US1376846A - Ignition system - Google Patents

Description

R. H. WHSLER.

IGNITION SYSTEM. APPLICATION FILED MAY 31. 1919.

Patented May 3, 1921.

carbon 'depositthe spark so produced isso thin and weak that it will not. afford satisl l v the secondary wi'ndin 16, forming part of 'GiI'cuitfB,.a .l current o higher voltage; which UNITED STAT-Es RALPH H;

PATENT oFFlcE-e.

wHIsLEn, on nETEoIT, MICHIGAN, AssIGNoE To EssEx-Morons, orl DETROIT, MICHIGAN, A CoEronATIoN or MICHIGAN.

IGNITION SYSTEM.

' To all whom 'it may concern:

Be it known that I, RALPH H. WHISLER, a citizen of the United States, residing at Detroit, county of Wayne, State of Michian, have invented a certain new and useful mprovement in Ignition Systems, of which the following is a specificatiomreference behad therein to the accompanying drawy invention has for its object an improvement in an, ignition system of the type ordinarily employed for ignitmg the charge of an internal combustion engine. The particular object of the invention is to provide a system which will be less liable to be short circuited at the spark plug by the accumula- I .tion of oil, carbon, soot and theflike, and

furthermore to provide a system, the sparks produced by which will be best 4.adapted to produce a complete andinstantaneous ignition of the explosive charge.

Heretofore especially in multiple cylinder internal combustion engines, Vgreat diflif Culty has been experiencedowing to thel fact that carbon and oil accumulates o n the spark plugs and short-circuits the spark plug so that' the system fails to' o erate. This tendency vis particularly troub esome in the present high speed internal combustion engines operating on'a liquid hydro-carbon of relatively poor quality. The fouling of the spark plugs is especially noticeable in the end cylinders of six and twelve cylinder engines.

t has already been proposed to produce at the points of the spark plug, a spark of extremely high lfrequency and highvoltage since such aspark is nota-ifectedfby the ac-V cumulation of carbon and oil, but I have found that whilesuch a sparkjumps the air gap between the sparkplug points in pref-- erence to passing through thecarbon deposit and therefore is not short' circuited by the factory ignition Vof -the charge- My, present invention provi system which overcomes the diiiiculties] 'If have heretofore experienced with va high fre'- quency high voltage .ignitionils stern .andf produces a. sparkat theplug whiyclijls very from the following-'description-whenjtakn Specificatiouof Letters Patent.

vsince certain des anfigxivition "fthrough the doublesparkgap niarywilldng 18 ofthe disru tive discharge t y Patented May 1921'. j Application md May. 5.31, 1919. Serial No. 301,071.

in connection with the accompanying draw#v ings, and the novel features thereof will be pointed out and clearly defined inthe claims' at the close of this specification. In the drawingsFigure 1 is a diagram showing my inventiony embodied in an ignition system supplied with 4current from atension magneto. "1

Fig. is al detail view of the `double spark gag unit.;-

eferring now to the drawings,`fFig. 1, the

vignition lsystem 'embodying my invention comprises threebircuits conveniently designated A, B and- C. The circuit A in the form shown in the drawings .contains a storage battery 11, a: circuit breaker 12 operated time with the engine, as for instance, by a cam 13, a condenser 14 connected across the terminals of the circuit breakerand the primary winding 15 of an induction coil.

The second' circuit contains the secondary Winding 16 of said induction coil, a conldenser 17 2 the primary winding 18 of a disruptive discharge coil and a fixed spark gap D -the construction and functions of which will'be hereinafter described. The third circuit C contains the secondary winding 19of said disruptive discharge coil and the electrodes 20, 21 of a spark plug 22.l 'The shell of the spark plug is grounded as shown at 23.- vThe second vcircuit B is preferably grounded as shown at 24 and 25. It will be understood that I do not limit myself to the details of arrangements of the three circuits eral as follows:l

The current from variationswill naturally occur Vto those' skilled in the art.

the battery being' broken v in time withthe en ine bythe circuit` breaker 12, energizes t eywrlimary winding 15.1of the induction coil. is Aproduces in charges the condenser 1 7. and discharges and the priios coiLQLThe' ls ark ap'7D"'a condenser 17 v'quen'cy voscillation `in the primary winding 18. This'. high frequency oscillation of mod- "Y ate voltage the winding 182,01.Y

im@ the' e ecm prodiieiega high fre'- l lio' circuit B produces 'in the ,secondary winding 19 in the third circuit C a corresponding current of equal fr uen'cy and extremely high voltage, and thls current is discharged across the points 20, 21 of the 'sparkplug. l In Fig2 is shown an exactly slmllar system except that theimoderate voltage current of circuit B is produced by means of a magneto- E havin a circuit breaker 26 and condenser 27 int e usual form.

