US2048896A - Magneto - Google Patents

Description

July 28, 1936. w J sp 2,048,896

MAGNETO Filed Jan. 16, 1934 INVENTOR BY 40 d. 45 001960 JULY/Less: e/

4 Sheets-Sheet l July 28, 1936.

W. J. SPENGLER MAGNETO Filed Jan. 16, 1934 4 Sheets-Sheet 3 INVENTOR Spenger W A TTORNE y July 28, 1936.

W. J. SPENGLER MAGNETO Filed Jan. 16, 1934 4 Sheets-Sheet 4 Patented July 28, 1936 MAGNETO Walter J. Spengler, Sidney, N. Y., assignor, by

mesne assignments, to Bendix Aviation Corporation, South Bend Delaware Ind., a corporation of Application January 16, 1934, Serial No. 706,857

15 Claims.

This invention relates to magneto generators and more particularly to a high tension generator particularly adapted for the ignition of internal combustion engines.

It is an. object of the present invention to provide a novel high tension generator which is simple and rugged in construction and efficient and reliable in operation.

It is another object to provide such a device which incorporates an impulse coupling formed as a unit therewith.

It is a further object to provide such a device in which the various moving parts are readily assembled and the bearings therefor are so arranged as to provide a rigid assembly free from end play or lost motion.

' It is another object to provide such a device which may be easily taken down, adjusted and reassembled without the use of special tools.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is .a view in perspective of a magneto generator embodying a preferred form of the present invention;

Fig. 2 is substantially a vertical axial section of the device;

Fig. 3 is a top top cover plate removed;

Fig. 4 is a perspective view partly in section of the drive shaft and its associated parts;

Fig. 5 is a perspective view of the rotor and its associated parts, partially disassembled;

Fig. 6 is a perspective view of the driving shaft and rotor in assembled relation;

Fig. 7 is a vertical section taken substantially on theline 1-1 of Fig. 3;

Fig. 8 is a vertical section taken substantially on the line 8-8 of Fig. 2;

Fig. 9 is a vertical section taken substantially on the line 9-9 of Fig. 2; and

plan view of the device with the Fig. 10 is a view similar to Fig. 9 showing the I parts of the impulse coupling in active position.

Referring first to Figs. 1, 2 and 3 of the drawlngs, there is illustrated an integral frame member I generally in the shape of a rectangular box having one open end which is arranged to be closed by an end cover plate 2 detachably fixed thereto as by means of studs 3, and an opening in the top adapted to be closed by a top cover member 4 detachably fixed to the frame 5. The closed end of the frame I is provided with a bearing seat 6, and the end cover plate 2 is also provided with a bearing seat I in alignment therewith.

by means of studs A driving shaft 8 (Figs. 2 and 4) is provided with a smooth surface of relatively-large diameter adapted to receive a hearing I I which is arranged to fit the seat I in the end plate 2. The bearing I I is adapted to be retained in end plate 2 by suitable means such as a thrust ring and grease retaining member ID which is held in position by swedging over the edge of the seat 'I in the end plate. Adjacent the portion 9 of the drive shaft, the shaft is reduced in diameter as indicated at I2, forming a shoulder I3. Toward the inner end of the shaft 8 a third smooth portion I4 of further reduced diameter is provided, and the portion I5 of the shaft between the parts I2 and I4 is still further reduced to provide a clearance space. The inner end of shaft 8 is provided with a bearing seat I6 of a diameter slightly smaller than the portion I4, on which a bearing I1 is arranged to be held by suitable means such as a locking ring I8 engaging in a groove I9 at the end of the shaft. Preferably a thrust ring and grease retaining element 2| is inserted between the bearing I1 and the shoulder 22 formed between the portions I4 and I6 of the shaft.

