US3485967A - Moving contact device for distributor mechanism - Google Patents

Description

Dec. 23, 1969 w. F. NEUMEISTER I 3,485,967

MOVING CONTACT DEVICE FOR DISTRIBUTOR MECHANISM Filed March 13, 1968 2 Sheetg-Sheet 1 Warren 1-. Neumeisfer INVENTOR.

Dec. 23, 1969 w. F. NEUMEISTER 3,485,967

MOVING CONTACT DEVICE FOR DISTRIBUTOR MECHANISM Filed March 15, 1968 2 Sheets-Sheet 2 Fig-4 Fig.5

it. Fi- 46 I 68 66 5 a I v 52 472 i Warren F. Neumeisfer 1N VENTOR.

United States Patent 3,485,967 MOVING CONTACT DEVICE FOR DISTRIBUTOR MECHANISM Warren F. Neumeister, 615 Wall St., Frackville, Pa. 17931 Filed Mar. 13, 1968, Ser. No. 712,780 Int. Cl. H01h 19/00, 7/08, 19/62 US. Cl. 200-19 9 Claims ABSTRACT OF THE DISCLOSURE This invention relates to improvements in the distributor mechanism associated with an internal combustion engine and more particularly to a modification of the contact breaker assembly of the distributor mechanism so as to improve operation of the distributor mechanism and prolong the useful life of the breaker points or contacts.

In a conventional automotive distributor mechanism, a control cam driven by the engine distributor shaft opens and closes a pair of contacts at a rate or frequency corresponding to the product of the number of cylinders of the engine and the number of combustion cycles per unit time. Thus, the breaker contacts are subjected to high electrical energy discharge at this frequency. Under such conditions, contact surface pitting is caused by particle transfer from one contact to another as well as an accumulation of particle deposits on one of the contacts causing a build up of oxidized metal having undesirable insulating characteristics. The efficiency of the breaker switch is thereby reduced with time causing a corresponding reduction in discharge of electrical energy. This also results in incomplete combustion within the engine cylinders to produce a build up of carbon on the ignition spark plugs which in turn gives rise to cylinder wall corrosion and a deterioration in engine performance.

The foregoing problems have been ameliorated by modification of the conventional distributor mechanism in accordance with the present invention to maintain desirable efiiciency of the breaker point contacts for a prolonged useful life, as much as three to four times that of the previously expected life of the breaker point contacts. This is accomplished by continuous movement of the con tact surfaces relative to each other so as to prevent a continuous discharge at one point on the contact surface area thereby preventing concentration of heat and build up of corrosion products.

In accordance with the present invention, the ground contact member in an automotive distributor mechanism is carried on an elongated mounting stud rotatably mounted by an adjustment drum about an eccentric axis oifset from the center of the cam operated contact member so that the contact surfaces overlap each other. The adjustment drum is continuously rotated about its own axis at a very low speed through self-locking, worm gearing forming part of a very high reduction gear drive between the adjustment drum and the engine driven distributor shaft associated with the distributor mechanism. The mounting stud for the ground contact member is connected to a constraining plate assembly producing rotation of the ground contact member about its own eccentric axis while it is being continuously rotated about the rotational axis of the adjustment drum resulting in an orbital "ice motion of the ground contact member in order to achieve the aforementioned objectives.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a top plan View with parts removed and shown in section of a typical automotive distributor mechanism modified in accordance with the present invention.

FIGURE 2 is an enlarged partial sectional view taken substantially through a plane indicated by section line 2-2 in FIGURE 1.

FIGURE 3 is a partial sectional view taken substantially through a plane indicated by section line 33 in FIGURE 2.

FIGURE 4 is a partial sectional view taken substantially through a plane indicated by section line 4-4 in FIGURE 3.

FIGURE 5 is a sectional view taken substantially through a plane indicated by section line 5-5 in FIG- URE 4.

FIGURE 6 is a perspective view showing the disassembled parts of the portion of the distributor mechanism embodying the present invention.

