Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2531638 A
Publication typeGrant
Publication dateNov 28, 1950
Filing dateSep 23, 1948
Priority dateJun 21, 1943
Publication numberUS 2531638 A, US 2531638A, US-A-2531638, US2531638 A, US2531638A
InventorsMiller Raymond J
Original AssigneeMiller Raymond J
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Ignition circuit
US 2531638 A
Abstract  available in
Images(2)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

lNov. 28, 1950 R. .1. MlLLER IGNITION CIRCUIT Original Filed June 21, 1943 2 Sheets-Sheet l 272 7: Z 337mm Qaymond d. Mf//er ...IIISIIIIIIII w, a/M- Nov. 28, 1950 R. J. MILLER IGNITION CIRCUIT 2 Sheets-Sheet 2 Original Filed June 2l, 1943 443 445/ Roqmonc/ J Mil/er @ttor/M m W Mm n f r i 3 /l ww....n....wuwwwwmmwwwwmmw. xS V... .........n..l1. A .V 4 1 -s e Patented Nov. 28, 1950 UNITED STATES PATENT oEFlcE IGNITIN CIRCUIT Raymond J. Miller, Detroit, Mich.

'Original application June 21, 1943, Serial No.

491,584. Divided and this application September 23, 1948, Serial No. 50,720

8 Claims. 1

This invention relates to engines, and more particularly to improved ignition systems for engines.

In conventional ignition systems, the voltage is stepped up and is transmitted through single high tension leads to the spark plugs to fire the combustible charge in the cylinders of the engine. Single electrode spark plugs are employed, and the circuit is completed by enclosing the entire ignition system in metallic covers, or by utilizing the engine as a ground to complete the circuit. The entire engine and vehicle thus becomes a part of the ignition circuit and acts as a variable capacitor.

' In accordance with conventional practice, a single high tension coil is used for each engine. In multi-cylinder engines, this coil is frequently overtaXed because the reluctance will not permit the coil to completely collapse before the next impluse is imposed on-it to provide the necessary high voltage sparkto fire the neXt cylinder when the engine is operating at high speed. In certain high speed engines it has been necessary to employ two or more high tension coils per engine to prevent overtaxing the coils.

Considerable current from the high tension coils is lost before reaching the spark plugs through leakage from the high. tension wires connected to the spark plugs. The efficiency of ignition systems now in use is therefore considerably below that desired.

In ignition systems as presently employed, undesirable signals are emitted whenever the engine is running. These undesirable signals are emitted from:

1. The sparking of high tension current jumping from the rotating distributor arm to the successive distribution points.

2. The sparking at the spark plug electrodes.

In military vehicles, the enemy can establish listening stations and readily pick up these undesirable signals emitted from the ignition system. The exact location of a vehicle or a convoy of vehicles can thus readily be ascertained by triangulation from spaced listening stations. Accurate gun re can then be brought to bear cn the vehicle or convoy of vehicles.

These undesirable signals emanating from the ignition system interfere with radio communication, both sending and receiving, and cause distortion of the images in the operation of television sending and receiving apparatus.

' Efforts have been made to overcome these objectionable features by using Suppressors hooked within the circuits; by the use of shielding surrounding the wires and electrical units, and by bonding the component parts of the vehicle together to maintain good electrical contacts between all parts of the vehicle. These efforts have not been very successful because of the expense and time required in their installation and the diiliculty of maintaining them in proper working condition.

An object of this invention is to provide a closed circuit ignition system wherein the above enumerated disadvantages are eliminated.

A further object of the invention resides in the provision of an improved ignition system wherein low voltage current is transmitted by a distributor to a compact transformer associated with each spark plug of the engine.

Another object is to provide an ignition system for an engine wherein dual electrode spark plugs insulated from the engine are supplied by high voltage circuits, each of which is completely contained within its associated spark plug.

