US2422150A - Magneto construction - Google Patents

Description

June 10, 1947. p UPTQN 2,422,150

MAGNETO CONSTRUCTION iled Feb. 10, 1945 4 Sheets-Sh 1 a mmu um m:

INVENTOR. Frederick P. Upton BY 4. f

JUDGE 10, UPTON 2,422,150

MAGNETO CONSTRUCTION Filed Feb. 10, 1945 4 Shee s-Sheet 2 INVENl "ULZ. w Frederick I". l/pim;

June 10, 1947. p UPTON 2,422,150

TTTTTTTTTTTTTTTTT on F. P. UPTON June 10, 1947.

MAGNETO CONSTRUCTION 4 Sheets-Sheet 4 Filed Feb. 10, 1945 INVEN TO R. k I? Upton Patented June 10, 1947 Frederick P. UptornNew Rochelle, N, Y. aaaignor to Geneto Corporation, Mount Vernon. N. Y.

Application February 1 0, 1945, Serial No. 577,281

17 Claims. 01. 1715 209) This invention relates to the construction of a dynamo-electric machine of the magnetotype especially adapted for furnishing electrical ignition for an internal combustion engine having a plurality of cylinders.

In the early days of magneto ignition, the usual magneto was of the two-pole type having a plurality of large horseshoe magnets for supplying magnetic flux to these poles, between which a shuttle-type armature was positioned to rotate,

givingtwo current impulsesper revolution. As the engine cylinders were increased, more com- .plications, entered into the design and construction of the magneto; For, example, a four-cylinder engine of the usual type, requiring two sparks per revolutionofthe crankshaft, required that the magneto armatureorrotor be driven at engine or crankshaft speed, necessitating gears to c drive a distributor at half -crankshaft or camshaft speed.

A six-cylinder engine. of the usual typ requiring three sparks per revolution, necessitated that therotor of the magneto be driven at one-and-ahalf crankshaft speed, with a distributor driven.

at camshaft speed.

In order to supply ignition for enginesv with a' greater number. of cylinders or dual ignition for multi-cylinder engineafurther complications in the design of the magneto were encountered, particularly in view of the fact that engines of today are being driven at very much higher speeds than in the early days of internal combustion engines.

Where the armature or rotor of the magneto is driven even at engine or crankshaft speed, as today, considerable wear is given the magneto, especially the cam and circuit breaker parts operated by the cam. which parts produce the spark through the medium of the ignition coil.

It is therefore the principal object of this invention to meet present-day requirements by pro- .viding a more efllcient magneto so the armature or rotor may be driven at, half-engine or crankshaft speed for a large majority of different types of engines, and yet will be able .to deliver the necessary number of sparks to take care of the Another object of my invention is to provide a magneto in which no distributor gears are required but wherein the distributor spool is uperateddirectly by the rotor shaft by preferably the use oi short magnetic circuits which are controlled so as to get a quick reversal of the flux through the ignition coils and hence more eifective sparks.

Another object of my invention is to provide a magneto so constructed that when'duai ignition is utilized, eachcircult breaker is independent of the other and arranged so that each may be arcuately adjusted with respect to the operating cam.

Another object of my invention islto provide a smaller magneto for a given condition and thereby save space and make it easier'to shield the whole machine. 15

c Other objects will no doubt be apparent to one skilled in this particular art on reading the following specification taken in connection with the annexed drawings, wherein:

' Figure 1 is a vertical section through the magneto on the line C-C of Figure 4, the top ignition coil being shown in elevation and with certain details removed in order that the subject matter may be more clearly shown.

Figurez is a view on the line A-A of Figure 1.

Figure 3 is a view on the line 3-8 of Figure 1.

Figure 4 is a view looking at the distributor or right-hand endotFigure 1.

Figure 5 is a view approximately on the line D-D of Figure 1.

Figure 6 is a perspective view showing the arrangement of magnets and rotor inductors with the coil cores and pole pieces for a two-spark, half-engine speed magneto for a four-cylinder, four-cycle engine.

Figure '1 is a diagrammatic illustration of the ignition circuits corresponding to the structure of Figure 6.

Referring to the drawings, wherein like numbers refer to corresponding parts, I is a framework carrying bearing supports 2 and I, each having similar anti-friction bearings 4 which carry a shaft 5 forming part of the rotor structure. Carried by the shaft 5, in spaced relation and fixed thereto as by pins or rivets 6, are two 1 various multiple-cylinder engines now being made. i

similar support members I and 8 of non-magnetic material. Each of the supports 1 and 8 car-- ries a, plurality of arcuately spaced inductors, those at the drive end of the magneto being designated by the numeral 9, and those at the breaker end, by the numeral I0. As indicated in' Figure 2, the inductors 9 are three in number, spaced on a l20-degree angle.

