US3375713A - Internal combustion engine ignition system distributor make and break analyzing apparatus - Google Patents

Description

Aprll 2, 1968 M. N. GOVER 3,375.713

INTERNAL COMBUSTION ENGINE IGNITION SYSTEM DISTRIBUTOR MAKE AND BREAK ANALYZING APPARATUS Filed March 28, 1966 VENTOR;

gym/HQ United States Patent 3,375,713 INTERNAL COMBUSTION ENGINE IGNITION SYSTEM DISTRIBUTOR MAKE AND BREAK ANALYZING APPARATUS Marcius N. Gover, 151 S. Oxford Ave., Los Angeles, Calif. 90004 Filed Mar. 28, 1966, Ser. No. 538,018 8 Claims. (Cl. 73118) ABSTRACT OF THE DISCLOSURE An automobile distributor tester having a circular distributor-mounted scale which cooperates with a pointer carried by the distributor shaft. The scale is calibrated to show the proper periods of make and break, for the particular automobile tested, of the distributor electrical contact points for a complete cycle of the operating cam carried by the distributor shaft. A light is provided to indicate when the distributor electrical contact points are open and when they are closed.

Generally speaking, the present invention relates to apparatus or means for indicating the optimum performance and the actual performance of the breaker switch means of the distributor of an ignition system of an internal combustion engine and for making it possible to very simply compare same for the purpose of reaching some quantitative conclusions as to the extent and direction of adjustment of the points assembly unit comprising said breaker switch means relative to the distributor cam which effectively opens and closes said breaker switch means, which seems necessary in order to cause the actual performance and operation thereof to approach that of the optimum performance and operation thereof.

In other words, the present invention provides a simple, inexpensive, accurate, compact, and portable means or apparatus for analyzing the make and break characteristics of the electrical contacts of the breaker point assembly comprising a part of the above-mentioned breaker switch means and located in the distributor of an internal combustion engine, such as the power plant of a motor vehicle.

Although the device is of extremely simple, inexpensive, and compact construction, this does not in any way reduce its effectiveness for providing an extremely high degree of accuracy in the readings obtainable and for providing all information necessary for the purposes outlined above.

One circular scale portion of the apparatus is adapted to be attached and mounted directly on and around the outside wall of a distributor housing while another indicating pointer portion of the device is adapted to be attached to the upper end of the distributor cam shaft. Both of these attachment or mounting operations may be performed very simply and easily in a matter of moments.

It will be understood from the foregoing description, that the readings obtainable amount to visual readings of the position of the indicating pointer portion relative to the circular scale portion and, therefore, are of an easily visibly observable type. Also, the readings are effectively magnified because the circular scale portion and the portion of the indicating pointer which overlies same are located in an annular area of effectively extended radius, this being the area around the fixed portion of the distributor housing. Thus, the directness and the effective magnification of the readings add to their inherent accuracy.

The present invention is particularly valuable for use in connection with the replacement, in a distributor, of a worn-out points assembly unit carrying electrical contacts with a new points assembly carrying new electrical con- 3,375,713 Patented Apr. 2 1968 tacts. This is frequently required in any internal combustion engine subjected to considerable usage, and this operation is normally performed at recommended periods of either absolute time or contact usage time. It is very important that the new set of electrical contacts of the points assembly units be installed so that when they are in the break, or open position, the resulting maximum gap between them must be of the precise distance recommended by the manufacturer thereof.

In conventional prior art practice, measurement of the contact gap of the points assembly unit, as referred to in the preceding paragraph, has been customarily accomplished by the use of what is known as a feeler gauge" employed in an attempt to adjust the position of the entire unit relative to the distributor cam lobe or point so that the gap is precisely that gap specified by the manufacturer. However, this conventional prior art gap adjustment and gap setting procedure is a very inadequate method because it involves a considerable amount of guess-work and trial and error, which try the patience of the person performing the gap-setting operation to a very considerable degree. This is because there is no way of intelligently estimating, in the correct direction, the actual extent of the plus or minus adjustments needed to assure the exactly-correct gap setting after the points assembly unit is tightened down with respect to the distributor by tightening the mounting screws thereof. Consequently, since a considerable amount of patience for multiple gap-setting operations is required, the final adjustment of the gap may or may not be exactly in accordance with the predetermined measurement specified by the manufacturer. This is purely because of impatience on the part of the person performing the gap-setting operation, which results from the nature of the gap-setting operation as described above.

