US3319018A

US3319018A - Dual point ignition system

Info

Publication number: US3319018A
Authority: US
Publication date: 1967-05-09
Anticipated expiration: 1984-05-09

Description

May 9, 1967 c. HUBBARD 3,319,018

DUAL POINT IGNITION SYSTEM Filed Dec 19, 1963 4 Sheets-Sheet 1 I I Flg-l 95 I I I I I Car/Ion Hubbard 3 INVENTOR.

l2 9 62 BY I4 78 C. HUBBARD May 9, 1967 DUAL POINT IGNITION SYSTEM 4 Sheets-Sheet 2 Filed Dec. 19, 1963 Fig.2

Fig. 4

May 9, 1967 c. HUBBARD 3,319,018

DUAL POINT IGNITION SYSTEM Filed Dec. 19, 1963 4 Sheets-Sheet 4 Car/Ion Hubbard IN VE N TOR.

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United States Patent 3,319,018 DUAL POINT IGNITION SYSTEM Carlton Hubbard, Atmore, Ala., assignor of 40 percent to Ira H. Rich, Centerville, Tenn. Filed Dec. 19, 1963, Ser. No. 331,839 11 Claims. (Cl. 200-19) This invention relates to a novel and useful dual point ignition system and more specifically to an ignition system including a distributor of more or less conventional design but having a pair of cam means mounted on the distributor shaft thereof with each cam means including a set of lobes spaced circumferentially about the shaft and sets of lobes carried by the two cam means including the same number of lobes and being alternately and substantially equally circumferentially spaced about the shaft. The distributor includes a pair of circuit making and breaking means each including an actuating cam follower for engagement with the lobes of the cam means and the cam followers are spaced circumferentially about the shaft an odd multiple of the degrees of circumferential spacing between adjacent lobes of the pair of cam means. In this manner, if both circuit making and breaking means are disposed in contact with all of the cam lobes the circuit making and breaking means will be simultaneously actuated a given number of times, each time the distributor shaft makes one complete revolution, equal to the number of lobes on each cam means. However, the dual point ignition distributor of the instant invention includes means by which the lobes on one of the cam means may be moved to a retracted position not engageable by the cam followers. With the one set of lobes positioned in the retracted positions, the pair of circuit making and breaking means will be alternately actuated a total number of times, each time the distributor shaft completes one revolution, equal to the number of lobes on each cam means.

In the former instance, assuming that the circuit making and breaking means are operatively associated with an otherwise conventional dual coil ignition system, each spark plug of the associated internal combustion engine or the like will be simultaneously actuated by both ignition coils of the ignition system. In the latter instance the two circuit making and breaking means will be alternately actuated and thereby the associated spark plugs will be alternately actuated by the dual ignition coils of the ignition system.

It is to be appreciated that simultaneous actuation of the circuit making and breaking means will supply a double amount of current to the associated spark plugs and each circuit making and breaking means will be actuated the same number of times per revolution of the distributor shaft as would be a conventional single circuit making and breaking means. However, when the circuit making and breaking means are alternately actuated, they are actuated one-half as many times per revolution of the distributor shaft in comparison to the number of times a conventional single circuit making and breaking means would be actuated. In addition, each ignition coil would also be actuated one-half the number of times a conventional single ignition coil would be actuated. Therefore, it may be seen that simultaneous actuation of the circuit making and breaking means will be beneficial when starting the associated internal combustion engine and when maximum or close to maximum power output of the associated internal combustion engine is desired. On the other hand, when the circuit making and breaking means are alternately actuated, the distributor shaft may .be rotated at higher speeds without the contact points of the circuit making and breaking means bouncing and with the associated ignition coils delivering close to maximum output at high speeds thereby enabling the associated internal combustion engine to be operated at higher speeds before ignition failure due to point bounce and inadequate spark plug volt-age.

It is therefore the primary object of this invention to provide an improved dual point ignition system including means by which the distributor thereof may be operated in a manner to double the normal voltage supplied to the associated spark plugs or to deliver the normal amount of voltage to the spark plugs while actuating each of the ignition coils and circuit making and breaking means of the distributor at one-half of the normal speed of their operation.

A- further object of this invention, in accordance with the immediately preceding object, is to provide a dual point ignition system including an improved distributor capable of utilizing many readily available components and yet providing improved operation.

Still another object of this invention is to provide an improved ignition distributor in accordance with the preceding objects and including means by which the operation of the distributor may be changed during operation of the latter.

