US2007373A - Magneto - Google Patents

Description

July 1935. L. P. KONGSTED 2,007,373

MAGNETO Filed NOV. 14, 1933 INVENTOR. 00707 Plfon arfied BY ATTORNEY.

lfa'tented July .9, 1935 UNITED STATES PATENT OFFICE MAGNETO Ludwig nx wted, 1m to United American Spring- Corporation, field, Mara, a corporation of New York ApplicationNovember 14, 193:, Serial 110.657 ,925 6 Claims. (cl. 171-252) This invention relates to. improvements in mag- .netos for the ignition systems of internal combustion engines and particularly to a magneto of the so-called timer type which is similar in appearance to timer distributors now employed with battery ignition systems.

An object or the invention is to provide a magneto that is simple in construction, inexpensive to make, efllcient in operation and easy'to service.

A further object of the invention is to providea ma neto in which the generating windings an s ationary and "which has a magnet structure to serve as the rotor, the latter preferably being made from a cast magnetic alloy of high coercive force. Thestator is laminated V and provides cores for the generating coils, and the entire construction is assembled in a single housing which, contains also a circuit breaker and distributor. The generating coils of the magneto are intended to be connected to a separate ignition coil, the low tension circuit of which-is periodicallyinter'rupted by the circuit breaker and the 'high tension circuit of which is controlled by the distributor in the usual way. These and other objects and advantages of the invention are made clear in the ensuing description and the novel features are pointed out in the appended claims; but the right is of course reserved to make changes in details of construction without departing from the principle of the invention.

On the drawing: Fig; 1 is an axial section through a according to this invention; Fig. 2 as section taken substantially on the line 2-2 in Fig. 1; Fig. 3 is a top view of the magneto with the distributor' casing removed showing the plan of a the circuit breaker; and Fig. 4 is a diagram of the circuits.

The houeing of the magneto-is made in two sections, the lower section I being preferably of cast iron and the upper section 2.preferably of die-cast aluminum. Between them is the laminated annular stator 3 surrounding therotor l with radial projections of alt rnating polarity. The rotor 4 is cast from cobal other magnetic material of high coercive force and is finished by grinding. Itis driven by a shaft 5 at the cam shaft speed of a '4 .cycle engine and the upper and lower sections, 2 and I respectively, are connected by a sleevefi of tubular sheet steel or brass which envlops the stator 3. The top of section 2 mounts the circuit breaker, to be described-presently, and sup ports the distributor cap I of insulation."

magneto:

magnet steel or The laminations of the stator 3 have internal projections or teeth I forming polepieces for the generating eofls Q. The number of projections I and the number of magnet poles of the rotor '4 depend on the number, of cylinders of the engine for which the magneto is intended, in this case eight. The rotor, which has a central hole at II for lightness, has on its upper and lower ends flanges II held together by rivets I 2 w means ofwhich the end flanges II are caused 10 to grip the rotor 4 flrmly between them. Each flange is provided with driving keys I3 of such size and shape that they flt tightly between the projections of the rotor, so that when the lower flange II is rotated the entire rotor is revolved. The two flanges II are of non-magnetic material such as die-cast bronze, and the keys II, which are preferably four in number on each of these flanges, are integral with the respective flanges. The lower end of sleeve 6 is secured to section I by means of screws I4 and to the section I by spinning the upper edge over a rib or shoulder II. e The lower section I of the housing has a bearing. I for the drive shaft 5 and within sec-- tion the shaft I carries a cup-shaped plate II to which is secured the governor weights I 8 on pivots I These weights are-each pivotally connected to studs 2! secured to the bottom flange II, the studs 2| being connected to the lower flange I I as indicated at 2| in any suitable way. To receive the studs 2| the weights I8 may be slotted so that when the weights are moved outward from the center by centrifugal force the angular relation between the shaft 5 and rotor I is altered to adjust the time of the spark in the well known way. The upper end of shaft 5 is providedhwith a ball bearing in the lower flange I I. The upper flange II has a shaft'projection 23 in line with the shaft I and received in a ball bearing in section 2. The upper part of shaft 23 passes through section 2 and carries the circuit breaker cam 24 and the distributor rotor 25 of insulation.

The outer face of section 2 has a concave seat for acondenser 26 held by a clip 21, and carries the metalcircuit breaker lever 28 on an insulated pivot 23. This lever has a rubbing block ll en-' gaging the cam 24, and a contact 3| engaging the: fixed contact 32. The coils 8 may be connected in series'or parallel or series parallel with each other and one end of their circuit is connected by conductor 33 to binding post 34, this conductor passing through a suitable opening in the top section 2. Afllxed to the insulated binding post 55 for depriving the engine of ignition by grounding- 34 and to the end of the lever 28 is the circuit breaker spring 35 and the conductor 38 leading to the insulated terminal of condens r 26. The

other end of the circuit of coils 9 is onnected by condenser 26 is also grounded on this section.

