US2711451A - Distributors for ignition systems of internal combustion engines - Google Patents

Description

June 21, 1955 J. P. BEAUCLAIR 2,711,451

DISTRIBUTORS FOR IGNITION SYSTEMS OF INTERNAL COMBUSTION ENGINES Filed Aug. 25, 1953 2 Sheets-Sheet l L TO C'O/L PIE/MARY ARMS 2 & l0

MOT/UNLESS INVENTOR tJbH/VPBEA (/CL AME ATTORNEY June 21, 1955 J E U L R 2,711,451

DISTRIBUTORS FOR IGNITION SYSTEMS OF INTERNAL COMBUSTION ENGINES Filed Aug. 25, 1953 2 SheetsSheet 2 Cowman/4% CLOSING CONTACTS A5- A5 HEL 0 /NEET/A CONTACTS /4 #4 CLOSED a 45 0, 5, Bur CLOS/A/G 1 N VEN TOR 'c/BHNPBE cLA/e,

BY rf ATTORNEY United States Patent DISTRIBUTORS FOR IGNITION SYSTEMS OF INTERNAL COMBUSTION ENGINES John P. Beauclair, Los Angeles, Calif.v

Application August 25, 1953, Serial No. 376,431

11 Claims. (CI. 20027) My invention relates to improvements in distributors for use in the ignition systems of internal combustion engines, and more particularly to an association of dual distributor-point mountings wherein two discrete sets of point are mounted and arranged for interdependent actuation by a single distributor timing cam actuating said sets of points from a single cam follower for the purpose of increasing the ratio of make-period to break-period of the circuit at all engine speeds.

Therefore, a primary object of my invention is to provide a dual distributor-point carrying and operating structure for use in distributor housings equipped for a single breaker point carrying structure whereby a substantial increase may be realized in the effective period of current flow through the ignition coil at all engine speeds, i. e. the interval of dwell during which the points are closed and during which interval the battery is supplying electrical energy to the ignition coil.

Among those skilled in the art it is well known that as the R. P. M. of an internal combustion engine is increased, the dwell period of the distributor points is decreased in direct proportion. This decrease results from the fact that the impedance presented to the fiow of current from the battery through the ignition coil is predominantly inductive for short dwell periods so that the current drawn by the coil during such periods builds up relatively slowly, approaching a constant value of, steadystate current limited only by the D. C. resistance of the coil and associated circuit. Hence, as the period of dwell of the points is decreased, the points will eventually be closed so short a time that the current through the coil will not have time to build up to its full steady-state value because of the impedance presented by the. buildup or" current therethrough by the coil inductance. Such a condition arises in the ignition system of an internal combustion engine during. normal operation thereof and as R. P. M. is increased. Thus a reduction in the flow of current through the: coil of the system occurs, to an increasing degree at the higher engine speeds with the particular result that the spark furnished to fire the cylinders is reduced at a time when the fuel in the cylinders must be fired most efficiently in order to burn it completely before the piston completes its power stroke.

When the dual arrangement of distributor points according to my invention is used in. place of. a standard breaker point mounting of an ignitionsystem of' an internal combustion engine, the effective dwell period and therefore the efficiency of the ignition system, particularly at high speeds, is greatly increased. In actual tests, the dwell period was increased by to over the dwell period of the standard distributor points with which the manufacturer provided the automobile engine on which the tests were run.

Another very important object of my invention is to provide a distributor point unit which may be interchanged with standard distributor point units as used in ignition systems of present day internal combustion engines; without the necessity of altering other parts of the Patented June 21, 1955 distributor, my replacement unit fitting the present distributor point-supporting plates and operating in conjunction with the engine timing cam in precisely the same organization as the one it replaces.

Another important object of my invention is to provide a dual distributor-point unit wherein the breaker arm of the present-day point systems is augmented by an auxiliary arm which will hereinafter be referred to as the maker arm. According to the present invention the dis tributor timing cam actuates a substantially conventional breaker arm, which in turn actuates the maker arm. Each of the two arms has associated therewith apair of contact points which are in effect connected in parallel between the ignition coil and ground and which operate according to the following cycle:

The points associated with the breaker arm, being initially closed, are opened by the timing cam when a lobe on said cam contacts the fibre cam follower on the breaker arm and pivots the latter from a position wherein the points are closed to a position wherein the points are open. As the breaker arm moves from closed position toward an open position, a second rubbing block which is interposed between the breaker arm and the maker arm is likewise displaced and transmits motion from the breaker armto the maker arm, a set of maker points associated with the maker arm being thereby closed and being maintained closed until the points associated with the breaker arm are again united to take over continuity of the circuit. The period of efiective dwell of the points is there by increased by the time interval during which the points associated with the maker arm are closed.

