US2856472A - Circuit breaker for internal combustion engine - Google Patents

Description

Oct. 14, 1958 c. N. HUMPHRIES CIRCUIT BREAKER FOR INTERNAL COMBUSTIONENGINE Filed Sept. '7, 1955 3 Sheets-Sheet 1 7 6 0 2 3 2 m 2 7/ s zmiw m 2123.3 3

E I N V EN TOR.

(HA e4 ES/VHUMPHR 1E5 ATTORNEYS.

Oct. 14, 1958 c. N. HUMPHRIES CIRCUIT BREAKER FOR INTERNAL COMBUSTION ENGINE Filed Sept. 7, 1955 3 Sheets-Sheet 2 22 HILUII 38 'lllliLlll I N V EN TOR. C HA 2L ES/YHUMPHRI ES llllllllllfill Oct. 14, 1958 c. N. HUMPHRIES 2,856,472

CIRCUIT BREAKER FOR INTERNAL COMBUSTION ENGINE Filed Sept. '7, 1955 3 Sheets-Sheet 3 FIG. 6

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I (M421. ESN/I UMPHEIES 764,444 1 76.9 W

ATTORNEYS.

nited States Patent CIRCUIT BREAKER FOR INTERVAL COMBUSTION ENGINE Charles N. Humphries, Pontiac, Mich.

Application September 7, 1955, Serial No. 532,824

17 Claims. (Cl. 200-24) This invention relates to the ignition system of internal combustion engines and particularly to circuit breakers used in said ignition system.

At the present time the ignition systems of internal combustion engines include a primary circuit for charging a coil which, upon being broken, causes a high tension voltage in a secondary circuit. The secondary circuit is connected in properly timed relationship to each of the spark plugs of the various cylinders of the engine. The making and breaking of the primary circuit is controlled by a circuit breaker switch held under tension in contact with a cam which, in turn, is rotated by the operation of the engine. The cam is provided with raised portions for opening the circuit breaker switch and breaking the circuit and with fiat or dwell portions during which the circuit breaker switch is closed and the primary circuit is completed for energizing the coil.

Such a construction has certain obvious disadvantages which have long been recognized. First, the rapid opening and closing of the single switch in the circuit breaker which makes and breaks the primary circuit for each of the spark plugs results in rapid pitting and wearing away of the contact points of the switch. As a result, the flow of current to the primary circuit when the switch is closed is substantially affected and the points of the switch must be frequently cleaned or replaced.

Second, since the making and breaking of the primary circuit is controlled by a cam against which the switch is held in tension, there is a tendency, because of centrifugal force and inertia, for the circuit breaker switch to remain open and to close belatedly and not as consistently as might be desired. Thus, the period during which the switch is contacting with the dwell portion of the cam may vary resulting in insufficient time during which the primary circuit is closed and the coil may not be sufiiciently energized to produce the high voltage spark which is required in the secondary circuit. This condition is aggravated when faster engines are used and the number of revolutions per minute of the engine is increased.

Third, the various parts being in frictional contact easily wear away and affect the making and breaking of the primary circuit, since the Wearing away of the parts, even to a small degree, substantially affects the opening and closing of the circuit breaker switch.

It is therefore an object of this invention to provide a circuit breaker which will make and break the primary circuit without any detrimental pitting or wearing away of the critical contact areas.

It is a further object of the invention to provide such a circuit breaker which is not affected by centrifugal force and inertia and wherein the dwell portion or portion wherein the primary circuit is made is longer than in circuit breakers-which are presently used.

It is a further object of the invention to provide such a circuit breaker which will operate satisfactorily at 2,856,472 Patented Oct. 14, 1958 high or low speeds of the internal combustion engine, providing a spark of high tension at all speeds.

It is a further object of the invention to provide a circuit breaker wherein the frictional contact is substantially eliminated thereby preventing the wearing away of the various parts.

