US2778893A

US2778893A - Ignition mechanism

Info

Publication number: US2778893A
Application number: US407435A
Authority: US
Inventors: Stephen C Baker
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-02-01
Filing date: 1954-02-01
Publication date: 1957-01-22
Anticipated expiration: 1974-01-22

Description

Jan. 22, 1957 s. c. BAKER 2,778,393

IGNITION MECHANISM Filed Feb. 1, 1954 2 Sheets-Sheet 2 II I! 1 nil I 500 J93. INVENYOR. 1 fi lg kw 3M67 United States atent O IGNITION MECHANISM Stephen C. Baker, North Riverside, Ill. Application February l, 1954, Serial No. 497,435

17 Claims. (Cl. 200-31) This invention is concerned with ignition of internal combustion engines, more specifically it is concerned with an improved distributor and breaker point mechanism.

Conventional breaker points for spark ignited, internal combustion engines provide a pair of similar, fiat-surface contacts opposed to one another and generally known as points. The breaker points are periodically moved out of contact with one another and back into contact with one another, conventionally stated, they are opened and closed, by a cam driven by the engine in synchronism therewith for providin" sparking energy to the spark plugs.

As the points or contacts move away from one another they effect the collapse of the field in the primary of the ignition coil to generate a high voltage in the secondary for causing sparks across the gaps of the spark plugs. As the contacts move away from one another an arc appears between the contacts which burns the contacts or points. More specifically, metal is carried from one of the contacts to the other by the are, thus forming a pit or crater in the first contact and a corresponding builtup pile or hill on the other contact. The metal is =Xidized as it is carried over, and consequently the pile or hill that is thus built up is a relatively poor conductor. This poor conduction leads to a poor spark. Additionally, this oxidation of the metal increases the volume and causes the hill to build up faster than the corresponding pit or crater is formed. The gap between the contacts when they are open thus is progressively decreased. As the gap is decreased, the arc becomes more severe and speeds up the burning. Furthermore, as the gap becomes smaller the proper ratio of opened to closed time of the contacts or points is upset. In fact, eventually the gap becomes so small that the contacts or points are permanently shorted out.

In my oo-pending application Serial No. 400,175, filed December 24, 1953, and entitled Ignition Element" 1 have disclosed an improved breaker point construction wherein one of the breaker points is moved from time to time in an orbital path whereby continuously to present fresh surfaces for contact. This results in much longer contact life and allows the initial gap to be set closer than heretofore thought possible, thereby generating a stronger spark and at the same time causing a sufiiciently severe are as to blow the oxidized metal away from the breaker points, thereby preventing the formation of a pile or hill on the points. The construction disclosed in my aforesaid application successfully solves a problem :of long standing. However, the parts for the breaker point construction disclosed in that application are special parts, thereby increasing the cost of manufacture and to some extent increasing sales resistance. Furthermore, the appearance of the construction varies somewhat from the conventional and this might have an undesirable psychological effect on some mechanics.

Accordingly, it is an object of this invention to provide an improved breaker point construction wherein one breaker point is from time to time moved in an orbital path to provide fresh contacting surfaces, and wherein Patented Jan. 22,

the appearance of the breaker point construction is very nearly conventional.

A further object of this invention is to provide a breaker point construction of the foregoing character wherein standard or stock parts are utilized to a substantial extent.

Yet another object of this invention is to provide a breaker point construction wherein one of the points is orbitally moved to present fresh contacting surfaces, and which is simply and economically fabricated.

Yet another object of this invention is to provide an improved breaker point construction wherein one of the points is orbitally moved about the axis of the other point and is positively restrained against rotation about its own axis.

Another object of this invention is to provide a breaker point construction having a pawl and ratchet mechanism for orbitally moving one of the breaker points to present clean contact surfaces wherein a single spring simultaneously urges the pawl against the ratchet and holds the pawl in position for operation by an operating member.