The present invention will replace the above relatively primitive prior art method with a logical, meaningful, convenient, and easier method for performing a gapsetting operation. In addition, the apparatus of the present invention will provide the only means for properly setting the gap of a newly-installed electrical contact assembly or points assembly unit of an encapsulated type such as is disclosed with great particularity in my copending patent application, Ser. No. 446,807, filed Apr. 9, 1965. This is so because the contacts of such an encapsulated unit are totally enclosed and, thus, the actual gap between the contacts cannot be measured by a feeder gauge.

The present invention will also provide a convenient and very accurate means for checking into the extended life of encapsulated electrical contacts of the type referred to above as being set forth in my co-pending patent application after they have been used for a long period of time. Any variation from the ideal make and break characteristics which may have occurred as a result of the extended use thereof will be clearly revealed and any required corrections will be indicated as to direction and, to a considerable degree, as to magnitude.

I am aware of the fact that various prior art apparatuses and equipment have been developed for the general purpose of analyzing distributor breaker points means operation. However, most such prior art devices known to me are of very elaborate, expensive, and bulky construction to a degree such as to virtually render them unavailable for the average do-it-yourself mechanic or for the mechanic in a small shop or garage. Such devices are usually of an electronic nature and electronically indicate make or dwell time of the distributor point assembly contacts on an electrical meter, an oscilloscope, or the like. Thus, such equipment is not only large, bulky, and expensive, but is beyond the understanding of the average do-ityourself mechanic, who would, in most cases, not be able to use and operate same.

The above-mentioned disadvantages of prior art distributor analyzers are completely met and overcome in and through the use of the present invention because it is of such an extremely simple, inexpensive, accurate, compact, and portable nature and of such an easy-to-use and easy-to-understand nature as to make itself effectively available for use by virtually any do-' -yourself mechanic, who can readily afford it and who will immediately be able to use it the very first time he tries, and with no difficulty whatsoever.

Additionally, it should be noted that the apparatus can comprise a completely independent unit powered by its own small battery and, thus, can be used anywhere. This makes it possible to analyze the operation of the distributor while it is mounted in a motor vehicle in its normal relationship thereto or to remove the distributor for analyzing the make and break characteristics thereof in a shop, or the like. Additionally, it should be noted that as an alternate to the above arrangement, the storage battery conventionally found in a motor vehicle may be employed for energizing the make and break analyzing apparatus of the present invention and may be provided with current-limiting means for positively preventing current flow therethrough of an extent such as to cause any arcing or pitting of the contacts of the distributor points assembly unit during the testing or analyzing operation.

With the above points in mind, it is an object of the present invention to .provide a novel internal combustion engine ignition system distributor make and break analyzing apparatus of the character referred to herein, generically and/ or specifically, and which may include any or all of the features referred to herein, either individually or in combination, and which is of extremely simple, inexpensive, maintenance-free, easy-to-rnount and easy-touse construction, which is also adapted for ready mass manufacture at an extremely low cost-penunit, whereby to be conducive to widespread manufacture, distribution, and use of the invention.

Further objects are implicit in the detailed description which follows hereinafter (which is to be considered as exemplary of, but not specifically limiting, the present invention), and said objects will be apparent to persons skilled in the art after a careful study of the detailed description which follows.

For the purpose of clarifying the nature of the present invention, two exemplary embodiments of the invention are illustrated in the hereinbelow-described figures of the accompanying single drawing sheet and are described in detail hereinafter.

FIG. 1 is a top plan view of a distributor with the cover removed and with the mechanical portions of one exemplary form of the novel analyzing apparatus of the present invention shown in mounted operative relationship with respect to an internal combustion engine distributor and showing the electro-optical portions of the apparatus in a somewhat simplified schematic and/or diagrammatic form. In this view, the distributor cam is shown in a position where it produces the maximum opening or break relationship of the two contacts of the distributor points assembly unit comprising the low voltage breaker switch means of the distributor. In other words, in this view, the gap of the contacts in the break position is at a maximum and the indicating pointer means of the analyzing apparatus of the present invention is shown in a break indicating relationship with respect to the annular scale means portion of the analyzing apparatus of the present invention. Additionally, the indicating lamp means of the electrooptical portion of the indicator means is shown in de-energized and non-illuminated relationship, which relationship is exactly coincident in time with the break time of the two contacts of the distributor points assembly unit.

