US2422151A - Single and mutispark magneto - Google Patents

Description

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vF. P. kUPTON SINGLE AND MULTISPARK MAGNETO Filed Feb. 10, 1945 2 Sheets-Sheet N @A 22N as M2 2 m" .1 11| I I Z \\M. N` W MN Il* Il N n. .W .v `N Lam `.U\u\

IN VEN TOR. FREDER/CK? UPTON BY ,i2/@wf June 10, 1947. F, p, UPTON 2,422,151

SINGLE AND MULTISPARK MAGNET@ Filed Feb. 10, 1945 2 sheets-sheet FIG 3 IN VEN TOR. FREE//CK- R UP TUN Patented. June l0, 1947 SINGLE AND MULTISPARK MAGNETO Frederick P. Upton,

New Rochelle, N. Y., assignor to Geneto Corporation, Mount Vernon, N. Y. Application February 10, 1945, Serial No. 577,282

8 Claims.

This invention relates to the construction of a magneto particularly adapted for furnishing ignition current for internal combustion engines having one or more cylinders. The construction to be hereinafter described is such that the elllciency of the magneto can be operated at onehalf engine crankshaft speed and still get firstclass ignition. Where the magneto is operated at this half-speed, its life is more than doubled as the Wear on the circuit breaker-one of the vital elements in the apparatus and subject to the greatest wearis materially reduced, especially where the engines of today are operated at much higher speeds than in the early days of the internal combustion engine.

It is therefore the principal object of this invention to provide a magneto having the advantages above set forth.

Another object of the present invention is to provide a'magneto which can be more cheaply made and assembled than prior-art structures. Another object of my invention is to provide a construction, the principles of which may be utilized in the manufacture of magnetos for single or multiple-cylinder engines, and when utilized for multiple-cylinder engine work a distributor need not be used, but a distributor spool may be mounted directly on the rotor shaft, thereby further reducing the size, weight and cost of the magneto.

A further object of my invention is to provide a magneto construction in which the magnetic circuit is short and a quick reversal of the flux through the core of the ignition coil is attained.

Other objects will appear to one skilled in the construction of magnetos from a reading of the following specication taken in connection with the annexed drawings wherein:

Figure l is a longitudinal, sectional view through'the magneto, certain of the parts being shown in elevation. i

Figure 2 is a section on theline 2-2 of Figure 1.

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

Figure 4 is a view on the line 4 4 of Figure 1.

In the various views wherein like numbers refer to corresponding parts, I is in general a framework having a mounting flange 2 with mounting holes 3 and 4 therein. The frame I -carries bearings 5 and 6 supporting the rotor structure having a shaft 1 of strong non-magnetic material. On the shaft 'I are mounted, in spaced relation and longitudinally of the shaft 1, circular members or discs 8 and 9. 8 has a plurality of arcuately spaced integral lobes I0 and II extending therefrom toward corresponding integral lobes I2 and I3 extending from the disc 9. As shown in the various figures, the rotorhstructure has four of these lobes spaced ninety degrees apart around the shaft The disc 2 l. On the circuit breaker end of the shaft l, is carried a cam I4 for operating a circuit breaker of any satisfactory type but which, for the sake of clarity, is not shown in the drawings as it forms no part of the present invention. However, it is old and well known that the circuit breaker controls the function of the primary of the high-tension ignition coil On the frame is positioned a semi-circular magnet I5 which is held in place between two semi-circular pole shoes I6 and Il through the medium of a bolt or screw stud I8 that is screwthreaded at I9 into a part of the frame and has a shoulder 20 to engage the opposite end frame member, it being understood that the head 2I of the stud I8 is slotted to receive a screwdriver for'drawing the pole shoes I6 and IT tightly against the edges of the magnet I5, it being further understood that the magnet I5 is magnetized in such a way that its polarities are as indicated in Figure l, thereby giving its DOle shoes I 6 and Il corresponding magnetic polarity. The magnet pole shoes I6 and Il have semi-circular arcuate faces for very close cooperation with the discs 8 and 9 which, as the shaft 1 rotates, pick up the magnetic ilux from the magnet pole shoes I6 and Il, and then through their respective lobes I0, I I-I2, I3, the magnetic flux is carried upwardly through the coil core pole pieces 22 and 23, and thence through the coil core 24 which carries the coil composed of a primary winding P and a secondary S switch, as shown in Figure 2, has ts turns staggered and provided with end insulators 25 and 26, while the entire coil has end insulators 21 and 28.

At this point, I desire to point out that the coil core pole pieces 22 and 23 are assembled on studs 29 and 30, preferably insulated from the laminations by tubular insulators 3| so as to prevent circulation of a short-circuited current which might occur through these studs due to the passage of the magnetic flux if the studs were not insulated from the laminations. As an alternative, the studs need not be insulated from the laminations so long as they are insulated from the frame support members, which construction would prevent the circulation of any current through the studs that would be detrimental to the operation of the magneto.

