US2630462A - Electrical apparatus - Google Patents

Description

March 3, 1953 R. M. PURDY 2,630,462

ELECTRICAL APPARATUS Filed Dec. 5, 1949 2 Sl-lEETSSl-IEET 1 IN VEN TOR.

ale Q. 6 ATTO/P/VAY March 3, 1953 R. M. PURDY ELECTRICAL APPARATUS 2 SI-lEETS-SHEET 2 Filed Dec. 5, 1949 mmvron. W 772. fwd? Tic. E.

Patented Mar. 3, 1953 UNITED STATES PATENT OFFICE ELECTRICAL APPARATUS Rolland M. Purdy, Bainbridge, N. Y., assignor to Bendix Aviation Corporation, New York, N. Y., a corporation of Delaware Application December 5, 1949, Serial No. 131,074

11 Claims.

This invention relates to electrical apparatus and more particularly to means for generating and distributing periodic impulses of high voltage electrical energy.

One of the objects of the present invention is to provide a novel magneto generator of a highly versatile nature that may be readily adapted for use in the ignition ystems of a wide variety of engines.

Another object of the invention is to provide a device of the above character wherein the parts are assembled and drivably and electrically connected with one another in. a novel manner which facilitates disassembly, re-assembly, and inspection thereof.

A further object is to provide in ignition apparatus a novel and simplified combination of a plurality of rotating parts, such as a circuit breaker cam, a magnetic flux distributing rotor, and an electrical current distributing rotor.

A still further object is to provide novel electrical connecting means for transmitting electrical energy.

Still another object is to provide novel means for mounting the rotating elements of an ignition distributor or the like on a rotating shaft for rotation therewith.

The above and further object and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended to define the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several iews,

Fig. 1 is a side view, mostly in section, of one form of magneto-distributor embodying the present invention;

Fig. 2 is an isometric exploded view of the circuit breaker cam and distributor finger assembly of the device of Fig. 1;

Fig. 3 is a partial end view of the distributor finger as viewed from the right in Figs. 1 and 2;

Fig. 4 is an enlarged detail view, partly in section and with parts broken away, showing part of the means for conducting energy from the transformer coil;

Fig. 5 is a detail end view of the spring and mounting member therefor shown in Fig. 4;

Fig. 6 is a detail sectional view, taken substantially on line 6-6 of Fig. 7;

Fig. 7 is an enlarged detail view of a contactor plate, taken on line 1-1 of Fig. 4;

Figs. 8 and 9 are end and sectional views, respectively, of a single lobe circuit breaker cam, the section of Fig. 9 being taken substantially on line 9--9 of Fig. 8; and

Figs. 10 and 11 are end view similar to Fig. 8 of interchangeable circuit breaker cams having two and four lobes, respectively.

The single embodiment of the invention illustrated in the drawing, by way of example, is shown in the form of a combined magneto generator and ignition distributor ior supplying electrical energy to the spark plugs of an internal combustion engine or the like. As shown, the working parts are enclosed and supported in a. simple two-part housing comprising a body porticn l0 and a cover ll suitably secured thereto. Rotatably supported in housing body It is a magnetic rotor l2 that may be of any suitable known construction. As shown, the rotor comprises permanent magnets l4 and four equally spaced laminated pole shoes l5 supported on a flanged hub member 16. The rotor is supported on and keyed to a shaft I! for rotation therewith. The right hand end of the shaft, as viewed in the drawings, is supported by a suitable bearing (not shown) in the end wall of easing member [0, and the other end is supported by a roller bearing l8 which is in turn mounted in a supporting bracket [9 that is removably secured in position against a shoulder 20 by stud bolts 2| (only one being shown) to thereby facilitate assembly and disassembly with a minimum of parts. Power may be transmitted to rotor l2 from the engine through an impulse coupling 22 that may be of any suitable knownv construction. Housing [0, ll may be secured to the engine casing for angular adjustment about the axis of rotor [2 by means of stud bolts (not shown) which project from the engine casing through arcuate slots 9 in a flange on the housing or from arcuate slots on an engine casing flange (not shown).