A final object of this invention to be specifically enumerated herein is to provide a dual point ignition system in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and easy to install so as to provide a device that will be economically feasible, long lasting and relatively trouble-free in installation.

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 vertical longitudinal sectional view of a distributor constructed in accordance with the present invention and diagrammatically illustrating portions of the associated ignition system;

FIGURE 2 is a top plan view of the distributor illustrated in FIGURE 1 shown with the distributor cap thereof removed and with the cam means of the distributor positioned so as to simultaneously actuate the dual breaker points of the distributor;

FIGURE 3 is a fragmentary longitudinal sectional view similar to that of FIGURE 1 but showing the shiftable cam means in an inoperative position;

FIGURE 4 is a top plan view of the distributor similar to that of FIGURE 2 and illustrating the actuation of the dual breaker points by only one of the cam means of the distributor;

FIGURE 5 is a horizontal sectional view taken substantially upon the plane indicated by the section line 5-5 of FIGURE 1;

FIGURE 6 is a fragmentary side elevational view of a portion of the distributor shaft with the pair of cam means mounted thereon and the shiftable cam means shown in the operative position;

FIGURE 7 is an exploded perspective view of the pair of cam. means of the distributor;

FIGURE 8 is a fragmentary vertical sectional view of a modified form of ignition distributor constructed in accordance with the present invention;

FIGURE 9 is a horizontal sectional view taken substantially upon the plane indicated by the section line 99 of FIGURE 8;

FIGURE 10 is a horizontal sectional view taken sub- 3 stantially upon the plane indicated by the section line -10 of FIGURE 8;

FIGURE 11 is a fragmentary vertical longitudinal sectional view similar to that of FIGURE 8 but showing the retractible cam means of the modified form of distributor in the inoperative positions; and

FIGURE 12 is a horizontal sectional view similar to that of FIGURE 10 but showing the retractible cam means in the retracted position.

Referring now more specifically to the drawings and to FIGURES 1-7 in particular, the numeral 10 generally designates the improved dual point ignition system of the instant invention. The ignition system 10 includes a somewhat conventional distributor housing 12 which has a distributor shaft 14 rotatably journaled therein, the shaft 14 being provided with a spiraled oil groove 16. The lower end of the shaft 14 is provided with the usual drive gear 1 8 and a pair of ignition point assemblies 20' and 22 of conventional design are mounted on a breaker plate 24 by means of the usual upstanding studs 26- and 28, respectively. The breaker plate 24 is secured within the open upper end of the housing 12 by means of a lock ring 30. The upper end of the distributor shaft 14 has a conventional centrifugal advance assembly 32 and a conventional rotor 34 mounted thereon. Disposed between the centrifugal advance assembly 32 and the breaker plate 24 are a pair of

cam bodies

36 and 38. The cam body 36 is fixedly mounted on the shaft 14 for rotation therewith and the cam body 38 is mounted on the shaft 14 below the cam body 36 and also for rotation with the shaft 14. However, the cam body 38 is keyed to the shaft 14 as at 40' and is axially slidable on the latter toward and away from the cam body 36. The cam body 36 includes a plurality of axially extending projections 42 between which are defined a plurality of axially opening recesses 44. The cam body 38 is similarly formed and includes projections 46 between which aredefined recesses 48.

Each of the projections 4-2 and 46 comprises a cam lobe and the projections 46 are receivable in the recesses 44 while the projections 42 are receivable in the recesses 48. Thus, as can best be seen from FIGURE 6 of the drawings, the

cam bodies

36 and 38 may be interlockingly engaged with each other in order that the

lobes

42 and 46 are disposed in-the same horizontal plane extending at substantially right angles to the longitudinal axis of the shaft 14.

The ignition or breaker point assemblies 22 and 24 include rubbing blocks 51! and 52, respectively, disposed in the same horizontal plane and circumferentially spaced about the shaft 14 an odd multiple of the degrees of circumferential spacing between adjacent pairs of

lobes

42 and 46, the

lobes

42 and 46 being alternately and substantially equally circumferentially spaced about the shaft 14.

From FIGURE 3 of the drawings it may be seen that the

cam bodies

36 and 38 include confronting counterbores 56 and 58, respectively, against whose inner ends the opposite ends of a compression spring 60 disposed about the shaft 14 abut. In this manner, the compression spring 60 normally yieldingly urges the cam body 38 to the retracted position illustrated in FIGURE 3 of the drawings with its lobes 46 out of horizontal alignment with the rubbing blocks 50 and 52.

