US1217484A

US1217484A - Magneto ignition system for internal-combustion engines.

Info

Publication number: US1217484A
Application number: US61518411A
Authority: US
Inventors: John Lewis Milton
Original assignee: Motor Ignition & Devices Co
Current assignee: Motor Ignition & Devices Co
Priority date: 1911-03-18
Filing date: 1911-03-18
Publication date: 1917-02-27
Anticipated expiration: 1934-02-27

Description

l. L. MILTON. MAGNETO IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION HLED MAR. 1a. 1911.

1 217,484. Patented Feb. 27, 1917.

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w W 071/72 ZJZi/Ltmw W W B W y Attorneys J.- L. MILTON.

MAGNETO IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED MAR. I8, 1911.

1,217,484. Patented Feb. 27, 1917.

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Witnesses. fizvenzfor W m r JFwY/L. Mbiforo W 7 I 5/ Atorrzeys J. L. MILTON.

MAGNETO iGNlTlON SYSTEM FOR INTERNAL COMBUSTLON ENGINES.

APPLICATION r1120 MAR. 18. 1911.

1,217,484. Patented Feb. 27, 1917.

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APPLICATION FILED MAR. I8, I911.

Patented Feb. 27,1917.

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UNITED STATES PATENT omuon JOHN LEWIS MILTON, OF TIFFIN, OHIO, ASSIGNOR T0 MOTOR IGNITION & DEVICES COMPANY, A CORPORATION OF WEST VIRGINIA.

MAGNETO'IGNITION SYSTEM FOR INTERNAL-COMBUSTION ENGINES.

Specificatidn of Letters Patent.

Patented Feb. 27, 1917.

To aZZ whom it may concern:

Be it known that 1, JOHN L. MILTON, acitizen of the United States, residing at Tifiin, in the county of Seneca and State of Ohio, have invented a certain new and Improved Magnet-o Ignition System for Internal-Combustion Engines, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to magneto ignition systems for internal combustion engines and its object is to provide means for producinga spark which will be hotter and larger than the sparks produced by the systemsheretofore known and commonly used, without involving the use of more apparatus and without incurring prohibitive expense.

An instance of my invention is illustrated in the accompanying drawings, in which Figure 1 is a diagrammatic representation of the circuit;

Fig. 2 is an end elevational View of the magneto machine which might be employed;

Fig. 3 is a view similar to Fig. 2 with the cover plates removed so as to reveal the construction of the timer and the distributer;

Fig. 4 is a vertical axial sectional View of the generator and the distributor and timer carried thereby; and

Fig. 5 is a detail view showing a mecliani cal embodiment of the special spark gap termina-ls referred to.

Like reference characters are applied to the same parts throughout the various fig- Referring first to Fig. 1, it will that the current is supplied by means of a generator G which is provided with the rotatable core R and the armature coil W wound thereon. One terminal of the windfour-cylinder engine and in one instance I be seen I have shown a structural embodiment of the spark plug. The current generated by the generator G is a low-tension current and in order that a high-tension current mav be supplied to the main spark gap terminals 8, s, I provide a transformer coil C, comprising a primary winding P and the secondary winding S, which is of such construction that it may withstand considerable heat and may therefore be mounted, by means of a. bracket B, directly on the spark plug. \Vhen the transforming means is thus so closely associated with the spark plug the considerably greater part of the circuit is required to carry merely a low-tension current. This transformer is preferably coreless and the primary winding is disposed outside the secondary winding. The primary winding comprises 12'} turns of No. 20 copper wire and the secondary winding comprises 850 turns of No. 30 copper wire. The

terminal T is common to both windings and the terminal T forms the other terminal of the primary winding, while the bolt M forms the other terminal of the secondary winding. The bolt M is connected by means of a clip N with the conducting post passing through an insulating sleeve in the spark plug and terminating in one of the terminals of the associated spark gap.

Each of the transformer coils has the terminal which is common to both the primary and secondary windings connected with a respective contact of the distributor. The other terminal of the secondary winding, as before stated, is'connected with one of the terminals of the spark gap while the other terminal of the spark gap is grounded, as indicated. The other terminal of each primary winding is connected to a conductor .g which leads to the stationary contact h of the timing device. This timing device is provided with the movable contact k which is subjected to the action of a rotary cam 0 and is grounded as indicated in the drawing.

The timing device is shunted by a branch circuit which includes a condenser E and a special spark gap X, this spark gap being adjustable so that the most effective size may be secured. The condenser E is preferably about 2 inches wide by 3 inches long and comprises about 8 sheets of tin insulated from each'other by means of split mica. A

' surrounding the bearing 13.

condenser F is connected in bridge of the generator winding. This condenser is of about the same construction as the condenser E except that it comprises about 12 sheets of tin.

