US1085340A - Apparatus for electric ignition. - Google Patents

Description

G. HONOLD.

APPARATUS FOR ELECTRIC IGNITION.

APPLICATION FILED MAR. 29, 1911.

Patented J an. 27, 1914 2 SHEETS-SHEET l.

MECHANICAL INTEFUPTE'I? wL/aplm F M wh czx/ G. HONOLD.

APPARATUS FOR ELECTRIC IGNITION.

APPLICATION FILED MAR. 29, 1911.

Pat :bed Jan. 27, 1914.

2 SHEETS-SHEET 2.

ITIJESSES UNITED sTATE-s PATENT OFFICE.

Go'r'rLoB HON'OLD, or STUTTGART, GERMANY, Assieivon TO THE new: or ROBERT BOSCH, or s'rn'r-rsnncr. GERMANY.

APPARATUS FOR ELECTRIC IGNITION.

Specification of Letters Patent.

Pitt outed Jan. 27, 1914.

le -(whoa it) myinveijitkm in order to ol vine: lhe necessity of Ii'ltiiilllg the spark.

and useful Improvements in Apparatus for i Electric Ignition; and I do hereby-declare the following to be a full, clear, and exact description of the invention, such as will on able others skilled in the art to which it appertains to make and use the same.

The present invention relates to a paratus for electric ignition of the combustible gases in a single or multiplecylinder internal combastion engine.

As is well understood by those conversant with the art, the full development of pressure produced in the cylinders of engines of this kind by the explosion of the fuel should always take place immediately after the crank has passed the dead point at the head ehd of the stroke. New under ordinary conditions the time which elapscs between themoment in which the ignitin spark is generated and the moment in wiich the exploding combustible 'niixture develops the-maximum pressure, is

more or less constant, and it follows that, if the maximum pressure is to be developed in a certain phase of the stroke, the moment of ignition or of generatin the spark must be advanced when the speed of the engine is increased. Hitherto therefore in engines of this kind means have invariably been provided for shifting the apparatus controlling the moment of lgnition, that is to say the interrupter of the primary current. ,This method of mechanically adjusting the igniting apparatus involves the necessity of making this apparatus accessible to the op.- erator either directly or by providing "transmitting means such as rods, levers, chains and such like.

It is the object of my invention to obviate the use of such mechanical transmitting members and substituting therefor electric means which are much more easily adapted to all such dispositions of mac inery in which'the operator controlling the engine cannot be given direct access to all parts of the machinery under his control during ing point or the point of interruption of the prm'ciry current ad ustable, I propose to take advantage of the fact that the time consumed between the moment of ignition and the moment in which the full pressure .of the explosion is developed, canbe made to vary considerably by varying the number of sparks employed to ignite the explosion mixture. I have found by experiment that, if, instead of, employing only one spark to ignite the explosive mixture in the cylinder, I employ a plurality of simultaneous sparks, the time consumed by the process of explosionor in other words the time elapsing between the moment of ignition and the moment in which the maximum p essure is develo ed is considerably reduced. Moreover have found that as the number of simultaneous igniting sparks is increased the time absorbed by the sion does not only diminis in inverse pro-- portion to the number of sparks, but according to a higher er. Theexact law by which the diminution of the time of explosion is governed is not readily capable of a geneml expression, because.it is subject to great variations depending upon the size and dimensions of the cylinder, the degree of compression and other similar conditions, that may vary considerably. In any case however the increase of speed of combustion with duplicate sparking plugs only is so great that I find it possible, even for -the highest practical speeds of the engine crank, to fix the moment of ignition so as to make it coincide with the dead point of the crank at the head end of the stroke or only very slightly in advance of the dead point. If then, by means hereinafter'more fully described, one of the pair of sparking plugs is made inoperative, the enginewill process of explothus be adapted tobe run at slow speeds or to he started 'without the risk of sudden reverses occurring. Y

My invention therefore consists in proyiding an internal combustion engine with a plurality of sparking plugs-for every cylinder and instead of4employingthe usual mechanical means for shifting the moment of ignition or of interruption of the primary igniting current according to the speed of the engine, I provide means for switching 1 the manner in which the .tially the samein all on or of! fine or more sparking plugs in every cylinder accordingly as the engine is to be adapted'to higher or lower s eeds.

In practice and more especiaii smaller size of engines I find it sufiicient to provide two sets of sparking plugs connected to the generating plant in such a manner that both plugs of each cylinder will generate their sparks simultaneously. In the accompanying drawings therefore I haveillnstrated an embodimentof my invention in which the number of sets of smrking plugs is thus limited, because comprehension of the nature of my invention is thus rendered more easy. But I wish it to be understood that I do not "limit myself to double sets of plugs. In unusually large engines or in cases in which unusual variations of eed are required, it may become necessary .or desirable to use a larger number of sets of plugs; But are to be employed according to-my invention will be substancases and any expert will be readily able according to rules well known and understood in the art to so mot lity and multiply the connections shown in the drawing as to adapt the arrangement to the use of multiple sets of sparking plugs.