A sleeve 62 is slidably received in the distributor shaft bore 64 formed in the housing 12 and the shaft 14 is rotatably journaled through the sleeve 62. A stop block 66' is mounted on the shaft 14 for rotation therewith and limits downward axial shifting of the sleeve 62. In addition, the housing 12 is provided with a transverse bore 67 in which the output end of a flexible cable 68 or the like is rotatably journaled. The bore 67 includes a first diametrically enlarged portion 70 in which a stop collar 72 secured to the cable 68 is received and an enlarged counterbore 74 in which a gear 76 is rotatably received, the

gear 76 being mounted on the cab-1e 68 for rotation ther'e with. In addition, from FIGURES 1, 3 and 5 of the draw ings it may be seen that the counterbore 74 opens inwardly of the bore 64 and that the teeth of the gear 76 are meshed with rack gear teeth 78 formed on and extending longitudinally of the outer surface of the sleeve 62. Accordingly, upon rotation of the flexible cable 68, the sleeve 62 will be axially shifted in a manner to axially displace the cam body 38-. Accordingly, it may be seen that the cam body 38 may be shifted from the inoperative position illustrated in FIGURE 3 of the drawings to the operative position illustrated in FIGURE 1 of the drawings. With attention now directed to FIGURES 2 and 4 in particular, it may be seen that both of the

cam bodies

36 and 38 are horizontally aligned with the rubbing blocks 50 and 52. In this manner, the

breaker point assemblies

20 and 22 are simultaneously actuated. However, in FIGURE 4 of the drawings it may be seen that the cam body 38 has been lowered to the inoperative position whereby the breaker points 20 and 22 are alternately actuated by the cam body 36. With attention now directed to FIGURE 1 of the drawings, it may be seen that a conventional form of distributor cap- 82 is provided and the distributor cap 82 includes a centrally disposed secondary circuit input electrode 84 with which a contact member 86 carried by the rotor 34 is electrically connected. A pair of

ignition coils

88 and 90 are provided and each includes a secondary circuit conductor 92 having one end thereof electrically connected to the secondary output of the corresponding coil. In addition, the other ends of the secondary circuit conductors are electrically connected to one end of a single header conductor 94 whose free end is then electrically connected with the input electrode 84. A conventional dual point ignition circuit is generally designated by the reference numeral 95 and it is to be understood that the

breaker point assemblies

20 and 22 are operatively connected to the ignitioncircuit 95. In addition, it may be seen that each of the secondary circuit conductors 92 includes an insulative body 96 maintaining a pair of separate sections of the corresponding secondary circuit conductor 92 in spaced relation thereby forming an air gap 98 to prevent feedback from one coil to the other.

In operation, the ignition system 10, when both the

cam bodies

36 and 38 are engaged by the rubbing blocks 50 and 52, causes simultaneous actuation of the breaker point'assemblies 20 and 22 and each

coil

88 and 90 to simultaneously fire each of the associated spark plugs (not shown). However, when the cam body 38 has been moved to the lowered inoperative position, the breaker point assemblies 20' and 22 are alternately actuated but at half speed.

With attention now directed to FIGURES 8-12 of the drawings there may be seen a modified form of distributor constructed in accordance with the present invention generally designated by the reference numeral The distributor 110 may be constructed basically the same as the distributor 12. However, the pair of cam means mounted on the distributor shaft 112 of the distributor 110 are generally designated by the

reference numerals

114 and 116; The cam means 114 comprises a hollow cam body 118 having a plurality of radially outwardly openings 120- formed therein. The body 118 includes a closed top wall 122 but the bottom wall 124 thereof has a centrally disposed aperture or opening 126 formed therein. A plurality of lobe elements 128 are pivotally secured to the cam body 118 as at 130 and are shiftable between the retracted positions illustrated in FIGURE 11 and the extended operative positions illustrated in FIGURE 8. Each of the lobe elements comprising the cam means 116 includes an abutment portion 132 which is engageable with the inner surfaces of the cam body 118 to limit movement of the lobe elements 128 toward the operative positions illustrated in FIGURE 8.

A plurality of arms 134 are pivotally secured at one set of corresponding ends to the free swinging portions of the lobe elements 128 as at 136 and the other ends of the arms 134 are pivotally secured to a shifting disk or washer 138 as at 140. The washer or disk 138 is keyed to the shaft 112 as at 142 for rotation with the shaft 112 and for axially sliding movement therealong.