FIG. 2 is a view very similar to FIG. 1 and, indeed, there are only three differences, all arising from the approximately 22 /2-degree counter-clockwise rotation of the distributor cam shaft, the distributor cam carried thereby, and the pointer means of the analyzing apparatus of the present invention, which allows the biasing spring of the distributor points assembly unit to close the two contacts thereof, thus closing the circuit to the perceptible lamp means of the electro-optical portion of the indicator means and causing same to be energized and illuminated, and also causing the outer end of the indicating pointer means to now lie over a dwell time or make time indicating portion of the outer circular scale means, which relationship continues for exactly the period of make time of the contacts of the distributor points assembly unit.

FIG. 3 is a fragmentary, partially-broken-away view taken substantially along the plane indicated by the arrows 3-3 of FIG. 1. However, it shows the distributor shaft and the distributor cam carried thereby in full elevation rather than in cross-section since this is in accordance with customary practice and since the sectioning of said distributor shaft and distributor cam would add nothing to the disclosure of the present invention.

FIG. 4 is a fragmentary view illustrating one exemplary one of a pair of battery clip-type electrical connectors for facilitating the connection of the analyzing apparatus of the present invention with respect to the distributor and the electric circuitry connecting same relative to the storage battery adapted to be carried in association with an internal combustion engine (not shown) which is adapted to rotate the distributor shaft when running.

FIG. 5 is a view very similar to FIG. 1, but illustrates a completely self-contained, slightly modified form of the invention wherein the electric circuit means is provided with its own battery (usually a very small, lightweight, and low-voltage battery), thus making the analyzing apparatus completely independent of the storage battery of a motor vehicle.

In FIGS. 13 the reference numeral generally designates a conventional internal combustion engine distributor with the cover removed, and it is shown as comprising an upstanding fixed distributor housing or outer wall 12 of substantially cylindrical configuration and provided with an inner disc-shaped panel portion 14 upon which the distributor breaker points assembly unit 16, comprising the breaker switch means of the distributor, is adapted to be positionally adjustably mounted by the mounting screws 18 positioned at opposite ends of a base plate member 20 and extending through laterally directed or elongated slots 22 therein. The lower ends of the fastening screws 18 are threaded into the distributor disc-shaped panel portion 14 and it will readily be understood that by merely loosening the screws 18, either end or both ends of the base plate 20 of the distributor points assembly unit 16 may be shifted either toward or away from the distributor cam, which is generally designated by the reference numeral 24, so as to adjust the gap 26 between the pair of contacts 28 and 30 of the distributor points assembly unit 16 to an optimum value.

'It should be noted that the base plate 20 is integrally connected to the contact 28, which is, in effect, grounded (usually to the frame of an associated motor vehicle) because the base plate 20 is connected to the distributor disc-shaped panel 14, which is adapted to be so grounded.

It should be noted that the other contact member 30 is connected by the conductive arm 32 and the through rivets 34 carried by the insulating arm 36, to one end of the flat spring member 38, which has its opposite end connected between washers carried by the terminal screw 42 (which is insulatingly mounted on an integral ear extending upwardly from the base plate 20) and is held in said position by the fastening nut 44. Thus, the screw 42 and fastening nut 44 effectively comprise a hot or positive terminal adapted to be connected by a lead 46 through the ignition coil generally designated by the reference numeral 48, and an ignition switch 50 to the positive terminal 52 of a storage battery 54, such as is customarily associated with a motor vehicle. Said storage battery 54 has its opposite or negative terminal 56 grounded as indicated at '8 (usually to the frame of the associated motor vehicle), thus completing the circuit.

It should be noted that the two contacts 28 and 30 are elfectively insulated from each other when separated in the manner shown in FIG. 1.

The distributor has a distributor cam shaft 60 which is adapted to be effectively coupled to and driven by an associated internal combustion engine (not shown) and which rotates the previously-mentioned eight-lobed distributor cam 24 and which, in addition thereto, is also adapted to rotate the rotor contact or switch arm 62 of a high-voltage distributor system, such as is generally designated by the reference numeral 64 for sequential engagement with the eight different contacts 66, each of which is adapted to be connected to a different internal combustion engine spark plug, the opposite side of which is electrically grounded, for providing the proper ignition potential to each of said spark plugs in the proper timed sequence for correct ignition of the air-gas mixture in the combustion chambers of the various cylinders of an internal combustion engine.