The rotor cooperates in the usual well known manner with laminated stator poles 23, 24 which are cast in the opposite side walls of casing. I0 or otherwise suitably secured therein by means of rivets or the like. The upper ends of the stator poles are magnetically connected by a laminated core 25 on which is wound the windings of a transformer coil 26. The coil and core are secured in position in a known manner by screw and spring sets 21, 28 which engage the upper surfaces of the core near the ends thereof.

Mounted in a novel manner on the reduced inner or left end of rotor shaft I! for rotation therewith is a circuit breaker cam 29 and an electrode-carrying distributor finger or rotor 30.

The mounting of these parts is such as to render the magneto readily and quickly adaptable for either right hand or left hand rotor rotation and for use with engines having one, two or four cylinders. As shown, the cam 29 is in the form of a sleeve having a sliding fit on the end of shaft H to which it is attached for rotation by a key 3|. The bore through cam sleeve 29 is slightly enlarged adjacent each end to form internal shoulders 32, 33, for a purpose to more fully appear hereafter. One end of the cam sleeve is provided with a segmental fiat 33 and the other end with a similar fiat 34, the planes of said flats making an angle of about 45 with each other in the embodiment illustrated. When the cam is in place on shaft I! one end engages the inner race of bearing l8, and the shoulder 32 in the other end is in a plane just slightly beyond the end of shaft I1. The flats on the cam are used in properly timing the magneto to the engine. This is done by aligning the flat with a timing mark on the housing when the latter is installed on the engine.

Cam sleeve 29 is secured against axial movement on shaft I! by a novel stub shaft 35, the threaded reduced portion of which engages a threaded recess in the end of the shaft. The cam is thus held in place by the shoulder 36 on the stub shaft between which and shoulder 32 of the cam are interposed a plain washer 31, a lock washer 38, and the web 39 of a bifurcated spring member 40.

The outer enlarged end of stub shaft 35 serves as a support for distributor finger or rotor 36 which is preferably made of molded insulating material and provided with a recess 4! for slidably receiving the shaft. Novel means comprising spring member 40 is provided to compensate for the necessary tolerances between the diameters of shaft extension 35 and recess 4|, and to thereby minimize chattering or vibration of the rotor during operation. For this purpose shaft extension 35 has oppositely disposed longitudinally extending grooves 42 cut therein for receiving the fiat leaf spring arms of member 46 when the web 39 of the latter engages shoulder 36. Central portions 43 of said spring arms are arched to resiliently engage the inner surface of recess 4| and thereby provide a suitably tight fit between the rotor member and the shaft. Except for the arches or bends 43 the sizes and shapes of grooves 42 and the spring arms are such that there will be no interference with rotor member 30 when the same is installed. Although two grooves 42 and cooperating spring arms are shown, one or more than two may be provided.

Distributor rotor 30 is angularly located and positioned in a novel manner with respect to cam 29 and hence, with respect to magnetic rotor l2. The novel means for thus positioning the distributor rotor also effects a driving connection for transmitting torque thereto from the cam which is in turn keyed to the shaft l1. As shown, rotor member 30 has an axial projection with a flat surface 44 that engages the flat 33 or 34 on cam 29 depending upon which way the reversible cam is installed. This permits use of the magneto for either right or left hand rotor rotation without changing any of the parts, the change from one to the other being accomplished by mere reversal of cam sleeve 29 on shaft IT. The various parts are so constructed that they must of necessity be properly assembled.

Although the spring loop 43, 43 tend to resist axial movement of distributor rotor 30 on shaft extension 35, novel means are provided for positively securing the same against such movement, said means being readily applied and removed irrespective of the relative positions of the rotor and the shaft. The latter is provided with an annular groove 45 which is preferably deeper than grooves 42. When rotor 39 is in proper axial position on the shaft, one or more transverse holes 46 in the hub 49 of rotor 30 register with groove 45 for receiving the straight portion 41 of a locking spring or pin which has a holding or retaining portion 48 bent back upon the portion 41 and shaped to engage the outer cylindrical contour of hub 49 to thereby resiliently hold the locking pin in installed position and yet permit relatively easy withdrawal thereof for purposes of disassembly.

