US1392364A - Ignition device for internal-combustion engines - Google Patents

Description

APPLICATION FILED APR-2. I921.

Patented Oct. 4, 1921.

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F. A. SMITH. IGNITION DEVICE FOR INTERNAL COMBUSTION ENGINES,

APPLICATION FILED APILZ, 192l- Patented Oct. 4, 1921.

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. FREDERICK ARTHUR PATENT OFFICE.

SMITH, 0F BRASTED, ENGLAND.

IGNITION DEVICE FOR INTERNAL-COMBUSTION ENGINES.

Application filed April 2,

To all whom it may concern: V

Be it known that I, FREDERICK AR/THUR SMITH, a subject of the King of England, residingat Brasted, Kent, England, haveinvented certain new and useful Improvements in I nition Devices for Internal-Combustion ngines, (for which I have filed an application in England Jan. 7, 1920, Patent No. 600,120,) of which the following is a specification.

This invention is for improvements in or relating to ignition devices for internalcombustion engmes of the type comprising an ignition or firing chamber provided with an electric igniter, and having at its inner end an inlet for an auxiliary ignition charge of explosive mixture, and terminating at its outer end in a spout or flame nozzle extending toward or into the main combustion chamber of an engine.

Ignition devices of the type referred to have been proposed but in all of such proposals the ignition or firing chamber is provided with a sparking-plug either at its inner end or approximately midway along its length, and is shaped like a bottle with a neck-that is narrow in relation to the diameter of its body. In such a construction there is an abrupt change of diameter where the neck joins the body of the chamber. Consequently, when compression takes place in the cylinder and compressed gases from the cylinder are forced through the narrow neck, violent turbulence ofthe gas or and effectively 'IIllX with themselves an ignitible charge that has been admitted into the inner end of the chamber. 'Under some conditions such a mixture cannot be readily 1gnited by the igniter.

This invention has for its main object to obviate this defect and to provide a construction wherein an ignitible charge admitted to a part of the firing chamber surrounding the igniter shall remain surrounding the operative part of the igniter while the gases from the cylinder are being compressed into'the chamber.

According to the present invention an ignition device of the type described for internal-combustion engines is characterized by the fact that the ignition or firing (chamber, or a portion thereof, 1s so constructed and shaped'as to form a pocket or space for accommodating the igniter points, which pocket or space is of regulartubular forma- Specification of Letters Patent.

Patented Oct. 4, 1921.

1921. Serial No. 458,059.

tion'without an abrupt expansionimmediately behind the outlet orifice, and it and the remainder of the ignition or firing chamber are of such proportions and shape, and so situated, relatively to each other and to the main combustion chamber of the engine that, during compression, only the auxiliary ignition charge is compressed Stratified around the igniter points, no turbulence being set up during such compression to displace the auxiliary ignition charge clear from the igniter points. By adopting such a construction, it will be insured that the ignition charge will be in a position to be ignited first and thus serve its proper purpose. If, how- .ever, the volume capacity of the firing chamber is limited to such a degree that the compressed auxiliarv charge is insufiicient to insure that the igniter points shall be imviously its utility will be destroyed. It is also important that any additional space constituted by a recess in-the sparking-plug or device should be borne in mind in calculating the volume of the pocket for the igniter.

For a more complete understandin' the invention there will now be descrilo by way of example only and with reference to the accompanying drawings, certain construbtional forms of ignition device according to the present invention. It is to be understood, however, that the invention is not limited to the precise constructional details illustrated.

In these drawings:- fFigure 1 is a sectional view through one form of ignition device in which there is shown a sparking-plug with a recess around its sparking points; 7

Fig. 2 is a similar view of a modified construction embodying a sparking-plug without such a recess;

Fig. 3 is a sectional view through a construction particularly suitable for use with large engines, an

Fig. 4 is a section ficat'ion.

Like reference numerals indicate like parts throughout the drawings.

Inthe construction shown in Fig. l-the ignition device comprises a passage 10 which is of larger cross section at its ends than toward its middle. One end 11 expands toward the engine cylinder thus forming a kind of bell mouth to emit a large spread through a further modiof ed,

'- ward its end 11 adjacent the duit 14 to the inlet 15 which has a ball valve 16. The sparking plug points are illus-' trated at 17 and 18 and around the former the sparking plug is formed with a recess 19, this being a well-known type of sparking plug. The expanded end 12 of the passage 10, together with the conduit 14: and

' recess 19 constitute in this construction the pocket or space aforesaid in which the aux.- iliary ignition chanrge is compressed around the igniter. In this figure the ignition charge is illustrated diagrammatically in the position it will occupy during compression and immediatelybefore ignition, by a series of dots. The remainder of the passage 10 will be occupied by the contents of the main engine combustion chamber. The volume of this pocket or space around the igniting points and the volume of the space extending away from the igniter toward the engine cylinder are so proportioned relatively to each other and to the main combustion chamber of the engine, and the walls of these spaces are so shaped, that during compression the main engine charge, or exhaust gases left in the engine cylinder, will be unable to reach such igniting points. Thus the auxiliary ignition charge will be in a position to be ignited first and thus serve its proper purpose.