'Each inductor is made'up of laminations of good flux-carrying material. The laminations are held together and to their respective supports l and 8 by rivets i i which are preferably insulated so as to prevent short-circuited currents in the inductors per so. It will be understood that the number and arrangement of the inductors 9 and It] at opposite ends of the rotor structure may be varied to suit the requirements with respect to the number of engine cylinders and whether 'the cylinders are arranged at odd or even angles.

The stator structure includes a pair of ignition coils l2 and I3, spaced on opposite sides of the rotor shaft 5, and each coil is composed of a primary P and a secondary S, the latter winding being preferably arranged in stages and having its ends protected by suitable insulators I4, I! and i6. Each of the coils l2 and I! has a similar core ll. The core I! for the top coil l2 has pole pieces i8 and 19, while the core II for the bottom coil [3 has arcuately extended pole shoes 20 and 21 at its opposite ends (see Figure 2). The pole pieces l8, l9 and shoes 29 and 2| are positioned in alignment with their respective inductors 9 and I0.

Carried by the frame as part of the stator structure, are two bar magnets 22 and 29, one on each side of a plane passing through the longitudinal axis of the magneto and through the axis of the coils i2 and I3. As shown in Figure 2, these bar magnets are equally arcuately spaced from all of the coil core pole pieces and pole shoes and have arcuate pole faces of a length corresponding to the arcuate length of the coil core pole pieces l9 and [9 to cooperate at their opposite ends with their respective inductors 9 and 10.

The bar magnets are magnetized and positioned in the frame so that their ends are of opposite polarity; for example, looking at Figure 2, the end of the magnet 22 is the north pole, and the end of the magnet 23 is the south pole, so that as the rotor turns, magnetic flux is sent through the respective coils l2 and I3 alternately in opposite directions; and since the magnetic circuit is relatively short, a high efllciency ignition circuit is obtained.

As will be seen from Figure 2, the pole shoes 20 and 2i are relieved between the points 24 and 25, leaving end faces of the same arcuate length as the pole pieces 19 and I9. While this is not necessary so far as the operation of the magneto is concerned, the construction saves time in the machining operation of the stator after its pole pieces and pole shoes, magnets, etc., have been mounted in place. It will also be noted from Figure 2, that the frame has side lugs 26 and 21 with slots 28 therein for mounting the magneto.

From Figure 2 it will be seen that each inductor 9, with its cooperative inductor at the opposite end of the rotor, will produce four sparks per revolution, so that the three inductors, as indicated, will produce twelve sparks per revolution or six sparks per half-revolution. Consequently, this particular structure will deliver two sparks per cylinder for a six-cylinder engine when run at half-crankshaft speed. As has been pointed out earlier in the specification, the ordinary magneto for a six-cylinder engine requires a geared distributor to distribute these sparks. However, with my new construction distributor gears are not necessary, but, instead, I mount on the end of the rotor shaft, a distributor disc 29 of suitable insulating material. The disc 29 carries a distributor contact 39 which is connected by means of a contact 3!, brush 32, spring 33, conductor 34, contact member 35 and terminal 38, with the high-tension winding S of the'coil l2.

The contact 30 moves in jump-spark position with respect to the stationary contacts 31 carried by terminals 39 that are carried by a distributor block 39. The ignition cable 49 is fastened to the distributor block 39 in any satisfactory manner as by snap plugs 4| which make snap contact with the terminals 98. The casing member 42 has cups 43 fastened thereto and within these cups extend projections 44 of the distributor block. Fitting over the cups 43 are screw caps 45, and between the cups 43 and caps 45, are grommets 19 of flexible insulating material which are used for making a moisture-proof joint with the ignition cable.

The distributor disc 29 also carries a jumpspark contact member 44 which is connected by jump-spark contacts 41 and 48 and conductor 49 with a contact member 50 and a terminal 5i connected to the high-tension secondary S of the coil II. It will be understood that the ignition 2 cables 49, which extend from the distributor end of the magneto, are properly connected to cooperate with the contacts 29 and 46 carried by the distributor disc.

Also mounted on the rotor shaft 5, adjacent the distributor disc 29, is a cam 52 for operating circuit breakers 53 and 54 which are connected to the primary P of their respective coils l2 and I3. Each circuit breaker 59 and 54 may be made of suitable insulating material and each mounted on its own ground contact plate 55 and 56, each bein arcuately adjustable independently of the other. A condenser 51 is connected across the contacts of the circuit breaker 53, while a condenser 59 is connected across the contacts of the circuit breaker 54. The circuit breaker end of the magneto shown in Figure 5 has been only briefly described as there is nothing unusual about the construction thereof and the details form no part of this present invention which is directed more particularly to the general construction of the magneto.

