US1389048A

US1389048A - Ignition system

Info

Publication number: US1389048A
Application number: US660783A
Authority: US
Inventors: Dow B Hughes
Original assignee: Motor Ignition & Devices Compa
Current assignee: Motor Ignition & Devices Co; Motor Ignition & Devices Compa
Priority date: 1911-11-17
Filing date: 1911-11-17
Publication date: 1921-08-30
Anticipated expiration: 1938-08-30

Description

D. B. HUGHES.

IGNITION SYSTEM.

APPLICATION men nov. 11, my

Patented Aug. 30, 1921.,

mmx

UNITED STATES! PATENT OFFICE.

now :3. nnenns, or NEW YORK, N. Y., nssre von', BY mnsnn assronmrs, TO MOTOR wmrron a DEVICES COMPANY, A. CORPORATION or wEs'r vmoma IGNITION SYSTEM.

Specification of Letters Patent.

Patented Aug. 30, 1921.

Application flied November 17,1911. Serial No. 660,783.

To all whom it may con cern:

Be'it known that I, Dow B. HUGHES, a

citizen of the United States, residin at New York cit in the county of New ork and State of ew York, have invented a certain ignition systems, and especially in those systems wherein the igniting arc' is produced by a low tension current, and is preceded by an arc produced by a high tension high frequency current.

It has been proposed to ignite a mixture in the manner above stated by means of a suitable source of current, such as a magneto, a condenser and a disruptive discharge coil suitably connected to the source of current and to the spark plug or spark plugs.

- and by a circuit breaker so arranged that when the latter is closed it shortcircuits the magneto, and when opened, permits the condenser to be charged and thence discharged, and constitutes part of the discharge circuit of the condenser'with the gap at the circuit breaker serving as a primary spark gap for disruptive discharges of the condenser. The condenser thus discharges across the gap of the circuit breaker, and through the primary of the disruptive discharge coil, causing the high frequency currents to be in-- duced in the secondary of the coil, and causing the high tension high frequency are to be established at the spark plug. This are is then followed by an arc produced by the so-called primary or low tension current passing from the magneto.

The main object of the present invention is to provide an ignition system particularlty of the type above stated, which is more e ficient than those which have been tried out heretofore and wherein the electrical results are obtained in a more satisfactory manner.

More specifically, the invention aims to provide an ignition system having a circuit breaker which serves merely to short circuit and to open the short circuit of the source of current, and having means independent of this circuit breaker for forming the spark gap across which the condenser is disruptively discharged, Further, the invention aims to provide such an arrangement wherein the spark gap is traversed merely by the high' frequency high tension current from the condenser and draws no current from "the main source of current, as may be the case when the circuit breaker performs the two functions above stated.

The above objects are accomplished in a very effective manner y a system having a plrcuit breaker for short circuiting and openmg the short circuit of a magneto, so that the condenser may be charged at the desired intervals, and having also a separate spark gap which may have aparallel connection with the c1rcu1t breaker, this spark gap being traversed-by the high frequency condenser currents and having assoclated therew'ithsome ,means such as an auxiliary condenser for preventing the simultaneous passage of current across the gap from the mam source of current.

My lnvention may be further briefly summarized as consisting in certain novel comblnatlons and arrangements of parts which will be described in the specification and set forth in the appended claims.

In the drawings, Figure 1 is a diagrammatic representation ofa system arranged for a four-cylinder engine and embodying one of the preferred forms of my invention; and Fig. 2 is a similar view showing a modification. 4

Referring now to Fig. 1, 10 represents the source of current which in this case is an armature winding of a magneto here shown in the usual conventional manner. One terhaving in this instance four stationary con-,

tacts 12", each of which is connected to a spark plug 13. Between the distributer and tho magneto, Iprovide a condenser 14, and a disruptive discharge coil 15. The primary 15= and. the condenser 14 are in series relation and have one terminal connected to conductor 11 extending between the magneto and the distributer, and the other terminal grounded, so that the condenser and primary are in fact in parallel with the magneto. The secondary 15 of the disruptive discharge coil 15 is connected directly in circuit between the magneto and the distributer. It will be understood that the disruptive discharge coil has a low inductance,

inasmuch as it is without an iron core, and the ratio of turns in the primary and secondary is such as to result in an induced high frequency current of proper voltage to obtain the desired results.

