US1368946A - Electrical systehl - Google Patents

Description

1. K. LEIBING. ELECTRICAL SYSIEM. APPLIICATION FILED NOV. 9, 1917. 1,368,946.. Patented Feb.15,1921.

2 SHEETS-SHEET lm z//vi'ra ubsEPH 1g. LE/B/HE JOSEPH K. LEIBING, OF NEWARK, NEW JERSEY, ASSIGNOR TO TBICAL COMPANY, OF NEW 5 srm'rnoar rang- NEW JERSEY.

ELECTRICAL SYSTEM.

incense.

Specification of Letters Patent.

Application filed November 19, 1917. Serial Ito. 202,759.

the ignition of gas engines employed on autovehicles, although not limited to such use. In the battery ignition systems in commercial use at the present time, the spark coils are, of necessity, very much of a compromised design, that is to say, a battery coil designed to give sufiicient heat energy at high speeds of the engine with which it is used will draw an abnormal amount of pri mary current at low speeds with consequent destruction of the breaker points and a drain on the battery or other energy source supplying current to theignition system. It is generally understood that in the make and break system a coil designed for certain given speed is not the best for some other speed. A coil, therefore, designed to .draw a permissible amount of current at low speed will lose a large amount of its secondary heat energy at high speed.

It is the principal object of my invention to improve the igniting characteristics of the spark coil at the higher engine speeds by suitably increasing the heat power or energy of the spark discharges, without correspondingly increasing the maximum current value attained in the primary amperage and consequently to make the energy per spark less affected by the engine speed. Stated in another way, my object is to suitably raise the speed limit above that usually obtained, for equal valuesof maximum current, in the case of the common and well known method of simply making and breaking the primary circuit of ordinary induction coils. In order to break down a given dielectric or insulating medium by disruptive discharges, it is known that not only must the gap voltage be sufliciently high, but also a certain minimum amount of energy must be available; for when the available energy'is insufiicient, it is all absorbed as merely electrostatic strains and slight corona efiects at the terminals, instead of disrupting the medium. The gap or secondary voltage is of course increased by increasing the number of secondary turns; the available energy, however, is not increased by the secondary turns but depends upon the primary voltamperes, or in other words, the energy stored in the magnetic field. Increasing the secondary turns beyond a certain limit is therefore of no avail, as the spark will fail to pass 1n all cases whenever the available energy 111 the primary falls below a certain minimum.

Providing then that the number of secondary turns is suiiiciently great, that apparatus which at high speeds has the greatest energy available in the primary, will also have the highest limit in operative speed, other things being equal. By showng that the primary energy at high speeds 1s theoretically greater in the case of my invention than in the case of common type inductlon coils, usin equal-maximum current in both cases, I wi 1 therefore consider it as sufiicient demonstration that the heat in the sparks at high speeds in actual operation 1s also greatest for my invention; which conclusions I have also proven by experiment.

In the appended -drawings, Figure 1 shows in diagrammatical form the means whereby I secure greater spark energy at high speeds, and in which also the energy per spark is less affected by the engine speed than in the common make and break types; Figs. 2 and 3 show modifications of the means illustrated in Fig. 1. Fig. 4 shows a special form of circuit breaker construction adapted for operating the apparatus represented by Figs. 1, 2 and 3 more efliciently under some conditions than the breaker shown in Fig. 1. It will be apparent however to those skilled in the art, that various other forms of circuit breakers may be used, and it is not my intention to limit myinvention to any particular form or type of circuit breaker. Figs. 5, 6 and 7 are descriptive diagrams intended to illustrate some of the theoretical considerations which afiect the operation. Fig. 8 illustrates one form of combined induction and accumulator coil construction.

Before describing the functions of parts illustrated in the drawings they will be more readily understood if I first explain some theoretical considerations which apply in the two respective cases, 2'. e. (1), the com- Patented Feb. is, roar.

mon type of make and break ignition; and (2 the system of my invention.

he case of the common type make and break ignition will be considered first. As is well known, after closing the primary circuit by the breaker, the current does not rise instantly to its full or finalvalue, but instead requires a measurable time to attain any particular value between zero and the ultimate E/R limit. This is due to the counter E. M. F. generated by the primary self inductance; the manner of rising from zero current value being according to the well known curve shown in Fig. 7. In this figure, R is the primary circuit resistance ohms), L the coeflicient of self-induction henries), and T the time interval after closing of the primary circuiti As R and L for any particular coil will usually be of a more or less fixed value, the time interval T can be regarded as the only variable affecting the value of the independent quantity RT/L; hence whether this latter will be large or small at any instant depends mainly upon whether T be large or small. \Vith large time intervals, 2'. e., low engine speeds,

the value of RT/L becomes relatively great, and the current then has time to attain practically 100% of its E/R limit; but with the higher engine speeds, T, and consequently RT/L, become proportionately less, forcing the value attained by the current continually further below the E/R limit. so that at 'high speeds the value attained by the current may easily become considerably less than 50% of the E/R limit.