A rotor indicated generally by numeral 23 (Figs. 2 and 5) is freely journalled-on the driving shaft 8 by means of the bearing portions I2 and I4 of said I shaft. The rotor 23 comprises a central hollow sleeve 24 formed at one end as at 25 to bear on the portion I2 of the shaft, and having a portion 26of reduced internal diameter for bearing on the portion l4 of the shaft. 'A magnetic end plate 21 is fixedly mounted in any suitable way on the end 25 of the sleeve 24, being positioned thereon preferably by means of interengaging shoulders 28 therebetween. A non-magnetic end plate 29 is mounted on the 'end 26 of sleeve 24 and is suitably fixed thereto as by means of-a groove 3| in the sleeve into which a lip 32 of the end plate 29 is forced when the'parts are assembled.

A plurality of bar magnets 33 of equal length are disposed axially about'the sleeve 24 between the end plates 21 and 29, being clamped tightly between said plates when the end plate 29 is assembled to the sleeve 24. As here shown, these bar magnets are four in number and are arranged in groups of two having their poles similarly disposed, the two groups having their poles oppositely disposed. The poles of each group of magnets adjacent the non-magnetic end plate 29 are united by means of pole pieces 34 of magnetic material, which are preferably formed as shown of laminations of pure iron. All the magnet bars are united by means of lamination's of non-magnetic material such as aluminum or brass, sufiicient laminations being used to comrim of the end plate 21.

pletely fill the space between the end plates 21 and 28 whereby when the end plate 28 is forced into position on the sleeve 24, all the parts of the rotor aretightly clamped together into a rigid unit. The laminations 85 of the rotor are further clamped together by means of bolts 36 traversing the magnetic end plate 21 and provided with nuts 31 which may be tightened by means of a screw driver, openings 88 being provided [in the non-magnetic end plate 28 for that purpose.

The rotor 23 is yieldably connected to the driving shaft 8 by resilient means in the form of a coiled spring 38 seated in the clearance space formed by the portion l5 of the shaft 8 and'anchored to said shaft at one end as by means of a terminal portion 4| traversing an opening in the shaft. The opposite end 42 of the spring is bent axially and extends into a slot 43 in the magnetic end plate 21, suitable slots 44 and 45 being provided in the sleeve 24 and laminations 35 to permit the assembly of the shaft and spring within the rotor. This resilient connection between the shaft and rotor forms one element of an impulse coupling whereby at low speeds of the driving shaft the rotor is retarded and accelerated periodically in order to generate adequate ignition current at the proper intervals.

In order to provide the retarding means of the impulse coupling, the magnetic end plate 21 is formed with a cup-like recess 46, and a centrifugal weight or latch member 41 (Figs. 9 and 10) is pivoted at 48 on the head of one of the bolts 36. The point 49 of the latch is adapted to project beyond the periphery of the cup 46 and engage a stop member in the form ofa stud 5| in the magneto frame, thereby obstructing the rotation of the rotor. Means are provided for tripping the latch-in the form of a stud 52 mounted on a flanged control member 53 which is rigidly fixed on the shaft 8 against the shoulder I3. The control member 58 is preferably rigidly attached to the shaft 8 by means of a knurled groove 54 formed in the smooth portion l2 of the shaft, a lip 55 of said control member being forced into said groove to make intimate contact therewith. It will be noted that the endsurface 56 of the control member provides a thrust bearing for the sleeve 24 of the rotor, cooperating with the thrust ring 2 to define the longitudinal position of the rotor on the shaft. By reference to Figs. 4 and. 6 of the drawings, it will be noted that a plurality of threaded openings 58 for the stud 52 are provided in the control member 58 in order that the amount of wind-up of the spring 88 prior to the tripping of the centrifugal weight 41 may be suitably predetermined.