The spark gap D previously referred to a double spark gap. It comprises a point 30 mounted onl a bracket 3l and adjustable by nuts 32, 33. A t 34 is shown another similar point mounted on a bracket 35 and similarly adjustable by nuts 3'6, 37. Between the two l 'polnts 30 and 34 is located another spark point 38 also mounted 'on a bracket 39. The

s ace between points 30 and 3'8, which space have designated a is very much greater than the space between the points 38 and 34 ,which space has been designated b. In prac- V tice, the gap b is made about one thousandth gap adjusted as described with one (,001) of an inch, while the gap a is about fifteen thousandths (.015) of an inch.

When employed with the doublel spark gap very much narrower than the other, a very remarkable improvement' in the system is' found.' The spark produced is very heavy, fat and-hot, and will not only pierce paper but ignite it. The difference in the running of the engine is also very noticeable.

While it is not possible tofstate with vab- 'solute certainty the reason why the insertion of this double spark gap inthe second circuit of a three circuit ignition system produces the remarkable improvement in the results which I have described, I believe it results from the following facts justed under all working conditions.

The operating voltage of the system is controlled by the gap asince the condenser 17 must be charged to a potential sufficient to jump the gap. This gap is therefore adso as to produce a spark at the plug If a single spark gap is employed, the air path between the two contact points is heated by the first dlschargeto such 'intensity that itpractically forms a short circuit between the two points and the remainder of the energy stored in the coil 16 and condenser 17 is' discharged acrossthe points. When a second spark gap, adjusted as described, is" employed, the points are so near together that after the passage of the first series of hlgh frequency sparks has occurred, the

4h eat is carried away so rapidly by the rela vtively large. masses of the gap points that no shortcircuit can be built up and the circuit is almost immediately interrupted. However, -since the coil 16 still-contains energy, it againcharges the condenser until the gaps c and?) break down and another shower of sparks'oc'curs both at the gap andat the spark plug. This How is, however, again interrupted by the absorption of heat by the gap points. These occurrences are repeated until theenergy remaining in thel secondary coil 16 is insufficient to jump the wide gap a. All of theseA occurrences which are practically instantaneous take place in a period of tlme too short for ordinary observation, .but if observed by means of rotating mirrors, it is found that when a single gapis used, Vone spark is produced followed by what appears to .be a purple or bluish streak which I believe to be the discharge produced .by the short circuiting of the gap points. On the contrary, when the double spark gap, ar-

ranged as described, is employed, there are seen in the ymirror successive bright sparks which correspond to the sparks observed when the single gap is used and insteadfof the bluish streak formed by the short circuit discharge, there are a series of from ten to' one hundred additional sparks. In

other words, the energy which was wasted' by reason of the short circuit discharge, is now employed in producing what for conveniencel may be termed a series of secondary high frequency sparks which give to the sparks at the spark plug the heavy, fat appearance which, as'is well known, is extremely desirable.

But whether the foregoing ex lanation of the operation be correct or not, have found 4by yobserving the operation of thev device under different positionsof the gap points, first that the` voltage of the discharge is controlled by the adjustment of the wide gap, and second, that the number of secondary sparks produced can be varied by changing the adjustment of the narrow gap.

The introduction into the three circuit high frequency high tension ignition system of thel double discharge gap herein. described, converts the system into a lhighly effective and thoroughly ractical ignition system for general use. ractical experiencewith this ignition system has proved 'that it will fire the mixture under almost any-condition which may obtain in the cylinders and that so far as I'have been able the engine, said discharge gap the discharge coil and the'electrode's of a spark plug in the combustion chamber of comprising pairs of gap point/s inl series, one pair of said gap points being spacedl farther apart lthan another air.

2. An ignition system of an internal com-l bustion englne com rlsing three circuits,

. spark timing means n one of said circuits,

there being mi the first circuit the primary of an induction'coil and means for producing therein a varying 'flow of current; there being in the second circuit the secondary of said induction coil a condenser charged thereby, a discharge gap and the primary of a disruptive dlschar e coil; and there being in the thirdcircult the secondary of the discharge coil and the electrodes of a spark plug in the combustion chamber of the' engine, said discharge gap comprising pairs of gap points, one pair being adjusted Wide enough to cause the condenser to discharge at the desired voltage and another

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