As will be seen by reference to Fig. 7 the curve for current rise approximates a straight line function of the independent variable RT /L for all current values from zero up to about 50% of maximum; beyond which point the curve continually bends over toward parallelism with the horizontal. The

cause for this bending over of the curve is the effect of ohmic drop (IR) in the primary circuit, which of course increases as the current rises. Were there no ohmic drop in the circuit, (2'. 6. R20), instead of approaching a limit the current would goon increasing indefinitely simply as a straight line function of ET/L; or more simply, the current at any instant would be directly proportional to T. In this imaginary case of zero ohmic drop, all energy drawn from the source during each interval would necessarily become .stored in the form of magnetic energy, since in this case there could be no resistance dissipation.

Since myinvention-is chiefly concerned with what occurs at the higher speeds, that is, those conditions giving current values considerably below the E /R limit, it will be assumed throughout my theoretical demonstration following that all current values at any instant can be'considered as being directly proportional to Thalving the time then resulting in also halving the current value attained--etc.; and (6), since this portion of the curve approximates a straight line, the ohmic drop effect for this portion c must therefore be small as compared to the self-inductive effects and hence approximately all energy drawn from the source during each interval can be considered as stored in the form of magnetic energy in the primary.

Starting with these assumptions, the relative amounts of energy stored during any given time interval may then be easily determined. Multiplying the average power value (lV durin a given interval, by the time of duration for the interval, gives the total energy (J) delivered in the period; or J=W,-T. If the source voltage (E) be invariable, W,=E-l,, Where I, is the arithmetical average for the instantaneous current values during the interval T. The instantaneous value of'the current being denoted by 2', the value of i at the beginning of (3) %L-z',, (since by transposition, T= t,,L/E).

The last equation (3) is the most usual form of expression for tie stored magnetic energy in a self-inductive winding, as in this form it is independent of the time element, or law for current increase. This is not the case however with equations (1) and (2).

both of which assume direct proportionality between 11,, and T.

Fig. 5 gives a'graphic representation of the foregoing relationships; the particular values given being purely arbitrary. The self-inductance L being considered as constant, a straight line relationship then exists between the amperes (21) in primary, and the flux in core; every additional ampere in Fig. 5 being assumed to result in the addition of 1000 flux-turns in the primary, such as points a, b, c, etc. Since a straight line rnlnl'innqlfiin lmhmmn H10 marrnnt values nnrl duration of the time interval is assumed, the points a b, 0, etc., may also be taken to represent as a function of i, each .001 second after closing of the circuit being assumed to add one ampere to the i value, and 1000 fluxturns to the primary winding. The relative amounts of energy delivered at the source' substantially all of which becomes stored in the primary-will then be represented by the number of triangular polygons within the shaded area considered. For example, from 0 to .001 second, 1 triangular polygon or energy unit is developed; from 0 to .002 second, 4 energy units; from 0 to .003 second, 9 units, etc.

Let the two cases be considered of T=.O04 second, and T=.002 second, respectively. The relative amounts of energy delivered in the two respective intervals are seen to be 16 units in the first case, and 4 in the second or a ratio of l to 1. In the first case the maximum current value attained is t,,=4= amperes; the average amperage for the whole interval being I -i,,=2 amperes. The total energy delivered during this .004 second interval is 5:.004X2 X E=.008 X E by equation (1). In the second case i,,=2 amperes; the average amperage for the whole interval being =%-i,,=1 amp. The.

- total energy delivered during this .002 second interval is therefore J='.002 1 E=.0o2 E,

or only i of the former amount; which checks with the method of comparin the numbers of polygons generated in the gure. While halving the time interval simply halves the a' value attained, it however is seen to quarter the energy delivered-since half the power value is then applied for one half as much time. This is in agreement with the equations (2) and (3) given previously, which show that J varies as the square of T and as the square of i It is thus evident that in the case of the common type make and break coil ignition systems now in use the'falling oif in the energy delivered to the primary as the higher speeds are reached must be very rapid, which fact is borne out in practice, since J falls away or decreases as the square of T. The condition in which the energy stored in the primary becomes insufficient to disrupt the gap medium is therefore rapidly approached as the higher speeds are reached; the spark discharge not only becoming very weak and thin but suddenly ceasing entirely.

It should here be noted that for the common type of induction coil the time interval (T) refers to the length of time for which the breaker actually remains closed,

'and not the whole interval between successive sparks. Owing to the inertia of movmg parts, and other mechanical limitations, it is impossible for the breaker to instantly return to the closed position after opening; and a certain amount of lost motion in the breaker therefore has to be allowed for, particularly at the higher'speeds. For example, in the caseof an 8 cylinder, 4 cycle engine running at 3000 R. P. M. the interval between successive sparks would be .005 of a second; but the breaker could not be expected to be in the closed position for more than say 75% of this time; the remaining 25% of each interval being required for the act of returning to the closed position. Since the energy delivered to the primary (at high speeds) varies as the square of the T value, the efiect ofthi-s 25% reduc- I or say only 50% of the energy which would be acquired if the Whole spark interval could be considered as the T value. To reduce this lost motion as much as possible, the practice has therefore been to lighten the breaker parts as much as possible so that the same shall have but small inertia, but beyond certain limits such reduction in weight will of course tend toward fragile construction and poor contact at the breaker with further loss in energy delivered from the coil.