Yet another object resides in the provision of a closed circuit ignition system wherein lowY voltage current is induced and is transmitted through low tension wires to small transformers positioned on dual electrode spark plugs insulated from the engine.

A further object is to provide an ignition system wherein transformers having primary and secondary windings wound in a bell shaped manner extend down over the body portions of dual electrode spark plugs to produce directed magnetic fields to provide controlled electric sparks at the electrodes of the plugs, and produce a blow-out condition at the spark gap to provide sharper more controlled points of ignition.

Another object of the invention resides in the provision of an ignition system wherein it is unnecessary to employ continuous shielding, bonding or Suppressors to prevent the transmission of undesirable signals capable of indicating the location of the vehicle and interfering with radio or television transmission or reception.

Other objects and advantages of this invention will be apparent from the following detailed description considered in connection with the accompanying drawings7 submitted for purposesl of illustration only and not intended to define the scope of the invention, reference being had for that purpose to the subjoined claims.

In the drawings wherein similar reference characters refer to similar parts throughout the several views:

' Fig. 1 is an enlarged sectional view illustrating a dual electrode spark plug having a transformer associated therewith.

Fig. 2 is a bottom plan view of the spark plug 3 illustrated in Fig. l, taken substantially on the line 2-2 of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a longitudinal sectional view of a modied form of dual electrode spark plug.

Fig. 4 is a longitudinal sectional View illustrating another modified form of dual electrode spark plug.

Fig. 5 is a fragmentary sectional view illustrating a casing adapted to surround a portion of a dual electrode spark plug, to Protect it against the entrance of moisture.

Fig. 6 is a fragmentary sectional View illustrating an adjustable resistor member adapted to be interposed between an electrode of the spark plug and a source of electric current.

Fig. '7 is a view similar to Fig. 6 illustrating a modified form of resistor member.

Fig. 8 is a longitudinal sectional View illustratinga further modified form of dual electrode spark plug.

Fig. 9 is a sectional View taken substantially on the line 0 0 of Fig. 8, looking in the direction' of the arrows.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

One desirable form of dual electrode spark plug having the primary and secondary coils mounted thereon is illustrated in detail in Figs. 1 and 2. The spark plug 40 comprises a base member |00 having threads |02 whereby the plug may be secured in the combustion chamber of an engine, and a wrench receiving portion |04 preferably of hexagonal shape.

The inner electrode 54 preferably has a body portion |06 and is provided adjacent its bottom end with an enlarged outwardly flaring portion |08. The outer electrode 56 is concentrically mounted on the inner electrode 54 and is insulated therefrom by suitable insulators ||0, ||2 and H4., and is insulated from the base member |60 by means of a suitable insulator IIS.

The insulator ||0 preferably extends over the entire cylindrical body portion |66 of the inner electrode 54, and may be formed of any suitable material such for example as mica. The insulators I|2 and I4 may be concentrically mounted on the insulator ||G and may for example be formed of ceramic material.

It will be noted that the lower body portion of the outer electrode 56 is ared outwardly in the base member |00. The insulator H6 may for example be formed of mica and may be tapered in accordance with the taper of the lower body portion of the outer electrode 56 whereby the unit consisting of the inner and outer electrodes 54 and 55 with the insulators I I0, ||2, ||4 and ||6 may be securely bonded to the base member |00 by means of upper and lower flanges |8 and |20 positioned to overlie the insulator i I6.

Discs |22 and |24 formed of copper or other suitable material may be interposed between the insulator H2 and the lower surface of an inwardly directed ange |25 formed on the outer electrode 56, and the insulator |4 and the upper surface of the flange |25 to take up mechanical differential in the manufacture of the parts,

CII

The upper end of the outer electrode is provided with threads to receive the base of a coil supporting member |3| surrounding the plug. The member |3| is formed adjacent its upper end with a section of reduced diameter to receive an insulator |33 formed of any suitable material such as Bakelite.