Referring now to the drawings in detail, FIGURE 1 illustrates an automotive distributor mechanism generally denoted by reference numeral 10 of a standard type except for the modification of the present invention. The distributor mechanism includes a cylindrical housing 12 to which the usual spark advance control device 14 is connected having a vacuum diaphragm actuator connected by conduit 16 to the engine manifold and a control rod 18. Mounted within the distributor housing 12, is a contact lever 20 pivotally mounted by the pivot 22 about a pivotal axis in parallel spaced relation to the rotational axis of the centrally disposed, engine driven distributor shaft 24 to which the control cam 26 is connected. Thus, during rotation of the enigne, the cam 26 is operative to oscillate the contact lever 20 on which the contact member 28 is fixedly mounted adjacent an end opposite the pivot 22. The contact member 28 as in the usual distributor mechanism, intermittently engages a ground contact member 30 which is electrically connected to ground. Also mounted within the distributor housing 12, is the capacitor 32 electrically connected in shunt relation to the contact members 28 and 30*. The foregoing descripion corresponds to a conventional contact breaker assembly associated with an automotive distributor mechanism. However, in accordance with the present invention the distributor housing 12 fixedly mounts therein a casing 34 within which the ground contact member 30 is positioned in offset relation to the contact member 28 and in perpendicular spaced relation to the engine driven distributor shaft 24.

As more clearly seen in FIGURES 3 and 4, the contact members 28 and 30 have confronting, circular contact surfaces 36 and 38 which engage each other in overlapping relation since the centers of the contact surfaces 36 and 38 are offset from each other. While the contact surface 36 of the cam operated contact member 28 is fixedly mounted on the contact lever 20, the contact surface 38 on the ground contact member 30 is continuously movable in an orbital path relative to the contact member 28 during operation of the engine. Toward this end, the ground contact member 30 is fixedly mounted on one axial end of a mounting stud 40. The mounting stud 40 is rotatably mounted about an eccentric axis within a cylindrical adjustment drum member 42 which in turn is rotatably mounted about a rotational axis in close parallel spaced relation to the eccentric axis of stud 40 within the housing 34. Accordingly, the adjustment member 42 includes reduced diameter bearing portions 44 at opposite axial ends thereof rotatably journaled within aligned openings in the housing 34. The upper end of the mounting stud 40 projects axially from the adjustment member 42 so as to mount the ground contact member 30 externally of the housing 34.

Formed adjacent the opposite end of the mounting stud 40 externally of the casing, is an externally threaded section 46 and a non-circular section 48, as more clearly seen in FIGURES 3 and 6. Motion constraining holding means generally referred to by reference numeral 50 is connected to the mounting stud adjacent its lower end. It will be observed that the holding means includes a traveling plate 52 having a non-circular opening 54 through which the non-circular section 48 of the mounting stud extends. Thus, the mounting stud is non-rotatable relative to the traveling plate which also is provided with an elongated slot 56 receiving an anchor stud 58 secured to the casing 34 as shown in FIGURES 2 and 3. The traveling plate 52 is thereby constrained to pivotal and slidable movement relative to the casing 34 causing rotation of the mounting stud 40 and the ground contact member 30 about the eccentric axis during rotation of the adjustment member 42 about its rotational axis. The traveling plate 52 is held assembled on the mounting stud by a spring washer 60 and an assembly nut 62 threadedly mounted on the threaded section 46. A ground shunt terminal 64 is clamped in assembled relation between the nut 62 and the washer 60 in order to establish a ground connection to the ground contact member 30 through the mounting stud 40. The terminal 64 is therefore connected by a slack, flexible cable 66 to a suitable grounding location.