I will now take up the theoretical considerations which apply in the case of my invention. The major portion of the magnetic energy in this case is stored in a separate self-inductive element, which I refer to as an energy accumulator, and is distinct from the high tension transformer element, this latter of course having both primary and seconda windings. Details regarding the constructlon and operation of both these elements will be given later, and it will suffice to state here that unlike the case of the common type of coil, the total energy stored in the accumulator element is never reduced to zero-the accumulator circuit being at all .times closed-so that the energy delivered to the transformer element is thus in the nature of a series of steps or energy decrements; there being one such decrement for each spark discharge. Immediately succeeding each spark discharge the accumulator energy then proceeds to recover itself, and continues to increase until the next succeeding spark.

The amount of energy increaseor the energy increment-received by the accumulator during the interval of recovery can be represented by the shaded area. in Fig. 6; in which the number of triangular polygons generated in any space will equal the relative amount of energy increase, similarly as in the previous case of Fig. 5. It should here be explained that the total energy dissipated at each spark discharge, that is, the energy decrement, will in each case equal the energy increment stored in the immediately preceding recovery interval, because the sum total for all decrements during an extended period of time must equal the sum total for all-the increments in the period, as otherwise the total energy held in reserve would be either continuallyaugmented or else wiped outaltogether. he shaded areas in Fig. 6, which really represent increments, may therefore also: be taken to represent relative values for the energy decrements, but it will be sufficient to refer to all fluctuations simply as increments or energy increases.

' As the comparison between my invention and the common type of coil system is to be made upon the basis of equal "5,, values in both cases, which refers to the i value attained at some given high speed and not the E/R limit, these values are shown equal in Figs. 5 and 6, viz., i,,=4 amperes; and to attain this 11,, value, equal time intervals are also shown in the two figures viz., T==.001 second. The rate of flux increasesor in other Words the counter E. M. F.are likewise shown equal in the two cases, viz., an increase of 1000 flux-turns for every .001 second while the current is increasing.

As will be later explained, if themost effioient operation is to be obtained, the self inductance of the accumulator coil must be appreciably greater than is usually found in the case of the primary incommon type coils, and for sake of demonstration is taken at exactly 5 times greater for Fig. 6 than for Fig. 5. The flux-turns per ampere in the accumulator winding will consequently have to be 5 times greater than in the case of Fig. 5, so that a value of 20,000 flux-turns is therefore shown for i =4 amperes in Fig. 6. Then as the total decrement in flux must equal the total increment in flux, and this latter must amount to 4000 flux turns for T=.004= in each figure, if equal counter E. M. F.s are to be generated in both fi ures, the flux turn value when T=O in ig. 6 must therefore be shown as triangular polygons generated is about 7 when T:.001; about 14 when T -.002; about 22 when T=.O03; etc., or in other words J is almost directly proportional to the first power of T, instead of varying as the square of T as in the common type cOll. Halving the time interval will therefore simply halve the energy per spark, instead of quartering it as in the case of common type coils, as previously explained.

That the energy per spark will vary approximately as simply the first power of T may also be demonstrated by energy formulae as follows: The total energy contained in the accumulator at the beginning of the recovery period being J with the corresponding current being 4),; and the total contained ener y at termination of the interval T being i with the corresponding current i the energy increment (AJ) for the period will be w 0 the above becomes But if the increment m is not too great,

as say not greater than 20% of the starting current value (that is, w 0.2) the term 05 in the above may be dropped since it becomes of negligible numerical value, thus making (5) AJ H15}- 21: =mL'i, (approx) In this equation, since the current increment w is directly proportional to T, AJ must consequently be proportional to T, or in other words AJ varies as the first power of T and not as the square of T, (that is, in all cases where a: is sufiiciently small to permit of m being neglected). It will also be observed that the coefficient %which appears in equations 1, 2 and 3disappears in equation,5;.which agrees with the-observable feature that the total shaded area in Fig. 6 is about twice as great as the total shaded area in Fig. 5.

Making use of Figs. 5 and 6 for comparing the relative energy values obtained in the two cases as the speed increases, it is seen that when T=.004, that is, equal 5,, values in both cases, about 30 triangular units are generated in Fig. 6, while 16 are generated in Fig. 5, or a ratio in this case of about 2: 1. But if the time interval now be considerably reduced as say to T:.001, the energy becomes about 7 triangular units in Fig. 6, but only 1 unit in Fig. 5, or the ratio in this latter case is about 7 :1 in favor of my system.

Another important characteristic possessed by my invention is that, as will be hereinafter shown, the T value for the interval of current rise is entirely independent of the amount of lost motion occurring in the iseaeae breaker-the value for T being equal to a full 100% of the whole spark interval in all cases. A reduction of 50% in the amount of obtainable energy (due to a 25% lost motion interval in the breaker) such as occurs in the common type coil systems as previousl explained, is therefore entirely absent in t e case of my invention.

Also since the lost motion interval may therefore be allowed to run up to almost 100% of the whole spark interval, the severity of the motion requirements in the breaker can thus be considerablv lessened, and a material saving efi'ected in the general wear and tear on the breaker parts, which, for the same reasons may also be made heavier, and therefore more rugged than is usually advisable in the case of the common type of battery breaker. In, connection with this matter of wear on the breaker parts, my invention, as will be described later, employs two breakers operating in alternation, so

that the wear on each in this case of two should therefore be cut in half.

