US3506796A - Distributor utilizing a stationary cam plate coacting with a resilient selfwiping contactor - Google Patents

Description

April 14, 1970 c. ROSCHILLA SELF WIPING CONTACTOR Filed Dec. 19, 1966 DISTRIBUTOR UTILIZING A STATIONARY CAM PLATE COACTING WITH A RESILIENT FIG. 2

ATTORNEY COS/M0 RUSCH/LLA INVENTOR- United States Patent US. Cl. 20019 Claims ABSTRACT OF THE DISCLOSURE A distributor system for an internal combustion engine wherein there is provided at least one spring loaded rotary self-wiping breaker point which engages in succession, as it rotates, a series of circumferentially arranged cam surfaces, each surface having a terminal high point such that as the rotating breaker point travels along each cam surface a charge is built up in the distributor systems electrical circuit. When the rotating, self-wiping breaker point moves oif the high portion of each of the cam surfaces a magnetic field collapse is caused. This collapse, aided by condenser action, induces the high voltage in the second winding of the ignition coil, which high voltage surge is led to the proper spark plug.

This invention relates to ignition distributors for internal combustion engines, and more particularly to novel distributor circuit make and break system therefor.

-In ignition systems heretofore available there has been a constant need for adjustment every four or five thousand miles of the distributor points of the distributor of an internal combustion engine. There has also been the ever present danger of improper and inadequate ignition due to pitting of the distributor points.

The present invention eliminates pitting of the points, removes the need for adjustment of points, and insures improved smoothness in engine operation due to the novel design constituting the invention wherein a resiliently biased breaker point travels along or from one to another of a series of circumferentially arranged cam surfaces having equidistantly spaced high portions which effect the desired break and make of the ignition current in order to actuate the spark plugs of the engine.

It is an object of the invention to provide a novel ignition circuit making and breaking mechanism having a rotatable member which is resiliently biased into engagement with circumferentially arranged fixed breaker point elements which effect the relative radial displacement bet-ween the rotating breaker point member and the fixed coacting elements such that during the travel of the rotating member between the fixed elements a charge is stored in the condenser of the ignition system, and

upon travel past each fixed breaker point element there is a magnetic field collapse in the circuit, which, aided by the condenser action, induces a high 'voltage in the secondary winding of the ignition coil, which high voltage surge is led to the proper spark plug.

It is a further object of the invention to provide a novel ignitor for the ignition system of an internal combustion engine which includes a rotary self-wiping point adapted to travel along or relative to circumferentially arranged cam surfaces having equidistantly spaced high portions formed or mounted on a fixed metal distribution plate for making and breaking the ignition circuit of an internal combustion engine.

The invention is further characterized by the provision of a distributor for an internal combustion engine having a fixed metal distributor plate provided with equidistantly spaced circumferentially arranged surfaces, equal in number to the number of cylinders of the engine, and rotatable 3,506,796 Patented Apr. 14, 1970 spring urged point means which ride upon and along such cam surfaces to effect the desired timing of the spark in the cylinders of the engine.

The invention further consists in the provision of a novel igniter mechanism for the distributor of an internal combustion engine which can form an original part of a distributor or which can also be installed with a minimum of effort in an existing distributor and thereby prevent pitting of points. A

With these and other objects not specifically mentioned in view, the invention consists in certain combinations and constructions which will be described fully hereinafter, and then set forth in the claims hereunto appended.

In the accompanying drawings which form a part of this specification, and in which like characters of reference indicates the same or like parts:

FIGURE 1 is an exploded view showing the cooperative parts of one form of distributor embodying the invention,

FIGURE 2 is a side sectional view of a preferred form of the invention,

FIGURE 3 is a plan view of a preferred embodiment of the breaker mechanism of the invention,

FIGURE 4 is a diagrammatic View of a suitable electric circuit showing the electrical relationship of the parts, and

FIGURE 5 is a view of a detail.