A compression spring 144, corresponding to the compression spring 60 is disposed about the shaft 112 and between the confronting faces of the washer or disk 138 and the inner surface of the top wall 122 of the cam body 118 and yieldingly urges the washer or disk 138 toward the lowered position illustrated in FIGURE 11 of the drawings and therefore the lobe elements 128 toward their retracted positions. However, the shaft 112 is journaled by means of a sleeve 146 slidably disposed in the bore 147 and corresponding to sleeve 62 and it may be seen that the sleeve 146 is axially shiftable in the bore 147 formed longitudinally through the distributor housing 110. In addition, the housing 110 is provided with a gear wheel 148 similar to the gear wheel 76 which is engaged with the rack gear teeth 150 formed on the sleeve 146 corresponding to the gear teeth 78 formed on the sleeve 62. The upper end of the sleeve 46 abuts the undersurface of the ring or washer 138 and may therefore be utilized to raise and lower the latter upon rotation of the gear wheel 148 for moving the lobe elements 128 between the extended and retracted positions illustrated in FIGURES 8 and 11 of the drawings, respectiveiy.

Although none has been illustrated, it is to be understood that the breaker plate 156 within the distributor housing 116 is substantially identical to the breaker plate 24 and that it is to be provided with a pair of breaker point assemblies corresponding to breaker point assemblies 2t) and 22 and having the same circumferential spacing between the rubbing blocks thereof as the spacing between the rubbing blocks 50 and '52.

Accordingly, it may be seen that the cam means 114 and 116 may be caused to actuate the associated breaker point assemblies (not shown) in the same manner in which the

cam bodies

36 and 38 may be caused to actuate the

breaker point assemblies

20 and 22.

A modified form of distributor cap 160 is mounted on the open end of the distributor housing 110 and includes a centrally disposed bearing 162 in its end wall which rotatably journals the upper end of a rotor 164 mounted on the upper end of the shaft 112. Instead of being provided with a centrally disposed electrode means such as the electrode means 84, the distributor cap 160 includes a pair of radially inwardly projecting

electrodes

166 and 168 to which the free ends of a pair of

secondary circuit conductors

170 and 172 similar to the conductors 92 but without air gaps are connected. The rotor 164 includes an annular conductor member 176 in lieu of the conductor member 86 and the inner ends of the electrode means 66 and 68 are spaced slightly radially outwardly of the annular conductor member 76 forming

air gaps

178 and 180 between the annular conductor member 176 and the

electrodes

166 and 168, respectively.

In view of the preceding description of FIGURES 8-12 of the drawings it may be seen that the distributor 1111 may be caused to operate in the same manner in which the distributor may be operated so as to alternately or simultaneously actuate the associated dual breaker points.

What is claimed as new is as follows:

1. A dual point ignition distributor including a housing, a driving shaft journaled in said housing, a pair of cam means mounted on said shaft each including a set of lobes spaced circumferentially about said shaft, said sets of lobes each including the same number of lobes and being alternately and substantially equally circumferentially spaced about said shaft, a pair of circuit making and breaking means each including an actuating cam follower for engagement with said lobes, said cam followers being circumferentially spaced about said' shaft an odd multiple of the degrees of circumferential spacing between adjacent lobes, one of said cam means being supported from said shaft for movement between an operative position for engagement by said cam followers and a retracted inoperative position, and means operatively connected to said one cam means for selectively shifting the latter between said operative and inoperative positions.

2. The combination of claim 1 wherein said means for selectively shifting said one cam means between said operative and inoperative positions includes actuating means operable from the exterior of said housing.

3. The combination of claim 2 wherein the last mentioned means includes means operable during rotation of said shaft relative to said housing.

4. The combination of claim 1 wherein said one cam means includes a sliding connection with said shaft for axial shifting of said one cam means into and out of said operative position.

5. The combination of claim 1 wherein said second cam means comprises a cam body mounted on said shaft and having the corresponding lobes projecting radially outwardly thereof, said cam body being hollow and defining a radially outwardly opening aperture between each pair of adjacent lobes on said cam body, the set of lobes of said first cam means being mounted in said body for movement between retracted positions disposed inwardly thereof and operative radially extended positions projecting radially outwardly through said apertures.

6. The combination of claim 5 wherein said cam body defines an opening opening in one direction axially of said shaft, said lobes of said first cam means being pivotally secured at the portions adjacent said opening for rotation about axes extending transversely of said shaft and substantially at right angles to the radii of said cam body on which said last-mentioned lobes lie, said means operatively connected to said one cam means comprising a plurality of arms each pivotally secured at one set of corresponding ends to the free end of the corresponding one of the pivoted lobes for rotation about an axis extending transversely of that arm and generally paralleling the corresponding one of said axes, a sleeve reciprocal on said shaft, the other set of corresponding arms being pivotally secured to said sleeve for oscillation about axes generally paralleling the first-mentioned axes, and means operatively connected to said sleeve for adjustably shifting the latter axially of said shaft.