If the relative amount of self induction in the accumulator coil be changed to other values than assumed for Fig. 6, the first direct effect will be to change the value of the current increment during a given time, or in other words, the slope of the line abT-0 will be altered. Greater inductance than that assumed in Fig. 6 would simply cause the line to become more nearly vertical, that is, the current increment or fluctuation values would be lessened. It is plain however that even if line abc were made perfectly erect so as to coincide with the ordinate line at i,,=4.0 amperes, the total shaded area would not be very much increased above that shown in the figure, so practically nothing is gained by making the accumulator self inductance considerably larger than the suflicient amount. On the other hand, if the accumulator inductance be reduced much below the assumed relative value for Fig. 6, it is evident that the current fluctuations must become relatively greater; and in the limit, line a-b--c inconstants, such as the speed limits desire .60

battery voltage, etc.

The general formula applicable to all conditions of operation, and in which the relative amounts of inductance necessary for the given cases is indicated, may be derived as below Solving for w in the equation and substitutin this expression for at in the exact formu a 4,.gives From equation 6, it is seen that the energy increase is made up of two components, one of which varies as T, and the other as T. This latter component-as shown by equation 7 will be relatively negligible whenever the numerical value of ET/2L is small relatively as compared to the numerical value of i the energy increase in this case being approximately equal to ET L.

On the other hand, if i, should be reduced to zero, that is, the accumulator current be made to start from zero value at the beginning of each interval as in the case of common type coils, then the first term in equation 6 would vanish, and the energy increase would then equal E T /2L; which is identicallto equation 2 given for the common type C01 Whether a: in equation 5 be large or small for a given set of operating conditions will therefore depend upon the ratio ET/2L:"i,; so that the suflicient value for L will depend upon the values which obtain for the three operating constants given, viz. E, T, and t,.

The application of the principal theoretical considerations involved in my invention will be now readily understood from the following detail description of the various devices shown dia ammaticall in Figs. 1 to 4 inclusive and ig. 8, in w ich like numbers refer to corresponding parts.

In Fig. 1, B is a battery or other energy source of direct current, one terminal of which is grounded at G. Starting from the insulated terminal of battery .B, current passes through 'a limiting resistance 1 or' its equivalent to the point 2-, where it divides between two self -'inductive windings 3 and 4, which form what I call energy accumulators. The two windings 3 and 4 are wound upon magnetic cores 5 and 6 which are preferably provided with air gaps 7 and 8, thus forming two seli inductances havi reluctance. Woun upon a closed iron core 9,- which has as low reluctance and few jointsas possible, is the prnnary wind ng 10 of the spark coil, the terminals of which are connected to the self inductive accumulator coils 3 and 4 respectively; so that collectively considered, a 1 these coils 3, 4 and 10 form a closed loop circuit. Wound upon core 9 is a high tension secondary wmdin 11, one terminal of which is grounded GE and the other end connected to the dlstrlbifter D. The circuit breaker employed is of the double acting type, that is to say, the contacts are closed or opened at two differ- 4 ent points by two different members, whichoperate more or less independently. A contact at 12 operated by the breaker arm 13 is connected to the junction of the coils 4 and 10; the other breaker arm 14 is connected in a similar manner by contact 15 to the junction of coils 3 and 10. y The two breaker arms 13 and 14 are suitably mounted on a grounded support 16. The arm 13 carries a bumper 17, and the arm 14 carries a bumper 18, both of which are engaged by noses on the operating cam 19, a spring 20 being used to return the breaker arms 13 and 14 to their normal closed positions after having been operated by the cam 19. It will be seen from an inspection of cam 19 that the construction is such that contacts 12 and 15 can never be opened at the same instant, but instead follow each other in turn in opening and closing, the one always closing before the opening of the other. A condenser C is connected across the terminals of the coil 10 to absorb the shock of the inductive kick during the flux reversals in the iron core 9, which result from operation of the breaker contacts as will be presently explained.

The current on arriving at the point 2 divides between the two accumulator coils 3 and 4, and assuming the contact 12 to be closed and contact 15 to be open, as shown in Fig. 1, the currentthrough the accumulator coil 4 will pass through contact 12, and arm 13 to ground at the base 16; while the current from coil 3, in orderto reach ground will have to first flow throughthe primary 10 of the spark coil before reaching ground through contact 12 and arm 13- the direction of current flow through primary 10 beingin this case from contact 15 to contact 12. Now on the rotation of the cam 19, contact 15 closes while contact 12 is still closed, and in this case current from coil 3 can then pass directly to ground through the contact 15 and arm 14; however,

more or less constant even if, the interval be prolonged suifi-- ciently to permit the magnetizin current in 10 to die down to zero, the residual flux in core 9 still remains at a large fraction of its previous value when contact 15 was yet open, this residual flux resulting from slight hysteresis in the iron, and the extremely low reluctance of the closed iron circuit obtained by using lapped joints, etc.

Assuming that all the events have occurred in the order just mentioned, when contact 12 subsequently becomes opened by impact between rotating cam 19 and the bumper 17, current from the accumulator coil 4 can thenonly reach ground by first passing through the spark coil primary 10 in the direction from contact 12 to contact 15, that is, reversed from that previously taken by the current which came from the accumulator coil-3. The flux in core 9 of the spark coil is therefore suddenly reversed by the sudden reversal of current in primary winding 10, and the result is a momentary induced discharge from the high tension winding 11 across that plug which has been properly connected to the distributer in the usual manner. These operations are successively repeated-the contacts 12 and 15 being alternately opened in succession but one or the other always being in closed position; with the result that successively reversed currents are sent through the primary winding 10 at each succeeding opening of the contacts 12 and 15, and thereby producing discharges in the high tension secondary winding 11 at every reversal of the flux-in the core 9.