Wrapped about the insulator |33 and the lower portion of the member I3| is the primary coil 36 wound with relatively coarse wire |36 as is customary. Surrounding the primary coil 36 is a core |33 formed of iron or steel or other suitable electrical conducting material.

The secondary coil 52 preferably formed of smaller wire |40 than the wire |36 of he primary coil 36 is wrapped about the core |38. The primary and secondary coils 36 and 52 are covered at the top by means of an insulator |42 formed of Bakelite or other suitable material having a section |44 of reduced diameter to lit within the core |38. A casing |48 is provided to overlie the insulator |42 and secondary coil 52 to function as an additional core to assist the core |38. The casing |46 is suitably secured to an upwardly directed flange |54 carried by the coil supporting member |32.

A furl |50 is positioned on the insulator |42 and connected through a wire |52 extending through the insulator |42 to the other end of the primary coil 36. The furl |50 may be separated from the pole |53 by means of a suitable portion |54 of the insulator |42, and from the casing |46 by means of a suitable insulator portion |56.

The core member |38 interposed between the primary and secondary coils 36 and 52 respectively, being of bell shaped contour, and the casing |46 surrounding the secondary coil 52 concentrate the magnetic lines of force. This concentrated electrical field induces a strong induction current in the secondary coil 52.

Opposite ends of the secondary coil 52 are connected to the inner and outer electrodes 54 and 56 of the spark plug 40. One end of the coil 52 may be connected. through a wire |58 embedded in the insulator |42 to a resistor' |60 engaging the end of the cylindrical body portion |06 of the central electrode 54.

The resistor |60 may be guided in a portion |62 of reduced diameter of the insulator |33, and may be yieldingly urged into engagement with the body portion |06 of the central electrode 54 by means of a spring portion |64 of the wire |58. The resistor |60 may be made of carbon or other good resisting material. Where a resistor similar to that illustrated is employed, the electrodes 54 and. 56 of the plug 40 will not be subjected to such prolonged current and will therefore be longer lived because the resistors tend to smooth out the electrical surge.

The other end of the secondary coil 52 is connected to the coil carrying member |3| as illustrated at |66. The flow of current is preferably from the secondary coil 52 through the central electrode 54, thence across the spark gap |68 to the outer electrode 56 and back to the secondary coil 52.

The inner and outer electrodes 54 and 56 and the coil supporting member |3| may be formed of any suitable material having good electrical conducting characteristics, such for example as steel.

It will be noted that this spark plug is thoroughly shielded against moisture and is advantageously insulated to prevent undesired elec- *fil 1.95565 Q1" ShQrt rcutnz. Greater voltage can therefore be exerted to fire the charge in the cylinder of the engine.

The entire circuit is self-contained and it is not necessary to use the engine or any other part of the vehicle as a ground. Since the vehicle is not used as a ground for the ignition circuit it is not effective as a variable capacitor, and the necessity for bonding the component parts of the vehicle together is entirely eliminated.

In view of the fact that low voltage current is transmitted to the transformers associated with the spark plugs, it is unnecessary to employ shielding on the spark plug wires to prevent leakage from the high tension wires as is now customary.

No spark gap is present in the distributor as the low intensity current is induced in the induction coils by movement of the magnet with reference to the coils. Undesirable signals from this source are therefore eliminated. The spark gap between the electrodes of the spark in the combustion chambers being insulated from the engine will not transmit undesirable signals as is customary with presently used ignition systems.

Fig. 3 illustrates a somewhat modified form of spark plug over that disclosed in Figs. 1 and 2. Corresponding parts have therefore been given corresponding reference numerals with the addition of 100.

It will be noted that the inner electrode 206 is shorter than the inner electrode of the plug illustrated in Figs. 1 and 2, and that the outer electrode 226 is provided with a plurality of spaced heat radiating fins 210, positioned beneath the threaded portion 230.

