US2085817A - Circuit breaker for spark distributors - Google Patents

Description

JUY 6, 1937. A. A. MELAcHER ET AL. y2,085,817

CIRCUIT BREAKER FOR SPARK DISTRIBUTORS Filed Feb. 12. 195e Patented July 6, 1937 UNITED STATES PATENT OFFICE CIRCUIT BREAKER Fon SPARKA DISTRIBUTORS Alfred A. Melcher and Albert G. H. Yanderpoel, Los Angeles, Calif., assignors of one-fourth to James OLaverty and one-fourth to David E. Seward, yboth of. Los Angeles, Calif.

Application February 12, 1936, Serial No. 63,562

' 1o claims. (01.123-117) 'Letters Patent led October 7, `1935, Serial No.

43,814 Patent No. 2,066,640 1937.

In our co-pending application, the position of the breaker arm with respect to the timing cam is controlled by a shaft or rod mounted for rocking movement and movable lengthwise by means of a pin that traverses an inclined slot in the sleeve that surrounds the rod or shaft and itis the prindated January 5,

cipal object of our present invention toeliminate the parts just mentioned and accomplish the same results by mounting the breaker arm on a rotary member that is arranged for movement on an axis that is offset or eccentric with respect to the axis of the timing cam, thus materially reducing the number of operating parts of the device and providing a construction that is relatively simple and practical, inexpensive of manufacture and positive in operation.

A further object of our invention is, to provide simple and -efcient means for automatically regulating the time period of electrical dwell or contact of the breaker contacts and thereby reg-.

the primary circuit to correspond with the speed of the'gaseous fuel mixture passing through the carburetor of the internal combustion engine, with which the device is associated and the demands of the output.

In connection with the ignition systems of internal combustion engines, it will be understood that while the engine is running at low or, idle speeds, a relatively short contact in the primary circuit produces sufficient saturation of the coil without oversaturation and that while the engine is running at high speeds, alonger contact is necessary to properly saturate the coil. Over.

Flg. 1.

saturation heats and burns out the coil and the contact points in the distributor head and these objectionable results are eliminated where myy primary current vflowing through the primary winding and I. around the core ofA the coil that magnetizes the core. Thus the core is magnetizd when the circuit is closed and demagnetized when Acoil for a constant milliampere the .circuit is open. The spark for igniting the gaseous fuel charges occurs when the coil is demagnetized by opening the primary circuit.

To produce a strong spark, the core of the coil must be completely saturated or magnetized and in order to do this, the primary circuit must be closed'by the contact points for a suflicient length of time by reason of the fact that the coil will not become magnetized instantaneously. A certain period of time is required. This being true, it will be seenthatthe spark or secondary current will grow weaker as the speed of the engine increases because 'the `speed of the cam that operates the circuit breaker correspondingly increases, wh-ich shortens the time of contact or dwell of the contact points of the primary circuit. lIt is oneof the purposes of our invention, to providefsimple and eicient means that is automaticallyv actuated, preferably by the velocity of .the flow -ofgaseous mixture through the .car-

buretor into the intake manifold, for controlling the periods ofcOntaCt or the time of dwell of the contacts iii-the".- primary circuit, corresponding with the. engine speeds, in order to bring about the propertiming ofthe saturation of the core of the coil. *I

With the 'foregoing and other objects in view our invention consists in certain novel featuresA of construction and arrangements of parts that will bev hereinafter more fully described and claimed andv illustrated in the accompanying drawing in wliichz;

Fig. 1 is a top vplan view of a circuit breaker and spark 'distributor f'constructed in accordance --with our invention and showing in section the Fig. 4 is aplan view ofthe eccentrically mounted breaker arm carrying plate and the disc or plate upon which the same is mounted.

Referringby numerals to the accompanying drawing which illustrates a preferred embodiment of our invention, i0 designates a conventional distributor head in which is mounted for rotation the usual axially disposed shaft I I carrying the timing cam I2. Y Suitably secured within the recessed upper portion of head I is a disc or plate I3 and the central portion of this disc or plate is pressed downwardly to form an eccentrically arranged circular recess I l.

An inwardly presented iiange I5 surrounds the lower portion of this recess.

ranged opening and surrounding the latter, is a` depending ange that is carried by the inner race I'I. As a result of this construction and particularly the provision of the eccentric recess I4, the antifriction bearing and the depending flange 23 of plate I9 are eccentrically arranged with respect to the axis of shaft Ii that carries the timv ing cam.