The control member 58 is provided with radially extending lugs 54 which are arranged to engage abutments 55 extending axially from the The engagement of the lugs 54 against the abutments 55 under the action of the spring as shown in Fig. Q'defines the normal rotary position of the rotor on the shaft. The, latch 41 is provided as shown with a weighted portion 51 which causes the engagement of the latch with the stop 5| at low speed as indicated in Fig. 10, but which causes the latch to be withdrawn by centrifugal force as 'soon as the rotor attains a proper operative speed. The frame I is provided with stationary magnetic pole pieces 58 and 58 (Fig. 8) preferably formed integrally therewithas by a casting process. These pole pieces are arranged to closely surround the pole pieces 84 of the rotor, and extend upwardly above the frame as indicated at 6| and 62. A coil assembly 68 having the usual primary and secondarywindings and'a magnetic core 64 is mounted'between the upwardly extending portions 6|, 62 of the stationary pole pieces, the core 64 being suitably fixed to said pole pieces at its ends as by means terminal 68 is held in place by a knurled mit 68a, the tightening of which compresses a soft rubber bushing 68b around the ignition cable so as to seal it against dirt and moisture. The terminal 68 is carried in the top cover plate 4 which is arranged to surround the coil 68 and completely close and seal the top opening of the frame I.

The insulated end of the primary winding of coil- 68 is connected by means of a lead 18 to a breaker mechanism mounted the closed end of the frame I. As shown more particularly in Figs. 2 and 7 of the drawings, this breaker mechanism comprises a cam 14 suitably keyed as indicated at 15 on the end of the rotor sleeve 24, and a follower 16 mounted on a spring 11 in position to engage a second spring element 18 carrying at its end a movable contact 18. The springs 11 and 18 are fixed as indicated at 8| to a bracket 82 which is detachably mounted in the frame I by means of a cap screw 83. Lubricating means for the cam follower 16 are preferably provided in the form of an oil saturated wick 84. e

A stationary contact 85 is carried by a bracket 86 in juxtaposition to the movable contact 18, the bracket 86 being carried by an insulated terminal member -81 extending out through the frame I. Terminal member 81 is fixed to the frame as by means of a nut 88, and serves as a binding post for a grounding lead adapted to be connected thereto by means of a nut 88. The bracket 86 is adjustably fixed to the terminal member 81 by means of a cap screw 8|.

The cap screw 8| serves further as a unitary means for attaching the primary lead 18 to the terminal member 81, and also for attaching thereto a condenser lead in the form of a spring strip 82 which'isflxed as indicated at 88 to thei cap screw 8|.

In assembling the magneto structure, the shaft 8 with the control member 68 and the spring 88 thereon is slid within the rotor 28 until the end of. the sleeve 24 engages the thrust surface 56 of the controlmember 58, and the lugs 54 of the control member come into operative 75 relation with the abutments 55 of the end plate 21. The thrust ring 2i and bearing H are then slid on the portion l6 of the shaft and retained thereon by the locking member l8. End cover plate 2 with the bearing ll seated therein is then placed on the portion 9 of the shaft, and a coupling member 98 of conventional form is fixed to the shaft as indicated at 99.

The shaft and rotor assembly is now inserted in the open end of the frame I until the hearing I! engages the seat 6 of the frame and the end cover plate 2 closes the end opening of the frame where it is retained by the studs 3. The breaker mechanism and condenser are then placed in position, the coil 63 mounted, the lead 13 is connected up and theb'reaker points adjusted and locked in position by tightening the cap screws 83 and 9|. The top cover plate 4 is then placed in position and anchored'by studs 5.'

It will be noted that the magneto here illustrated is of the left-hand drive type; that is, the rotor turns counter-clockwise when viewed from the driving end. To convert the machine to right-hand drive, it is merely necessary to change the centrifugal weight 41 over to the other-bolt 48, move the stop member 5| to the other side of the frame I in place of the dummy member 5|, exchange the spring 39 for a right-hand type, and reset the breaker cam 14 on sleeve 24, an opposite keyway I5 being provided for righthand rotation. The rest, of the breaker mechanism is designed to operate in either direction of rotation.