The lower portions of the inner and outer electrodes 206 and 226 have parallel, preferably angularly disposed side walls 212 and 214 respectively to define there-between a spark gap 216. The parallel spark gap 216 gives greater opportunity for the plug to clear itself in the event of fowling and will therefore frequently prevent short circuiting of the plug.

A transformer of the general type illustrated in Fig. l may be employed with the plug illustrated in Fig. 3, or it may be connected to conventional magneto or distributor circuits. When so used, the central electrode 206 is preferably connected to the high tension lead, and the outer electrode 226 is grounded back to the electrical source. A confined circuit is thus provided in conventional magneto or distributor circuits whereupon it is unnecessary to employ the body of the engine or vehicle to complete the circuit from the source of electric current such as a battery or magneto.

The spark plug illustrated in Fig. 4 is similar in many respects to that illustrated in Fig. 1. Corresponding parts have therefore been given corresponding reference numerals with the addition of 200.

It will be noted that the base member 300 is provided adjacent its upper end with screw threads 380 to receive a threaded plug 382 having an inwardly directed flange 384 to overlie the upper edge of the insulator 3|6 to clamp the component parts of the spark plug in assembled relation. The inner electrode 306 is provided adjacent its upper end with a threaded portion 386 to receive a threaded member 388 to engage the insulator 3| 4 and maintain the upper portions 0f the plug in the assembled relation. This plug may be readily disassembled for cleaning purposes or for the replacement of new elements.

The wire 315 may be connected through the resistor or contactor 36| with the central electrode 306, and the wire 311 may be connected to the outer electrode 326 as illustrated. I'he housing 38| is provided with a threaded ring 390 to which the wire 311 may be connected. The ring 390 may be screwed onto the threaded portion 330 of the outer electrode 326 to securely seal the upper end of the spark plug assembly.

If desired a shield may be positioned on the spark plug where the dual electrode plugs are employed without the transformers, and the high voltage current is transmitted to one of the electrodes of the spark plug. Fig. 5 illustrates one desirable form of shield 40| having a threaded end section 403 adapted to receive a furl 405 surrounding the casing 319 having the current carrying wires 315 and 311 housed therein. If desired the casing 40| may be split and have overlapping edges to securely seal the upper end of the spark plug against the entrance of moisture. The shield may be formed at the bottom end with an inwardly directed flange 401 to overlie the housing V38| of the embodiment illustrated in Fig. 19.

Fig. 6 illustrates a modified form of resistor element adapted to be interposed between one of the yelectrodes of the spark plug and the wire 4| connected to a transformer associated with the spark plug or to a high tension wire, where separate transformers are not employed at the spark plugs. A removable and replaceable resistor element 4|3 may be interposed between the electrode and a shell 4|5, connected to the wire 4| I, and shaped to receive the resistor 4| 3. A spring 4|1 yieldingly urges the resistor 4|3 into engagement with the electrode 406 of the Spark plug. The resistor 4| 3 may be removed and replaced by resistors of different lengths to vary the resistance, or resistors formed of different material but of the same length may be employed to vary the resistance introduced. The resistor 4|3 may advantageously be formed of carbon, powdered metal, tungsten or other suitable material.

Fig. 7 illustrates a further modified form of resistor wherein a resistor element 42| having a groove 423 formed adjacent one end is provided with a spring clip 42 5. The spring clip 425 may be introduced into a cylinder 421 formed in a threaded member 43| operably connected to one of the electrodes 406 of the spark plug. Resistors of this type may be formed of different material to provide the desired variation of resistance, and may also be formed of different lengths to provide the desired operating characteristics.

Figs. 8 and 9 illustrate a further modified form of spark plug having spaced parallel electrodes 435 and 431. The electrodes are positioned in a threaded base member 439 adapted to be secured in the cylinder of an engine to position the spark gap forming portions 44| and 443 of the electrodes 435 and 431 respectively in the combustion chambers of the engine.

