US1021219A

US1021219A - Igniting apparatus for gas-engines.

Info

Publication number: US1021219A
Application number: US31003406A
Authority: US
Inventors: Elihu Thomson
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1906-04-05
Filing date: 1906-04-05
Publication date: 1912-03-26
Anticipated expiration: 1929-03-26

Description

E. THOMSON.

IGNITI NG APPARATUS FOR GAS ENGINES. APPLIOATION FILED 1123.5, 1906.

1,021,21 9. Patented Mar. 26, 1912.

2 SHEETSSHBET 1.

* fihu Thomson M/Aa; I Atty E. THOMSON. IGNITING APPARATUS FOR GAS ENGINES.

APPLICATION PILEDAPILB, 1906. 1,021,219.

2 SHEETS-SHEET 2.

Witness es.-

- //71 ent0/1- A EL/hu Thomson y Atty.

Patented Mar. 26, 1912.

UNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF SWAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

IGNITING APPARATUS FOR GAS-ENGINES.

Specification of Letters Patent.

. Patented Mar. 26, 1912.

Application filed April 5, 1906. Serial No. 319,034.

To all whom it may concern:

Be it known that I, ELIIIU THOMSON,

a citizen of the United States, residing at I This invention relates. to improved means for producing spark ignition of gasolene,

, gas and oil eng1nes and emhodiesvarious novel arrangements of a dynamo and the other parts of the system whereby the ign .tion is reliable, and furthermore, can be timed to suit the speed of the gas or other engine without the employment of hand levers or other omplicated mechanism such as is commonly used to eifect this result. The details of my invention will be better understood by reference to the following description taken in connection with the drawing forming a part of this specification.

,. Figure 1 is an elevation of my improved form of dynamo; Fig. 2 is an end elevation of the same; Figs. 3, 4, and 6 are diagrams showing the polar pro ections of the dynamo represented in Fig. 1, and illustrating variouspositionsof the rotating element of the dynamo with respect to these polar pro-' jections; Fig. 7 is a perspective view of a polar projection; Fig. 8 is a perspective view of the rotating element of the dynamo; Fig. 9 is a representation of the pressure wave generated by the dynamo; Fig. 10 shows one means for applying my improved form of dynamo to a gas engine to produce ignition of the charge in the engine cylinder; Fig. 11 shows my improved system as applied to a two cylinder engine and equipped with a selective distributor for automatically delivering current to the respective cylinders at proper time intervals; Fig. 12 shows asystem in which the two coils of the dynamo are connected in series through a timing device to the low potential winding of a transformer; the high potential winding of which is connected directly to the twocontacts of the spark plug; Fig. 13 represents a similar system with the two dynamo coils in parallel; Fig. 14; represents a system applicable toa two-cylinder engine in which the two coils of the dynamo supply two separate spark plugs through separate transformers.

The dynamo represented in Figs. 1 and 2 comprises a plurality of permanent magnets 1 and 2 arranged in the same plane and with thin like poles presented toward each other.- The poles are magnetically bridged by laminated polar projections 3 and 4, on which are mounted the generating coils. 5 and (5. One of these polar projections is clearly shown in perspective in Fig. .7 and embodies a central portion 15 on which the generating coil is wound. Two protruding pole tips 11 and 13extend outward beyond the coil. I prefer to make these polar projections 3 and 4 of considerable length, and subject them not only to the magnetic flux from the magnets 1 and 2, but also to that-of other pairs of' similar magnets arranged side by side along the polar projections, as shown in Fig.- 2, in which the

magnets

7, 8 and 9 correspond in all respects to the magnet 2, and cooperate with other magnets arranged on the opposite side of the polar projections. The rotor or movabl element 10 ofthis dynamo is shown in perspective in Fig. 8, and consists merely of a shaft carrying a plurality of iron laminations arranged one above another and secured to the shaft. This rotor when set in motion between the polar projections 3 and4 produces a change in direction of the magnetic flux threading the coils 5 and 6, and thereby nets, and the projection 4 is in contact with the corresponding south poles or the same magnets so that a vertical magnetic flux is established through the space in which the rotary element 10 lies. When the rotor is in the position shown in Fig. 3, the magnetic flux will thread through it from the pole tip 11 to the pole tip 12, and very little 20 a flux is about to shift back to the pole tip 11,

assuming a left-handq-otation. The peculma netic flux will pass through the tips 13 an 14. When the rotorassumes the position shown in Fig. 4 the main flux will traverse the tips 18 and let and very little will pass through the other pole tips. As-

suming a left hand rotation-for the rotor,.