From the foregoing description, it will be evident that the circuit from battery B to ground 16 through each of the accumulator coils 3 and 4 is never actually opened; so that the transfer of energy from the battery to each accumulator coil is continuous and without intermission, so long as the necessary connections are left complete. The recovery or building up period for the accumulator coils is therefor wholly independent of the amount of lost motion, or fractional part of the interval during which the breakers may individually remain open between sparks; the only requirement being that each breaker shall close sometime before the other opens, and the lost motion period may therefore amount to nearly 100% of messes motion occurring in the breaker.

of low reluctance.

Several other advantages inherent in my .invention may be now mentioned. One is that the flux in the spark coil core 9- is carried through only half of a complete hysteresis cycle for each spark discharge, that is, after producing a spark by a reversal in flux to the opposite polarity, this latter polarity then maintains until the instant for reversal for the next succeeding spark. The iron losses are therefore only one half of what they otherwise would amount to in the case of employing a complete hysteresis cycle between successive sparks, such as have been employed in various other forms of sparking apparatus utilizing closed iron circuits Another advantage is that owing to the comparatively low reluctance of the iron core 9, the number of turns required in the primary winding 10 in order to secure sufficient volt-ampere energy is materially reduced below the number required in the usual, forms of make, and break coils having long air paths in the magnetic circuit. The relative resistance of coil 10 can therefore be made extremely low so that the discharge surges from the condenser C are considerably less interfered with by ohmic resistance of the winding, thereby resulting in a greater condenser ethciency. Still another advantage of my invention attained in the particular case of Fig. 1 is that the building up period, or interval for increment growth of current in the individual accumulator coils is double the length of interval between the succes sive sparks, since each of the two coils 3 and 4 are afi'ected by the breaker at only every other spark. It may be remarked that the effect of the momentary back kick in the s ark coil primary 10 at the instant of each fl fix reversal is to somewhat reduce the current in that particular accumulator coil with which 10 is in series at that instant; the amount of such reduction being equal to the current increment previously attained during the period of increment growth, which in the particular case of Fig. 1 is twice the spark interval.

A further advantage which will be quite apparent on comparison is that my system of inductance does not have to provide large leakage areas as in some other forms using a closed circuit transformer and choking coil; hence my spark coil or transformer can be made relatively small with a consequent lower cost of production.

In Fig. 2 the parts and operation thereof are substantially the same as in Fig. 1; the

main difference being that the two accumulator coils 3 and 4 of Fig. 1 are replaced in Fig. 2 by a single accumulator coil 21, with the connection to the spark coil primary 10 being made at the center thereof. The remaining"'pa'rts are the same as in Fig. 1, and need not be again described, except to say that for sake of convenience in illustration, a spark gap S'is shown connected direct to the secondary in place of the distributer 1). When current from the accumulator coil 21 arrives at the point 22, which is the central portion of the primary winding 10, it flows either upward to contact 12, or downward to contact 15; the magnetizing effect upon core 9 for these two directions of flow being directly opposite, or opposed to each other. When both of the contacts 12 and 15 are in the closed position at the same time, the prevailing current tends to follow the direction pursued while the latest closing contact was yet open; due, as in the case of Fig. 1, to the self inductance in the winding 10. Since all the current supplied to the spark coil primary 10 in Fig. 2 enters at the middle point 22, by operation of the double acting circuit breaker the point of current egress is successively shifted from one terminal to the other in alternation; and these intermittently reversed currents through the half portions of primary 10 thus serve to reverse the flux in core 9 at each breaker opening, and a high tension discharge being thereby induced. in the high tension winding 11. The requirements in the operation of the circuit breaker and the intervals of proper opening and closing are identical with those described in connection with Fig. 1; the interval of recovery or building up in Fig. 2 being, as previously, entirely unaffected by the fractional part of the spark interval for which the breaker may remain open. The building up interval, however, in Fig.' 2, simply equals the spark interval, instead of being twice the spark interval, as in the case of Fig. 1.

Fig. 3 is substantially the same as Fig. 2, except that the central point of the primary winding 10 is connected to ground, instead of being connected to the accumulator winding 21. The operation of the double acting circuit breaker-in this case is to successively shift the point of current entrance to primary 10 from one outside terminal to the other, in alternation. Ordinarily, however, the arrangement of Fig. 2 is preferable to that of Fig. 3, since the circuit breaker arms are usually grounded by their support, but which, in the case of Fig. 3 would have to be insulated.

As has been explained in connection with Figs. 1 and 2, whenever both of the contacts 12 and 15 are in the closed position at the same time,'the' current in the spark coil primary 10 tends to ersist in the same direction as that previously followed while one of the contacts was yet opened, due to the self-inductance in winding 10. At the higher speeds, the current in winding 10 for this reason does not have time to die down to any great extent before the next succeed ing reversal; regardless for what fraction of the spark intervals both breakers may be in the closed position. At low speeds however such dying down may become more or less complete, unless the construction is such as to cause the respective breakers to remain open individually for nearly 100% of the whole spark interval. 'It must be very apparent that it is vitally important however for each contact to become closed in every case before the other contact opens, forif both breakers should be open at the same instant, the accumulator circuit would then be completely open circuited and the principle of operation would. consequently be nullified. The requirements for obtaining the most efiicient operation at low speedsare therefore that each breaker should individually remain open for 100% of the full spark interval; but each however must close before opening of the other. Both of these requirements are realized by use of the modified form of breaker construction shown in Fig. 4, in which arrangement of circuits, and connections between battery, accumulator coil, and spark coil, are shown the same as in Fig. 2.

