US2149397A - Electric ignition system - Google Patents

Description

March 7, 1939. p QKONGSTED 2,149,397

ELECTRIC IGNITION SYSTEM Filed Janf23, 1937 I INVENTOR. 75 v IZZdVQ' 2 Jforzysted /QM. )4. Quad ATTORNEY.

Patented Mar. 7, 1939 PATENT OFFICE ELECTRIC IGNITION SYSTEM Ludwig P. Kongsted, Longmeadow, Mass., assignor to American Bosch Corporation, Springfield, Mass., a. corporation oi New York Application January 23, 1937, Serial No. 121,932

3 Claim.

This invention relates to systems for igniting and starting internal combustion engines, and more particularly to a system which incorporates a battery and an externally excited magneto in 5 combination.

The battery systems for starting and igniting as "commonly employedin automotive use at the present time supply a greater ignition current and spark at starting than does a magneto ignition system. The low rotational speeds at which a magneto is driven during the engine starting operation produce arelatively small ignition current. Once the engine is started, the current output of the magneto increases rapidly with increase of rotational speed up to a certain range beyond which the primary currentremains practically constant due to the inherent characteristics of the generating circuit. Thus sparks of approximately the sameintensity. are delivered at all operating speeds of the engine. The converse is true of the battery ignition systems which inherently become inefllcient at high engine speeds due to the decrease in the time period of contact closure of the interrupter in the primary circuit of the ignition coil. The invention herein described provides means for employing a battery starting and ignition system to startthe engine into operation under its own power, and to subsequently employ a magneto ignition system during the normal operation of the engine. It will be appreciated that a starting and ignition system which combines the merits of the fore- I going described'system's will provide better engine performance at high speed and easier starting than either' system singly.

It is an object of this invention, therefore. to

provide a startingand ignition system for internal combustion engines which is more eiilcient in the starting period and during the operation of an engine.

Another object is to provide starting and ignition means which incorporate in a single system the merits of the battery and of the magneto systems.

Another object is'to provide a starting and ignition system which is more simple in design and economical-in construction.

. A further object is to provide a starting and ignition system which functions 'as'a battery system during the engine starting period and as a magneto system subsequently.

Still a-further object is to provide a combined battery and magneto type ignition system in which. the magneto field excitation is supplied by the battery and in which the magneto primary and secondary coils function as a battery energized ignition coil during the engine starting period.

Other objects and advantages will in part be specifically'stated and in part beobvious when the following specification is read in connection with the drawing, in which:

Fig. 1 is a front elevation of the magneto employed in the improved ignition system; and Fig. 2 is a diagrammatic view of the ignition system and related circuits.

Referring in more detail to Fig. 1, the numeral secondary winding. and having a laminated core 2 which is supported on laminated pole pieces 3. Field windings 4 are carried on core members 5 which are supported between the pole pieces 3 and 6. A rotatable flux distributor I is mounted in the circular opening defined by the pole faces 8. While a four pole magneto is illustrated and described it will be obvious that the invention may be employed in connection with magnetcs having a difl'erent number of poles.

In Fig. 2 is illustrated a schematic wiring diagram of the present starting and ignition system, employing a battery excited magneto as above described and in which like parts bear the same reference numerals as in Fig. 1. There is shown a battery 9 having one terminal thereof grounded and the other terminal connected to an ignition switch iii. A conductor ll leads from the switch ID to one end of the series connected field windings 4, the free end. of which is connected to ground to complete a return circuit to the battery 9. A series starting motor I 2 has its armature connected to ground on one side through the winding I3, and the other side is connected through the winding I4 and a conductor including a normally open starting switch IE to the ungrounded terminal of the battery 9. A conductor It connects the winding H with the primary winding of coil I, the other end of which is connected by conductor I! to an interrupter lever l8 carrying a contact l9. Cooperating with the movable contact I! is a grounded sta-' tionary contact 20. A cam 2| operates the interrupter lever It in the usual manner, and the customary condenser 22 is connected in shunta'cross the contacts I! and 20. The secondary winding of the 0011- I is connected to any suitable distributor (not shown) which distributes ignition current to the spark plugs of an associated internal combustion engine.

. In the operation of the system, the ignition switch 10 is closed and the magneto field windl indicates a coil comprising a primary and a l the engine spark plugs.

ings 4 are energized by the battery 9. The starting. switch I is closed to operate the starting" motor I! and turn over the associated engine, notshown. The primary winding of the coil l is connected to the battery 9 through the starting switch l5 and conductor I6, and through conductor I! to the interrupter l8. The interrupted current in the primary winding of coil l produces ahigh 'voltage ignition current in the secondary winding which is led in proper timed relation to The flux distributor I of Fig. 1 is being rotated by the engine, and as the thereof perm field windings 4 are energized the magneto generates alternatingv current which during the cranking of the engine is of small magnitude compared with the current drawn directly from the battery through conductor l6. Sparks of practically the same intensity are therefore delivered to all of the spark plugs during the cranking period. When the engine starts under its own power, the starting switch I5 is opened, disconnecting the starting motor I! and the primary winding of coil I from the battery 9, and the ignition system operates as an externally excited magneto system. The primary circuit under magneto operation is from the primary winding of coil I through conductor l6 and'the low resistance windings ll and I3 of'the starting motor l2 to ground, throughinterrupter contacts 20 and I9, and conductor 11 to the other end of the primary winding. An engine driven generator may be connected as well known in the art to maintain the charge of the storage battery 9'.

It is to be expressly understood that the drawing herein is intended solely for the purpose of illustrating the invention and is not to be construed as in any way limiting the scope, or thevarious possible applications of the invention. Many changes and modifications may be made by anyone skilled in the art without departing from the subjectgnatter of the invention. as expressed in the following-claims.

Having described the invention, what is claimed 1. In ignition apparatus for an internal combustionengine, means for successively providing battery ignition and magneto ignition for said engine comprising a magneto having a primary winding and a secondary winding, a circuit permanently maintaining one end of said windings at a common poteritial} a battery, means including a switch for conducting interrupted battery current through saidprimary winding and deriving battery ignition current from said secondary winding, exciting windings on the stator member of said magneto and having one end ently-connected to ground, a connection between said battery and said exciting windings including a switch independent of said 1 first mentioned switch for energizing said exciting windings during both successive periods of battery and magneto ignition, a rotatable flux distributor in said magneto, and means for conducting interrupted magneto-electric current through-said primary winding and deriving magneto ignition current from said secondary wind- 2. In ignition apparatus for an internal combustion engine, means for successively providing battery ignition and magneto ignition for said engine comprising a magneto having a primary winding and a secondary winding, a circuit permanently maintaining one end of said windings at a common potential, a battery, a connection including a switch between said battery and said circuit, means for conducting interrupted battery current through said primary winding and deriving battery ignition current from said secondary winding, exciting windings on the stator member of said magneto and; having one end thereof permanently connected to ground, a connection-between said battery and said exciting windings including a switch independent of said first mentioned switch for energizing said excit-' ing windings during-both successive periods of battery and magneto ignition, a rotatable flux for conducting interrupted battery current through said primary winding when said switch is closed and deriving battery ignition current from said secondary winding, exciting windings on the stator member of said magneto and having one end thereof permanently connected'to saidbattery, a connection between the other end of said exciting windings and said battery including a second switch independentfof said first mentioned switch forvenergizing said exciting windings during both successive periods of battery and magneto ignition, a rotatable flux distributor in said magneto, and means for conductinginterrupted magneto-electric current through said primary winding and deriving magneto ignition current from said secondary winding.

LUDVIG 'P. KONGSTED.

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