Another important object of this structure is to fixthe rubbing block, which is located between the breaker arm and the maker arm, in such a position that a considerable amount of mechanical advantage is transmitted from the breaker arm to the maker arm so as to close the points associated with the latter arm very rapidly. By this interdependent actuation of the two arms, the angular velocity of closing of the contacts associated with the maker arm is made greater than the angular velocity of the breaker arm in opening the contacts associated therewith, and the result is that the period of time during which both sets. of contacts are open is greatly reduced, as compared with the period during which the points of a singlearrn breaker point system are open in a conventional distributor.

An important advantage of the present structure therefore resides in the fact that the fuel in the engine is burned much more efliciently particularly at high speeds, thereby greatly decreasing the gasoline consumption of the engine with which my novel distributor unit is used.

Another important feature of my invention is that the parts of the unit device may be made of sheet metal, thereby reducing the expense of manufacturing the device and, in addition, providing a device which readily lends itself to mass-production manufacture.

In addition, my device is so designed that the gaps between the respective points may be readily adjusted and thereby adapted for advantageous use in distributors of various types of engine ignition systems.

Other objects and advantages of my invention will become apparent during the following discussion of the drawings, wherein I. have illustrated one practical embodimerit of my invention.

Figure l is a plan view of a distributor equipped with my novel point assembly, the distributor head having been removed to expose to view the distributor point assembly therein.

Fig. 2 is a section view along line 2-2, Fig. 1.

Fig, 3 is a section view along line 33, Fig. 1'.

Fig. 4 is a detail view of the fibre rubbing block which transmits angular motion from the breaker arm to the maker arm.

. Fig. 5 is a section view along line 55, Fig. 1.

Fig. 6 is a detail view of the pivot pin which serves to rotatably mount the maker arm to the distributor point assembly.

Fig. 7 is a detail view of the maker arm, this viewbeing taken in the plane normal to the plane of Fig. 1.

Fig. 8 is a partial view corresponding to Fig. 1 but showing the respective distributor arms travelling in the direction of the arrow A.

Fig. 9 is a partial view corresponding to Fig. l but showing thedistributor arms at rest in another position of the distributor cam; and

Fig. 10 is a partial view corresponding to Fig. l but showing the distributor arms travelling in the direction of the arrow A.

Referring now to one practical embodiment which I have shown in the drawings, in Fig. l is illustrated the lower body portion of a distributor D, the distributor having a plate P adapted to support the distributor point assembly and also the usual condenser B. As is conventional in present-day distributors, the plate P has a circular opening through which the distributor shaft S extends and supports near its upper end the timing cam C. In the type of distributor illustrated in the drawing the plate P has mounted thereon a pivot M, Figs. 1 and 2,

which pivot M serves as one of the supporting members for the removable distributor point assembly. This assembly is also supported by a hold-down screw H and is further provided with an eccentric adjustment screw E which serves in the making of fine adjustments in the position of the distributor point assembly with respect to the timing cam C. All of the members mentioned thus far will be recognized by those skilled in the art as comprising standard parts of conventional and well-known distributors, and these members form no part of the present invention.

The novelty of my invention resides in the mounting and the structure of the parts shown assembled to a distributor point base 1. As shown in Fig. l, the base 1 is shaped so that it will fit within the distributor and lie flat against the distributor plate P, the base it having a hole la, Fig. 2, adapted to fit over the pivot M and thereby fix the left end of the base 1 with respect to the distributor plate P. The pivot M extends upwardly and above the level of the base 1 and the breaker arm 2 is journaled on the pivot M in insulated relation thereto.