Basically, the circuit breaker comprises a housing adapted to be positioned within the usual distributor housing, with the distributor shaft passing through the circuit breaker housing. Positioned within the circuit breaker housing and surrounding the distributor shaft is a fixed plate of electrically conductive material having an annular groove therein. The plate is provided with a series of circumferentialy spaced insulators positioned in the annular groove. Also positioned within the circuit breaker housing is a multiplicity of balls of electrically conductive material which are adapted to ride in the groove of the plate and are maintained in circumferentially spaced relationship by a race fixed to the distributor shaft. When the distributor shaft rotates, the balls are moved successively in contact with the conductive portions of the plate and subsequently with the insulated portions. The number of balls and insulators is preferably equal to the number of cylinders in the internal combustion engine. When the balls are in contact with the conductive portions of the plate, a multiplicity of parallel electrical circuits or paths through the plate and balls are established. When the balls are in register with the insulated portions of the plate, the circuits or paths through the plate and balls are broken.

In addition, the circuit breaker includes contacts on the plate and contacts on the race of the balls positioned in advance of the insulators and balls, respectively, in such a manner that the circuit through the contacts is first made before the circuit through the balls is broken, and the circuit in the contacts is broken before the circuit through the balls is remade.

The housing is filled with a suitable transformer oil and the circuit breaker is preferably provided with means for maintaining the plate and balls in contact and a thrust bearing for further reducing the friction.

By this arrangement, the primary electrical circuit is made through rolling contacts having a minimum of friction resulting in a minimum of wear. The use of an additional set of contacts insures that any pitting which might occur will occur in the additional set of contacts and not through the rolling contacts or balls which are used to charge the primary circuit. The circuit breaker is not affected by centrifugal force and inertia and the making and breaking will occur at the same angular position without regard to the speed of rotation of the distributor shaft. The period of dwell or during which the primary circuit is being charged is much greater than that in circuit breakers using the cam and switch arrangement. The provision of a multiplicity of balls provide multiple paths of flow of current in the primary insuring a more ready passage of current in the circuit, thereby eliminating reliance on a single contact such as the case where a single cam and switch are used. 7

In the drawings:

Fig. 1 is a part sectional elevational view of a distributor housing embodying the circuit breaker which is the subject of this invention and showing the circuit diagrammatically.

Fig. 2 is a part sectional, exploded view of the circuit breaker shown in Fig. 1.

Fig. 3 is a fragmentary plan view of a portion of the circuit breaker.

Fig. 4 is a sectional view taken along the line 4-4 in Fig. 3 showing, in addition, the relative position of other parts.

Fig. 5 is a part sectional, exploded view of a modified portion of the circuit breaker.

Figs. 6, 7 and 8are fragmentary, diagrammatic views showing the relative position of .the parts just prior to, at breaking of, and after breaking of the circuit.

Fig. 9 is a diagrammatic plan view of the parts just prior to breaking of the circuit.

Referring to .Fig. 1, there isshown -a distributor housing it having projecting therethrough a distributor shaft 11 which is rotated in the .usual manner by the operation of the internal combustion engine with which the housing is associated. .An arm 12 is mounted on the end of the shaft 11. A cap 13 is mounted over .the end of the housing and is provided with suitable .intcrengaging means whereby the position .of .the cap 13 relative to the housing 10 is fixed. Positioned circumferentially of the cap 13 are contacts 14 which are .connected by wires to the spark plugs 14a of the internal combustion engine. A contact is mounted on the arm 12 and has one end 15 thereof projecting radially outwardly to make electrical contact successively with the contacts 14 as the distributor shaft rotates. The other end 17 makes continuous contact with a centralconnector 16 which is connected to the secondary of the coil 16:: in the ignition system. The structure heretofore described is .conventional and is presently used in distributors for internal combustion engines.