In Fig. 4, the breaker arms 13 and 14 are for convenience shown as consisting simply of flat stripsprings, mounted upon a rigid support 25 of insulating material; both the springs 13 and 14 exerting a downward pres.-

sure at'the free ends. As shown in the figure, contact 12 is closed and contact 15 opened, with the arm 14 in its extreme lower position; the arm 13 then being completely disengaged from arm 14. As the latter then rises by further rotation of the .cam, the contacts 15 first become closed,

and almost simultaneously therewith the contacts 12 become open, due to lifting of arm 13 by the contacts 15, which are carried upward by the continued rising of arm 14. The cam noses are so designed that the lifting of arms 13 and 14 1s continued until the contacts 12 are opened to the same limits as was the case with the contacts 15, when opened. As the arms then begin to descend, the closing and opening of the individual contacts occur in the reverse order to that previously; namely, contacts 15 remain closed until the contacts 12 become closed; the motion of' arm 13 is thereby arrested and simultaneously therewith the contacts 15 open, due to arm 14 continuin on its downward motion. Each contact t erefore remains open for practically 100% of the full spark interval, but each however must always close before opening of the other can occur.

The resistance I may take the form of a tungsten lamp having a filament of the requiredcross section and length. It is well known that the resistance of tungsten lamps when cold is quite low-but when current passes through the filament the resistance.

time such a device, suitably chosen, will not introduce enough resistance in the primary circuit to prevent mefrom utilizing a low resistance primary winding in my transformer for the purposes which have been heretofore explained. The use of a resistance in the form of a lamp or visible signal, as just described, serves the purpose of acting as a telltale should the operator, or some unauthorized erson, turn on the ignition switch 26, which is placed in the primary circuit, and leave the circuit closed through the accumulator coil or through the accumulator coil and the primary of the ignition coil, should the engine stop with both breaker arms in closed position. It will be understood from the drawings and specification that when the switch 26 is closed there will be a flow of current from the battery B through one or more branches of the main circuit and hence the value of such limiting resistances as just described will be ap reciated.

Fig. 8 I have shown how the accumulator coil 21 may be combined into a unitary structlire with the transformer element .whose core extends outward into limbs 23 and 24 with a yoke Y having gaps 7 and 8 but the forms of circuit breakers, details of construction thereof, construction and arrangement of the accumulator and spark coils, may be varied over a wide range in order to carry out to the fullest extent the broadest conception of my invention, as outlined in the description herein and the theoretical demonstrations; and I therefore do not wish to be limited to any particular form other than what said forms may be limited by the scope of the appended claims.

Having thus described my invention what I claim 1s 1. In an ignition system, a transformer having a closed magnetic circuit with primary and secondary windings, a pair of con tacts connected to said primary winding, a source of current, accumulator coils connected to said source of current and means coacting with said contacts to reverse the current I from the' accumulator coils through said primary winding for the purpose described.

2. In an ignition system, a transformer having a magnetic circuit of low reluctance with primary and secondary windings, a source of current, a pair of contacts connected to said primary winding and to one terminal of said source of current, means connected to the other terminal of said source of current and coacting with said contacts to reverse the direction of current through said primary Winding and means in circuit with the current for accelerating the action of said primary Winding on the secondary.

3. In an ignition system, a transformer having a magnetic circuit of low reluctance with primary and secondary windings, a sparking circuit connected to said secondary, a source of current, a pair of contacts connected to the extremities of said primary winding and to one terminal of said source of current, means connected to the other extremity of said source of current and 00-- acting with said contacts to reverse the direction of current through said primary winding and means in circuit with the current for boosting the eifect of the primary on the secondary whereby the heat energy of the secondary spark is increased as described.

4. In an ignition system, a transformer having a magnetic circuit of low reluctance with primary and secondary windings, a sparking circuit connected to said secondary, a source of current, a pair of contacts connected to the extremities of said primary winding and to one terminal of said source of current, means connected to the other extremity of said source of current and coacting with said contacts to reverse the direction of current through said primary winding and an energy accumulator coil in circuit with the current for boosting the effect of the primary on the secondary whereby the sparking speed of the system is augmented.

5. In an ignition system, a transformer having a magnetic circuit of low reluctance with primary and secondary windings, a sparking circuit connected to said secondary,- a source of current, a pair of contacts connected to the extremities of said primary winding and to one terminal of said source of current, a circuit breaker connected to the other extremity of said source of current and coacting with said contacts to reverse the direction of current through said primary winding and means in circuit with the current adapted to re-act on the primary winding to compensate for lost motion in said breaker, whereby the sparks from the secondary are augmented.-

having a magnetic circuit of low reluctance" with primary and secondary windin s, a

sparking circuit connected to said secon ary, a source of current, a pair of contacts connected to the extremities of said primary winding and to one terminal of said source of current, a circuit breaker connected to the other extremity of said source of current and coacting with said contacts to reverse the direction of current through said primary Winding, an energy accumulator coil in circuit with the current adapted to re-act on the primary winding to compensate for mechanical lag in said circuit breaker, whereby the sparks from the secondary winding are augmented.