In Figure 6, I have shown diagrammatically an arrangement of a pair of bar magnets associated with a rotor having a pair of inductors at each end for cooperation with a pair of ignition coil cores and pole pieces. In this figure, the coil cores are indicated at 69 and 5 I, the core 69 having pole pieces 62 and 63, while the core 9| has pole pieces 64 and 95. The bar magnets are illustrated by the numerals 68 and 61. The inductors of the rotor at one end are 68 and 69, while at the other end of the rotor they are illustrated by the numerals n and H.

Figure 7 illustrates diagrammatically the function of the structure of Figure 6; that is to say, as the rotor turns the inductors 69 and 10 will produce four double sparks pe revolution, while the inductors 69 and ll will also produce four double sparks per revolution, or a, total of eight 50 sparks per revolution. For a four-cylinder, fourcycle engine, two sparks are required per revolution. Consequently, the structure of Figure 6 may be driven at half-engine speed and produce two sparks for each cylinder as indicated in Figure 7. A cylinder is illustrated by the letter C, and the distributor by the letter D. The ignition coils may be represented by the same numerals l2 and I3 as heretofore, the primary and secondary being marked P and S, respectively, while 70 the distributor disc is in the form of a double arm having contacts 12 and I9 which engage alternate contacts 14 and 15.

From what has been said, it will be readily appreciated that the details entering into the construction may be varied without departing from the spirit of'my invention or the scope of the appended claims. For example, I may reduce the length of the bar magnets as illustrated by the lines ll--18 in Figure 6, and hence the cost there of, and use suitableiron pole pieces bearing the the numbers 6661 at both ends.

What I claim is:

l. A magneto including a frame, a pair of permanent magnets carried by the frame, one on each side of a plane through the longitudinal axis of the magneto as specified herein, a pair of coil core pole pieces carried by the frame in arcuate spaced relation between said magnets and operatively connected with each end of a coil core, the said pole pieces being disposed, one each, adjacent opposite ends of said magnets, a pair of pole shoes carried by the frame and disposed, one each, directly opposite the coil core pole pieces, the shoes being operatively connected one at each end of another coil core, each of said cores carrying an ignition coil and a rotor carried by the frame and having arcuately spaced inductors at each end of the rotor for cooperation with said magnets, coil core pole pieces and pole shoes for producing flux changes through said coil cores as and for the purposes described.

2. A magneto including a frame, a pair of bar magnets carried in spaced relation on opposite sides of the frame, a pair of coil core pole pieces spaced between and opposite the ends of the mag-' nets, a pair of arcuately formed pole shoes of extended arcuate length carried by the frame, one at each of its ends, with a coil core end in engagement with each shoe, each pai of coilcore pole pieces and shoes being bridged by a separate core of magnetic material carrying an ignition coil, and a rotor carried by the frame and having inductors at each end for cooperating with the magnets, coil core pole pieces and pole shoes for sending magnetic flux simultaneously through said coil cores as and for the purposes described.

3. A magneto as defined in claim 2, further characterized in that the said pole shoes have a length such that two inductors at each end of the rotor will jointly overlap their cooperative pole shoes.

4. A magneto as defined in claim 2, further characterized in that the said pole shoes have a length such that two inductors at each end of the rotor will jointly overlap their cooperative pole shoes, while the bar magnets are positioned in the frame in reverse polarity for getting alternate reversals of the magnetic flux through the coil cores.

5. A magneto as defined in claim 2, further characterized in that the rotor has its inductors atone end arranged a relatively wide distance from the inductors at the opposite end and beyond the ends of the ignition coils.

6. A magneto as defined in claim 2, further characterized in that the rotor for a two-spark,.

six-cylinder engine has two spaced groups of three inductors, each group being arranged on similar 120 radius lines, whereby each pair of inductors of the cooperative sets will produce four sparks per revolution of the rotor, and the whole rotor will produce twelve sparks per revolution, or two sparks for each cylinder of a six-cylinder engine when the rotor is run at half-engine speed.

7. A magneto as defined in claim 2, further characterized in that the said po'le shoes have a length such that two inductors at each end of the rotor will jointly overlap their cooperative pole shoes, said pole shoes having projecting polar areas at their opposite ends, the arcuate length of these areas being substantially the same as the arcuate length of the said magnets and coil core pole pieces.