The electrodes 435 and 431 may be insulated from each other and from the base member 439 and engine by any suitable form of insulating material such for example as stacked mica disks 445. It will be apparent that the lowermost disk is supported on shoulders 441 formed in the base member 449 and in the lower shanks of the electrodes 435 and 431. The upper end of the base member 439 is formed with an inwardly directed flange 449 to overlie disks of larger diameter and maintain the plug in the assembled relation.

It will be noted that the electrode 435 is somewhat longer than the electrode 431 to separate their upper ends and prevent short circuiting between the upper ends of the electrodes and to insure the formation of the charge firing spark in the spark gap between the portions 44| and 443 of the electrodes.

A ring 453 is positioned adjacent the top of the electrode 43'! and is contoured to overlie a. group of the disks 445 and maintain a desired pressure on the disks 445 between it and the flange 449 of the base member 439. The upper end of the electrode 431 is flared outwardly as illustrated at 455 over the ring 453 to insure good electrical contact therewith. The inner portion of the ring 453 may be cut out, and contoured mica or other suitable insulating disks 459 positioned therein as illustrated in Fig. 8.

A ring 135i may be positioned above the smaller disks surrounding the longer electrode 435, and the upper end of the electrode 435 may be ared outwardly as illustrated at 451 to maintain a desired pressure on the upper disks and thus insure good electrical contact therewith.

A transformer 463 similar to that illustrated in Fig. 1 may be employed with this spark plug, the low intensity contacts from the source of electrical energy being connected with opposite ends of the primary Winding. One end of the secondary winding of the transformer may be connected to the electrode 435 through a contactor 467 engaging the ring 46| engaging the electrode 435. The other end of the secondary winding of the transformer' may be connected to the electrode 43'! through the ring 453, threaded to receive the transformer 4553 as illustrated at 455.

It will be understood that if desired this spark plug may be used without the transformer as discussed above.

This application is a division of my application Serial Number 491,584, led June 21, 1943, now Patent 2,461,293 issued February 8, 1949.

I claim:

l. In a spark producing assembly, a central spindle terminating in a sparking electrode, a transformer having its primary winding surrounding said spindle, and its secondary winding surrounding said primary winding, a metallic casing surrounding said secondary winding, said casing having an extension surrounding said sparking electrode and constituting a co-operating electrode, and means connecting the ends of said secondary winding with said spindle and casing, respectively.

2. In a spark producing assembly, a central spindle terminating in a sparking electrode, a transformer having its primary winding surrounding said spindle, and its secondary winding surrounding said primary winding, a metallic casing surrounding said secondary winding, said casing having an extension surrounding said sparking electrode and constituting a cooperating electrode, means connecting the ends of said secondary winding with said spindle and casing, respectively, a pair of concentric terminal posts at the outer end of the assembly, and means connecting the ends of said primary winding to said posts.

3. In a spark producing assembly, a central spindle terminating in a sparking electrode, a transformer having its primary winding surrounding said spindle, and its secondary winding surrounding said primary winding, a metallic casing surrounding said secondary winding, said casing having an extension surrounding said 5 sparking electrode and constituting a co-operating electrode, means connecting the ends of said secondary winding with said spindle and casing, respectively, an attaching base for said assembly, and means for insulating said second electrode from said attaching base.

4. In a spark producing assembly, a central spindle terminating in a sparking electrode, a transformer having its primary winding surrounding said spindle and its secondary winding surrounding said primary winding, a second electrode surrounding said first-named electrode, and means connecting the ends of said secondary Winding with said spindle and second electrode, respectively.

5. In a spark producing assembly, a central spindle terminating in a sparking electrode, a transformer having its primary winding surrounding said spindle and its secondary winding surrounding said primary winding, a metallic casing surrounding said secondary winding, said casing having an extension surrounding said sparking electrode and constituting a cooperating electrode, means connecting the ends of said secondary winding with said spindle and casing, respectively, a pair of concentric terminal posts at the outer end of the assembly, and means connecting the ends of said primary winding to said posts.