In the exemplary first form of the invention illustrated, the make and break analyzing apparatus takes the form of visibly' perceptible mechanical indicator means includingfirst and second relatively movable portions adapted to be mounted, respectively, relative to a fixed portion, such as the distributor housing wall 12 of the distributor 10- and relative to the distributor cam shaft 60.

In the exemplary first form of the invention illustrated, said visibly perceptible mechanical indicator means is generally designated by the reference numeral 68 and said first portion thereof comprises a circular or annular scale member or means 70 and said second portion thereof comprises an indicating pointer means 72.

The circular or annular scale means or member 70 may be made of plastic, cardboard, or any other relatively inexpensive thin-sheet material and has a hole 74 therein of a size such as to allow the entire scale member 70 to be exteriorly frictionally slipped down over and engaged with the outside of the cylindrical distributor housing wall 12.

The indicating pointer means 72 may be made of wire or any other suitable material and has a rear engagement loop means or portion 76 which is sufiiciently resilient to provide an effective resilient frictional engagement with the exterior of the distributor cam shaft 60 when forced downwardly thereover so that said pointer means 72 will not shift its rotative posiion relative to the distributor carn shaft 60 but will remain in a predetermined relationship with respect thereto during slow manual testing rotation of the distributor cam shaft 60,

The annular scale member 70 is provided at circumferentially spaced locations therearound with optimum make and break visibly perceptible portions, such as are designated by the reference numerals 78 in the case of make portions and 80 in the case of break portions. It will be noted that the make and break portions 78 and 80 are multiple in number and are alternately circumferentially arranged around. the annular scale member 70 with each of the make portions corresponding to closed-circuit make or dwell time condition of the contacts 28 and 30 such as shown in FIG. 2 and with each of the break portions 80 corresponding to open circuit or break relationship of the contacts 28 and 30, such as in shown in FIG. 1.

Of course, once the distributor cap is removed and the indicating pointer means 72 is mounted on the distributor cam shaft 60, said indicating pointer 72 is forcibly rotatablyadjusted relative to the cam shaft 60- until such time as it lies in directly superimposed relationship with a line of demarcation such as that shown at 82, for example, between a rotatively preceding make portion 78 and the break portion 80 over which the pointer 72 is shown superimposed in FIG. 1. This adjustment is made at the precise moment that a portion of the cam 24 near to the corresponding apex 84 of the cam 24 has moved the cam follower 86 outwardly to a degree such as to separate the contacts 28 and 30. The adjustment may be made in this manner or it may be made at the end of the break portion when the pointer overlies the line of demarcation between it and the next succeeding make portion 78, at which time the contacts 28 and 30 should be just closing.

Of course, theabove-mentioned correlated adjustment of the indicating pointer 72 relative to the annular scale member 70 may be made by rotating the scale member 70 relative to the distributor housing wall .12 rather than by rotating the pointer 72 relative to the cam shaft 60, if desired.

It should also be noted that in making the abovementioned initial adjustment, the determination of when the contacts 28 and 30 open, as referred to above, or close, as referred to above, is made by observing the indicating lamp 88, which is connected by electric circuit means, generally designated at 90, from the terminal screw 42 of the distributor points assembly unit 16 to the positive terminal 52 of the storage battery 54. Of course, it will be understood that whenever the contacts 28 and 30 are open, the lamp 88 will be de-energized and nonilluminated, as is shown in FIG. 1, and that whenever said contacts 28 and 30 are in closed relationship, the lamp 88 will be energized and illuminated, as shown in FIG. 2, thus clearly and visibly perceptibly indicating to the person analyzing the operation of the distributor points assembly unit 16, at what precise instant the com tacts 28 and 30 open and close.

It should be noted that during the testing operation referred to above, the ignition switch 50 should be open so that no potential will be applied to the contacts 28 and 30 through the ordinary ignition system which, because of the slow opening and closing movement thereof, might tend to cause substantial arcing and consequent damage thereto. In order to avoid the same problem as a result of the application of potential across said contacts '28 and 30 by the analyzing and testing apparatus of the present invention, a current-limiting means such as is generally designated at 92 may be placed in the electric circuit means 90 for limiting the current which can flow through said circuit and through the contacts 28 and 30 as a result thereof to such low values as to prevent any possibility of arcing and consequent pitting or damage to the contacts 28 and 30 occurring. The current-limiting means 92 may comprise a resistor having a high-enough resistance to bring about the desired current limiting effect. Or, if desired, a variable rheostat potentiometer, voltage divider, or any conventional standard currentlimiting device may be employed in lieu thereof, if desired, In FIG. 1, the distributor cam 24 is shown as being rotated (usually in a counter-clockwise direction) into a position where one of its eight apexes, such as the one shown at 84, has pushed the cam follower 86 away from the cam center which comprises the axis of the cam shaft 60. The cam follower 86 has rotated around a pivot 94 against the torque resistance provided by the biasing spring 38. The conductive arm 32 rigidly attached to the insulating cam follower 86 and holding the electrical contact 30 has been moved away from its mating stationary electrical contact 28 by reason of the engagement of the cam apex 84 and the cam follower 86.