Hence whenever the contacts 3i and 32 engage each other the circuit of the coils 9 is complete. and when the contacts II and 32 are separated this circuit is broken.

The top of the section 2 has an outside shoulder 39 to receive the rim at the lower open end fo the distributor cap I, which has hightension terminals 49 projecting inside thereof and enlarged at their outer ends to provide sockets 4| embedded in the bosses 42 of the cap for receiving tho sparkplug cables. The upper end of cap I is closed by a plate 43 having a similar central boss 42 and socket 4|, the inner end of this terminal carrying a brush 44 which contacts with a spring 45 secured to the distributor terminal 46 and rotor 25 by rivet 41. The cam 24 has a hollow. projection 48, the outer end of which is counterbored at 49 to provide a shouldef for screw 58 and lock washer. This screw enters a threaded bore in shaft 23 and, when tightened, holds the cam fast on the shaft. The rotor 25 is hollow to receive the projection 48 and is keyed to the projection on the cam as shown .at 5|.

The rims of the sections i and 2 of the housing are shouldered at 52 to provied seats for the stator 3 and the end laminationsare thick, as shown at 53,};0 engage these seats.

The housing of .the magneto may have a hand lever 54 for manual timingin addition to the governor adjustment.

In Fig. 4, the separate ignition coil is indicated with primary winding 56 and secondary winding 51. One terminal of the primary is connected to the binding post 34 and for this purpose the distributor cap may have an opening 55. The other /the other terminal is connected to the primary as 'shown or separately therefrom if desired. The

circuit between the coils 9 and the-lever 28may include a hand switch 58 mounted on the magneto in any suitable position, or a primary grounding switch may be mounted at any convenient point on the engine or instrument board terminal 34. Two generating coils 9 are shown in series. r

' in each of the coils 9, which may therefore be connected in series or parallel combinations to give a suitable primary current for the separate ignition coil. The interrupter 28 is opened successively at or near the point of maximum cur-1' rent by the lobes on the ca'm 24. The energy stored in the magnetic field is prevented from forming a destructive arc at the'contact points 3l' and 32 by the condenser 26, the energy being quickly transferred to the primary winding 56 of the ignition coil. The'rapid change of flux in the core caused by the building up of the prima y current in winding 56 causes a high voltageto be generated in the secondary 51 of sufficient intensity to produce a good hot spark at the spark- P u ingwindings 9 standard ignition coils, such as those now used for battery ignition systems, may be used without change. This,\together with the simple construction of the timer, which has no high tension windings within it, makes this magneto an economical unit to manufacture. By

1 using cast magnetic alloy having high coercive force, the rotor and thus the entire magneto is of suitable size and weight'for mounting on a timer shaft as shown- Though illustrated in Fig. 4 as connected across the primary circuit, the breaker lever may also be in series with the coils 9 and 56.

If desired, the projections of rotor 4 may have laminated pole-shoes secured to their ends in any suitable way. The principal advantage of making the rotor in the shape of a casting resides in the large saving in the machining'operations, since all that.is

necessary is to assemble the cast -rotor and finish grinding it to the proper diameter. At least one magnetic alloy of, high coercive force is adapted for castings. The high coercive forcereferred to is of the order, or higher than that, of 15% cobalt ma t steel.

Having thus described the invention, what is claimed is:

1. In a magneto of the timer type, a housing comprising upper and lower sections, a stator secured between said sections and bearing generating fwindings, a rotor in the housing sur-' terminal carried thereby mounted upon said shaft projection to'be actuated by the rotor.

2. In a magneto of the timer type, a housing comprising upper and lower sections, a sleeve uniting said sections, a stator bearing generating windings secured between the sections, a rotorwithin the housing surrounded by the stator, the

rotor having a shaft. projection-passing through.

one section, a cam and an insulated movable terminal mounted on said shaft projection, a

circuit breaker. on the outer end of said section to be controlled by the cam, an insulating distributor casing secured to said section, fixed ter- 1 find that with the proper design of generatminals carried by said section in cooperative relation to said terminal; and a cap for said casing having a central terminal with a tip inside said casing and a spring attached to the movable terminal bearing upon said tip.

3. A magneto comprising a magnet member with polar projections, a flange secured at each end of said magnet, a plurality of projecting keys on one of said flanges, said keys extending into apertures between said polar projections and establishing a firm driving connection therewith.

4. A magneto comprising a magnet member with polar projections, a flange secured at each end of said magnet, and aplurality of integrally formed keys on each flange, said keys extending into apertures between said polar projections and establishing a firm driving connection therewith.

5. A magneto comprising a magnet member having polar projections, a flange secured to said 8.0 am 3 magnet, and means for establishing a firm drivribs, a non-magnetic flange secured at each end ing connection between said magnet and said flange, said means including a Projecting key on said flanges and engaging said magnet said flange.

a firm driving connection is formed. 6. A magneto comprising acylindricai magnet member having a plurality oi! radially projecting whereby 5 LUDVIG P. KONGBTED.

of said magnet, a plurality of projecting keys on

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