In the operation of this device, slow rotation of the shaft 8 from the engine through-the coupling 98 as during the -cranking operation, causes the rotor 23 to turn therewith until the latch 41 engages the stop 5| as shown in Fig. 10. Further rotation of the shaft causes the spring 39 to be wound up until the stud 52 engages the end 51 of the latch and trips the same. Thereupon the rotor quickly accelerates until the lugs 54 of the control member engage the abutments 55 of the end plate 21. It will be understood that this period of rapid rotation of the rotor isso timed V as to occur in proper relation with the functioning of the engine, and that the breaker points 19 and 85 are timed to open at the proper ,instant to obtain the spark at the correct time. As soon as the'engine becomes self-operative, the speed of the magneto causes the weight 41 to be moved into its inoperative position by centrifugal force, after which the rotor and shaft rotate as a unit.

It will be seen that there is here provided a magneto in which an impulse coupling is incorporated as an integral part of the magneto itself, and the bearings of the various rotating parts are so dimensioned and spaced axially as to secure an extremely rigid construction. It will further be noted that the device may be taken down and assembled without the use of special tools, and that the parts of the breaker mechanism are exposed for easy adjustment upon the removal of the top cover 4.

Although one embodiment of the invention has been shown and described in detail, it will be understood that other embodiments are possible and that changes may be made in the design and arrangements of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is: 1. In a magneto a frame having spaced bearings therein, a driving shaft mounted in said bearings, a rotor loosely mounted on said shaft between said bearings, and an impulse coupling within said rotor connecting said shaft and rotor.

2. In a magneto a frame having spaced bearings therein, a driving shaft mounted in said bearings, a rotor loosely mounted on said shaft between said bearings, resilient means within the rotor for driving the rotor from the shaft, means for periodically obstructing the rotation of the rotor, and means for periodically releasing the rotor and permitting it to be rapidly accelerated into rotation with the drive shaft.

3. In a magneto a frame having spaced bearings therein, a driving shaft mounted in said bearings, a rotor loosely mounted on said-shaft,

between said bearings, and bearing at its ends on said shaft, a coiled spring mounted on the shaft Within the rotor and connected at its ends to the shaft and rotor respectively means on the rotor and frame adapted to engage periodically and obstruct the rotation of the rotor, and means on said shaft adapted to disengage said obstructing means after a predetermined winding-up of said spring.

4. A magneto generator having a frame of generally rectangular outline, bearings mounted in the ends of said frame, a drive shaft mounted in said bearings, a rotor journalled on said shaft between" said bearings, cooperating means on the shaft and rotor adapted to engage and limit advance rotation of the rotor on the shaft, resilient means on the shaft normally maintaining the rotor in a fixed position thereon, cooperating means on the rotor and frame for periodically erally rectangular outline, bearings mounted in the ends of said frame, a drive shaft mounted in' said bearings, a rotor journalled on said shaft between said bearings, a control element fixed to said shaft adjacent the rotor, an abutment on said a rotor adapted to engage said control element, yielding means urging said abutment into such engagement, a stop on the frame, a latch on the rotor adapted to engage said stop, and a trip on 'said control element arranged to disengage said latch,

6. A magneto comprising a frame having an integral body portion with a bearing seat at one end-and an end plate having a second bearing seat, a driving shaft, a rotor journalled thereon, a resilient coupling between the shaft and rotor, bearings on the said shaft adapted to fit said bearing seats, and means for retaining said bearings on the shaft whereby, end plate, the shaft, rotor, coupling and bearings are removable from the frame as a unit.