As 'furthershown inFig. 1, circuit breaker 18 is positioned within thehousing and the shaft 11 passes through the circuit breaker. The circuit breaker .18 includes a cylindrical housing 19 and a cover 20 threaded into the top of the housing 19 or fastened in some other suitable manner. The housing 19 is supported within the distributor housing 10 by arms 21. A circular plate 22 surrounds the shaft 11 within the circuit breaker and is held in fixed position within the circuit breaker by means of a conductive plate 23. Plate 23 is held in fixed position by a bolt 24 extending through the wall of the circuit breaker housing 19 and the distributor housing 10 to the exterior. The bolt is provided With a nut 25 for making an electrical connection thereto. The plate 22 is made of electrically conductive material and is provided with an annular groove 26 near the periphery thereof (Fig. 3).

A series of circumferentially spaced electrical insulators 27arepositioned along the annular groove 26. The insulators 27 are preferably positioned in such a mannor that the centers thereof are displaced radially outwardly from the center of the groove such that the outer edge of the insulators is near the outer periphery of the plate 22 (Figs. 3 and 9).

A multiplicity of contact balls 28 are adapted to ride in the groove 26 and are held in circumferentially spaced relationship by means of a cage 29 .held in fixed relationship to the shaft 11 .by means of a set screw 30. The contact of the plate 22 with the balls 28 is maintained by means of a spring 31 positioned between the undersurface of the cover 20 and an insulator ring 32 over the top surface of the plate 22. The balls 28 also ride in a groove 33 of a floatingring 34. In order to reduce the friction, a thrust bearing is provided and includes a second floating ball bearing race 35 positioned below the floating ring 34 and the balls thereof .ride in a groove 36 in floating ring 34 and a groove 37 in a ring -38 mounted in the bottom of the housing 19. In order to maintain the floating ring 34 in proper spaced relationship, the cage 29 is provided with a downwardly projecting collar 39 spaced from the shaft 11. In addition, a thin tube 40 projects upwardly from the bottom of the housing v19 surrounding and spacedfrom the shaft 11.

As shown in Fig. 2, the plate 22 and the cage 29 are provided with lugs 41, 42,-respectively, positioned in advance of the insulated portions and balls, respectively, as presently described.

The circuit breaker housing 19 is filled with a suitable transformer oil which preferably has some lubricating properties. In order to prevent the leakage of oil from the housing, oil seals 46 and 47 are provided at the top and bottom of the housing, respectively.

The number of contact balls 28 is equal to the number of insulatedportions 27 whereby when the balls are in register with the insulated portions, there can be no circuit through the balls. The number of contact balls is preferably equal to the number of cylinders in the internal combustion engine or to some sub-multiple thereof obtained by dividing the number of cylinders by an even number. For example, in an eight-cylinder engine, eight contact balls are preferred, but four or two may be used. In a six-cylinder engine, six contact balls are preferred, but three may be used. The insulators 27 are preferably circular in cross section and have the same diameter as the balls 28.

Referring to Fig. 1, .as the distributor shaft11 is rotated, the contact balls 28 are successively brought into position whereby a circuit may be made or broken through the contact balls. When the contact balls are in contact with the conductive portions 50 ofthe plate 22, an electrical circuitmay be made through eachof the contact balls thus providing a multiplicity of parallel circuits.

The primary electrical circuit through the circuit breaker may be made througha grounded portion of the circuit breaker, for example, the shaft 11, the cage 29., the balls 28, the conductive portions 50 of the plate 22, conductive plate 23, .bolt .24 and from there to the primary of.the coil 16a. Suitable insulators 43, 44 and 45may1be provided to prevent short circuiting.

The operation of the circuit breaker may be understood by referring-toFigs. .6, 7 and .8. Just priortothe movement of the contact balls into register .with the ;insulators 27, the lugs .41, 42 come into electrical contact. This electrical contact may be by actual physical contact or by such close proximity that an electrical circuit may be completed through each paircf lugs. .As ,the balls continuertomove, .they :move into register with the insulatedportions, thus breaking the circuits through the contact balls, but the circuits through the lugs is'continued. In this manner no arcingoccurs in-the areaof contact of the contact balls with the plate .22. Further movement will cause .the lugs '41, 42 ,to move apart breaking the circuits through the lugs at .the same time that'the'balls are still in register .with the insulated ,portions (Fig.7). Furthermovement oftheballs willbring the balls into contact with .the conductive portions 50 remaking the electrical. circuits.