Fig. 5 shows its position midway between the two positions illustrated in-Figs. 3 and Y 4, which position is. approximately that at which the magnetic flux shifts from the pole tip 11 to the pole tip 13, and byso doing cuts through the coil normally mounted on the narrow connecting piece 15. ,By making the rotor of considerable length I am able to make this shifting over of the magnetic flux very abrupt, and as a consequence I am able to secure a pressure wave having a very sharp peak at the maximum point,

as shown diagrammatically in Fig: 9.. Fig. 6 shows the second mid-position when the iarities of design and operation embodied inthe dynamo above described give the peculiar wave form shown in Fig. 9, and the height of the positive and negative peaksis determined by the speedof rotation of'the element 10 and the number of turns in the coils 5 and 6; so that by varying either or bothof these factors I can secure" any va' riation in the maximum value of the pressure wave within very wide limits. I find that-by making the coils 5 and 6 of many comparatively small numberof turns, and

to interpose'a-transformer between the dy-- namo andQthe-spark plugs. Such a system is shown diagrammatically in Fig; 10 in which the dynamo 16 is shown connected I permanently to the: terminals,of the trans former primary 17,- thereby supplying energy to the high potential coil 18 of the transformer which has one. terminal grounded to the frame of .the engine 19, and the other terminal connected to a rotating selector 20 which operates to deliver current to a receiving shoe 21 at the proper t1me interval, so that when the current umps from one electrode of .the spark plug 22 to the other electrode, and thence re-.

' turns through the frame to thetransformer, the spark so produced will occur justat the t1me the explosive charge in the engine cylinder is ready for i ition. The'rotating contact finger 20 is rigidly connected to. the

- gear wheel 23meshing with the gear 24 cartion of the engine.

ried by the gas engine, these two gears having such diameters that the contact hnger 20 makes one rotation to every two oi the gas engine shaft, and consequently pro-- duces an igniting spark every second revoludriven in any suitable manner, as by a belt 25 driven by a pulleyon the gas engine axle. The continuous rotation of the dynamo l6 develops a continuous series -of peaked waves in the transformer secondary 18, though these pressure waves are utilized only during the brief interval when the The dynamo 16 may be 7 selector 20 is in proximity to the receiving shoe 21. If desired, the electrical circuit between the

members

20 and 21. may be completed by mechanical contact, but I prefer to separatethe parts sufliciently to prevent such contact, and to rely on theelectromm tive force of the electrical energy to break down this gap and establish electrical connection'through'the spark so formed. This arrangement obviates entirely the mechanical wear of ,one part on another, and fur; thermorc provides means for the automatic advance, of the spark as the engine speed increases, this eii'ect being produced in part by the increase in dynamo voltage as the speed goes up, and in part by the curved the position corresponding to the minimum distance bet-Weenthetwoelements and will therefore give an automatic advance of the spark directly proportional to the increase in speed; By curving the receiving shoe 21 awayirom the arc of the rotating linger 20, I can secure any desired I relation between the speed and the spark advance.

shape of the receiving shoe 21, for it will be readilyunderstoodthat as the voltagegoes up, the current will ump to the contact shoe before, the revolving selector 20 reaches 1 05 By using a belt drive between the dynamo 16 and the gasengine I am able to secure a speed much highemthan that of the engine, and in fact so high that each spark discharge .in the engine cylinder may embody .fseveral complete cyclesof the dynamo" current. Maximum speeds as high as three thousand revolutions per minute may be used, as the revolving element is small and consists merely of iron laminatio'ns without windings of any sort-thereon. This method of connecting the dynamo to the gas engine obviates the necessity for synchronous speeds betweenthe two, and thus makes it possible to remove the dynamo from the-engine frame for repairs and to return it to its posit-ion without danger of disarranging the phase relationbetween the dynamo cur-p rent and the engine piston, this difiiculty" being one commonly; experienced with geared igniters. The high speed makes it I possible to obtain a'ma-ximum voltage from. the dynamo coils and'in fact with a fine.