In FIG. 2 the cam 24 is shown after it has rotatedin a counter-clockwise direction approximately 22 /2 degrees from its position as shown in FIG. 1 so that one of its flats is now opposite the cam followeru86i The torque action of the spring 38 has thus been enabled to move the cam follower 86 toward the center of the cam shaft 60 and at the same time this action has resulted in movement of the electrical contact 30 toward the stationary electrical contact 28 and into engagement therewith. Positional adjustment of the entire distributor points assembly unit 16 is such that, in this position, the cam follower 86 does not touch the flat of the cam 24. The entire resistance to the torque action of the spring 38 is effected by the stationary contact 28, which stops the action of the movable contact FIG. 1 shows that as the distributor cam 24 rotates, any one of its apexes 84 will cause the electrical contacts 28 and 30 to separate or to form a gap such as the one shown at 26 in FIG. 1. When this occurs, a break or opening of the electrical circuit including the ignition lead 46 occurs.

FIG. 2 shows that as the distributor cam 24 continues to rotate in a counter-clockwise direction, any one of its flats will cause the electrical contacts 28 and 30 to touch each other. When this occurs, a make or a closing of the ignition circuit including the ignition lead 46 takes place.

The proportions of time that constitute each cycle of make and break are of great importance for the proper functioning of the distributor 10. The amount of time for each break should be a minimum, but if this time is too small, a complete break or opening of the ignition circuit will not take place because arcing will continue across the gap 26. C-onversely the amount of time for each make should be a maximum because a relatively longer closed circuit time or dwell time is necessary for the electrical current to properly energize the primary winding 96 of the ignition coil 48, which is connected in circut with the distributor points assembly unit 16. The importance of having a maximum make or dwell time increases for engines having a greater number of cylinders and for engines that are operated at high speeds.

It is an important feature of the present invention to show the correct proportions of make and break time as recommended by the manufacturer of any particular distributor. It is also a feature of this invention to compare the actual make and break characteristics of the electrical contacts of any distributor with the correct or optimum proportions of make and break time as recommended for that distributor. This is accomplished by the simple, inexpensive, accurate, compact, and portable means of the present invention comprising three simple units that are attached to the distributor temporarily for testing it. These are the previously-mentioned annular scale means or chart 70, the previously-mentioned indicator pointer means 72, and the electro-optical indicator means comprising the electrical circuit means 90, the indicator lamp 88, and, in certain cases, current-limiting means 92.

The annular scale member or chart 70 may have the make and break portions 78 and 80 actually formed thereon in relief or they may merely comprise markings appropriately provided thereon with effective radial lines of demarcation therebetween. The pointer means 72 may take any of several forms, the first form of which, as illustrated in FIGS. 1-3, has already been described. The electro-optical indicating means may also take any of several forms, the first form of which, as illustrated in FIGS. 1-3, has already been described. In connection therewith, it should be noted that the connections of the opposite ends of the electric circuit means 90 with respect to the rest of the regular igniion system, as indicated by the arrowheads designated by the reference numerals 98, are merely shown diagrammatically in FIGS. 1 and 2. However, actually they might take the form of various different types of electrical connectors such as the battery type clip shown at 98 in FIG. 4, which may be clipped to appropriate portions of the conventional ignition circuit at locations such as indicated in FIGS. 1 and 2, or elsewhere as desired.

The electric lamp 88 should be of a type having a voltage rating compatible with the storage battery 54 as modified by the current-limiting means 92.

With the annular scale means 70, the pointer means 72, and the indicator light circuit 90 in posit-ion with respect to the distributor 10, which is to be analyzed,

the operation of the first form of the invention may be briefly described as follows.