As is shown in Figs. 1 and 2, the breaker arm 2 is actually a shaped sheet-metal channel having at its left end an insulating sleeve 3 which not only serves as a hearing for mounting the breaker arm 2 on the pivot M but which also prevents the flow of electric current between said arm and the pivot M which is grounded to the dis tributor plate P.

Near the center of the breaker arm 2 is fixed a fibre cam follower 4 which faces outwardly of the arm in the direction of the timing cam C. The fibre cam follower serves the purpose of transmitting motion from the cam to the breaker arm 2 and at the same time electrically insulates the breaker arm from the cam. The cam follower 4 may be secured to the breaker arm 2 by any conventional means, usually a rivet 4a as shown in Figs. 1 and 2, and this rivet also serves to aflix one end of a spring 5 to the breaker arm 2.

Referring to Fig. 3, it will be seen that the base 1 has an upstanding lug 1b which supports a fibre insulating block 6, the block 6 being secured to the lug 1b by means of a rivet 6a, which rivet 6a also transfixes a bracket 7 and rigidly secures the same in the position shown in Figs. 1 and 3 for the purpose hereinafter stated. The left end of the insulating block 6, Fig. 1, has a bore 6b therethrough wherein is supported a terminal screw 8 secured to the block by a nut 8a. The screw 8 provides a connection for the wire W connected at its other end to the condenser and, in addition, the screw 8 forms a mechanical anchor for the other end of the spring 5,

which spring serves two functions. The spring 5 not only electrically connects the breaker arm 2 to the terminal screw 8 but also strongly biases the breaker arm 2 in the direction of the timing cam C, which structure and purpose is well known in the prior art.

A lead L is also shown connected at one end to the terminal screw 8 and the other end of this lead is connected in the conventional. manner to a primary circuit of the ignition coil (not shown).

As will be seen in Figs. 1 and 3, the aforementioned bracket 7 which is rigidly supported by the lug 1b is also electrically connected to the lug 1b and base 1 by the rivet 6a. The other end of the bracket '7 extends outwardly from the lug 1b over the base 1 in parallel relation thereto. Near the outer end of the bracket 7 is a tapped bore 7a, which receives the threaded upper end 9a of the pivot pin 9, Fig. 6. Directly below the tapped hole 7a is a small clearance hole 10 in the base 1, and when the pivot pin 9 is screwed into the tapped hole 7a the lower end of said pivot pin is confined against transverse motion within the hole 10 in the base 1. On the pivot pin 9 is journaled the hub 10a of the maker arm 10, and a small coil spring 11 is wound around the hub 10a, one end of the coil spring 11 being fixed in a bore 7/) in the bracket 7, and the other end of the coil spring being fixed in a bore 10b in the maker arm it}, for the purpose hereinafter stated.

By reference to Figs. 1, 5 and 7 it will be seen that the maker arm 10 supports a transversely disposed mounting member 100, having a pair of spaced slots 10d, the mounting member 100 serving to support an insulated fibre rubbing block 12, Fig. 4, which block 12 has a pair of the mounting holes 12a and a slot 12b, whereby when the rubbing block 12 is mounted on the maker arm 10, upper and lower screws 10a will secure the rubbing block 12 to the maker arm 10 in adjustable relation with respect thereto. The screws we transfix the holes 12a in the rubbing block 12 and also transfix the slots led in the supporting member 100 so that when the screws are tightened, the rubbing block 12 will be secured against displacement With respect to the maker arm 19. it will further be seen that when the screws 10c are loosened the rubbing block 12 may be longitudinally positioned with respect to the maker arm 10 by sliding the screws we in the slots ltib. Figs. 1 and 5 show the distributor point dual-contact structure wherein a breaker contact 14 is mounted on a lug 1d, upstanding from the base 1. Opposite said fixed contact 14 is a mating breaker contact 14a which is secured to the right end of the breaker arm 2.

Figs. 1 and 5 further show that the breaker arm 2 has a transverse extension 2a having at its outer end an upstanding ear 2b to which is fixed a maker point 15 disposed opposite another maker point 15a, the latter being secured to the outer end of the maker arm 10. The transverse extension of the breaker arm 2 extends below the maker arm 10 and above the base 1 in spaced relation with respect to each so that the extension will not drag against either the maker arm 10 or the base 1 and thereby impede its motion.

The respective sets of contact points 14-14:: and 1515a are the dual distributor points to which I have referred in the objects of this invention.