Other and further objects and advantages of the present invention will be apparent from the following description wherein:

Fig. l is an end view of one distributor of conventional manufacture incorporating the principles of my invention;

Fig. 2 is a side view with a part of the distributor housing broken away to illustrate the internal parts;

Fig. 3 is an enlarged detailed view taken along the line 33 of Fig. 1;

Fig. 4 is a cross-sectional View taken along the line dof Fig. 3;

Fig. 5 is a perspective view of a part of the orbital moving mechanism;

Fig. 6 is an end view of a different distributor of commercial production embodying the principles of my invention;

Fig. 7 is a side view of the distributor shown in Fig. 6 with a part of the distributor housing broken away to show the interior thereof;

Fig. 8 is an end view of yet another commercial form of distributor modified in accordance with the principles of my invention;

Fig. 9 is a fragmentary View similar to a part of Fig. 6 showing a modification thereof;

Fig. 10 is a cross sectional view along the line 10-10 of Fig. 9;

Fig. 11 is a cross sectional view along the line 11-11 of Fig. 9; and

Fig. 12 is an exploded perspective view of the operating mechanism of Figs. 911.

Referring now in greater particularity to the drawings, and first to Figs. 1 and 2, there will be seen a distributor of well known commercial construction generally indicated by the numeral 16. The distributor ill includes a body 12 of well known construction and adapted to receive a distributor cap which has been omitted for purposes of illustration. A fitting 14 is conventionally mounted on the side of the distributor and includes a vacuum diaphragm for advancing the spark in accordance with engine requirements. A coupling is provided at 16 for attachment to a vacuum line leading to the carburetor of the engine. A capacitor or condenser 18 is mounted on the side of the distributor body by means of a metal strap or bracket 2b which serves also to ground the capacitor or condenser to the distributor body. The other terminal of the condenser is connected by means of a wire 22 to a stud 24 which extends through and is insulated from the distributor body.

The distributor further includes a rotary shaft 26 extending upwardly above the housing for receipt of a distributor rotor and extending from the bottom of the distributor for coaction with a timing gear as is well known in the art. A cam 28 is fixed on the shaft 26 for opening the breaker points and is provided with a plurality of lobes or high spots 30 determined in accordance with the number of cylinders in the engine. In the present instance there are eight such high spots or lobes for operation of an eight cylinder engine.

The distributor further includes a breaker plate 32 mounted for rocking movement concentric with the shaft 26 as is well known in the art. An arm 34 is pivotally connected to the breaker plate 32 as indicated at 36 and is attached to the diaphragm within the vacuum fitting 14 for advancing the plate in a clockwise direction as seen in Fig. 1 against the action of the usual biasing or positioning springs (not shown) mounted beneath the plate. The breaker plate, is grounded to the distributor body through a wire 38 connected to the pivotal connection 36 and also affixed' to a screw 40 extending through the side wall of. the. distributor body 12.

A breaker point unit 42 is mounted on. the breaker plate 32 and comprises a. web 44 havinganopening therein adjacent one end for fitting over a stud 46 fixed to the breaker plate 32. An. eccentric screw 48 extends through a slot 50 in the web 44. and is threaded into the breaker plate 32 for adjusting the position of the web about the stud 46 toward andaway from the cam. 28. A clamping screw 52 extends through an arcuate slot 54 in the web 44 adjacent the opposite end thereof andis threaded into a suitable tapped. aperture in the breaker plate 32 for locking the web in adjusted position. A movable breaker arm 56 is rotatably mounted on, the stud 46 and is insulated therefrom. The breaker arm 56 is made of metal and carries a cam follower or rubber 58 of fibre or other suitable insulating material for riding against the cam 28 to control movement of the breaker arm 56. The breaker arm is biased to hold the cam follower 58 against the cam by a leaf spring 60 which is attached to the arm and follower by the same means that. the follower 58 is mounted. on the arm. This means-conventionally comprises a peened over stud (not shown) carried by the arm., The leaf spring is looped'as at 62 around the pivoted end of. the arm- 56-and is restrained against lateral movement by a lug 64 projecting from the arm through a slot in the spring. The other end of thespring is held as at 66 beneath an eyelet 680a a wire 70 connected to the stud 24 for forming a connection from the breaker arm to the condenser or capacitor'18. A. screw 72 is passed through an insulating mounting block 74 and through theeyelet .68-and the spring end 66 for mounting the same on this block, a nut 76 threaded on the. end of the screw serving to hold thesame in place. The insulated mounting block 74 is mounted onv a. flange 78 upstanding fromthe edge of the web 44 by suitable means such as a rivet 80.