Pivotally mounted in the conventional manner on plate I3, is a breaker arm 2I of the usual con- `struction and which carries at its free end a contact point 22.

Carried by the intermediate portion of the breaker arm 2 I is a block or shoe 23 that is adapted to be engaged by the high points of the timing cam I2.

Contact 22 is adapted to engage a fixed contact 24, the latter being carried by a screw 25 that is seated in a bracket 26 and which screw is secured in its adjusted position by means of a lock nut 21. Bracket 26 is carried by plate I3.

Pivotally connected to plate I3 adjacent the pivoted end of the breaker arm 2I, is one end of a link 28, the same extending substantially tangential from said plate through a housing 29 that -s connected to the breaker head I0 and the outer end of this link is pivotally connected to the cenlter of a diaphragm 30. The edge of this diaphragm is clamped between the divided parts of a housing 3-I and one of the parts of said housing having a tubular extension 32. The outer end of this extension 32 is closed and extending through said closed end and communicating with the chamber in the extension 32 is a tubular duct 33 that leads to the chamber within a conventional carburetor 34, preferably at a point between the throttle valve T andi the venturi V.

Interposed between the central portion of diaphragm 30 and the outer end of the tubular member 32, is an expansive coil spring 35 which yieldingly resists the movement of the diaphragm toward the side ofthe housing 31| having the tubular extension 32.

That portion of tube 33 that extends into the carburetor functions as a Pitot tube to control the pressure exerted on the diaphragm 30. In some instances, to produce the desired results,.tube 33 may be extended directly into the venturi or into the carburetor at or -near the point of highest velocity flow of the gaseous mixture therethrough.

jeous mixture passing through the carburetor is not strong enough to overcome the-tension of Fig; 1.

Under such conditions plate or disc I5 supported on the antifriction bearings in the eccentric recess I4 in disc I 3, occupies a position so that when contact 22 carried by the free end of said breaker arm isin engagement with adjustable contact 24, the face of shoe 23 is spaced a very slight distance away from the central portion of one of the angular faces of cam i2.

Under such conditions the time period of engagement between the contacts 22 and 24 is comparatively short, but even so such comparatively short dwell of the contacts is sufficient to permit the flow of sufficient current through the contact and other connections to bring about the desired degree of saturation of the coil.

As the cam I2 moves a short distance, one of the faces thereof will engage shoe 23 and as a result of such engagement breaker arm 2I will be swungAoutwar'dly away from the cam, thus separating the contacts 22 and 24 and the flow of current to the coil ceases.

Thus under slow or idling speed there is a relatively short period of dwell or contact between the contacts 22 and 24 and a much longer time period of separation between such contacts and as a result the coil is saturated for only a short -time or while the contacts 22 and 24 are closed.

As, the throttle is opened to increase the speed of the engine, the corresponding increase in the velocity of the gaseous fuel mixture from the carburetor to the intake manifold produces suction through tube 33 and this suction is exerted upon diaphragm 30 to draw the same toward the side of housing 3| having the extension 32 and the movement thus imparted to said diaphragm is imparted by link 28 to the disc or plate I3, such movement causing partial rotation of said disc or plate in the eccentric recess I4.

Due to the fact that plate I3 carrying the breaker arm 3| is eccentrically mounted with respect to the axis of the cam I2, the breaker arm will be carried into a position whereby the face of contact shoe 23 occupies a position a greater distance away from the axis of the shaft carrying the cam with the result that the high portions of the cam only engage the face of shoe 23 for shorter periods of time than under the'conditions previously described while the engine is idling and such action increases or lengthens the dwell or periods of contact between the contacts 22 and 2`4, thus correspondingly lengthening the time periods of saturation of the coil and which result is desirablefor higher engine speeds.

Thus when the engine is run at its maximum or highest speed, the swell or time period of contact between the contacts 22 and 24 are of longest duration and this brings about the desired degree of saturation of the coil with the contact point.