As hereinbefore indicated, continuous adjusting movement of the ground contact member 30 is effected by slow rotation of the adjustment member 42 about is rotational axis. Toward this end, high reduction gearing of the selflocking type is utilized. In one embodiment of the invention, this gearing including a worm wheel 68 externally fixed to the adjustment member 42 in mesh with a worm gear 70 rotatably mounted by the casing 34 in perpendicular spaced relation to the rotational axis of the adjustment member 42. A second worm wheel 72 is connected to the worm gear 70 and meshes with a driving worm gear 74 rotatably mounted by the casing 34 about an axis parallel to the rotational axis of the distributor shaft 24. A relatively large gear 76 is connected to the worm gear 74 and meshes with a pinion 78- fixed to the distributor shaft as more clearly seen in FIGURE 6 in order to establish a relatively high reduction gear ratio between the distributor shaft and the adjustment member 42. Thus, during operation of the engine, rotation will be imparted to the adjustment member 42 at a fixed reduction ratio causing orbital movement of the ground contact member 30 relative to the cam operated contact member 28 with which it is intermittently engaged. This results in a continuous change in the contact surface of the engaging contact surfaces 36 and 38 so as to avoid pitting and accumulation of corrosion deposits that would otherwise occur at a considerably higher rate because of the high frequency electrical discharge between the contact surfaces.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a contact breaker for an engine distributor including an engine driven distributor shaft, a ground contact assembly having an adjustable contact member and a cam operated contact member controlled by the distributor shaft for intermittent engagement with the ground contact member, a device for prolonging the useful life of said contact members comprising means rotatably mounting the ground contact assembly for guiding movement of the adjustable contact member relative to the cam ope-rated contact member, and reduction gear means drivingly connecting the distributor shaft to the rotatable mounting means for effecting continuous movement of said ground contact assembly during rotation of the distributor shaft.

2. The combination of claim 1 wherein said cam op erated contact member has a relatively fixed contact surface disposed substantially in parallel overlapping relation to the adjustable contact member of the ground contact assembly.

3. The combination of claim 2 wherein said ground contact assembly comprises an elongated mounting element having opposite ends, said adjustable contact member being fixedly mounted on one of said opposite ends, adjustment means drivingly engaged with said reduction gear means for rotatably supporting the mounting element along an eccentric axis, and holding means engaging the other end of the mounting element for effecting rotation of the adjustable contact member about said eccentric axis relative to the adjustment means during rotation thereof.

4. The combination of claim 3- wherein said rotatable mounting means comprises a fixed frame rotatably mounting the adjustment means about an adjustment axis parallel to the eccentric axis in perpendicular spaced relation to the distributor shaft, and anchor means pivotally and slidably mounting the holding means on the frame.

5. The combination of claim 4 wherein said reduction gear means includes self-locking gearing interconnecting the distributor shaft and the adjustment means at a fixed reduction drive ratio.

6. The combination of claim 1 wherein said ground contact assembly comprises an elongated mounting element having opposite ends, said adjustable contact member being fixedly mounted on one of said opposite ends, adjustment means drivingly engaged with said reduction gear means for rotatably supporting the mounting element along an eccentric axis, and holding means engaging the other end of the mounting element for effecting rotation of the adjustable contact member about said eccentric axis relative to the adjustment means during rotation thereof.

7. The combination of claim 6 wherein said rotatable mounting means comprises a fixed frame rotatably mounting the adjustment means about an adjustment axis parallel to the eccentric axis in perpendicular spaced relation to the distributor shaft, and anchor means pivotally and slidably mounting the holding means on the frame.

8. The combination of claim 7 wherein said reduction gear means includes self-locking gearing interconnecting the distributor shaft and the adjustment means at a fixed reduction drive ratio.

9. The combination of claim 1 wherein said reduction gear means includes self-locking gearing interconnecting the distributor shaft and the ground contact assembly at a fixed reduction drive ratio.

References Cited UNITED STATES PATENTS 3,434,027 3/1969 Cummings 200-31 ROBERT K. SCI-IAEFER, Primary Examiner J. R. SCOTT, Assistant Examiner U.S. Cl. X.R. 200--31, 38

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