Referring to the drawings, the distributor shown in FIGURES l and 2 comprises a support 2 adapted to be mounted in known manner on an internal combustion engine (not shown) having a gear (not shown) fixed to distributor shaft 4 which meshes with gear (not shown) on the cam shaft of the engine and driven thereby in the usual manner.

Support 2 comprises an elongated sleeve 3, an enlarged cylindrical part 6, and a central hub 8 to which is secured a mounting plate 10.

The distributor is provided with conventional counter weights 12 pivotally mounted at 13 on cam weight base plate 14 fixed to shaft 4. Springs 16 each have one end attached to a pin 15 on the free end of a weight 12. Their other ends are secured to pins 17 on plate 18 attached to cam weight base plate 14. Counter weights function in known manner to control high speed advance of the spark.

A distributor rotor 20 of known design is attached by screws 21 to cam weight base plate 14. Distributor cap 22 which is provided with a central contact 24 and eight spark plug controls or contacts 26, because this disclosure relates to an eight cylinder engine, is detachably mounted on support 2 by means of spring biased hooks 28 of suitable conventional design.

The mechanism for effecting the desired make and break of the ignition circuit comprises a metal or conducting plate 30, which is attached by screws 32 to mounting plate 10, and rotating resiliently supported breaker point member 52. As best shown in FIGURES l and 2, breaker plate 30 is supported in non-conducting relationship relative to plate 10 by cylindrical insulating posts 34 and cap insulators 36 which can be made of rubber or other non-conducting material. Breaker plate 30 can be of any suitable thickness. I have found that a plate gives satisfactory results.

. In the illustrated embodiment of the invention, breaker plate 30 is round so that it can fit readily within distributor cap 22. Plate 30 is provided with a series of radially inwardly directed spark controlling cam sections designated generally 38. Each of these sections has a high portion or breaker point 40 and a low point 42. Since the engine for which the invention is being described herein has eight cylinders, it will be understood that eight cam sections 38 and breaker points 40 are provided. Sections 38 extend from points a to b and subtend central angles of 45 See FIGURE 3. The invention can be used equally well with six, four and other suitable number of cylinder engines. In case of a six cylinder engine, cam sections 38 are provided with breaker points 60 apart. In the case of a four cylinder engine there are four cam sections 38 having breaker points 40 circumferentially spaced 90 apart.

As shown in FIGURES 1, 2 and 3, breaker point member 52 is carried by rotor 44 attached to shaft 4 and rotating therewith. In the form selected to illustrate the invention rotor 44 comprises a clamp collar 46 secured by clamp screw 47 to shaft 4, and a breaker point mount, such as cylindrical, tubular extension or arm 50, preferably formed integrally with collar 46. This construction provides for yielding and resilient movement of self-wiping breaker point member 52 during engagement and travel along cam surfaces 43 of sections 38 of plate 30. Member 52 is biased radially outwardly in its support arm 50 by spring 54 (FIGURE 2). Pin 56 mounted in member 52 with its ends extending through slots 58 in arm 50 limits the extent of radial movement of breaker point member 52 to and from cam surfaces 43 and high points 40 of sections 38. The length of slots 58 is so designed that optimum movement of member 52 is assured.

As best shown in FIGURE 5, breaker point member 52 preferably is formed with an inclined or tapered cam face 55. This is provided in order to prevent damage to cam plate 30 sections 38, if for any reason the engine misfires or backfires and rotor 44 is driven in the opposite direction. If this should happen cam face 55, upon engaging a high point 40 would act to cam or push member 52 radially inwardly in its support arm 50.

It will be appreciated that with some engines shaft 4 may be rotated counterclockwise, rather than clockwise, as viewed in FIGURE 3. In this case, cam sections 38 of plate 30 and breaker point member 52 will be reversed in their operating positions. Otherwise, the construction and operation are the same as shown and described hereinabove.