Operation As stated in the objects of this invention, the purpose of my improved structure is to provide an auxiliray arm which I have called the maker arm 10, which operates in such a way as to close the circuit through the primary of the ignition coil (not shown) during part of the time when the breaker points are opened, whereby the interval of time during which battery current is flowing through the primary of the ignition coil is increased with respect to the period of time during which the circuit through the primary of the ignition coil is broken. The

7 N) structure which I have provided to accomplish this purpose performs the following cycle, which cycle is illustrated in the drawings in Figs. 1, 8, 9 and 10.

In order to better understand the operation of my contact points, it should be borne in mind that battery current will flow through the primary of the ignition coil whenever either contacts 1515a or contacts 1414a are closed, or whenever both sets of contacts are closed.

It will be seen in Fig. 1 that the cam follower 4 is on a high spot of a lobe of the cam C so that the contacts 14-14a are maintained open and the rubbing block 12 has deflected the arm upwardly so as to maintain contacts 1S15a closed. The direction of the rotation of the cam in each of Figs. 1, 8, 9 and 10 is illustrated by an arrow R. As stated above, the spring 5 which urges the arm 2 in the direction of the cam C is a very strong spring and the spring 11, Fig. 3, which. urges the arm 10 in the direction of the arm 2 is a weak spring, the spring 11 having been provided only to damp the motion of the arm 10.

The cam C rapidly rotates as the engine runs and will thus quickly rotate to the position shown in Fig. 8, in which position the cam follower 4 is rapidly descending from the cam lobe toward the axis of the shaft S and therefore the contact 14 a is rapidly approaching the contact 14. Because of the fact that the spring 11 is very weak in comparison with the spring 5, and because of the fact that I have provided the arm 10 with a certain amount of inertia, as the arm 2 travels rapdily in the direction shown by the arrow A it is the contact pressing against the contact 15a which provides most of the force urging the arm 10 in the direction of the arm 2. Therefore during the rapid descent of the cam follower 4 in the direction of the arrow A the contacts 1515a will be maintained closed until the contacts 1414a have closed and the motion of the arm 2 in the direction of the arrow A has been arrested. Note that during this portion of the cycle the rubbing block 12 actually loses contact with the back of the arm 2 and does not regain such contact until the motion of the arm 2 has been arrested and the mechanism is in the position shown in Fig. 9.

In the position of the mechanism shown in Fig. 9, both arms 2 and 10 are at rest, the contacts 1515a being then opened and the continuity of the primary circuit of the ignition coil having been taken over by the contacts 1414-a, which contacts actually close before the contacts 1515a open. It should be noted that in thisv position of the mechanism the rubbing block 12 has again regained contact with the back of the arm 2 and that the cam follower 4 is actually out of contactwith the cam C, the spring 5 maintaining the contacts 14-14a tightly closed.

A short interval of time later the cam C will have rotated into the position shown in Fig. 10 so that the cam follower 14 is beginning to ride up again on the following lobe of the cam, and the cam follower 4 has thus begun to rotate the arm 2 in the direction of the arrow A. In the position of the mechanism shown in Fig. 10 the contact 14a has just moved away from the contact 14 and the. back of the arm 2 has just begun to press the rubbing block 12 in the direction of the arrow A but has not yet pressed the arm it) far enough to close the contact 150 against the contact 15. Thus it will be seen that in this position of the mechanism, both the contacts 14-4 and the contacts 1515a are open, and the primary circuit of the ignition coil is broken, thereby firing the appropriate cylinder of the engine in the conventional and-well known manner. As the mechanism travels from the position shown in Fig. 10 to the position shown in Fig. l to complete the cycle which I am presently describing, the contacts 1414a will be opened still further until they reach the position shown in Fig. 1 and the rubbing block 12 will be further pressed in the direction of the arrow A until the arm 10 has rotated from the position in which the contacts 15-15a are closing, but still open, to the position shown in Fig. 1 where the contacts 1515a are closed.