7. In an ignltion system, a transformer having a magnetic circuit of low reluctance with primary and secondary windings, a

sparking circuit connected to said secondary, a source of current, a pair of contacts connected to the extremities of said primary windingand to one terminal of said source of current, means connected to the other extremity of said source of current and coacting with said contacts to reverse the direction of current through'said primary winding, and means introduced into circuit with the primary winding by said first mentioned means for acting on said winding to produce a spark from the secondary while the mag netic flux in the transformer is passing through one half a cycle.

8. In an ignition system, a transformer having a magnetic circuit of low reluctance with primary and secondary windings, a sparking circuit connected to said secondary,

' a source of current, a pair of contacts connected to the extremities of said primary winding and to one terminal of said source of current, a circuit breaker having its moving elements connected to the other terminal of said source of current and coacting with said contacts to reverse the direction of current through said primary winding, an ac cumulator coil introduced into circuit with the primary winding by said circuit breaker, said coil re-acting on said primary winding to produce a spark from the secondary while the magnetic flux in the transfO IiIlBI is passing through only one half cyc e.

9. In an ignition system, a transformer having primary and secondary windings, a source of current, an interrupter having contacts connected to the terminals of said primary winding and to said source of current, energy accumulator coils connected to the other terminal of said source of current, said interrupter being adapted to direct the for the purpose describe 10. A source of energy, anda primary circuit therefor including an energy accumulator coil, a secondary circuit in inductive relationship to said primary circuit and means for causing said energy accumulator coil to discharge in said prlmary circuit alternately in reverse direction as and for the purpose described.

11. A source of energy and a primary circuit therefor including an energy accumulator coil and the prlmary winding of a transformer, a secondary winding on the transformer in inductive relationship tosaid primary Winding, and means for discharging at intervals the energy of the accumulator coil through said primary winding alternately in reverse direction for the purpose described.

-12. A source of energy and a primary circuit therefor including the primary wind-- ing of a transformer, a seconda winding adapted to be energized by sai primary winding, and means comprising an energy accumulator coil for augmenting alternately in reverse direction the normal action of the primary on said secondary winding.

' f 13. A source of energy and a circuit 5O speed limit and energy of the spark from the therefor including the primary winding of a transformer, an accumulator coil in said primary circuit, a secondaccumulator' coil adapted to be connected in said primary circuit, a secondary winding energized by said primary winding, means for momentarily short circuiting said primary winding and then breaking the short circuit and lntro- 'ducing the second accumulator coil whereby said second accumulator coil discharges through said primary winding for the purpose described.

14. A source of energy and a circuit therefor including energy accumulator coils and the primary of an induction coil, a secondary winding on the induction coil and having a spark gap'in circuit therewith and means comprising an interrupter for momentarily short circuiting said primary winding and then breaking the short-circuit whereby one of said energy accumulator coils acts on the primary in reverse direction to the other accumulator coil to increase the secondary.

15. In an'ignition system, an induction coil having primary and secondary windings, asparking circuit connected to said secondary, an interrupter having contacts con nected to the ends of said primary winding,- a pair of energy accumulator coils connected to said contacts, a source of current connected to said accumulator coils, said interrupter being adapted to discharge first one accumulator coil and then the other throu h said primary winding for the purpose escribed.

- 16. In an ignition system, an induction coil having primary and secondary windings, .a sparking circuit connected tojsaid secondary, an interrupter having contacts connected to-the ends of said primary winding, a pair of energy accumulator coils connected to said contacts, a source of current connected to said accumulator coils, said interrupter being adapted to first short circuit both the energy accumulator coils and said primary winding then to break the short circuit whereby said accumulator coils are allowed to alternately discharge in reverse direction through said primary winding for the purpose described.

17. In an ignition system, a source of direct current energy and multiple circuits therefor, an induction coil having its primary winding in one of said multiple circuits and its secondary Winding in circuit with a park gap, an energy accumulator coil inthe other of said multiple circuits, a second energy accumulator coil in the first mentioned multiple circuit and means for reversing' the relationship of said accumulator coils with respect to said circuits and said primary windin 18. A sourceoienergy and a multiple primary circuit therefor, an energy accumulator coil in each of said multiple circuits, an induction coil'having primary and secondary windings and means for alternately connecting said primary winding into each of said multiple circuits for the purpose described. 19. .A source of energy and multiple primary circuit therefor, an energy accumulator coil in each of said multiple circuits, an induction coil having a closed magnetic circuit' of low reluctance and primary and secondary windings thereon and a circuit breaker-for alternately connecting said primary winding into each of said accumulator circuits. l y

'20. A source of electrical energy" and a multiple circuit therefor, a primary winding in one of said circuits, a secondary wind-' ing, and means comprising a'naccumulator coil exclusively in the other of said circuits with means for switching said coil into the circuit including the primary winding forboosting the inductive effect of the primary windingon thesecondary. 7

21. A source of electrical energyand a multiple circuit therefor, a primary winding in one of said circuits, a secondary winding, and means comprising an accumulator coil exclusively in the other of said circuits and an interrupter for switching said coil into the circuit including the primary winding for augmenting the inductive effect of the primary winding on the secondary.