In the accompanying drawings Figure 1 is a diagrammatical illustration of the means employed for reducing my invention to practice by means of a magneto igniter and of the manner in which such means are to be connected in order to act according to my invention. Fig. 2 is a. diagrammatical illustration of a modification of the means shown in Fig. 1 and Fig. 3 is a diagrammatic illustration of. a modification of the connections shown in Figs; 1 and2, as employed in case in which the igniting sparks are to be generated by means of a battery instead of a magneto.

Corresponding parts are designated by the' same reference characters in all the drawings.

Referring to Fig.1 0 represents the head end of a cylinder of an internal combustion engine the inner end being drawn broken away and I the piston thereof.

K, and K are a pair of sparking plugs ofv usual construction having one electrode connected, to a clamping screw at the head of the plug and the other electrode connected to the mass of the cylinder or to ground.

A is a magneto-generator of usual construction supposed to be driven bythe engine or in any other suitable and usual manner.

S, and S, are a. pair of sliprings prefen ably mounted on the armature shaft of the magneto and rotating therewith and being connected to the terminals ol the seoomlary armature winding by means of insulated wires I and E I5, and 15 are a pair of brushes adapted to slide on said sliprings S, and S, and connected\ by leads L and L to the clamping screws of the sparking plugs K and K D is the contact lever of a switch connected by'a. lead L, to the mass of the cylinder and being capable of making connection alternately with-contacts D and D connected by leads L, and L to points. on leads L and L intermediate the brushes B and B and the plugs K and The primary winding P, of the magneto armature includes a mechanical interrupter, which is operated according to rules well known in the art either from the armature. shaft or any other suitable moving part of the engine so as periodically to short circuit and to, interrupt the primary winding and according to my presentinvention thisLinterrupter may have a fixed adjustment, so as to cause an interruption every time the piston arrives at the dead point of the stroke or very shortly before that point. Likewise it will be understood that, in order. to accommodate a plurality of cylinders instead of a single one, as shown in the drawing, a distribute!" which,- according to methods well understood, may be placed either in the circuit of the primary or.that of the secondary current. The arrangement thus illustrated operates as follows: Every time a current impulse is 9 generated by the armature of the magneto itis transmitted through the slipr'ings S, and 5 the brushes B and It, the leads L and L to the plugs K and K \Vhen the switch I) is in the central position, as shown in the drawing, both plugs are connected in series and simultaneous sparksare generated in both, thus adapting the engine to high \V hen low speeds are required or speeds.

when the engine has been at rest and it is intended to start it, the switch lever D is turned to make contact either with D or 1),. In thetirst. instance the plug D and in the second instance .the plug D is short circuited and the current impulse generates a single spark in the remaining plug. The time elapsing between the moment of ignition and the development of the full pressure of the explosive is thus increased and the la thus obtaincdis SutIr llg h cicnt to obviate reverses of the engine in starting and to produce a good output, when the engine is kept at low speeds for a longer period of time.

In Fig. 2 a modification of this arrangement is shown which differs from that illustrated in Fig. 1 only in the arrangement of the/brushes and sliprings, these parts being disposed in such a manner as to obviate the necessity of placing both sliprings in vdit' ierent planes, thus diminishing the length of armature shaft required to aeconnnoilalethe sliprings. Instead of providing twoseparate sliprings, in this case I divide one slipiing into two segments S, and 3 arranged at the head end 85 will have to be added ga;

therefore 1 l0 neonate in the same plane and connect the terminals of the secondary iii-mature. winding A with these egments exactly in the same manner as described with reference to the separate sliprings in Fig. 1. This arrangement has the etl'ertv that the direction of every second mirrenr impulse passing through the plugs is reversed. But, since the direction of the current whichis employed for generating an igniting spark is of no importance, this (iitlerenee does notQpro-ducc any change in the operation of the arrangement.

Fig. 3 illustrates the eonni-xctions used for embodying my invention in such cases in which a battery is preferred for generating the sparking current. One terminal of a battery B is grounded at B and is thus in connection with the mass of an interrupter I, the latter connettion being made separable by means of a SWlkCli at that drawn opened but is supposed to be closed during operation. ()n a. lever l tulcrumed at 2 on the frame of the interrupter is disposed a movable contact pin 3 and on a block 4 secured to the frame of the interrupter but insulated therefrom is disposed another contactpin 5. A spring ti seouretjl at ore end to a block fastened on or integral with the frame 'ilate of the interrupter and secured at the other end to the tail end t lever 2 tends to retain the pins 3 and in (mutant with each other. Block -11 is connected to one terminal of a primary winding G, an induction coil G the other terminal. being connected to the second terminal of the batter The frame plate of the int iter is supposed tmbe mounted on a. rotating part of the en ine soas to take part. in the rotation in accordunoe with the well understood practice of the. art and a cum 8 deflects the tail end at lever 1 at determined periods and thereby separatrs th mintsct pins and in terrupts the circuit.