As shown in phantom in FIGURE 3, if desired, a plurality of arms 50 can be provided. Thus, if for any reason, breaker point member 52 of one arm should become inoperative, as for example, if a spring 54 should break, the proper ignition can be maintained through another breaker point member 52 which coacts with plate 30.

As shown in FIGURES l and 3, cam surfaces 43 are curved radially inwardly increasing from points b to points a. This results in a smoother travel of breaker point member 52 therealong. It also effects the maximum compression of spring 54 well before it reaches the breakoif or high point 40 of a cam section 38, thereby causing a cleaner and more rapid breaking of the primary circuit of the ignition system than would be effected if member 52 traveled along a straight line path between these points.

Breaker point member 52, as illustrated, is cylindrical. If desired, any other suitable shape could be used, as long as arm 50 is designed to accommodate it for free sliding radially inwardly and outwardly relative to cam surfaces 43 during the rotation of shaft 4 in order to effect the desired self-wiping action thereof on cam surfaces 43 as it travels therealong. The construction and operation of breaker point member 52 and cam sections 38 are such that in operation there is no danger of pitting of the coacting elements, as is the case of the pitting of points in the case of a present type of conventional distributor. Thus, the invention contributes to the markedly improved smoothness of operation of the engine it serves, and a freedom from ignition troubles.

The end or tip of member 52 which engages and runs along cam surfaces 43 is rounded, e.g. generally U or V-shape with the curve portion thereof substantially tangent to the cam surface. Therefore, when spring 54 forces member 52 radially outwardly in arm 50 as it moves or snaps off each high point 40, there will be no chipping or indenting of the cam surfaces, thereby insuring long physical life of these parts. When a tip is provided on the free end of member 52, the tip 53, is shaped as described above. Spring 54 is so designed that it insures a clean snap of member 52 off each high point 40.

Referring to FIGURES 4 and 5, it will be seen that each cam section 38 is provided with an insert or facing strip 57 on its cam surface 43 which is tracked by member 52. Although member 52 and cam surfaces 43 of sections 38 can be hardened in order to prevent wear and burning, it is preferred to provide tip 53 of tungsten, platinum, silver, or a suitable commercial type of heat and wear resistant alloy, e.g., silver tungsten, attached as by welding to or mounted on the end of member 52, and to provide inserts or facings 57 of similar metals or alloys on the cam surfaces 43.

The end of member 52 when no tip 53 is used, and tip 53 are equal in width to the thickness of plate 30. There is, therefore, no overhang between these members relative to plate 30, and tendency to are is minimized.

In operation, as shaft 4 rotates, it moves clockwise, as viewed in FIGURE 3. In response to this movement member 52 travels from one cam section 38 to another. Member 52 is connected in the engines electrical ignition circuit as shown diagrammatically in FIGURE 4. Therefore, during the time member 52 is moving along insert or facing 57 of surface 43 (or when members 52 are moving therealong, when more than one member 52 is provided) en route to a high or snap off point 40, the primary circuit is closed and condenser 60 is being charged. When, however, member 52 rides or snaps off each high point 40 of a cam section 38, the collapse of the magnetic field, which, aided by the discharge of condenser 60, induces a high voltage in the secondary winding of a coil 62 to central lead 24 in distributor cap 22 through spring contact 25 of distributor rotor 20 to spark plug contacts 26 in cap 22, and thence through lead 24 in succession to activate the several spark plugs.

What I claim is:

1. A device of the type described for making and breaking a distributor ignition circuit comprising a centrally located continuously rotating shaft, a breaker plate mounted on a support and in a plane at a right angle to the longitudinal axis of said shaft, a plurality of centrally located circumferentially, equidistantly spaced breaker point protrusions on the breaker plate for successively and repeatedly breaking said circuit in response to continuous rotation of said shaft, a breaker point carried by said shaft and means mounting said last named breaker point for yielding movement relative to the protrusions on said breaker plate as said breaker point is rotated by said shaft into engagement with the protrusions on the plate.