The magneto machine which I have illustrated diagrammatically at G in Fig. 1 and which is shown in some detail in Figs. 2, 3 and 4 is a model D Splitdorf Standard machine except that the distributer has been modified somewhat. T have tried this magneto in connection with the system illustrated in Fig. 1 and hereinbefore described and, finding that excellent results were obtained, it make mention of a specific form which T have employed and of the sizes of wire and sizes of condensers, in order that those skilled in the art may be fully informed.

The illustrations, Figs. 2, 3 and 4, are full size and are drawn substantially to scale. The pole frame is indicated at 6 and the four horseshoe magnets which are associated therewith are shown at 6, 6. On one side the pole frame is provided with an end plate 7 which is secured thereto and to the adjacent magnets in any suitable manner and which provides the bearings for the armature shaft and the distributer shaft as will be pointed out presently. On the other side the pole frame is provided with a small end plate 8 which is secured thereto in any suitable manner. The armature is illustrated at 9 and is mounted upon

trunnions

10 and 11 which are journaled in

suitable bearings

12 and 13 in the respective side plates. The trunnion 10 is adapted for the reception of a gear or belt wheel by way of which it may be driven. The armature winding is illustrated at W. One terminal thereof is grounded to the machine and the other is connected by means of a rod 15, extending through the trunnion 11 but insulated therefrom by means of a sleeve 16 with brushes 17. 17 which make electrical connection with the inside of a stationary cup 18. This cup carries the binding terminal 19 which will be referred to later.

The trunnion 11, where it extends beyond its bearing, is provided with or is formed into a cam 0 with which is associated a follower roller 21 mounted upon a follower arm 71: pivoted at 23 to a cup structure 24 which'is slipped on over the circular wall A helical spring 25 tends to hold the follower down upon the cam and a leaf spring 26, secured to the inside of the cup, assists in this behalf. The follower arm in forms the movable member of the timing device and the stationary member [L which is carried by but insulated from the cup, is associated therewith. This stationary member is in the form of a screw, which may be set in any adjusted position, mounted in asupporting 'must be geared to piece 28 secured to the cup by means of a bolt 29 but insulated therefrom by means of insulation 30. A binding post 31 is supported with the piece 28 and is electrically insulated with the stationary contact. The binding post 32 affords means for securing a conductor to the magneto frame and in this way electrical connection to one terminal of the armature winding and to the movilllle member of the timing device may be lad.

The trunnion 11 carries a pinion 33 which meshes with a gear 34 carried upon a shaft 35 mounted in

bearings

36, 36 set in aboss 37 on the end plate 7. This gear carries the insulating block 37 upon which is mounted a conducting plate 38 and the wiping contact springs A, A. An insulating cover 40 is secured over the gear and the insulating block carried thereby and this cover carries the four contacts a, b, c and (Z which are so disposed asto be equidistant from the axis of the gear. The wiping springs A, A are so positioned that as they revolve they may engage with the four contacts and in this way the distribution of the current to .the various cylinders of the associated combustion engine is secured. The insulating cover 4( is provided with an axial plug 41 which is provided with a central socket 42 in which a plunger brush 43 is confined against the tension of a coiled spring. This plunger brush makes contact with the member 38 and consequently is electrically connected with the wipers A, A. A connector 43 connects the binding post 19 with the plug 41 and in this way one terminal of the armature winding is connected with the rotatable member of the distributer.

. A mechanical embodiment spark gap X is illustrated in Fig. 5. It is convenient to mount two conducting

plates

44, 45 upon an insulating block 46 which may be secured to the side of the magneto machine by means of a screw 47. The conducting

plates

44 and 45 are provided with

lugs

48 and 49 respectively and each of these lugs is provided with a contact terminal member 50. One or both The condensers E and F are shown as disposed together within the horse-,

shoe magnets.

Since spark plugs are provided for a fourcylinder engine, the distributer brush A the armature of the generator m a two to one ratio so that the armature may make two complete revolutions during a single revolution of the brush. As-

suming the distributer blade to be in electrical connection with any one of the contacts of the distributer it will be seen that the current wave generated upon rotation of the armature may be traced from one terminal of the winding W to the distributer brush A, thence through the distributer contact I), thence through the primary winding P of the associated transformer coil, thence through the conductor 9 to the stationary contact of the timing device or interrupter, and then through the movable member In W thereof and back to the other terminal of the winding WV. The cam mechanism is timed to open the interrupter contacts slowly when the spark is to be produced in the engine cylinder. The timing is arranged so that these contacts will be opened at or reasonably near the peak of the current wave set up in the generator. I do know that a tremendously hot and powerful spark is caused to jump between the spark contacts of the plug and apparently at the same time a very small spark jumps between the contacts of the spark gap X. The distance between the contacts of the gap X is preferably small. Although the exact pathspf the primary and secondary currents may not be determinable with absolute certainty, I find that when the circuit breaker is opened,

either one or both of the condensers disruptively discharges across the fixed spark gap and through the primary of one of the coils, so that a high frequency current traverses the primary, causing a high frequency current of higher voltage to be induced in the secondary and to jump the gap of the corresponding spark plug, and causing a relatively low voltage, high amperage current from the magneto or source to follow the are which is produced at the plug by the induced high frequency current, resulting in a flaming arc of high heat value. It is to be noted that as each transformer coil is coreless, the fixed spark gap and one or both of the condensers and the primary of a coil are in a series circuit of low,impedance so that the condenser or condensers may disruptively discharge therethrough;