At 16 is shown a circuit breaker which is arranged to short circuit the magneto, the circuit breaker having one terminal connected to the magneto or to the conductor 11 extending between the magneto and the distributer, and having its other terminal grounded. It will be understood that this circuit breaker, as well as the distributerare both operated by the engine at the proper speeds and proper relative speeds, the circuit breaker for a four-cylinder engine being driven at twice the speed of the dist-ributer.

When the circuit breaker is closed, the magneto is short circuited, and a certain amount of energy is stored in the magneto during the interval that the circuit breaker is closed. When the movable distributer arm 12 is in engagementwith one of the stationary contacts of the distributer, the circuit breaker, is opened and the ener y previously stored I in the magneto is a sorbed by the condenser, fully charging the latter. In ignition systems prior to my invention, and based on the principle of operation which has been explained above, the condenser is immediately disruptively discharged through the primary 15 and across the ap formed at the circuit breaker, the oscillations of the condenser which pass through the primary, causing a high voltage high frequency current to be induced in the secondary 15", which high frequency current causes an arc of low heat value to be established at one of the spark plugs so as to lead on or precede current from the magneto, this latter being of higher amperage than the high frequency current, and producing a hotter arc than that produced by the high frequency current. This method wherein the circuit breakerserves to short circuit the magneto and later as part of the condenser discharge circuit or as a spark gap device for the condenser is successful, but it has the disadvantage that part of the current from the magneto 1O follows across the gap with the high frequency current.

To avoid this objection, and to provide a system which is more efiicient and effective than the prior systems, I provide in the discharge circuit of the condenser a separate spark gap device 17 for the oscillating discharges of the condenser, this spark gap device preferably having terminals arranged at a fixed distance apart and being arrangedin parallel relation with the circuit breaker. In this case, one of the terminals of this spark gap 17 is connected to the conductor 11, and the other terminal is grounded.

To prevent the passage of the magneto current across the spark gap 17 at the time a it is traversed by the high frequency currents produced by the oscilla ng discharges of the condenser, I providn circuit with the spark gap 17, a condenser 18, which may be traversed by the high frequency currents, but obstructs the passage of the (11- i rect or substantially direct current from the magneto.

The method of operation will now be apparent. As with prior systems, the circuit" ,When the movable member of the distributer engages with the proper stationary contact of the distrlbuter, the circuit breaker is opened and the energy stored in the magneto rushes into the condenser and fills the same.

The condenser immediately .disruptively discharges with great rapidity, -not across the gap of the circuit breaker, but across the terminals of the spark gap 17 which is in parallel to the circuit breaker. In thesame manner as before, this causes high frequency high high .tension currents to be induced in the secondary 15 and results in the establishment of an arc of low heat value at the spark plug which is then followed by a low tension. current from the magneto, producing the hot are suitable for total ignition of the mixture. The circuit breaker will remain open substantially during the interval that the movable member of the distributer is in engagement with this particular stationary contact of the distributer, and as a result, the arc of high heat value may be sustained for a considerable period by the high frequency current, or high frequency arc. 1

With this arrangement,the circuit breaker may be opened a greater amount than in a system in which it serves as a spark gap for. the condenser discharges, and'the break at the circuit breaker will be cleaner and will not be accompanied by any material arcin The present arrangement has a further advantage in that it is unnecessary to adjust the circuit breaker very carefully to produce the desired results, it being immaterial just to what extent the circuit breaker is opened, inasmuch as the oscillating condenser discharges pass along the parallel connection, including the spark gap 17.

This gap 17 forms the return path for the induced or high tension high frequency currents, as well as for the primary high frequency currents.

tem for a multiple cylinder engine, that only a single condenser or only a single disruptive discharge coil be employed. I may desire to employ a single condenser with a number of disruptive discharge coils, one

. for each cylinder, or I may employ a separate condenser and a separate coil for each cylinder.