As the speed -oi the engine decreases its idling speed, l the suction produced through the carburetor correspondingly decreases and diaof the breaker arm and particularly the contact shoe 23 with respect to the axis of the cam and `the periods of dwell or contact between the contacts 22 and 24 will be correspondingly increased so as to bring about the desired degreefof lsaturation of the coil during the decreasing and idle speed of the engine. Thus it will be seenV that in our improved circuit breaker, the mounting of the contact arm on a rotary member having an axis offset. or eccentric with respect to the axis of the shaft carrying the cam provides simple and eiicient means for increasing or decreasing the gap in the ignition circuit according to the speed of the engine and the demands of the coil fora constant milliampere output and the velocity of the gaseous mixture owing from the carburetor to the intake manifold automatically controlling the position of the breaker arm and the contact shoe carried thereby relative to the cam that operates said breaker arm.

The use of our improved circuit breaker enables a higher voltage coil to be used in the ignition system and such lcondition is especially desirable and advantageous inasmuch as it produces the desired results, particularly at vhigh engine speeds.

Our improved form of circuit breaker may be advantageously employed in connection with the present forms of automatic timers and ignition devices by merely substituting our improved form of breaker arm carrying ring or plate and its supporting plate, for the corresponding parts now utilized in standard forms of circuit breakers and spark distributors.

The eccentrically mounted plate `that carries the breaker arm is lmounted so that when the engine speeds up so as to impart movement to said plate, such movement is in the opposite direction from that of the rotary movement of the shaft carrying the cam and as a result of this movement, the spark is automatically advanced and such advance is proportionate or in keeping with the engine speed.

As illustrated by the arrow and legend ADV. in Fig. 1, the rotary movement of the plate I9 when actuated as a result of increased engine speed, is anti-clockwise and at all times the shaft Il, carrying timing cam l2, rotates clockwise as indicated by the arrows Figs. 1 and 2. When the engine speed decreases, the rotary movement of the plate I9 is clockwise as indicated by the arrow and legend RET. in Fig. 2.

Obviously as the breaker arm carrying plate returns to its normal position it moves in the same direction with that of the cam and the spark is correspondingly retarded as the engine slows down.

In order to regulate the tension of spring 35, a rod 36 is screw-seated in the tting that connects tube 33 to the tubular extension 32 of the diaphragm housing 3|, and the inner end of this screw rod carries a disk 31 that provides a bearing for the adjacent end of spring 35.

Thus the action of the diaphragm may be read- A ily controlled.

As a result of our improved construction, it is not necessary to employ the conventional Weights Y utilized in connection with the shaft of the timmounted so that the distance between its axis spark due to the correct period of dwell oi contact to bring about the proper degree of coil saturation. l

Thus it will be seen that we have provided a circuit breaker for spark distributors that is relatively simple in construction, inexpensive of manufacture and very eiective in performing the functions for which it is intended.

It will be understood that minor changes in the size, form and construction of the various parts of our improved circuit breaker for spark distributors may be made and substituted for those herein shown and described without departing from the spirit of the invention, the scope of which is set forth in the appended claims.

We claim as our invention:

1. In a circuit breaker for spark distributors including a cam, a contact carrying' breaker arm and a relatively fixed contact, a member mounted for rotary movement on an axis that is eccentric relative to the axis of the cam, said rotary member carrying said breaker arm and said relatively xed contact and automatically operating means controlled by the velocity flow of the gas air mixture through the carburetor with which the circuit breaker is associated for imparting movementto said rotatably mounted member.

2. In a circuit breaker f or spark distributors including a rotary cam, a member mounted for rotary movement on an axis that is eccentric to the axis of said cam, a contact carrying breaker arm pivotally mounted on said member, a relatively xed contact carried by said member and automatically operating means controlled by the velocity flow of the gas air mixture through the carburetor with which the circuit breaker is associated for imparting movement to said member to change the position of said contact carrying breaker arm and the relatively xed contact with respect to said cam.

3. In a circuit breaker for spark distributors including a rotary cam, a member mounted for rotary movement on an axis that is eccentric to the axis of the cam, a breaker arm pivotally' mounted on said'member, a shoe carried by said breaker arm, which shoe is adapted to be engaged by the cam during its rotary movement, a contact carried by said breaker arm, a relatively xed -contact mounted on `said member and radapted to be engaged by the contact carried by the breaker arm and automatically operating means actuated and controlled by the velocity oW of the gas air mixture through the carburetor with which the circuit breaker isasso- `ciated for imparting movement to said member so as to change the position of the parts carried thereby with respect to said cam.

