rotatable member 21 driven by shaft 10 will be attached by means of metallic screw 22 to the shaft inorder to fix the electrical potential of member 21 to be the same as that of shaft 10. Hence, when member 14 is driven by shaft 10, member 21 will likewise be driven, member 21 being substantially aligned with cutout 16. Stationary member 17' is physically located in line with member 17. Stationary member 18' is physically located in line with member 18. Stationary member 19' is physically located in line with member 19, and stationary member 20' is physically located in line with member 20.

It should be noted that ground potential will be shown herein synonymous with negative potential of the battery and will be illustrated by conventional ground symbology as at 25 everywhere in the specification.

Stationary members

17, 18, 19 and 20 will each be connected to an individual diode 60 in order to pass the current supplied in a single direction and reject current flow in the opposite direction. Such diode is preferable when used in a system wherein the power means is radio frequency energy, and is not needed in such systems where the power supplied is DC directly from the battery. However, in all instances even in the radio frequency energy type system, diodes 60 are optional inasmuch as some charge will remain in the primaries of the several transformers to be hereinbelow described.

Assuming the diodes are used, then one diode 60 is connected between member 17 and transformer primary 41 of transformer interposed in wire 37 that connects member 17 and transformer primary 41. Other diodes 60 interposed respectively in wires 37 enable these diodes to be connection in series with the other three transformer primaries 41 of transformers 40 to connect these transformers respectively with

stationary members

18, 19 and 20. The secondary windings 42 of transformers 40 will be connected respectively by means of wires 39 to

stationary members

17, 18, 19, and 20'. The other ends of the transformer primaries and the transformer secondaries are generally connected together in this configuration. By connecting

leads

36 and 38 thereof together, the connected-together leads terminating in leads 35. Leads 35 are connected to spark plugs or igniters at terminals 51.

Terminals 51 are generally fed-through metallic rods that extend through an insulating bushing and the insulating bushing is seated in a metallic seat 53, so that a member such as at 52 connected to seat 53 may form a gap as at C between rod 51 and member 52. These igniters being seated in the framework of the engine provide ground potential to member 52 as shown at 25.

Spring member 23 generally of beryllium copper acts as a contacting brush against metallic sleeve 13, so as to provide RF power to sleeve 13 and hence to member 14 by means of a wire connecting to the high end of signal generator 24. The other end of signal generator is at ground potential as shown at 25. The signal generator may be of conventional solid state type and may range preferably between kilohertz and 10 megahertz. This signal generator is powered by being connected to ignition switch 27, the other side of the ignition switch being connected to the positive terminal of battery 26. The negative terminal of battery 26 being connected to ground or engine chassis as shown at 25. When the end of arm 21 is positioned opposite any of the

stationary members

17, 18, 19', or 20', a capacitance C, will be exhibited thereat. In the illustration, the end of arm 21 is shown opposite member 17. Likewise in the illustration slot or cut out 16 of member 14 is shown opposite member 17, so that slot 16 and the end of arm 21 will be simultaneously rotated opposite their corresponding

stationary member combinations

17 and 17, 18 and 18, 19 and 19, and 20 and 20.

Referring to FIG. 2, this figure is exemplary of a modification to FIG. 1 wherein the primaries and secondaries of each of the transformers are not directly connected to each other. Accordingly, transformers 40' will be substituted for transformers 40. Exemplary of this substitution is that one side of primary of 41' is connected by wire 37 to stationary member 17, the other side of the transformer being connected by means of wire 36 to ground 25. One side of secondary 42 is connected by means of wire 39 to stationary member 17, the other side of the secondary being connected by means of wire 38 to terminal 51 of the igniter. The other transformers will be respectively connected as herein described to

terminals

18 and 18', 19 and 19, and 20 and 20'.

It should be noted that the manner in which the transformers 40 as connected in FIG. 2 may be used in FIG. 1, except that in FIG. 1 a diode 60 may be desirable to be interposed in wires 37, similar to such interpositions as shown in FIG. 1.

Finally, it should be noted that in FIG. 1, FIG. 1 as modified by FIG. 2, power supply means 24 may be a unipolar pulse source having a repetition frequency of the pulses outputted therefrom that may or may not resonate with the primaries of the several transformers to charge the transformers in accordance with the requirements of this invention. In this instant diodes 60 need not be interposed in wires 37.