1 the construction shown in Fig. 2 the ignltion or firing chamber 10 contracts toengine cylinder. At its other end it is fitted with an inlet valve 20 and close to this latter with a sparking plug 13. In this construction the pocket or space into which the ignition charge is.

to be compressed is constituted by the large end 12 of the chamber 10 and an enlarged portion 21 of this chamber.

In the construction shown in Fig. 3 the igniter 13 and inlet valve 20 are arranged c ose together at the inner end of a comparatively narrow tubular its other end opens into a larger box or chamber 23 which communicates withflame nozzle 24. This enlarged chamber 23 is suitable for receiving a large auxiliary ignition "charge for use in big engines.

'In Figs. 1 and 2 the ignition chamber takes the form of a straight narrow passage and this is in some instances advantageous but it is not essential as in other constructions, as for instance that shown in Fig. 4, the chamber may take the form of a curved conduit 25 o'penlng at one end into a flame nozzle 26 and having at its other end the inlet valve 16 and igniter 13. H

In another construction the ignition chamber maybe of tubular shape as at 22 in Fig.

ing at the other end into a flame nozzle incates with the flame nozzle.

pocket 22 which at igniter and openstead of, as shown in Fig. 3, into an enlarged chamber 23, which itself communi- In this construction of ignition device the tubular ignition chamber may be parallelthroughout its length except .for the portion immediately adjacent the flame nozzle, where it may be gradually contracted to a small'extent. Furthermore, in such a construction the, parallel tubular portion of the ignition chamber may be occupied by a solid member having tacts with the inner walls of the ignition chamber one or more helicalpassages leading from end to end of such member, namely from near the igniter to near the flame nozzle.

.Many other constructions may be adopted without departing from the spirit and scope of the invention, and it is to be understood that the use of the ignition device according to the present invention is not restricted to any particular type of main charge, the essential point being that the igniter points are arranged in a ocket or other portion of the ignition cham er which pocket or, other chamber portion, and the remainder of the ignition or firing chamber, are of such dimensions and shape, and so situated, relatively. to each other and to the main combustion space of the engine that during com- .pression the auxiliary ignition charge is .compressed around,

to 1secure by Letters invention and desire atent 1s An ign tion device for internal-combustion engines comprising an ignition chamber, an electric igniter therein, an inlet at the inner end of the chamber for an auxiliary i ition charge of explosive mixture, and a ame nozzle at the outer end of the chamber which nozzle extends toward the main combustion chamber of the engine, said ignition chamber being so constructed and s aped as to form a space for accommodating the i iter points, which space is of regular tu ular formation-without an abrupt expansion immediately behind the orifice and it and the remainder of the igniltion c amber are 'of such roportions and shape, and so' situated, re atively to each other and to the main combustion chamber of the engine, that, during compression, only the auxiliary ignition stratified aroundthe 'i iter points, ;no turbulence being set up uring such compression to displace the auxiliary ignitionl charge clear from the igniter points.

charge 1s compressed An ignition device for internal-com around its exterior which conoutlet chamber, an igniter therein, an inlet into said chamber for an auxiliary ignition charge of explosive mixture, and a flame nozzle at the outer end of the chamber which nozzle extends toward the main combustion chamber of the engine, a portion of said ignition chamber being so constructed and shaped as to form a pocket for accommodating the igniter Without an abrupt expansion immediately behind the outlet ori-' fice, and said pocket and theremainder of the ignition chamber being of such proportions and shape, and so situated, relatively to each other and to the main combustion chamber of the engine,'that, during compression, only the auxiliary ignition charge is compressed Stratified around the igniter, no turbulence being set upduring such compression to displace the auxiliary ignition charge clear from the igniter.

3. An ignition device for internal-combustion engines comprising an ignition chamber, an electric igniter therein, an inlet .at the inner end of the chamber for an auxiliary ignition charge of explosive mixture, and an outwardly flaring flame nozzle at the outer end of the chamber which nozzle extends toward the maincombusti'on chamber of the engine, said ignition chamber being so constructed and shaped as to form a space for accommodating the igniter points, which space is of regular tubular formation without an abrupt expansion immediately behind the outlet orifice, and it specified.

4. An ignition device for internal-combustion engines comprising an ignition chamber, an electric igniter therein, an inlet at the inner end of the chamber for an auxiliary ignition char e of explosive mixture, andva flame nozz e at the outer end of the chamber which nozzle extends toward the main combustion chamber of the engine, said ignition chamber being so constr'ucted and shaped as to form a space for accommodating the igniter points, which space, and the remainder of the igniter are of such proportions and shape, and so situated, relatively to each other and the main combustion chamber of the engine that, during compression, only the auxiliary ignition charge is compressed stratified around the igniter points, it (the auxiliary ignition charge) not being displaced clear therefrom by any part of the contents of the main engine combustion chamber, for the purpose In testimon whereof I aflix my signature. FRED RICK ARTHUR SMITH.

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