A circuit breaker (not shown) of any conven tional or suitable design may be mounted on bracket or semi-partition [9 in the half of casing II] which is removed by the section in Fig. 1. This circuit breaker is suitably positioned for periodic operation in the usual manner by cam 29. A portion only of the circuit breaker mounting plate is shown at 59. A complete showing of the circuit breaker is believed to be unnecessary in view of the fact that the construction thereof may be conventional and does not, per se, constitute any part of the present invention.

Distribution rotor 39 has secured thereto an electrode 5| which during rotation periodically moves into spark gap relation with an output electrode 52. The latter is suitably insulated and associated with one half 53 of a plug and socket type connector removably mounted in cover H. A suitable conducting lead may be provided be tween connector part 53 and the spark plug of an engine. If the engine on which the magneto is used has a plurality of cylinders, such as two or four, additional output electrode-connector combinations 54 similar to the part 52, 53 may be provided. The output electrodes are equally spaced from each other on a circle with its center at the axis of rotor 30 so that rotor electrode 5| will move successively into spark gap relation therewith.

Rotor electrode 5i is operatively connected with the secondary or high-voltage winding of coil 26 by novel means mounted in cover I I. In the form shown said means comprise an insulating block 55 secured inside of the cover by some suitable means such as a plurality of stud bolts 56 and extends across the axis of shaft IT. The electrical connection from electrode 5| to the coil is through a spring contact 51 which yieldably engages a button 58 molded in block 55 and connected by a conductor 59 to a contact 60 also molded in block 55 at the inner end of a recess 6!. This contact is preferably connected to the coil through a spring 62, a resistor 63, a spring 64 novelly mounted on block 55, and a contact washer 65 secured in a novel manner to a ribbontype conductor 66 that emerges from the side of the coil.

Coil spring 64 is novelly mounted on block 55 for automatic contact with washer 65 when cover H is put in place. The mounting means consists of an anchoring member 6! which is best seen in Figs. 4 and 5. Said member may be fabricated from a flanged metallic tube 68 by rolling a marginal end portion thereof outwardly and forming a head 69 over the end convolution of the spring. The flange at the other end of the tube is cut to form spaced portions that are then curled outwardly to form resilient tongues ga e in. When member 61, thus formed, is pressed into an enlarged portion of recess 6! against a shoulder ll, tongues are biased outwardly against the wall of the recess so that the corners thereof bite into the surface of the recess and resist withdrawal thereof.

The ribbon conductor 66 which emerges from coil 26 and represents the high potential end of the secondary winding thereof is passed through a slot 73 in washer E5 and locked therein in a novel manner. Said slot is originally rectangular in shape and is deformed by staking the washer with a suitable tool at 72, 72 (Fig. 7) to reduce the width of slot i3 at one face of the washer and, hence, provide opposed lips which effect a biting action against opposite surfaces of the conductor 86 to prevent removal of the washer therefrom. Lips 75 are sufilciently flexible to permit easy installation of the washer in the direction of the arrow in Fig. 6 but bite into the conductor when the direction of movement is reversed.

As heretofore pointed out it is only necessary to reverse the cam member 29 on shaft ll, i. e., turn it end for end, for changing the magneto from counter-clockwise operation to clockwise operation. To adapt the magneto to engines with one, two, or four cylinders, it is only necessary to use a cam having one, two, or four properly positioned lobes, respectively, as shown in Figs. 8, l0, and 11. The single lobe cam 29 of Fig. 8, for example, will operate the circuit breaker once during each revolution of the rotor shaft at a time when electrode Si is adjacent the single output electrode 52. The two-lobe cam 29' of Fig. 10 and the four-lobe cam 29" of Fig. 11 will operate the circuit breaker twice of four times, respectively, during each cam revolution at times when electrode 5! is adjacent the additional output electrodes installed in cover ll in the manner heretofore explained. Coil 26 has the primary winding thereof connected in a conventional manner with the circuit breaker across which is connected a condenser 16 also supported by the partial partition 59. As is well understood in the art, a high voltage is induced in the secondary winding of the coil each time the circuit breaker is opened to interrupt the circuit of the primary winding. This secondary voltage is impressed across the gap 5|, 52 and, hence, upon the spark plug to which electrode 52 is connected.