Operational Relationships In accordance with the description of the structural relationships for FIG. 1, RF power will be supplied upon the closure of ignition switch 27 through capacitance C,, which is the capacity between member 14 and the stationary members peripherally placed with respect to the rotatable member, except at cut-out 16 wherein capacitance C smaller in size then C will result. Consequently, when power is supplied through capacitance C each of the primaries 41 will have a current flowing therethrough and through capacitance C The sum total of equivalent capacitance C, and C are chosen so that they are preferably at resonance with primary winding 41 to obtain maximum efficienty from power source 24. This action will, when diode 60 is in series with primary 41, as hereinabovedescribed, provide a series of pulses only one-half, either positive or negative, it making no difference which is used, to charge the primary and hence the transformer in a single direction. Such charge will be present in the transformer so that when member 14 is rotated as shown in the figure, wherein the capacity C, is changed to capacity C by virute of cut out 16 being opposite of the particular stationary member connecting to the transformer, and at the same time member 21 having a negative or ground potential being opposite its stationary member, in this illustration being opposite 17', the charge of the primary will be a voltage representing the inductance of the primary and the charging current which would substantially be a steady state current, such voltage across the primary will be transferred by transformer action to the secondary 42. Secondary 42 having a larger number of turns than primary 41 provides a substantially larger voltage such as common to ignition systems, but the difference being that it will provide this voltage instantaneously across its terminals, and no discharge can occur until arm 21 is opposite the particular stationary contactor to which the transformer secondary is connected at which point a capacitance C, between arm 21 and the particular stationary terminal will be exhibited, in this instance between arm 21 and stationary terminal 17 Hence, the high voltage across the transformer secondary will arc over across capacitance C, seeking ground or negative potential as provided by arm 21 and shaft 10, to provide a high voltage to member 51 of ignitor 50. This high voltage being present between ground 25 or member 52, which is at ground potential, will cause an arc to occur between the lower portion of rod 51 and member 52, or across C thereby igniting the gas in the cylinder of the engine. Similar action will occur when shaft is rotated so that cut-out l6 and arm 21 are opposite the other stationary members for igniting respectively the gas in the other cylinders in the same manner as hereinabove described.

Referring to FIG. 2, the operation is substantially similar to that described in FIG. 1 except that capacitance C will only be part of the secondary circuit and not of the primary transformer circuit. Since the primary of the transformer is directly at ground potential and isolated from the secondary, this will permit a larger amount of energy to be present in the transformer available for discharge, assuming the same transformer is used.

Actually, diodes 60 as hereinabove described are not actually needed but are optional. The reason is that there will be many cycles of RF present to charge the several primaries in question and it is quite likely that switching of the RF power at a point other than the zero axis of the radio frequency voltage supplied to any of the systems herein using RF power, will occur.

The advantage of the use of RF power over DC is obvious in view of the possibility of obtaining resonance and hence larger amount of stored energy in the transformer over the DC power supply, wherein resonant voltage across the igniter when needed rather than the delay time encountered in a conventional Kettering ignition system, which due to the large inductances of the transformer current flow in the primary needed to charge it, and to provide a voltage to secondary, cannot change instantaneously but rather takes a substantial amount of time, making it necessary to advance the timing particularly at high engine speeds. All this is eliminated with the precharged transformer waiting to make available to the particular ignitor the high voltage needed to fire it. It should be noted that a voltage across an inductor, herein the secondary of the transformer, will change instantaneously, but the current necessary to charge it will not, and herein lies essential difference between any of the systems described and the conventional Kettering method.

If typically C 10 X 10 farads, inductance of the primary 41' of the transformer is in the order of millihenries, where the separately grounded primary windings as in FIG. 2 are used. The frequency of circuit 24, to obtain resonance of the primary circuit, will compute to 1.6 megahertz, just above the upper frequency of conventional AM radios to avoid interference due to radio noise.

In the case of FIG. 1, C will be in series with C,, an consequently the equivalent capacitance of C approximated at 4 X 10 farads in series with C,, will be about 3.5 X l0- farads, and the frequency required for resonance will be about 270 kilohertz, or below the broadcast band frequencies, also avoiding interference due to radio noise.