It will thus be apparent in following through the described cycle of the mechanism from Fig. 1 through Figs. 8, 9 and 10, and back to Fig. 1, that when the mechanism is in the position shown in Fig. 1 wherein the arms 2 and 10 are momentarily motionless, the contacts 1515a have just closed the circuit through the primary of the ignition coil, the contacts 14-1461 being fully open. As the mechanism is then moved in the direction of the arrow A in Fig. 8, the inertia of the arm 10 resists clockwise rotation thereof and it is the contact 15 pressing against the contact 15a that returns the arm 10 in the downward or clockwise direction, the contacts 1515a remaining closed until the contacts 1414a have closed and the clockwise rotation of the arm 2 has been arrested. This position is shown in Fig. 9 wherein the contacts 1515a are fully open, the rubbing block 12 has regained contact with the back of the arm 2, and the cam follower 4 is out of contact with the cam C. Thus during the portion of the cycle during which the arms 2 and it) are moving in the direction of the arrow A, Fig. 8, the contacts 15-15a are held closed in order to maintain the electric continuity through the ignition coil until the contacts 1414a have closed, and the contacts 1414a are open but closing. Then during the portion of the cycle in which the arms 2 and 10 are moving in the direction of the arrow A, Fig. 10, the contacts 1515a remain open and the contacts 14-14a are opening in order to break the circuit through the primary of the ignition coil. During this operation of the cycle, the contacts 1515a and 1414a remain open until the back of the arm 2 has pressed the rubbing block 12 far enough in the direction of the arrow A to close the contact 15a against contact 15 and thereby re-energize the primary circuit of the ignition coil.

By inspection of Fig. 1 it may be seen that the points 1515a are offset a few degrees from a line drawn through the center of the pivot M and the pin 9. The slight offsetting of the contacts 1515a from this line causes the points to rub slightly against each other in a direction transverse to the motion of the outer ends of the arms 10 and 2. so as to provide a slight burnishing between the contacts in order to keep them clean. Although it is desirable to have contacts 1515a offset slightly from this line, it is not desirable to have the contacts offset very far since, if the contacts are offset to much therefrom, there will result undue rubbing and burnishing between the contacts which will have a tendency towear them out too rapidly. It is believed that a 20 offset as measured from the pivot M is a practical maximum, and that a lesser offset is probably desirable.

By inspection of Figs. 1, 4, 5 and 7 it will be seen that the rubbing block 12 is mounted on the supporting member by two screws the, which screws transfix the holes 12a in the rubbing bloc-l: and the slots N0 in the supporting member 160. By loosening these screws the rubbing block will then be free so that it may be moved ina direction substantially axial of the arm 10 so that the location of the rubbing block 12 with respect to the pin 9 pivotally supporting the arm 10 may be changed. By this adjustment 1 have provided means whereby the relative angular velocity of the arm 10 as it travels in a counterclockwise direction with respect to the angular velociw of the arm 2 traveling in the same direction. may be altered, and thereby the timing of the closing of the contacts 15-15a as the mechanism moves in the direction of the arrow A, Fig. 10, may be adjusted. The spacing between the contacts 1414a when they are in their fully open position, Fig. l, is adjustable by loosening the hold-down screw H and rotating the eccentric E so as to move the base 1 about the pivot M in order to adjust the position of the contact 14 relative to the cam C, this latter adjustment being well known in present day distributor point assemblies.

I do not limit my invention to the eXact form shown in the drawings for obviously a number of modifications may be made in the structure within the scope of the appended claims.

I claim:

1. In a distributor point system including a pair of breaker points wherein one point is fixed and grounded and the other point is carried on an insulated arm adapted to be oscillated by a timing cam, a device for increasing the interval of time during which the points are closed relative to the interval during which the points are open comprising a pair of maker points, the first maker point being carried by said arm, and the second maker point being carried in opposed relation by a movable mount and being grounded; and lost motion means between said arm and said mount whereby as the arm is cammed in a direction to open the breaker points said means will move said mount in a direction to close said maker points, and whereby as said arm is moved in a direction to close said breaker points said first maker point will press against said second maker point to return said mount and linkage toward said arm, the maker points remaining closed at least until said breaker points close.