Furthermore, by assembling the laminations as units in the manner just described and then assembling them directly on the frame members 38 and 39, made of non-magnetic material such as aluminum or other suitable metal, brings about a material saving in cost of construction, as prior-art practice has been to assemble the core pole pieces and then send them outto a molding factory for them to be molded or cast into the frame.

For protecting the coil, a cover 32, preferably of strong insulating material, is ntted over the coil and then fastened to the frame in any satisfactory manner. The cover 32 has molded therein a plug socket-type contact member 33, the plug end of which is adapted to contact with a spring 34 fastened to the ignition coil in any satisfactory manner and connected to the nongrounded end of the secondary S. Therefore, in order to make connection with the coil, a conductor cord from the engine spark plug is inserted into the socket portion of the member 33. While the circuit breaker parts have not been shown, a space for a chamber 35 is provided for them and a cover 36 is held by screws 31 to a frame member.

By using a stationary magnet as described, I can use a rotor composed of two identical pieces as heretofore set forth, made of drop-forgings from ingot iron having high fiux-carrying ability, thereby necessitating only a very small amount of machine work on these parts. The magnet pole shoes I6 and Il are also made of high fluxcarrying ingot iron, and after they have been assembled in the manner described, along with the coil core pole pieces, a simple machine operation places the whole stator structure in condition to receive the rotor structure. Since there is substantially no air gap between the magnet pole shoes i6 and i1 and the edges of the magnet, and a very small air gap is used between the rotor discs 8 and 9 and the magnet pole shoes i6 and Il, a very short and eiiicient magnetic circuit is established which adds to the emciency of the operating characteristics of the magneto. To assist in visualizing the passage of the magnetic flux, a polarity has been assigned (Figure l) to the magnet l5, its pole shoes i6 and il and their cooperating inductor discs 8 and 9, and their Arespective lobes.

By using a fixed semi-circular magnet in the manner described, I have found that this provides a much cheaper construction than the mounting of a permanent magnet of the Alnico type on the rotor shaft. Furthermore, since the rotor structure is made of ingot iron, it is far easier to get a dynamic balance by removing metal from some part thereof, than it is to remove metal from a hardened rotating magnet, so that much time is saved in getting a perfectly balanced rotor.

While I have shown a magneto for a single cylinder, four-cycle engine, the principles involved in the construction of this magneto may be applied to a multi-cylinder engine as it will be seen that since the rotor carries four lobes, a plurality of sparks may be obtained from the ignition coil for each revolution of the rotor; hence, it is only necessary to use the proper type of cam for operating the circuit breaker and a distributor of the general type as shown in my application Serial No. 577,281, filed February 10, 1945.

Furthermore, while I have shown the lobes of the rotor as being equally spaced, they may be set at any desired angle to provide ignition for engines whose cylinders are not set at uniform angles; and, likewise, the number of the lobes may be changed to suit conditions.

What I claim is:

l. A magneto having a, frame, a semi-circular magnet carried by the frame, the magnet having its magnetic poles located on its opposite axial edges, semi-circular pole shoes held in the frame in edge contact against said magnet edges and each other in arcuate spaced relation for passing lcharacterized in that the rotor inductor units the magnet flux, picked up by said discs from the magnet, to said coil core pole pieces and through said core to excite said coil.

2. A magneto as set forth in claim l, further characterized in that the magnet is carried by the frame directly opposite to the location of the ignition coil.

3. A magneto as set forth in claim 1, further characterized in that the magnet is carried by the bottom part of the frame below the rotor structure.

4. A magneto as set forth in claim l, further are alike and each unit is one piece of material having high permeability such as ingot iron. A

5. A magneto as set forth in claim l, further characterized in that the rotor inductor units are alike and each unit is one piece of material having high permeability such as ingot iron, and further characterized in that the magnet pole shoes are each in one piece and also of a material having high permeability such as ingot iron.

6. A magneto as set forth in claim 1, further characterized in that the coil core pole pieces are composed of laminations of high permeability assembled as units and insulatingly mounted in the frame.

'7. A magneto having a stationary semi-circular magnet with its poles located on its axial edges, a rotor having a shaft and carrying two integral inductor` units spaced longitudinally on the rotor, stationary means engaging said axial edges for conducting the magnetic flux from these axial edges of the magnet to the inductors, an ignition coil having a core with pole pieces positioned so said inductors will pass the magnetic flux to them and through the coil core alternately in reverse direction.-

8. A magneto having a stationary semi-circular magnet with its poles located on its axial edges, a rotor having a shaft and carrying two integral inductor units spaced longitudinally on the rotor, each inductor unit comprising an annular disc having lobes extending toward each other but in arcuate spaced relation, semi-circular magnet poles located against the axial edges of the magnet and having arcuate surfaces in close alignment with said discs for conducting the magnetic flux from the magnet to said discs and their lobes, an ignition coil having a core with pole pieces positioned so said lnductors will pass the magnetic flux to them and through the coil core alternately in reverse direction.

FREDERICK P. UPION.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,853,220 Nowosielski Apr. 12, 1932 FOREIGN PATENTS Number Country D ate 214,682 Great Britain Apr. 22, 1924

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