2. The invention defined in claim 1, wherein said means mounting said breaker point on said shaft comprises an arm carried by said shaft, a yieldable support for said last-named breaker point and spring means biasing said breaker point into engagement with said breaker points on said breaker plate.

3. A device of the type described for making and breaking a distributor ignition circuit comprising a centrally located continuously rotating shaft, 21 breaker plate mounted on a support and in a plane at a right angle to the longitudinal axes of said shaft, a plurality of circumferentially located equidistantly spaced projecting breaker points on the breaker plate for successively and repeatedly breaking said circuit in response-to continuous rotation of said shaft, said breaker points including cam sections having high portions, a breaker point supported on an arm carried by said shaft and spring means mounting said last-named breaker point for yielding movement relative to said breaker points on said breaker plate, said spring means effecting a rapid disconnect relative to the high portions of said cam sections in response to the travel of the arm supported breaker point along and off said cam sections as said arm-supported breaker point is rotated by said shaft into engagement with the breaker points on the plate.

4. The invention defined in claim 3, wherein said cam sections comprise curved cam surfaces extending radially inwardly on said breaker plate towards the center of rotation of said shaft, said cam surfaces providing means for substantially immediately effecting the compression of said spring means, whereby said rotating breaker point is readied for rapid disengagement from said breaker points of said plate, and means for limiting the extent of movement of the traveling breaker point relative to said arm.

5. The invention defined in claim 4, wherein said rotating breaker point is formed with a cam face on its rear portion and a rounded portion adapted to engage and travel along said cam surfaces, said cam face being constructed and arranged to prevent damage to said rotating breaker point and its supporting arm and said points on said breaker plate in the case of possible undesirable rearward movement of said arm due to misfire or backfire of the engine with which the distributor forms an operating part.

6. The invention defined in claim 4, wherein said arm comprises a tubular support, and said rotating breaker point is slidably mounted therein, and said spring means normally tend to urge said arm supported breaker point outwardly into engagement with said points on said breaker plate.

7. The invention defined in claim 3, wherein said breaker point carried by said shaft and said cam sections, respectively, are provided with heat and wear resistant tip and surface means selected from the group including tungsten, platinum, silver, gold and alloys and mixtures of said metals capable of effecting long and efficient oper ating conditions.

8. The invention defined in claim 5, wherein said rotating breaker point is provided with a high heat and wear resistant metal tip, and wherein said cam sections of said plate are provided with similar metallic wear and heat resistant surfaces which are engaged by said rotating breaker point.

9. In a distributor having an ignition circuit, a pointed breaker plate, a plurality of circumferentially equidistantly spaced breaker point protrusions on the breaker plate for successively and repeatedly breaking said circuit, at least one member having a plurality of yieldably mounted breaker point members coacting with the plate including means for mounting said members on a continuously totating shaft in substantially equidistant relationship and spring means biasing said breaker point members into engagement with the protrusions on said plate, said continuously rotating shaft effecting relative continuous r0- tary movement between said members and said protrusion on the plate, thereby successively and repeatedly making and breaking said ignition circuit.

10. The invention defined in claim 9, wherein said breaker points on said' plate are high portions of circumferentially arranged cam sections formedon said plate, and wherein said cam sections have radially inwardly curved cam faces positioned to be tracked by said breaker points carried by said members.

References Cited UNITED STATES PATENTS 1,400,561 12/1921 Mason.

1,669,372 5/1928 Despard 2008 X 1,873,527 8/1932 Afinnsen et al. ZOO -B 3,164,708 1/ 1965 Theobald.

3,263,033 7/1966 Metzger 200-66 X 3,359,393 12/1967 Anthony ct al 200155 FOREIGN PATENTS 77,981 11/1918 'Switzerland. 674,176 6/ 1952 Great Britain.

ROBERT S. MACON, Primary Examiner

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