' on the speed of the gas engine. VVhile- I shoe 29 to secure the exact relation desired of the 'spark transformer to raise the voltage of the dyto the one shown in Fig. 10, except that it revolvingfinger 31 approaches the receivits pivotal sup ort 32, thereby increasing primary 34 and a selector distributer 35.

Winding for the generator coils I am able'l to deliver a sharp hot spark tothe spark plug of the engine without theme of a Iiaino. The fact that each discharge at the spark plug embodies several complete cycles of current makes unnecessary any adjustment in position of the dynamo field to compensate for the time advance in the spark as is common practice when the dynamo runs in synchronism with the gas engine, this adjustment being necessary tocompleting the circuit at the instant when the pressure wave is very low, for in such cases the voltage might not be sufficient to generate a spark'to' ignite the engine charge.

Fig. 11. shows my improved system applied to a two-cylinder engine represented by the two

spark plugs

26 and 27, which alternately receive current from the selector distributer 28. This distributer is similar includes two receiving

shoes

29 and 30 by which the charges are led to the two spark plugs. This distributor embodies the feature of automatic advance 'described in connection with distributer 20, for when the ing shoe 29, the -electrical discharge will jump across the intervening gap and the distance jumped will depend on the voltage. of the dynamo which in turn is dependent contemplate.adjusting'the curve of contact between speed and advance of the spark,

thereafter dep'endingentirely on the automatic action of the device, it will be under-, stood that other adjustments may be made, if desired, by shifting the shoe 29 about the minimum dlstance of the spark gap and also readjusting the other distances through which the spark must jump as the engine speeds up. v

Although I have shown only tWo spark plugs to represent a two-cylinder engine it will be understood that the system is equally applicable to four-cylinder engines by merely adding other receiving shoesaround the arc of the rotating selector 31. If desired I may dispense with the transformer 33 and connect the dynamo directly across the circuit.

Fig. 12 is a diagram of the connections of the dynamo showing the two coils 5 and 6 connected in series through a transformer The high potential transformer winding 36 isconnected directly tothe two terminals plug 37. This arrangement simplifies the ighpotential circuit as all interruptions of current take place at the secure by Letters Patent of the United States, is,"

1. The combination with an explosive engine, of sparking terminals for igniting the explosive charge of said engine, means for developing electrical energy for supplying said sparking terminals, and means for de termining the instant at which said energy is delivered to said terminals and for automatically advancing the discharge with respect to the engine piston as the speed of the engine increases including a rotating arm and a receiving shoe, said shoe beng curved away from the arc of the rotating arm.

2. .The combination of an explosive en-- gine, a dynamo for developing energy to explode the charge of said engine, and automatic means for advancing the time of explosion as the speed of the engine increases including a rotating arm'and a movable receiving shoe, said shoe being curved away from the arc of the rotating arm and at a sparking'distance therefrom 3. In an igniting system for explosive engines, a current distributor comprising a 1'0- tating arm, a receiving shoe at a sparking distance from said rotating arm out out of contact therewith, and a circuit including a spark plug and a source of power connecting said rotating arm with said receiving shoe, said receiving sho'e being curved away from the arc of the rotating arm as to automatically advance the discharge with respect to the engine piston as the speed of the engine increases. i

4. The combination with a inulti-cylinder engine, of a plurality of spark plugs therefor, a receiving shoe connected with each spark plug, a rotating arm movable to a sparking distance from each of said receiving shoes, and a source of electrical energy for causing current to jump from said rotating arm to each of said shoes successlon, said receiving shoes beingcurved away" respect to the engine piston as the speed of,

the engine increases.

.' 5. The'combination with an explosive engine, of a source of electrical energy delivering a peaked current wave, and a circuit connected therewith including a spark plug, 'In witnees whereof, I have hereunto set erotatmg arm and a recelvmg shoe at a my hand thls second-day of Aprll, 1906. sparklng dlstance awayfrom szud arm, sald' shoe being eurved'awhy from the are of the ELIHU THOMSON.

rotating arm so' as to automatically advance itnessesz the discharge with respect to the engine pis- JOHN A. MCMANUS, J r.,

ton as the speed of the engine increases. v PHILIP F. HARRINGTON.

Capies of this patent may be obtained for five cents each, by addressing the Commissioner of-Patents.

Washington, I). C.