The angular relationship from the path of movement of the ball and the lugs i shown in Fig. 9. While ,the balls are in contact with the insulators through thearc A, the lugs are in contact Within the arc B which is less than the are A and the arc B terminates within the are A. Thus, the operation may be summarized as follows: As the'balls move in electrical contact with the plate 22 and prior to theirmovement to non-electrical contact with the'insulators 27, an electrical contact is made bythe lugs 41, 42. The circuits through'the ball .are then broken by movement of the balls into registry-with the insulators; but the primary circuit is not broken, since electrical contact continues through the lugs 41, 42. Upon further move ment of the balls, the-primary circuit is broken through the lugs 41, 42 while the balls are still in non-electrical contact with the insulators 27.

It can thus be seen that by this arrangemennthere is no danger of arcing and resultant pitting or otherwise affecting the surface in which the contact balls ride. 'In addition, since the insulators 27 are displaced radially outwardly as shownin Figs. 3 and 9,'any arcing which may possibly occur from the peripheries of the balls and insulated portions will be directed toward the outer edge .5 of the plate 22 and not in the annular groove of the plate in which the contact balls ride. As a result, any pitting will occur in the areas in which the balls do not ride and will therefore not be detrimental.

By the above arrangement, the electrical contact, whereby the primary circuit is made, is through as many balls as are used, in the case of an eight-cylinder engine, preferably through eight parallel paths. The primary circuit is thus more readily charged to capacity which is 1mportant in multi-cylinder, high speed, internal combustion engines. In addition, each of the balls is in con tact with a conductive portion of the plate 22 for an arcuate distance along the length of a groove which is more than sufficient to provide for the passage of current in order to charge the primary circuit. For example, in a circuit breaker utilizing eight contact balls, the balls will each be in electrical contact with the conductive portionof the plate for approximately 42 between insulated portions.

A modified form of the circuit breaker is shown in Fig. 5. In this form of the invention the lugs 41, 42 have been eliminated and the insulated portions 46 are positioned along the groove 26. The insulators 46 are preferably positioned in such a manner that the centers thereof are displaced radially outward from the center of the groove such that the outer edge of the insulators is near the outer periphery of the plate 22. In this structure, the primary circuit is made and broken through the balls 28. When the balls are in contact with conductive portions of the plate 22, a multiplicity of electrical paths are established between the plate and the balls. When the balls move into register with the insulated portions, the electrical paths through the balls are broken, and when the balls move from the insulated portions onto the conductive portions, the electrical paths are again established.

In the forms of the invention which are shown in the drawings, the cage 29 which maintains the balls in circumferentially spaced relationship is rotated and the plate 22 is maintained stationary. The circuit breaker would also be operative if the cage 29 were maintainedstationary and the plate 22 rotated, with obvious changes in the structures necessary to provide for such a relative movement.

I claim:

1. In a circuit breaker for the primary circuit of an ignition system used in internal combustion engines, the combination comprising a plurality of rollers of electrically conductive material, means for maintaining said rollers in circumferentially spaced relationship, a member made of conductive material provided with a circular path along which the rollers may roll, said member being provided with a multiplicity of electrically insulated portions along said path, said member and said rollers adapted to be in circuit with the primary of an ignition coil, said rollers being adapted to form parallel conductors in said primary circuit, whereby electricalcontact between the member and the rollers is broken when the rollers are in register with said insulated portions, means for causing relative rotational movement between said member and said rollers, whereby said rollers will move relative to said member along said path, the number of insulated portions being equal to the number of rollers and circumferentially spaced in the same manner as the rollers.