All of the foregoing structure. is conventional, and the conventional structure is completed. by a contact or breaker point 84,carried on the outer end of the arm 56. This contact hereinafter will be referred to as the relatively movable contact. The remaining structure departs from the conventional, and its construction per se and in cooperation with the conventional structure form the subject matter of my invention.

A breaker pointor contact 86is mounted in substantially, opposed relation tothe relatively-movable breaker point 84.and is carried bya flange 8S upstanding from the web 44. The breaker point 86is mounted for orbital movement about the axis of the relatively movable breaker point 84. Although the point 86 is movable orbitally, it takes the place of the fixedcontact in conventional constructions, and for purposes of distinction it will hereinafter be called therelatively fixed contact or breaker point. The manner in which this breaker point is mounted for orbitalmovement can best be seen in Figs. 3 and 4. As shown inthese figures, the flange 88'is formed with acircular aperture 90 in which a hub 92=ona rotatable member, 94%is1journaledr This rotatable:

member is provided with an upstanding or axially extending peripheral flange having ratchet teeth 96 thereon more or less in the form of a crown. A stud or shaft 98 projects through an eccentric bore 100 in the rotatable member 94 including the hub 92 thereon. The stud or shaft 98 is formed at one end with a flat flange or cap 102 to which the relatively fixed breaker point 86 is welded or otherwise suitably secured.

An elongated member or tab 1134 is provided with an opening or hole 106 adjacent one end and frictionally encircling the shaft or stud 98 immediately below the flange or cap 102. A stud 106 fixed in the flange 88 projects through a longitudinally elongated opening 108 in the tab 104 for preventing rotation of the same about the stud 98. Friction between the tab 104 and the stud 98, and also between the tab and cap 102 prevents rotation of the stud, cap, and relatively fixed breaker point 86 about its own axis. A washer 110 encircles the stud on the opposite side of the rotatable member 94, and a split washer or 0 washer 112 fits in a suitable peripheral or arcuate groove 114 adjacent the end of the stud 98. A coil spring 116 encircles the stud 98 and bears against the

washers

110 and 112 to urge the stud to the left and the rotatable member 96 to the right. The assembly comprising the rotatable member and the stud and its associated parts obviously cannot move through the aperture 90 to. the right (as shown in Fig. 4), while the tab 104 prevents it from moving from the aperture to the left.

The web 44 is provided with an upstanding post 118 adjacent the slot 54,. and lever arm 126 is pivotally mounted on this post, the upper end of the post being peened over to secure the lever arm 120 against retraction therefrom. The lever arm comprises a web 122' and a pair of flanges 124 extending at right angles thereto.

The flanges are provided with ears 126 in which the post 118 is received. The flanges 124 also are provided at the opposite end of the lever arm with outwardly ex tending lugs or cars 128 between which a cam follower roller 130 is rotatably journaled on a pin 132 secured in suitable apertures in the lugs or ears 128.

A pawl 134 is carried by the lever arm 12b and comprises a forwardly extending tongue 136 and enlarged section 138 having shoulders 140 thereon received in suitable slots or notches in the lever arm 120. The pawl 134 further includes an integral body portion 142 extending generally at right angles to the tongue 136 and enlarged portion 138 and received within the space betweenthe flanges 124 of the lever arm 120.