Coil. G is provided with a secondary wind mg (i, one terminal of which connected to the rotating contact. or brush of a distribu to F, and the other with the corresponding brush of a distribute! F Four cylinders C C C and (here shown, the head plates only being drawn and each cylinder is pro rided with two sparking plugs, cylinder C having the plugs K, andv ii the cylinder (.3, the plugs lib" and IQ" and so forth filtl the inwulaied electrodes (5 w 'gi ug-= are connected in thrspective ordc, .-.illi tioinir contacts v f, 1", ."th of dietributers F, and F The term ill;- of the sec {iii f and I' l.

v winding t} are bridgiui by a switch D with contacts i and D arranged as ii the modifications described ith n-lrreiiri'e to Fig nd The l'll:ll'.S of 1 u em? to roiipl-ri in such a ins-inne that httt' t'lll'l't llll t lz ljl .rl lgfr with the srco'ntlurv whirling t w r l ithi'flil for ,develop full When the switch lever D is moved into,

contact either with D or D either the set. of sparking plugs indexed 1 or the set indexed 2 is shorteircuited and the other set only remains in operation thereby increasing the time elapsing between the moment of interruption and the moment in which the maximum pressure is developed by the explosive and enabling the engine to ower at low speeds or making it capable 0 being started without danger of reverses.

It stands to reason that the action of the arrangement illustrated in Fig. 3 would be substantially the same if for the battery a magnetogenerator was substituted for generating the sparking current and also that a number of other modifications of the connections herein illustrated by way of example might be elaborated for producing the same effect. But I wish it to be understood that my invention is not concerned with these details which are all well knownand understood, but that it refers only to the described method of and means for varying the time consumed in the process of ex plosion for the purpose of obviatin the use of means for shifting the moment 0 i ition or the moment of interruption of t e primaly current.

Vvhat I claim is: w

1. In an electric ignition system for an internal combustion engine, a .lurality of spark plugs in a cylinder of e engine, a source of sparking voltage including a single secondary winding, means for generating in said secondary Winding at all speeds of the engine a sparking voltage in fix d time relation to the successive periods oi maximum compression in the cylinder, tilzfillltflil" connections for coi'inecting the serondary winding to all the spark plugs to produce sparks simultaneously thereat, and a switch and connexrtions for rendering permanently inoperative one of said spark p ngs at will without rendering other or u is of the spark plugs inoperative.

J in an electric ignition system for an incombustion engine, two spark plugs in a cylinder of the engine, a source of :parking voltage including a single secondary winding, means for generating in said goo secondary winding at all speeds of the engine a sparking voltage in fixed time relation to the successive periods of maximum compressiOn in the cylinder, electrical connections for connecting the secondary Wind-' ing to all the spark plugs to produce sparks simultaneously thereat, a multi-point switch and CullllOCtlGIlS for rendering both spark plugs operative, for short-circuiting at will one of the spark plugs to render it permanently inoperative, and for short-circuit ing at will the other of the spark plugs to render it permanently inoperative.

3. In an electric ignition system for a multiple cylinder internal combustion engine, a plurality ofspark plugs in each cylinder, a magneto-generator having a primary and a secondary circuit, means felr periodically short-cireuiting and interrupting the primary circuit to gererate at all speeds at sparking potential in fixed time relation to the successive periods of maximum compression in the several cylinders, electrical connections including a distributer for successively connecting the generator with the spark plugs in the several cylinders to produce sparks thereat substantially at the time when the maximum pressure exists plugs,

in each cylinder, and a switch and connections for rendering inoperative one or more spark plugs in each of the several cylinders.

4. In an electric ignition system for an internal combustion engine, two spark plugs in the cylinder of the engine, a magnetogenerator having primary and secondary windings and a slip ring comprising two insulated segments electrically connected to the terminals of the secondary winding, means for periodically closing and interrupting the circuit of the primarv winding in fixed time relation to the period of maximum compression in the engine cylinder, a

pair of diametrically disposed brushes adapted to contact with the slip ring, electrical connections for connecting the brushes with the insulated edectrodes of the spark and a switch and connections for rendering inoperative one of the two spark plugs. i

In testimony whereof I' have affixed my signature, in presence of two witnesses.

G OTTLOB HONOLD.

Vitnesses MAX Ansontirz, REIN HOLD ELWERT.

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