Additionally, it should be noted that the secondary of the coil and spark slug are likewise in a circuit of low impe ance so that they may be traversed by the induced high frequency current, and as this circuit including the secondary and plug, is connected by the distributer directly to the magneto, current from the source may readily flow across the gap of the plug when its resistance is reduced by the induced highfrequency current. The sparking between the contacts h and 1c is very slight.

' It might be well to mention in connection with the other details that the transformer coils C of this system are of the kind described in my copending application, Serial No. 591,930, filed November 12, 1910. They are about 2?; inches in diameter and about 5 of an inch in thickness.

\Vhat I claim as new and desire to secure by Letters Patent is:

1. In combination in an ignition system, a source of current, a spark plug, a primary coil, a secondary coil, a condenser connected to the source, a fixed spark gap, said condenser, spark gap and primary coil being in a circuit of low impedance, and said secondary and spark plug being in a circuit and having a connection with the source.

2. In combination in an ignition system, a source of current, a spark plug, a primary coil, a secondary coil, a condenser connected to the source, a fixed spark gap, said condenser, spark gap and primary coil being in a circuit through which the condenser may discharge, said secondary coil and spark plug being in a circuit and having a connection with the source, and a circuit breaker connected to the source and adapted to open a) and close a circult including the latter.

3. In combination in an ignition system, a source of current, a spark plug, a primary coil, a secondary coil, a condenser connected to the source, a fixed spark gap, said condenser, spark gap and primary coil being in a circuit through which the condensermay discharge, said secondary coil and'spark plug being in a circuit and having a connection with the source, and a circuit breaker adapted toopen and close a circuit including the source,-said spark gap and condenser being in shunt to the circuit breaker.

4. In combination in an ignition system, a source of current, a spark plug, a primary coil, a secondary coil, a condenser connected to the source, a fixed spark gap, said condenser, spark gap and primary coil being in a circuit of low impedance, said secondary coil and spark plug being in a circuit and having a connection with the source, and a secondcondenser connected between the terminals of the source.

5. In combination in an. ignition system, a source of current, a spark plug, a primary coil,'a secondary coil, a condenser connected to the source, a fixed spark gap, said condenser, spark gap and primary coil being in a circuit through-which the condenser .may' discharge, said secondary coil and Fits a condenser connected to the source and adapted to be disruptively discharged, a fixed spark gap, a highfrequency coil including a primary connected in series relation with the condenser and spark gap, and a secondary in series relation with the spark plug.

7. In an ignition system, in combination with a spark plug, means for producing at the spark plug a high frequency are followed by a hot low tension arc comprising a source of current connected to the plug, a condenser connected to the source and adapted to be disruptively discharged, a fixed spark gap, a high frequency coil including a primary connected in series relation with the condenser and spark gap, and a secondary in series relation with the spark plug, and a circuit breaker for opening and closing a circuit including the source.

8. In an ignition system, in combination with a spark plug, means for producing at the spark plug a high frequency are followed by a hot low tension arc comprising a source of current connected to the plug, a condenser connected to the source and adapted to be disruptively discharged, a fixed spark gap, a high frequency coil including a primary connected in series relation with the condenser and spark gap, and a secondary in series relation With the spark plug, and a circuit breaker for opening and closing a circuit including the source, said condenser being connected in shunt to the circuit breaker.

ted to be disruptively discharged, a

9. In an ignition system, in combination with a spark plug, means for the spark plug a high frequency are followed by a hot low tension are comprising a source of current connected to the plug, a condenser connected to the source and adapted to be disruptively discharged, a fixed spark gap, a high frequency coil in cluding a primary connected in series relaand spark gap, and

producing at tion with the condenser a secondary in series relation with the spark plug, and a circuit breaker for opening and closing a circuit including the source, said condenser and spark gap being in shunt to the circuit breaker.

10. In an ignition system, in combination with a spark plug, means for producing at the spark plug a high frequency are followed by a hot low tension arc comprising, a source of currentconnected to the plug, a condenser connected to the source and adaptfixed spark gap, a high frequency'coil including a primary connected in series relation with the condenser and spark gap, and a second ary in series relation With the spark plug, and a second condenser connected across the terminals of the source.

In witness whereof, I hereunto subscribe my name this 14 day of March, 1911.

JOHN LEIVIS MILTON.

Witnesses:

ALEX. KISKADDIN, EUGENIA K. ADAMS.