In view of the fact that under the fastest motor speed, or worst condition, of 5000 revolutions per minute, the charging time for each ignition transformer will be at least in the order of 0.01 seconds, in the inventive configuration, which is a longer time than needed to fully charge such ignition transformer. This will permit using a larger inductance in the primary winding with smaller wire diameter than currently used in ignition coils. As a result a greater resistance of the primary winding will result in effect to draw current in the milliampere range, rather than the larger amperage drawn by conventional ignition transformer primaries. The wire diameters being smaller, the primary and secondary windings will occupy less space and result in small ignition transformers in the order of less than one third the volume occupied by conventional ignition transformers. Of course in building a new ignition transformer, it would be advantageous to individually isolate the primary from the secondary such as transformer 40' in FIG. 2.

In conclusion it is important to take note that all the ignition transformers have been connected to provide a charge therein by passing a current through their respective primaries during the period when no demand for ignition power is made upon these transformers, therefore the transformers have sufficient time requisite to fully charge them. Subsequently when the particular transformer secondary requires a voltage to fire an igniter, a voltage maybetransformed instantaneously across any secondary; though it is notpossible to force a current through aninductorinstantaneously, and the total voltage capable of being created by the transformer secondary i'savailable exactly whenaneeded to fire the igniter, thereby avoiding all the defects of the Kettering system described inthe Background of the Invention.

lclaim: 1

1. An ignition system having. igniters, and a shaft driven during operative mode of said system, the combination comprising:

first rotary switching means comprising a generally circular member driven by said shaft during said operative mode, said member having an outer periphery, an aperture at said outer periphery, and a plurality of first electrode means at said outer periphery positioned at regular intervals,;

a plurality of transformers, each of the transformers having a primary and secondary winding, one of the primary windings being connected to only one of said first electrode means; and

second rotary switching means comprising an arm one end of which is mounted on said shaft and the other end of said arm describing a circular path during said operative mode, and a plurality of second elecrode means, equal in quantity to said first electrode means, positioned at locations described by said circular path at regular intervals, one of the secondary windings being connected to only one of said second electrode means.

2. An ignition system having igniters, a plurality of inductive means and ignition selection means responsive to a driven shaft, the combination comprising:

means for charging said inductive means during the non-firing period of all but one of said igniters, the means for charging comprises:

first means having an outer periphery and an aperture at said outer periphery and being insulated from and coupled to said driven shaft;

a first plurality of stationary members disposed about said outer periphery and spaced from each other and from the first means; and

means for providing electrical energy coupled to the first means; and

means for discharging said inductive means, synchronized with the means for charging, during the firing period of any one of said igniters, the means for discharging comprises:

second means having one end attached to said driven shaft and having a free end opposite to said one end, said driven shaft being in circuit with the second means; and I a second plurality of stationary members disposed about the locus of the free end of said second means and spaced from each other and from the second means, each one of the second plurality of stationary members having associated therewith one of the first plurality of stationary members.

3. The invention as stated in claim 2:

the inductive means being a plurality of transformers,

each transformer having a primary winding, and a secondary winding with a larger number of turns than the primary winding, each transformer having one of the igniters associated therewith.

4. The invention as stated as claim 3:

in each of the transformers one end of the primary winding is connected to one end of the secondary winding and to the ungrounded portion of its respective igniter, the other end of the primary winding is connected to its corresponding member of the first plurality of stationary members, and the other end of the secondary winding is connected to its corresponding member of the second plurality of stationary members.

5. The invention as stated in claim 3:

in each of the transformers one end of the primary winding is at ground potential, and one end of the secondary winding is connected to the ungrounded portion of its respective igniter, the other end of the primary winding is connected to its corresponding member of the first plurality of stationary members, and the other end of the secondary winding is connected to its corresponding member of the second plurality of stationary members.

6. The invention as stated in claim 4, including:

a diode connected between each of the first plurality of stationary members and its corresponding primary winding in series with the wire connecting such members and winding.

7. The invention as stated in claim 5, including:

a diode connected between each of the first plurality of stationary members and its corresponding primary winding in series with the wire connecting such member and winding.