7. The combination of claim 6 wherein said sleeve is disposed outwardly of said opening.

8. The combination of claim 1 wherein said second cam means comprises a cam body mounted on said shaft and having the corresponding lobes projecting radially outwardly thereof, said cam body being hollow and defining a radially outwardly opening aperture between each pair of adjacent lobes on said cam body, the set of lobes of said first cam means being mounted in said body between retracted positions disposed inwardly thereof and operative radially extended positions projecting radially outwardly of said apertures, said cam body defining an opening in one direction axially of said shaft, said lobes of said first cam means being pivotally secured at the portions adjacent said opening, for rotation about axes extending transversely of said shaft and substantially at right angles to the radii of said cam body on which said last-mentioned lobes lie, said means operatively connected to said one c am means comprising a plurality of arms each pivotally secured at one set of corresponding ends to the free end of the corresponding one of the pivoted lobes for rotation about an axis extending transversely of that arm and generally paralleling the firstmentioned axes, and means operatively connected to said sleeve for adjustably shifting the latter axially of said shaft, and means operatively connected between said cam body and'said sleeve yieldingly urging said sleeve in said one direction axially of said shaft.

9. The combination of claim 1 wherein said cam means comprise a pair of cam bodies mounted on said shaft for rotation therewith and at axially spaced positions on said shaft, said cam bodies including opposing complementary axially extending projections and recesses, said one cam body being axially'slidably mounted on said shaft, said projections comprising said lobes and the projections of the cam body comprising said'one cam means being receivable in the recesses of the other cam body and said operative position aligned radially of said shaft with said cam followers.

10. The combination of claim 9 including means ope-ratively connected between said cam bodies yieldingly urging said one cam body axially of said shaft away from said other cam body and toward said inoperative position out of radial alignment with said cam followers.

11. The combination of claim 10 wherein said means for selectively shifting said one cam means between said operative and inoperative positions includes a sleeve rotatable and axially shift-able on said shaft and disposed on the side of said one cam body remote from the other cam body.

References Cited by the Examiner UNITED STATES PATENTS 1,324,430 12/1919 Midgley.

1,922,655 8/1933 Beeh et a1. 200-19 1,964,698 6/1954 Walther et al.

2,107,709 2/1938 Oberdick 200-19 2,176,164 10/1939 Arthur 200-19 2,718,564 9/1955 Collins et al. 2002l 2,863,011 12/1958 Mallory zoo-27 JOHN F. COUCH, Primary Examiner. W. E. RAY, K. D. MOORE, Assistant Examiners.

Claims

1. A DUAL POINT IGNITION DISTRIBUTOR INCLUDING A HOUSING, A DRIVING SHAFT JOURNALED IN SAID HOUSING, A PAIR OF CAM MEANS MOUNTED ON SAID SHAFT EACH INCLUDING A SET OF LOBES SPACED CIRCUMFERENTIALLY ABOUT SAID SHAFT, SAID SETS OF LOBES EACH INCLUDING THE SAME NUMBER OF LOBES AND BEING ALTERNATELY AND SUBSTANTIALLY EQUALLY CIRCUMFERENTIALLY SPACED ABOUT SAID SHAFT, A PAIR OF CIRCUIT MAKING AND BREAKING MEANS EACH INCLUDING AN ACTUATING CAM FOLLOWER FOR ENGAGEMENT WITH SAID LOBES, SAID CAM FOLLOWERS BEING CIRCUMFERENTIALLY SPACED ABOUT SAID SHAFT AN ODD MULTIPLE OF THE DEGREES OF CIRCUMFERENTIAL SPACING BETWEEN ADJACENT LOBES, ONE OF SAID CAM MEANS BEING SUPPORTED FROM SAID SHAFT FOR MOVEMENT BETWEEN AN OPERATIVE POSITION FOR ENGAGEMENT BY SAID CAM FOLLOWERS AND A RETRACTED INOPERATIVE POSITION, AND MEANS OPERATIVELY CONNECTED TO SAID ONE CAM MEANS FOR ELECTIVELY SHIFTING THE LATTER BETWEEN SAID OPERATIVE AND INOPERATIVE POSITIONS.