2. A point assembly for use in a distributor having a timing cam, comprising a base; a conducting arm pivotally mounted at its inner end to said base and insulated therefrom, said arm carrying at its outer end a breaker point; an opposed breaker point carried by said base and grounded thereto; means for transmitting motion from said cam to said arm to oscillate the latter and open and close said breaker points; a maker point on said arm; a lost-motion movable mount carried by said base and having an insulated rubbing block facing said arm; and a second maker contact on said mount facing said first mentioned maker point and grounded, whereby as the arm is cammed outwardly to open said breaker points the block will move said mount outwardly to close said maker points, and as said arm returns inwardly to close said breaker points, said first maker point will press against said second maker point and remain thereagainst while returning said mount inwardly, said maker points retaining contact at least until said breaker points reclose.

3. A point assembly for use in a distributor having a timing cam, comprising a base to be mounted in said distributor adjacent said cam; a grounded breaker point secured to said base; a maker arm pivotally secured to said base at its inner end, said maker arm carrying at its outer end a grounded maker point; a breaker arm pivotally secured to said base at its inner end and electrically insulated therefrom, the outer end of said breaker arm terminating between said grounded points and carrying respectively a second breaker point facing said grounded breaker point and a second maker point facing said grounded maker point; an insulated cam follower i on said breaker arm and facing toward said cam; an insulated rubbing block on said maker arm and facing said breaker arm; and spring means urging said breaker arm toward said cam, whereby when said cam pivots said breaker arm outwardly to open said breaker points said rubbing block will pivot said maker arm outwardly to close said maker points, and when said cam permits said spring to return said breaker arm inwardly to close said breaker points, said second maker point will press against said grounded maker point to return said maker arm inwardly, said maker points remaining closed at least until said breaker points reclose to take over electrical continuity.

4. In a device as set forth in claim 3, relatively Weak means for biasing said maker arm toward said breaker arm to reduce bouncing of the maker points, and the inertia of the maker arm being sufiicient to hold said maker points in contact during closing motion of the breaker points.

5. In a device as set forth in claim 3, the mating faces of the maker points when in contact lying within 20 degrees, as measured from the pivot point of the breaker arm, of a line drawn through the respective pivot points of the maker and breaker arms.

6. In a device as set forth in claim 3, means for adjusting the gap between the breaker points when fully open.

7. In a device as set forth in claim 3, said rubbing block being positionable on said maker arm to permit adjustment of the closing of the maker points as the breaker points are opening.

8. A distributor point assembly for use in the primary circuit of the ignition coil of an internal combustion engine, the distributor having a lobe-type timing cam, comprising a base to be attached to said distributor adja- 4 cent said cam; a breaker arm pivotally mounted at its inner end in insulated relation to said base and having an insulated cam follower extending in the direction of the cam, and said arm having at its outer end a first and a second contact point respectively spaced from each other transversely of said arm; a contact point fixed to said base and facing said first contact point to form therewith a pair of breaker points, a strong spring urging said breaker arm toward said cam to close said breaker points; a maker arm disposed substantially parallel to said breaker arm and pivotally connected at its inner end to said base, a maker contact point on the outer end of said maker arm facing toward said second contact and forming therewith a pair of maker points; a relatively weak spring biasing said maker arm toward said breaker arm in a direction to open said maker points; and an insulated rubbing block on said maker arm to transmit angular motion thereto from said breaker arm when the latter is oscillated by said cam, the primary circuit of said coil being connected to the breaker arm whereby current will flow therethrough whenever either of said pairs of contact points is closed, said springs maintaining the breaker points closed and the maker points open when said cam follower is between lobes, said follower riding up on a subsequent lobe to open said breaker points and break said primary circuit, and said rubbing block being so located with respect to said arms as to close said maker points as said follower reaches the high point on the lobe, the breaker arm then returning rapidly to close said breaker points as the lobe passes, and said second contact point pressing against said maker contact point during the return of the breaker arm to maintain the maker points closed against the inertia of the maker arm at least until the breaker points have reclosed.

9. In a device as set forth in claim 8, the mating faces of the maker points when in contact lying Within 20 degrees, as measured from the pivot point of the breaker arm, of a line drawn through the respective pivot points of the maker and breaker arms.

10. In a device as set forth in claim 8, means for adjusting the gap between the breaker points when fully open.

11, In a device as set forth in claim 8, said rubbing block being positionable on said maker arm to permit adjustment of the closing of the maker points as the breaker points are opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,352,266 Hirsch Sept. 7, 1920

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