8. A magneto having a stator structure, ignition coils and a co-related rotor structure so that rotor need only be driven at half-engine crankshaft speed, to deliver two simultaneous sparks for each cylinder of a four-cylinder, four-cycle engine, the rotor structure having two sets of equally arcuately spaced inductors, each set being spaced apart on the rotor shaft a substantial distance, the stator having ignition coils oppositely positioned on a diameter of the magneto,

each coil having a core of magnetic material with polepieces at opposite ends of the cores, bar magnets positioned in arcuately spaced relation between the pole pieces of one coil andthose of the other coil, the arcuate length of the magnets, pole pieces and rotor inductors being such as to produce four sparks per rotor inductor per revolution of the rotor.

9. A two-spark magneto including; two independent coils with cooperative cor'es and pole pieces the latter of which are positioned entirely outside the planes of the coil ends, two independent sources of magnetic flux comprising bar magnets extending in a. direction parallel to said coil cores, a single rotor structure carrying fluxdirecting members having distributing surfaces outside the planes of said coil ends and in cooperative alignment with the core pole pieces to direct the magnetic flux simultaneously from aid sources through said coil cores alternately in opposite directions, and a separate circuit breaker for controlling each coil,

10. A two-spark magneto including; two independent coils with cooperative cores and pole pieces the latter of which are positioned entirely outside the planes of the coil ends, two independent sources of magnetic flux comprising bar magnets extending in a direction parallel to said coil cores and'arcuately positioned in spaced relation, one on each side of one of said coils and its core, a single rotor structure carrying flux-directing inductors having distributing surfaces outside the planes of said coil ends and in cooperative alignment with the core pole pieces to direct the magnetic flux simultaneously from said sources through said coil cores alternately in opposite directions, and a separate circuit breaker actuated by said rotor structure for controlling the action of each coil.

11. A two-spark magneto including; two independent coils with cooperative cores and pole pieces, two independent sources of magnetic flux each composed of a, bar magnet having arcuate polar faces and spaced on opposite sides of a planepassing through the axis of the magneto and the center lines of the two coil cores and extending substantially parallel with the cores, 9, single rotor structure carrying flux-directing inductors operable to direct the magnetic flux simultaneously from said bar magnets through said coil cores alternately in opposite directions, and a separate circuit breaker actuated by said rotor structure for controlling the action of each coil.

12. A magneto including; a plurality of independent coils with cooperative cores and pole pieces thelatter of which 'are positioned entirely outside the planes of the coil ends, a plurality of independent sources of magnetic flux comprising bar magnets extending in a direction parallel to said coil cores, 3, single rotor structure carrying flux-directing members having distributing sur- 7 faces outside the planes of said coil ends and in cooperative alignment with the core pole pieces to direct the magnetic flux from said source through said coil cores alternately in opposite directions, and a separate circuit breaker for controlling each coil.

13. A magneto including a frame, a plurality of independent ignition coils with cooperative cores and pole pieces the latter of which are positioned entirely outside the planes of the coil ends, a plurality of independent sources of magnetic flux comprising bar magnets extending in a direction parallel to said coil cores all carried by the frame, a single rotor structure also carried by the frame and carrying flux-directing members having distributing surfaces outside the planes of said coil ends and in cooperative ali ment with the core pole pieces to direct the magnetic flux from said sources through said coil cores alternately in opposite directions, circuit breaker means for controlling each coil, a casing member carried by the frame, a distributor block carried by said casing member, and a distributor spool carried by the rotor structure for cooperation with said block.

14. A two-spark magneto as defined in claim 9, further characterized in that the sparking current is distributed in said coils to a cooperative distributor block by a double contact spool, one contact for each coil, carried directly by the rotor structure.

15. A magneto as defined in claim 1, further characterized in that the coils are controlled by separate circuit breakers actuated by cam means on the rotor structure which also carries directly a distributor spool having contacts connected, one each, to each of said coils, and a distributor block carried by the frame for cooperation with said spool.

16. A magneto having a stator structure and a rotor structure in cooperative relationship so as to be capable of delivering two sparks simultaneously even when the rotor structure is driven at one-halr engine crankshaft speed, the rotor having two separated sets of arcuately spaced inductors, the sets being longitudinally spaced from each other a considerable distance, the stator structure having ignition coils oppositely positioned on opposite sides of the rotor, each coil having a. core of magnetic material with pole pieces at opposite ends of the core in alignment with the inductors of their respective sets, bar

magnets carried by the stator structure and positioned in arcuately spaced relationship away from the pole pieces so the inductors will produce sparks from the coils when they leave the mag- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,564,102 Nowosielski Dec. 1, 1925 FOREIGN PATENTS Number Country Date 214,682 Great Britain Apr. 22, 1924

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