22. A source of direct current electrical energy and a closed circuit therefor including a coil, a second coil inductively related topthe first coil and having aspark gap in circuit therewith and means for storing energy in an independent device and transferring said energy to the first coil to cause sparking current from the second coil to Jump said gap.

23. A source of electricaLenergy and a circuit therefor including the primary winding of a transformer, a secondary winding having a spark gap in circuit therewith, an energy accumulator device adapted to store energy from said source and switching means for periodically storing, withdrawing, and transferring such a portion of said stored ener y to the primary winding at the interval 0 sparking that the succeeding amount of energy restored varies as the first power of the time interval (T).

24. A source of direct current energy and "a circuit therefor including the primary winding of a transformer, a secondary winding having a spark gap in circuittherewith, a magnetic energy accumulator coil adapted to store ener y from said source and switching means for periodically storing, withdrawing, and transferring such a portion of said stored energy to the primary winding at the interval of sparking that the succeeding amount of energy restored varies as the first power of the time interval (T).

25. A source of direct current energy and a circuit therefor including the primary winding of a transformer, a secondary winding having a spark gap in circuit therewith, a magnetic energy accumulator coil included in a closed circuit with said source of direct current whereby energy is continuously stored in said coil and switching means for periodically withdrawing and transferring such a portion of said stored energy to the primary winding at the interval of sparking that the succeeding amount of energy restore-d varies as the first power of the time interval (T).

I 26. In an electric circuit, a transformer provided with a magnetic circuit of low reluctance and having a low resistance primary and a secondary winding connected to a sparking circuit; a source of electric current; means for passing the current from said source through a magnetic coil and storing up energy therein, means for discharging only a portion of 'said stored energy through said primary and means for then restoring such energy in continuous cycles accordin to the first powerof the time interval s 27. In an electric circuit, a transformer provided with a low reluctance magnetic circuit, a low resistance primary winding and a secondary winding connected to a sparking circuit; a source of electric current; means for passing the current from portion of the storedenergy through said primary winding and means for then moving the breaker to put back into the energy coil the amount of energy equal to that taken out, such replacement bein independent of the lost motion of the circuit breaker.

28. In an electrical circuit, a transformer provided with a low reluctance magnetic circuit, a low resistance primary winding and a secondary winding connected to a sparking circuit; a source of direct current in the primary circuit of the transformer; and a pair of energy accumulator coils, said accumulator coils and primary winding being connected in closed looped circuits; means including contact members foralternately passing current from said source into the looped circuits via one of the accumulatorcoils and the primary winding and then via the other of the accumulator coils and the primary winding, whereby said energy coils are caused to alternately discharge in. reverse direction a portion of their stored energy into the said primary winding, there by augmenting its action on the secondary.

29. In an electric circuit, an induction coil having primary andsecondary' windings and a magnetic circuit of low reluctance therefor, a source of electric current, means for passing said current through the primary winding and continuously through an accumulator coil, thus storing energy therein and means for periodically discharging a portion of the energy of said acrupter for producing an alternating fiux.

therein at the instant of ignition, means for preventing a leakage of said flux, and a circuit comprising a spark gap and a coil upon said core. 1

- 31. In an ignition system the combination of, an electrical transformer having a stationary magnetizable core, and means for producing an alternating magnetic flux therein, of means for preventing the leakage of said flux, and means for boosting the value of said flux at the instant of ignition to' produce an electric spark.

32. A transformer core, a coil for setting up from a constantly applied electrical source a magnetic flux therem, a second coil having a spark gap, and an energy accumu lator-coil distinct from the transformer core adapted to augment the action of the flux thereof with respect to the second-coil at the instant of the spark discharge.

33. A transformer core, a coil for setting up from an electrical source a magnetic flux ductive influence of the core, vand a third coil independent of the transformer core for storing energy and a circuit breaker for passing a portion of the stored energy through the first mentioned coil to augment the flux action therein, at the time when one of the circuit breaker contacts opens, whereby the second coil may be intermittently energized.

34. A transformer core, a coil for setting up from an electrical source energy in the core, a second coil subject to inductive influence ofthe core and a third coil adapted to store energy independent of the transformer and means for passing only a part of said stored energy through the first men tioned coil for rapidly changing the flux condition of said coil at the time when one of the circuit breaker contacts opens whereby the energization of the second coil is augmented.

35. A transformer core of low reluctance, a coil for setting up from an electrical source, energy in the core, a second 'coil subject to inductive influence of said core and a pair of coils adapted to store energy independent of the transformer and further adapted to coact with said first and second coils, interru ter mechanism for controlling the action 0 said pair of coils with respect to the first and second coil, whereby the energization of' both coils varies as the first power of the time interval.

'36. In a device for the generation of electricty, the combination with a plurality augmenting said c anges in all of said mag netic paths at the time when one of the cuit breaker contacts opens.

37. In a device for the generation of electricity, the combination with a magnetic path of low reluctance, of means including interrupter contacts to induce a magnetic flux change in said magnetic path and electrical means including magnetic energy accumulator coils for augmentin said changes in said magnetic path at t e time when one "ofthe clrcuit breaker contacts opens.

In witness whereof, I affix m signature.

JOSEPH K. L IBING.

cir-

Images