7. A magneto comprising a, frame having an integral body portion with a bearing seat at one end and an end plate having a second bearing seat aligned with said first seat, a stator fixed upon removal of the in the frame between said bearing seats, a straight rigid driving shaft, a rotor journalled thereon, a resilent coupling between the shaft and rotor, bearings on said shaft adapted to fit said bearing seats, and means for retaining said bearings on the shaft whereby, upon removal of the end plate,

. the shaft, rotor coupling and bearings are removable from the frame as a unit, said shaft, when the 8. In a magneto, a rotor comprising a. hollow 'parts are assembled, serving to maintain the parts non-magnetic sleeve having a shoulder at one end, a magnetic end plate seated against said shoulder, a non-magnetic end plate fixed to said sleeve adjacent its opposite end, a plurality; of bar magnets spaced circumferentially about said sleeve between said end plates, magnetic pole pieces mounted on the poles of the magnets adjacent the non-magnetic end plate. non-magnetic means for uniting the remaining portions of the magnets with the sleeve, a driving shaft journailed within said sleeve and coupling means for rotating said sleeve from the driving shaft.

9. In a magneto, a rotor comprising a hollow non-magnetic sleeve having a shoulder at one end, a magnetic end plate seated against. said shoulder, a non-magnetic end plate fixed to said sleeve adjacent its opposite end, a plurality of axially arranged bar magnets spaced circumferentially in groups having their poles in alternation about said sleeve between said end plates, magnetic pole pieces uniting each group of poles of the magnets adjacent the non-magnetic end plate, non-magnetic means for uniting the remaining portions of all the magnets with the sleeve, a driving shaft journalled within said sleeve, and coupling means for rotating said sleeve from the driving shaft.

10. In a magneto, a rotor comprising a hollow non-magnetic sleeve, an end plate fixed thereon formed to-provide a cup, a latch carried in said cup, a driving shaft journalled in said sleeve having a flange member rigid therewith forming a closure for said cup, resilient means connected respectively to the sleeve and shaft for driving the rotor from the shaft, and means on said flange member for tripping said latch after a predetermined fiexure of the driving means.

11. In a magneto, a rotor comprising a hollow non-magnetic sleeve, anend plate fixed thereon formed to provide a cup, a centrifugal latch carried in said cup, a driving shaft journalled in said sleeve having a flange member rigid therewith forming a closure for said cup, aspring within said sleeve anchored at its ends to the sleeve and shaft respectively, and means on said flange member for tripping said latch after a predetermined fiexure of the spring.

12. A magneto comprising an integral frame in the form of a box open at the top and at one aoaaaee end a rotonand breaker cam assembly and an end plate insertable as a unit in the open end of the 'frame,.'a;coil unit mounted on the top of the frame, breaker mechanism insertable through the ,top of the frame and detachably mounted in position to cooperate with said cam, and a cover plate and high tension terminal detachably mounted on the top of the frame.

13. A magneto comprising an integral frame in the form of a box open at the top and at one end, and containing stationary pole pieces, a rotor and breaker cam assembly and an end plate insertable as a unit in the open end of the frame, said rotor having magnetic elements arranged to cooperate with said pole pieces, a coil unit mounted on the top of the frame having a core in magnetic circuit with said pole pieces, breaker mechanism insertable through the top of the frame and detachably mounted in position to cooperate with said cam, and a cover plate and high tension terminal detachably mounted on the top of the frame, surrounding said coil and closing the frame.

14. In a magneto an integral frame in the form of a box open at the top and at one end, a drive shaft, rotor and breaker cam assembly and an end cover plate insertable as a unit in the open end of the frame, a condenser and breaker mechanism insertable and adjustable through the top of the frame, and unitary means readily operable through the top of the frame serving to hold the condenser in place and to maintain the adjustment of the breaker mechanism.

15. In a magneto an integral frame in the form of a box open at the top and at one end, a drive shaft, rotor and breaker cam assembly and an end cover plate insertable as a unit in the open end of the frame, a stator including a coil assembly fixed on the frame, a condenser and breaker mechanism insertable and adjustable through the top of the frame, a low tension lead from the coil to the breaker mechanism, and unitary means readily operable through the top of the frame for holding the condenser in, place, maintaining the adjustment of the breaker mechanism, and serving as a binding post for said low tension lead.

WALTER J. SPENGLER.

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