The casing if), H is preferably dust-proof, ventilation being provided through suitable filters T1. The filters shown are of known type and comprise stacks of thin wavy washers i8 sur-- rounding a duct 19 in the casing member H.

There is thus provided a novelly constructed magneto-distributor adapted for use in internal combustion engine ignition systems and having considerably greater versatility than similar devices heretofore provided for the same purpose. Considering the capabilities of the device, the number of parts have been reduced to a minimum of readily accessible parts, and the novel features of the construction greatly facilitate assembly and disassembly of such parts. The several novel details of construction herein described contribute to the over-all efficiency and simplicity of the complete device and particularly to the ease with which inspections of the vital parts and adaptations for different engines may be accomplished.

Although only a limited number of embodiments of the invention are illustrated in the accompanying drawings and foregoing description,

it is to be expressly understood that the inven-' tion is not limited thereto. In addition to the modifications hereinabove suggested, various additional changes may be made in the design and arrangement of parts illustrated without departing from the spirit and scope of the invention as will now be understood by those skilled in the art. For example, the cam 29 may be positioned on shaft I? by means of a shoulder on the latter in lieu of engagement with the inner race of bearing 18.

What is claimed is:

1. In electrical apparatus of the class described, a housing comprising a body member and a cover for the open face of said member, a partial partition removably secured across the open face of said body member, a magnetic flux distributing rotor comprising a shaft journalled in the wall of said body member and said partition, a pair of stator poles in said body member operativcly associated with said rotor, a transformer coil having a core magnetically connecting said stator poles, a circuit breaker mounted on said partition, a cam slidably mounted on the rotor shaft for rotation therewith to actuate said circuit breaker, a stub shaft having a reduced portion threaded into a recess in the end of Said rotor shaft for securing said cam against axial movement on the latter, a distributor finger slidably mounted on said stub shaft, radially biased resilient means interposed between said stub shaft and the interior of said finger, the latter having an eccentric fiat surface engaging an eccentric fiat surface on said cam for positioning the finger relative to the cam and for rotatably connecting the same, means for holding said finger against axial movement on the stub shaft including a pin extending through an opening in the hub of said finger and a circumferential groove in said stub shaft, at least one output electrode removably mounted in said cover, an electrode mounted on said finger adapted during rotation of the latter to periodically move into spark gap relation with said output electrode, means mounted in said cover for electrically connecting said finger electrode to the high potential end of the secondary winding of said coil, said connecting means including conducting means in an insulating block having a recess, a spring and a metallic tube having resilient laterally extending tongues thereon for securing one end of said spring in said recess, and a slotted plate adjacent said coil and having a biting engagement with a ribbon conductor constituting the end of the secondary winding, said plate being engageable by said spring when the cover is installed.

2. In a magneto generator a housing comprising a body member and a cover for the open face of said member, a partial partition removably secured in said body member across the lower portion thereof, a magnetic flux distributing rotor comprising a shaft journalled in the wall of said body member and said partition, a pair of stator poles in said body member operatively associated with said rotor, a coil having a core magnetically connecting said stator poles, whereby electrical energy is induced in said coil during rotation of said rotor, a circuit breaker in circuit with the coil and mounted on said partition, a cam slid-ably mounted on the rotor shaft for rotation therewith to actuate the circuit breaker, a stub shaft having a reduced portion threaded into a recess in the end of said rotor shaft for securing the cam against axial movement on the latter, and a distributor finger mounted on said stub shaft and having operative engagement with said cam, whereby the finger is positioned relative to the cam and rotatably connected therewith.