4. In a circuit breaker for spark distributors including a rotary cam, of a member mounted for rotation adjacent said cam, the axis of which v member is eccentric with respect to the axis of the cam, a breakerarm pivotally mounted on said rotatably mounted member, a shoe carried by said breaker arm, which shoe is adapted to be engaged by said cam, a contact carried by the breaker arm, a relatively fixed contact that is adapted to be engaged by the contact carried by said breaker arm, and automatically operating means actuated and controlled by the velocity ow of the gas air mixture through the car.- buretor with which the circuit breaker is associated for Iimparting'rotary vmovement to said eccentrically arranged member.

5. In a circuit breaker for spark distributors including a rotary cam, a member mounted for rotation adjacent said cam and having an axis that is eccentric with respect to the` axis of said cam, a breaker arm pivotally mounted on said member, a shoe carried by said breaker arm with which said cam is adapted to engage, a contact carried by said breaker arm, a relatively xed contact carried by said member with which the contact carried by the breaker arm is adapted to engage and means actuated and controlled by the velocity of the gas-air mixture through the carburetor with which the circuit breaker is associated for'imparting movement to said member to change the positions of the parts carried thereby with respect to the cam so as to increase or decrease the periods of contact or dwell between the contact carried by the breaker arm and the relatively stationary contact.'

6. In a circuit breaker for spark distributors including a rotary cam, a member mounted for rotation adjacent said cam and having an axis that is eccentric with respect to the axis of said cam, a breaker arm pivotally mounted on said member, a shoe carried by said breaker arm with which said cam is adapted to engage, a contact `carried by said breaker arm, a relatively xed contact carried by said member with which the contact carried by the breaker arm is adapted to engage and means controlled by the speed of the engine with which the circuit breaker is associated for imparting movement to said member to change the positions of the parts carried thereby with respect to the cam so as to increase or decrease the periods of contact or dweil between the'contact carried by the breaker arm and the relatively stationary contact.

'1. The combination with a -spark distributor head and the rotary cam associated therewith, of a member mounted for rotation on said head and having an axis that is eccentric relative to the axisV of said cam, a'breaker armpivotally mounted on said member, a shoe carried by said breaker arm and adapted to be engaged by said cam, a contact carried by saidbreaker arm, a relatively iixed contact carried by said member and adaptedto be engaged by the contact carried by the breaker arm and means actuated and controlled by the now of gas-air mixture through is associatedior imparting movement to `said member to change the position thereof and the aosaeir i positions oi the parts carried. thereby with respect to said cam.

8. The combination with a spark distributor head and the rotary cam associated therewith, of a member mounted for rotary movement on said head, the axis of which member is eccentric with respect to then axis of the cam, a breaker arm pivotally carried by said rotatably mounted member, a shoe carried by said breaker arm and adapted to be engaged by said cam, a contact carried byv said breaker arm, arelatively stationary contact carried by said member and adapted to be engaged by the contact carried by said breaker arm and automatically operating means actuated and controlled by the velocity ow of the gas air mixture through the carburetor with which the spark distributor is associated forimparting movement to said eccentrically mounted member.

9. The combination with a spark distributor head and the rotary cam associated therewith, of a member mounted for rotary movement on said head, the axis of which member is eccentric with respect to the axis of the cam, a breaker arm pivotally carried by said rotatably mounted member, a shoe carried by said breaker arm. and adapted to be engaged by said cam, a contact carried by said breaker arm, a relatively stationary contact carried by said member and adapted to be engaged by the contact carried by said breaker arm and automatically operating means actuated and controlled by the speed of the engine with which the circuit breaker pis associated for imparting rotary movement to said eccentrically mounted member.

10. In a circuit breaker for spark distributors, including a rotary cam, a member surrounding said cam and mounted for rotation on an axis that is eccentric with nespect to the axis of said cam, a breaker arm pivotally mounted on said member, a shoe carried by said breaker arm with which said cam is adapted to engage, a contact carried by said breaker arm, a relatively xed contact carried by said breaker arm with which the contact carried by the breaker arm is adapted to engage, means located adjacent the distributor for converting vacuum suction into movement, and means connecting said converting means with the eccentrically mounted breaker arm car` vrying member.

ALFRED A. MIELCHER. ALBERT G. H. VANDERPOEL. l

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