Referring to FIGS. 1 and 2, the cam 24 should be rotated in a counter-clockwise direction as illustrated (although it may be in the opposite direction if that is the normal direction of rotation of the cam 24 when the driving internal combustion engine is running). At the precise time when the indicator lamp 88 goes out, the annular scale 70 should be rotated relative to the distributor housing 12 (or, conversely, the pointer 72 should be rotated relative to the scale 70) until the pointer 72 is just beginning to enter any one of the dark areas comprising a break time portion 80. At this moment the pointer 72 should be in precise overlying alignment with the beginning border of that dark area or break time portion 80. Thereafter, the annular scale 70 is left in the adjusted position and/ or the pointer 72 is left in the adjusted position relative to the cam shaft 60.

Further, manual rotation of the cam 24 will cause the pointer 72 to sweep over the break portion and at the precise time that the indicator light 88 goes on, the pointer 72 should begin to enter the next succeeding light area or make portion 78 and said pointer 72 should be precisely vertically superimposed over the line of demarcation between the adjacent dark and light areas comprising the break and make portions 80 and 78.

From the foregoing instructions, which set the annular scale 70 into the proper posit-ion with respect to the pointer 72 (or vice versa), it will be seen that all of the dark areas 80 show when the indicator light 88 should be out and that all of the light areas 7 8 show when the indicator light 88 should be on as the pointer 72 passes over the corresponding dark areas 80 and light areas 78.

If while rotating the cam 24, the pointer 72 is still in a dark area 80 when the light 88 goes on, this will indicate insufficient break time. This is caused by insufficient gap between the contacts 28 and 30'. The amount of this error can be intelligently estimated by observing the difference in readings of when the light 88 goes on and when it should have gone on, namely, at the border of the light area 78. Gap adjustment corrections can be made accordingly.

If while rotating the cam 24, the pointer 72 enters a light area 78 with the light 88 still out, this will indicate excessive break time. This is caused by excessive gap between the contacts 28 and 30. The amount of this error can also be intelligently estimated by observing the difference in readings of when the light 88 goes on and when it should have gone on; namely, at the border of the light area 78. Gap corrections can be made accordingly.

The making of a master scale member 70 from which subsequent scale members 70 can be duplicated for largescale production by a manufacturer is a relatively simple operation and may be accomplished as outlined below.

A new points assembly unit, such as the one shown at 16, for example, is installed in a particular distributor. The maximum gap between the electrical contacts 28 and 30, as recommended by the manufacturer of that particular distributor, is set very precisely. This may be accomplished by using a feeler gauge or a console type of electronic analyzer. Then a blank annular member similar to the scale member shown at 70 but with no dark and light areas or portions such as those shown at 80 and 78 in FIGS. 1 and 2, is mounted around the distributor housing 12 in a relationship similar to that shown in FIGS. 1 and 2, and a pointer such as that shown at 72 is also mounted on the distributor cam shaft 60 in a relationship such as that shown in FIGS. 1 and 2. Also, the indicator light circuit 90 is connected in a manner similar to that shown in FIGS. 1 and 2. Then the cam 24 is rotated slowly in the direction of its normal enginedriven rotation, and as it rotates, the indicator light 88 will go on and off in a manner similar to that described hereinbefore. At the precise location of the pointer 72 when the light 88 goes out, a mark is made on-the anprise the make, portions 78 such nular member 70. At the precise location of the pointer 72 when the light 88 goes on, another mark is made. This marking operation is continued around the entire annular member 70 until all of the lines of demarcation between areas or portions which are to subsequently become the previously-described make portions 78 and break portions 80 have been marked on the annular member'70. Then said annular member 70 is removed from the distributor housing 12 and the areas between lines of demarcation when the light 88 was out, are darkened or otherwise modified so as to comprise visibly preceptible discrete portions which correspond to those shown at 80 in FIGS. 1 and 2. The remaining areas corresponding to when the light 88 was on may remain in their original undarkened color or unmodified form to eifectively comas those shown in FIGS. 1 and 2. Subsequently, any number of additional semicircular scale members 70 intended for use on that particulartype of distributor can be printed or otherwise produced.

There can be no single scale member 70 which can be used on all distributors because there are differences in the distributors themselves. The number of cylinders in an engine which the distributor services makes a difference in the distributor. The recommended manufacturers gap setting between electrical contacts 28 and 30 makes differences in the characteristics of the distributors. Also, the outside diameter of various distributors varies and thus requires that the scale member 70 correspondingly be modified for different distributors. In other words, a number of different scale members 70 must be made for use with various different types of distributors which serve various different types of engines. However, once a master scale member or chart 70 has been made for each such different distributor, no further different types of scale members need be made since all distributors of a particular type will be adapted to be analyzed by a scale member 70 identical to the master scale member 70 corresponding thereto and initially produced as outlined above.