3. In ignition apparatus, such as a magneto generator, a rotatable shaft, a cam mounted on said shaft for rotation therewith, a distributor finger slidably mounted on said shaft and having direct driving engagement with said cam, and means for fixing said finger against axial movement on said shaft including a pin extending through both a portion of said finger and a portion of a circumferentially extending groove in said shaft.

4. Apparatus as defined in claim 3 including radially biased resilient means interposed between said shaft and the adjacent surface of the distributor finger to resist radial movement of the finger relative to the shaft.

5. In apparatus of the class described a rotatable shaft having an axially extending groove and :a circumferentially extending groove, a member having a recessed hub slidably mounted on said shaft around said grooves, resilient means in said axially extending groove and biased radially outward against the inner surface of said hub, means for holding said member against axial movement on said shaft, said holding means including a pin extending through both a portion of said hub and a portion of said circumferentially extending groove and a spring arm extending from said pin and engaging the outer periphery of said hub for resisting withdrawal of said pin, and means for drivably connecting said member to said shaft for rotation therewith.

6. In a magneto generator, 21. housing comprisin a body member and a cover for the open face of said member, a coil mounted in said body member, means for inducing electrical energy in said coil including a rotatable shaft, a distributor finger mounted on said shaft having an electrical contact at the axis of rotation thereof, and insulated conductor means mounted wholly within said housing on said cover for electrically connecting said contact with said coil when said cover is operatively mounted on said body member, said last named means comprising an insulating block having a recess therein, a coil spring extending from the recess to a terminal of the coil and means for fastening one end of the spring in said recess, said fastening means being constituted by a tubular member operatively secured to one end of the spring and having a plurality of outwardly curved spring fin gers engaging the walls of said recess under radial compression.

7. Apparatus as defined in claim 6 wherein the coil terminal comprises a washer having a .slot therein, and a flat conductor extending through the slot, the sides of said slot at one face of the washer being pressed together against the conductor to exert a biting action thereon and resist removal of the washer from the conductor.

8. In electrical apparatus, a terminal compris ing a washer having a slot therethrough, and a conductor extending through said slot, the sides of the latter being bent inwardly at one face of the washer into biting engagement with the conductor to resist movement of the washer along the conductor in one direction While permitting movement thereof in the other direction.

9. In a, magneto generator, a four-pole magnetic rotor, a two-pole stator mounted in operative relation with said rotor, a coil having a core connecting said stator poles, a circuit breaker in circuit with said coil, a single lobe cam mounted on the shaft of said rotor for rotation therewith to operate said circuit breaker, a distributor finger mounted on said shaft and having means engageable with said cam for drivably connecting and relatively positioning the same, said cam being reversible on the shaft for different directions of rotation thereof, a contact on said distributor finger, means for electrically connecting said contact with said coil, and a single output terminal mounted for cooperation with said distributor finger contact once during each revolution thereof.

10. Apparatus as defined in claim 9 wherein the cam has two oppositely disposed lobes and wherein there are two output terminals disposed on diametrically opposite sides of the axis of rotation of the distributor finger for successive cooperation with said distributor finger contact.

11. Apparatus as defined in claim 9 wherein the cam has four equally spaced lobes and wherein there are four output terminals equally spaced around the axis of rotation of the distributor finger for successive cooperation with said distributor finger contact.

ROLLAND M. PURDY.

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

UNITED STATES PATENTS Number Name Date 1,588,546 Gilchrist June 15, 1926 1,886,566 Mallory Nov. 8, 1932 1,933,304 Bell Oct. 31, 1933 2,013,335 Beeh Sept. 3, 1935 2,016,669 Davis Oct. 8, 1935 2,144,218 Dunham Jan. 17, 1939 2,198,892 Twining et al Apr. 30, 1940 2,228,138 Larkin Jan. 7, 1941 2,430,831 Simmons Nov. 11, 1947 2,502,539 Tinnerman Apr. 4, 1950

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