8. The invention as stated in claim 2, wherein:

the electrical energy is of the radio frequency type.

" T I UNITED STATES PATENT OFFICE 5 CERTIFICATE OF CORRECTION Patent -No. 1 I Dated June 3, 19:75

Inventor s Martin E. Gerry I It is certified that error appears in the above-identified patent and that said Lettex s Patent are hereby corrected as shown below:

pRAwlfic ISICORRECTED TO READ Signed and Scaled this severrteenth Day 0f February 1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Offic Commissioner ofPatents and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated June 3, 1975 Paterit No.

Martin E. Gerry Inventor (s) Dove-identified patent d as shown below:

It is certified that error appears in the a and that said Letters Patent are hereby correcte THE DRAWING IS CORRECTED TO READ:

FIG. 2

Signed and Scaled this seventeenth Of February 1976 [SEAL] A ttes t:

RUTH C. MASON C. MARSHALL DANN Commissioner of Patents and Trademarks Arresting Officer UNITED STATES PATENT OFFICE 5 CERTIFICATE OF CORRECTION Patent 63. 3 I I Dated n 9:

' Inventor (s) Martin E. Gersy 4 It is certified that error appears in the above-identified patent and that said Lettex s Patent are hereby corrected as shown below:

DRAWING ISICORRECTED TO READ:

FIG. 2

Signed and Scaled this seveii teen th D ay Of February I 976 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner nj'Patents and Trademarks

Claims

1. An ignition system having igniters, and a shaft driven during operative mode of said system, the combination comprising: first rotary switching means comprising a generally circular member driven by said shaft during said operative mode, said member having an outer periphery, an aperture at said outer periphery, and a plurality of first electrode means at said outer periphery positioned at regular intervals,; a plurality of transformers, each of the transformers having a primary and secondary winding, one of the primary windings being connected to only one of said first electrode means; and second rotary switching means comprising an arm one end of which is mounted on said shaft and the other end of said arm describing a circular path during said operative mode, and a plurality of second elecrode means, equal in quantity to said first electrode means, positioned at locations described by said circular path at regular intervals, one of the secondary windings being connected to only one of said second electrode means.

2. An ignition system having igniters, a plurality of inductive means and ignition selection means responsive to a driven shaft, the combination comprising: means for charging said inductive means during the non-firing period of all but one of said igniters, the means for charging comprises: first means having an outer periphery and an aperture at said outer periphery and being insulated from and coupled to said driven shaft; a first plurality of stationary members disposed about said Outer periphery and spaced from each other and from the first means; and means for providing electrical energy coupled to the first means; and means for discharging said inductive means, synchronized with the means for charging, during the firing period of any one of said igniters, the means for discharging comprises: second means having one end attached to said driven shaft and having a free end opposite to said one end, said driven shaft being in circuit with the second means; and a second plurality of stationary members disposed about the locus of the free end of said second means and spaced from each other and from the second means, each one of the second plurality of stationary members having associated therewith one of the first plurality of stationary members.

3. The invention as stated in claim 2: the inductive means being a plurality of transformers, each transformer having a primary winding, and a secondary winding with a larger number of turns than the primary winding, each transformer having one of the igniters associated therewith.

4. The invention as stated as claim 3: in each of the transformers one end of the primary winding is connected to one end of the secondary winding and to the ungrounded portion of its respective igniter, the other end of the primary winding is connected to its corresponding member of the first plurality of stationary members, and the other end of the secondary winding is connected to its corresponding member of the second plurality of stationary members.

5. The invention as stated in claim 3: in each of the transformers one end of the primary winding is at ground potential, and one end of the secondary winding is connected to the ungrounded portion of its respective igniter, the other end of the primary winding is connected to its corresponding member of the first plurality of stationary members, and the other end of the secondary winding is connected to its corresponding member of the second plurality of stationary members.

6. The invention as stated in claim 4, including: a diode connected between each of the first plurality of stationary members and its corresponding primary winding in series with the wire connecting such members and winding.

7. The invention as stated in claim 5, including: a diode connected between each of the first plurality of stationary members and its corresponding primary winding in series with the wire connecting such member and winding.