Since the scale members 70 manufacture, a kit containing members may be supplied to a purchaser so that he may merely select the proper one for use on the particular distributor in his motor vehicle.

The pointer means may be made of a virtually universally adaptable type capable, by reason of the resilient nature of the engagement loop 76, of being mounted on different sizes of distributor shafts 60 and the outer porare very inexpensive to a full set of said scale tion thereof may be made of a length and shape such as to be adaptable for cooperation with any of the various different types of scale members 70 adapted to be mounted on any of the various different types of distributors.

The electro-optical indicator means 90 of the apparatus may be the same in all of the kits referred to above.

If desired, the different scale members for different distributors may be individually supplied and sold and different pointers 72 may be individually supplied and sold, in each case being specifically and particularly adapted to one particular type of distributor.

FIG. 5 is a view similar to FIG. 1 but illustrates a very slight modification of just the electro-optical indicator means portion of the apparatus as designated at 90 in the first form of the invention and as designated at 90' in the second form of the invention. Also, it will be noted that there is one additional difference in that the resilient engagement loop portion 76' of the FIG. 5 modification of the invention is effectively keyed by having a fiatted portion 100 engaging the correspondingly flatted portion 102 of the distributor cam shaft 60. Otherwise the engagement of the pointer means 72 relative to the distributor cam shaft is identical to that of the first form of the invention. The major effect of this is to make it impossible to rotatively adjust the position of the pointer 72 relative to the cam shaft 60, thus making it necessary for all relative rotative adjustment of the scale member 70 with respect to the pointer 72, to be accomplished by rotating the scale member 70 with respect to the distributor housing 12.

The electro-optical indicator means of FIG. 5 is different from that of the first form of the invention in that it has a self-contained battery 54' in circuit therewith and this makes it possible for the battery to be a very low-voltage, physically small, and lightweight battery such as a flashlight battery, or the like. correspondingly, the lamp means 88 may be of a type adapted for energization by such a modified battery 54', which may have a relatively low-voltage output. The coupling of the electric circuit means leads may be by Way of battery clips of the type illustrated at 98 in FIG. 4 and may be coupled respec tively to the terminal screw 42 and to any grounded portion of the distributor at the opposite end of said electric circuit means 90'. This makes it possible to have a very small lightweight, completely self-contained testing and analyzing unit which can be used while the distributor is in its normal mounted position with respect to an engine or which can be used in a garage or shop when the distributor has been removed from such normal mounting. When it is desired to keep the distributor in its normal mounted position with respect to the engine while using the appartus of the present invention, the rotation of the distributor cam 24 can be accomplished by using the engine self-starter conventionally associated with such an engine (not shown), operating it in short pulses. However, it should be understood that in either the modified form of the invention illustrated in FIG. 5 or the first form of the invention illustrated in FIGS. 1-4, the distributor cam 24 may be rotated by hand rotation, self-starter rotation of the type just referred to, or rotation in any other suitable manner. In other words, the type of rotation and the means for effecting same are not to be construed as being limited to any particular form, and the invention is to be broadly construed as covering all such arrangements.

Also, it should be noted that the modified type of flatted resilient engagement loop portion 76' of the FIG. 5 form of the invention may be employed in the first form of the invention illustrated in FIGS. 1-4, if desired, and/or the non-fiatted version thereof shown in the first form of the invention illustrated in FIGS. 1-4 may be employed in the FIG. 5 modification of the invention, it desired. In other words, either of the forms of the invention illustrated may employ either type of resilient engagement loop portion, such as illustrated at 76 in the first form of the invention and such as illustrated at 76' in the second form of the invention. Neither form of the invention is limited to the particular type of engagement loop portion of the corresponding pointer 72 illustrated in association therewith in the drawings.

It should be understood that the figures and the specific description thereof set forth in this application are for the purpose of illustrating the present invention and are not to be construed as limiting the present invention to the precise and detailed specific structure shown in the figures and specifically described hereinbefore. Rather, the real invention is intended to include substantially equivalent constructions embodying the basic teachings and inventive concept of the present invention.