For example, in Fig. 2, I have illustrated a system having the arrangement last referred to In this system, I employ as in the first instance a main source of current 10, a circuit breaker 15, a separate spark gap 17 having connected in serles therewith the condenser 18, the two being arranged in parallel to the circuit breaker, and I employ also a similar distributer 12 which is connected as before to the magneto by means of the conductor 11. In this case, however, each of the stationary contacts 12 of the distributer are connected to a spark plug 19, to a separate disruptive discharge coil 20, and to a separate condenser 21, the secondary of each coil and the plug being series relation, and the primary and the condenser being in series relation, and the secondary and plug, and the primary and condenser being in parallel or in separate legs of a divided circuit. The method of operation is in this case similar to that of the system first described. and is as follows:

When a circuit breaker is closed, energy is stored in the armature winding, and when the movable member of the distributer engages one of the stationary contacts of the distributer, this energy rushes in and fills the particular condenser connected to that st a tionary contact of the distributer which happens to be engaged by the movable member thereof. The condenser is then imme diately discharged through the primary, through the condenser 18, and across the spark gap 17, with the same results as first described. As the movable member of the distributer engages the next stationary contact, by means of the next condenser and disruptive discharge coil, the same results are obtained .at the next spark plug. In each instance, however, the spark gap 17 and condenser 18, while preventing the passage of current from the magneto, form a return path for the oscillating discharges of the condenser, and also for the induced or secondary high frequency current.

Having thus described my invention, what I claim is:

1. In an ignition system, a spark plug, a source of current, a condenser, a disruptive "discharge coil having its primary connected to the condenser, and its secondary connected to the spark plu means for causing periodic charging o the condenser from the source of current and the discharge thereof through said primary comprising a circuit breaker'having connection with the source and with the condenser, said system having means for preventing the condenser d1scharging across the terminals of the circuit the source, a disruptive. discharge coil, hav- 111g its primary connected to the condenser and its secondary connected to the spark plug, means for controlling the charging and discharging of the condenser, comprising a circuit breaker operatively connected to the source and to the condenser, said condenser having a discharge circuit independent of the circuit breaker, and including a spark gap and a second condenser.

3. In an ignition system, a spark plug, a source of current connected to the spark plug, a condenser connected to the source and adapted to be charged thereby, a disruptive discharge coil having its primary connected to the condenser and its secondary connected to the spark plug, means for causing periodic charging and subsequent discharging of the condenser comprising a circuit breaker connected to the source so as to short-circuit the same and to open the short circuit, said condenser having a discharge circuit independent of the circuit breaker and including a fixed spark gap device across which the condenser may be disruptively discharged, said spark gap device being connected to the system in parallel to the circuit breaker.

4. In an ignition system, a spark plug, a main source of current, a condenser connected to the source and adapted to be charged thereby, a disruptive discharge coil having.

its primary connected to the condenser and Its secondary connected to the spark plug,

means for causing periodic charging and subsequent discharging of the condenserco'inprising a circuit breaker connected to the source so as to periodically short-circuit the same, said condenser having a discharge circuit independent of the circuit breaker and including a spark gap device across which the condenser may be disru tively discharged, said spark gap device having associated therewith means for preventing the passage of current fromthe main source of current across said spark gap. device.

5. In an ignition system, means for forming an arc of low heat value by a high tension high frequency current which is followed by an arc of high heat value produced by a current of comparatively lowtension, comprising a spark p ug, a source of current adapted to be connected to the spark plug, so as to supply the low tension current, a condenser connected to the source, a disruptiye discharge coil havmg a primary connected to the condenser, and a secondary connected to the spark plug, a circuit breaker for short-circuiting the source and for opening the circuit so as to cause the condenser to be periodically charged and thence discharged, said condenser having a discharge circuit independent of the circuit breaker-including a fixed spark gap for causing the a condenser to be .disruptively discharged through the primary.

6. In an ignition system, a spark plug, a source of current, a condenser connected to the source, a disruptive discharge coil having its primary connected to the condenser and its secondary connected to the spark plug, means for controlling the charging and discharging of the condenser, comprising a circuit breaker operatively connected to the source and to the condenser, said condenser having an independent, normally open, discharge circuit adapted to become closed when subjected to a predetermined potential surge. a

- 7. In an ignition system, a source of current, a disruptive discharge coil, a condenser connected to the source through the primary oi" said coil, a spark plug connected to the secondary of said coil, a circuit breaker operatively connected to the source and the primary of said coil, said condenser having an independent, normally open, discharge circuit adapted to become 010 (1 under a predetermined surge of potential.

In testimony whereof, I hereunto affix my signature in the presence of two witnesses. DOW B. HUGHES. Witnesses:

H. R. SULLIVAN, A. F. KwIs.