2. The combination set forth in claim 1 wherein said rollers comprise balls.

3. The combination set forth in claim 1 wherein said member is provided with a groove which forms the circular path along which the rollers roll.

4-. '5 he combination set forth in claim 1 wherein said member along which the rollers roll is fixed against rotation and the means for maintaining the rollers in spaced relationship is provided for relative movement with respect to said member.

5. In a circuit breaker for the primary circuit of an ignition system used in internal combustion engines, the

combination comprising a first member made of conductive material, a second member made of conductive material and rotatably mounted with respect to said first member, one of said members being provided with a multiplicity of circumferentially spaced insulated portions, the other said member being provided with a multiplicity of electrical contacts, the number of said insulated portions being equal to the number of said electrical contacts, said electrical contacts being circumferentially spaced on their respective member, the circumferential extent of each said insulated portion being less than the circumferential extent of the portions between the insulated portions of said member having said insulated portions, said members and said electrical contacts adapted to be in circuit with the primary of an ignition coil, whereby when said contacts register with said insulated portions, electrical contact between the other said member and said contacts is broken.

6. In a circuit breaker for the primary circuit of an ignition system used in internal combustion engines, the combination comprising a first member made of conductive material, a second member made of conductive material, a shaft fixedly connected to one of said members, means for rotating said shaft, one of said members being provided with a set of rolling contacts which are adapted to make electrically conductive rolling contact with the other said member, the other said member being provided with a multiplicity of insulated portions which are adapted to register with said rolling contacts and thereby prevent the flow of current through said contacts, the circumferential extent of each said insulated portion being less than the circumferential extent of the conductive portions between the insulated portions of said member having said insulated portions, each said member being provided with a set of electrical contacts positioned in such a manner that a circuit is completed between said set of contacts and said other said member before said rolling contacts are brought into register with said insulated portions and said circuit is broken before said rolling contacts are brought out of register with said insulated portions, said members and said rolling contacts adapted to be in circuit with the primary of an ignition coil.

7. In a circuit breaker for the primary circuit of an ignition system used ininternal combustion engines, the combination comprising a first member made of conduc tive material, a second member made of conductive material, a shaft fixedly connected to one of said members,

- means for rotating said shaft, one of said members being provided with a set of balls which are adapted to make electrically conductive rolling contact with the other said member, the other said member being provided with a multiplicity of insulated portions which are adapted to register with said balls and thereby prevent the flow of current through said balls, the circumferential extent of each said insulated portion being less than the circumferential extent of the conductive portions between the insulated portions of said member having said insulated portions, said member being provided with a set of electrical contacts positioned in such a manner that a circuit is formed between said set of contacts and said other said member before said set of balls is brought into register with said insulated portions and said circuit is broken before said set of balls is brought out of register with said insulated portions, said members and said rolling contacts adapted to be in a circuit with the primary of an ignition coil.

8. In a circuit breaker for the primary circuit of an ignition system used in internal combustion engines, the combination comprising a housing, a plate mounted within said housing, said plate having an annular groove therein and being formed with a multiplicity of circumferentially spaced insulators along said groove, a multiplicity of balls adapted to roll in said groove, a cage for maintaining said balls in circumfer'entially spaced relationship in such a manner that when one of said balls is in register with an insulated portion the remainder of said balls is also in register with insulated portions, the circumferential extent of each said insulated portion being less than the circumferential extent of the portion, said plate and said balls adapted to be in circuit with the primary of an ignition coil, said balls forming parallel condoctors in said primary circuit, said means for maintaining said balls in spaced relationship being rotatably mounted relative to said plate, and transformer oil in saidhousing and covering said plate and balls.

9. The combination set forth in claim 8 wherein said plate :andsaid cage are provided with pairs of lugs adapted, when in register, to make electrical contact, each said lug onsaid plate being positioned in advance of an insulated portion, each said lug on said cage being positioned in advance of a ball, respectively, whereby electrical contact between said lugs is made before said balls comeinto register with said insulated portions vand electrical contact between said'lugs-is broken before said balls move out of register with said insulated portions.