I claim:

1. An internal combustion engine ignition system distributor make and break analyzing apparatus, comp-rising: visibly perceptible mechanical indicator means including a complete 360-degree interchangeable and replaceable physically discrete annual scale means comprising a make and break indicating comparator defining optimum manufacturer-specified make and break settings and characteristics of a distributor cam and set of distributor contact points for one complete cycle of operation thereof for a particular internal combustion engine, said annular scale means comprising an annular thin-sheet substantially 1 1 horizontally planar ring member having a central aperture of a size such as to be capable of being exteriorly frictionally but controllably rotatably positionally adjustably mounted on a correspondingly shaped circular exterior of a particular specified ignition system distributor housing associated with a particular internal combustion engine, said mechanical indicator means also including an indicator pointer means and means for mounting same in a selected position with r spect to a distributor cam shaft and adapted to be rotat ed thereby relative to said complete 360-degree annular scale and comparator means in correspondence with the operation of an associated internal combustion engine whereby to visibly perceptibly indicate optimum manufacturer-specified make and break characteristics of the distributor cam and distributor contact points during such rotation and to correspondingly indicate optimum manufacturer-specified dwell time of the distributor contact points, said annular scale means of said indicator means being provided at circumferentially spaced locations therearound with optimum make and break visibly perceptible portions of two different alternately circumferentially arranged kinds comprising a dwell or make-time designating portion corresponding to closed circuit relationship of the breaker contact points of the breaker switch portion of a distributor, and a break-time designating portion corresponding to open circuit relationship of the breaker contact points arranged in an optimum relationship for the ignition system of a particular internal combustion engine; and perceptible electrically operable indicator means including electric circuit means adapted to be electrically connected with respect to the distributor breaker contact points for effective closure of said electric circuit means during the make portion of the operative cycle of said distributor contact points and adapted for effective opening of said electric circuit means during the break portion of the operative cycle of said distributor contact points, said electrically operable indicator means also including electrically energizable perceptible signalproducing means in circuit therewith for energization and perception whenever said circuit means is in closed relationship for de-energization thereof whenever said electric circuit means is in open relationship; said annular scale means and said pointer indicator means being relatively rotatively adjustable for placing s'aid pointer indicator means in a correlated relationship with respect to the junction between a circu-mferentially adjacent pair of said dwell or make-time designating and break-time designating portions at the precise instant in time when the breaker contact points change condition between open and closed relationship, and vice versa, as the distributor cam shaft is rotated.

2. Apparatus as defined in claim 1, wherein said electric circuit means is provided with connection means for electrically connecting it with respect to the electric power supply means of an internal combustion engine.

3. Apparatus as defined in claim 1, wherein said electric circuit means is provided with connection means for electrically connecting it with respect to the electric power supply means of 'an internal combustion engine and being further provided with current-limiting means in circuit therewith.

4. Apparatus as defined in claim 1, wherein said pointer indicator means is provided with a resilient frictional rear engagement means adapted for forcible frictional resilient and controllably rotatably adjustable engagement with the upstanding distributor cam shaft of an ignition system distributor.

5. Apparatus as defined in claim 1, wherein said pointer indicator means is provided with a resilient frictional rear engagement means adapted for forcible frictional resilient and controllably rotatably adjustable engagement with the upstanding distributor cam shaft of an ignition system distributor and has an effectively keyed flat portion non-rotatably engageable with respect to a corresponding keyed fiat portion of the distributor cam shaft.

6. Apparatus as defined in claim 1, wherein said pointer indicator means is provided with a resilient frictional rear engagement loop means adapted for forcible frictional resilient and controllably rotatably adjustable engagement with the upstanding distributor cam shaft of an ignition system distributor.

7. Apparatus as defined in claim 1, wherein said electric circuit means is provided with and is connected to a suitable self-contained, portable source of electrical energy for energizing said perceptible signal-producing means.

8. Apparatus as defined in claim 1, wherein said perceptible signal-producing means comprises a visibly perceptible lamp means adapted to produce a visibly perceptible light signal when energized as a result of said circuit means being in said closed relationship and for producing an opposite condition, visibly perceptible, nolight signal whenever said circuit means is in said open relationship.

References Cited UNITED STATES PATENTS 1,772,829 8/1930 Giampaoli. 2,043,931 6/1936 Morgan. 2,355,211 8/1944 Erickson 33-181 X 2,560,259 7/1951 Stewart 73-118 2,648,816 8/1953 Schuch 324-15 RICHARD c. QU-EISSER, Primary Examiner. JERRY W. MYRACL'E, Assistant Examiner.

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