6. In a spark producing assembly, a central spindle terminating in a sparking electrode, a transformer having its primary winding surrounding said spindle and its secondary winding surrounding said primary winding, a metallic casing surrounding said secondary winding, said casing having an extension surrounding said sparking electrode and constituting a co-operating electrode, means connecting the ends of said secondary winding with said spindle and casing, respectively, an attaching base for said assembly, and means for insulating said second electrode from said attaching base.

'7. In an ignition system for an internal combustion engine, the combination of a dual electrode spark plug and a transformer having primary and secondary windings comprising a central electrode, a second electrode concentrically mounted relative to the central electrode and cooperating therewith to form a spark gap, a base having external threads adapted to be received in the cylinder of the engine, insulating means between the central and second electrode and between the base and the second electrode, the primary winding concentrically mounted on said electrodes, spaced ttings operably connected to the opposite ends of the primary winding, the secondary winding being concentrically disposed relative to the primary winding, connecting means between one end of the secondary winding and the central electrode, and connecting means between the opposite end of the secondary vlinding and said second electrode.

8. In an ignition system, the combination of a dual electrode spark plug and a transformer having primary and secondary windings comprising a central longitudinally extending electrode, a second electrode concentrically mounted relative to the central electrode and cooperating therewith to form a spark gap, insulating means between the central and second electrode, a base having external threads adapted to be received in the cylinder of an engine, insulating means between said base and the second electrode, a transformer supporting flange threaded to the second electrode, a bell shaped primary winding supported by said flange and concentrically mounted on the electrodes, spaced fittings operably connected t to opposite ends of the primary Winding, a. secondary bell shaped winding being supported by said flange and concentrically disposed relative to the primary winding, connecting means between one end of the secondary winding and the central electrode and connecting means between the opposite end of the secondary winding and said second electrode.

RAYMOND J. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

Number 10 UNITED STATES PATENTS Name Date Orswell Dec. 14. 1915 Powell Oct. 21, 1919 Sullivan Dec. 18, 1923 Hooven Nov. 21, 1939 Robinson Dec. 16, 1941 Harkness et al. Jan. 21, 1947

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1164113 *Apr 26, 1907Dec 14, 1915Orswell Igniter CompanySparking plug.
US1319487 *Jan 15, 1919Oct 21, 1919 Spark-plug
US1477784 *May 20, 1920Dec 18, 1923Splitdorf Electrical CoSpark plug
US2180358 *Mar 9, 1938Nov 21, 1939Hooven Frederick JIgnition system
US2266614 *May 9, 1940Dec 16, 1941 Ignition system and spark plug
US2414692 *Nov 23, 1942Jan 21, 1947 Ignition system unit
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4509033 *May 12, 1983Apr 2, 1985Robert Bosch GmbhIgnition coil construction for engine ignition system
US6462637Nov 15, 1999Oct 8, 2002Itt Manufacturing Enterprises, Inc.Electrical connector
US6670740Aug 30, 2001Dec 30, 2003William W. Landon, Jr.High electrical stiction spark plug
US7256533Jul 27, 2004Aug 14, 2007Landon Jr William WHigh electrical stiction spark plug
DE3841931A1 *Dec 13, 1988Jun 29, 1989Ngk Spark Plug CoNiederspannungs-kriechentladungs-zuendkerze
DE3841931C2 *Dec 13, 1988Aug 20, 1998Ngk Spark Plug CoNiederspannungs-Kriechentladungs-ZŁndkerze
Classifications
U.S. Classification315/276, 313/138, 336/231, 174/152.00S, 313/134, 174/397, 315/185.00R, 338/66, 315/57, 313/140, 338/51, 313/137, 336/107, 313/144, 336/233, 313/141, 336/192, 315/58
International ClassificationH01T13/00, H01T13/44, H01T13/05
Cooperative ClassificationH01T13/44, H01T13/05
European ClassificationH01T13/05, H01T13/44