10. The combination set forth in claim .8 including means for maintaining saidballs in contact with saidp comprising a spring positioned insuch a manner as to provide a compressive force between said plate and said balls.

11. The combination set forth in claim -8 including a thrust bearing positioned insaid housing in .sucha manner as to minimize the friction :causedby ;the ;relative rotation between saidplate and said cage.

12. The combination set forth .in claim ,8 including means for causing the relative rotation between saidgplate and said cage comprising a :shaft projectingthrnugh said housing and rotatably mountedjnisaidhousing- 13. In a circuit breaker for the primary circuit of an ignition system used in internal combustion engines, the combination comprising a first member made, of conductive material and provided with a multiplicity ofcircurn ferentially spaced electrically insulated portions, at'secqnd member made of conductivematerial, said ,second memher being provided with a multiplicity of rolling contacts adapted to contact said first member thereby providing a multiplicity of parallel circuits when said contacts are in contact-with electrically conductive portions of said first member, ,said contacts being circumferentially spaced in the same manner as said electrically insulated portions on thegfirstmember, the circumferential extent of eachsaid insulated portion being less than the circumferential extent of the portions of said first member between the ,insulated portions, said members and said rolling contacts adapted to be in circuit with the primary of an ignition coil, whereby when said electrically insulated portions and said contacts are in registry all of said parallel circuits are interrupted.

14. In a distributor and circuit breaker for internal combustionengines having a multiplicity of cylinders, the combination comprising a shaft adapted ,to be operatively connected to a rotatable part of the engine, a member made of electrically conductive material, a plurality of rollers of electrically conductive material, means for maintaining said rollers in contact with :said member in circumferentially spaced relationship, means responsive to the rotation of said shaft for causing relative rotational movement between said member and said rollers, said member being provided with a multiplicity of electrically insulated portionsspaced circumferentially along the path of the rollers, the circumferential extent of said insulated portions being less than the circumferential extent of the portions of said member between said insulated portions, the number of .insulated portions being equal to the number of rollers and circumferentially spaced in the same manner as the rollers, whereby electrical contact between the member and the rollers is broken when the rollers are in register with said insulated portions, said member and said rollers adapted to he in a circuit with the primary of an ignition coil, said rollers adapted to form parallel conductors in a primary circuit, whereby a circuit to the primary coil is completed when said rollers are out of register with said insulated portions and a circuit to the primary .,-coil is broken when said rollers are in register with said insulated portions.

15. The combination set forth in claim 14 wherein said member isfixed on ;-said shaft and said means for maintaining the rollers in spaced relationship being mounted on said shaft :for rotational movement relative to said member.

16. The combination set forth inclaim 15 wherein said rollers comprise balls.

.17. The combination set forth in claim 14 wherein said means for maintaining said :rollers in circumferentially spaced relationship comprises a race, each of said member and said .race being provided with a set of electrical contacts, said contacts adapted to be in circuit with the primary of the ,ignitioncoil and positioned in such a manner that said set of contacts is closed before the rollers are brought into register with the insulated portions and said set of contacts is opened before said rollers are brought out of register'with said insulated portions.

References Cited in the file of this patent UNITED STATES PATENTS 621,263 Maccoun Mar. 14, 1899 860,383 Hutchinson July 16, 1907 886,225 De L'a'Valette Apr. 28, 1908 937,522 Haniquet Oct. 19, 1909 958,908 "Cuno May 24, 1910 1,658,508 ,Anderson Feb. 7,1928 1,997,288 Anderson Apr. 9, 1935 2,181,713 ,Svoboda Nov. 28, 1939 2,257,781 Bohli Oct. 7, 1941 FOREIGN PATENTS 17,463 Great Britain July 30, 1907

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