The shoulders 140 on the pawl 134 and their engagement in the slot or notch in the lever arm 120 serve as a knife edge pivot for pivoting movement of the pawl 134 to allow proper cooperation thereof with the ratchet teeth 96 of the rotatable member 94. A single spring is utilized to bias the end of the pawl into engagement with the ratchet teeth and simultaneously to bias the lever arm 120 in such manner as to maintain the cam follower roller 131) in proper engagement with an operating cam. This spring identified by the numeral 144, is a leaf spring having one end 146 thereof bearing against the flange 78 which serves as a fixed stop therefor. An intermediate portion 148 is formed into substantially a U-shape and lies against the pivot pin 118 as a fulcrum, while the opposite end 150 of the spring is trapped beneath the body portion 142 of the pawl 134. This pivots the pawl in a counterclockwise direction as seen in Pig. 1, and also urges the lever arm 120 to the right.

A cam member in the form of a rigid metal strip 152' is aflixed to the inside of the distributor housing 12 by means such as a screw 154 extending through the distributor. housing and threaded into a suitable aperture in the cam member. The cam member is provided at one end with a more or less triangular raised or active cam portion 156. against which-.the camfollower roller 130 av /sacs ggiierally bears under the influence of the biasing spring Each time the vacuum in the carburetor or intake manitold increases due to acceleration or otherwise increasmg loads on the engine, the arm 34 will be pulled to the right as shown in Fig. 1 by the vacuum diaphragm (not shown), and consequently the breaker plate 32 will be rotated in a clockwise direction. Similarly, when the vacuum decreases the parts will be returned by a suitable spring means (not shown). Each time the breaker plate 32 moves in a clockwise direction the cam follower roller 136 will be pulled over the active portion 156 of the car Such movement of the cam follower roller over the active portion of the cam causes counterclockwise rotation or pivoting movement of the lever arm 120, and this causes the pawl 1.34 to bear against the ratchet teeth 96 for rotating the rotatable member 94. The angular position of the pawl 134 may be seen in Fig. l, and it is to be understood that this angular position is such as to cause the pawl to wedge down into the corner or angle between adjacent teeth. Accordingly, only a relatively light spring force is needed to hold the pawl against the ratchet teeth. Consequently, when the parts return to their original positions and the lever arm 120 pivots to the right, the spring will not hold the pawl against the ratchet teeth with sufficient force to cause retrograde movement of the rotatable member 84.

in Figs. 6 and 7 I have illustrated my invention incorporated in another distributor of conventional construction, but ditiering somewhat from that shown and described with regard to the previous figures. Since the distributor is basically the same, and many of the parts are equivalent or even substantially identical, similar numerals with the addition of the suffix a have been utilized to identify parts, thereby rendering it unnecessary to describe the conventional or repeated parts of the distributor in great particularity. The distributor 10a comprises a metallic body or housing 12:: having a vacuum fitting 14a on the side thereof containing a vacuum diaphragm (not shown). Provision is made at 16a for connecting the vacuum fitting to a line or tube running to the carburetor or intake manifold.

in the distributor now under consideration the condenser lda is mounted on the breaker plate 32a by means of a bracket 2th; and a screw passing therethrough and threaded into the breaker plate. A rectangular opening 153 is provided in the breaker plate for receiving part of the bracket to stabilize the same against movement about the mounting screw. The wire 22a from the condenser or capacitor 18:: leads directly to the contact screw 72:: on the breaker point unit 42a. This screw also is used for attaching the primary lead of the ignition coil as is well known to those skilled in the art.

The distributor also includes a shaft 26a with a cam 28a afiixed thereon. The cam again is provided with a number of high spots 31in determined in accordance with the number of cylinders of the engine.

A breaker plate 32a is mounted for rotation or rocking movement about the shaft 26a and is provided with a pair of holes 16th through which pins 162 afiixed in the distributor body or housing 12a project. Movable pins are fixed on the breaker plate 32a for movement therewith and are positioned near the fixed pins 162. Springs 166 are stretched between each pair of fixed and movable pins for normally retaining the breaker plate in the position shown. As is well known in the art these springs difier in their initial tension so that more complete control of the position of the breaker plate can be effected over a wide range of engine speeds. The connection from the vacuum diaphragm (not shown) to the breaker plate 32a comprises a rod 340: extending beneath the breaker plate and having an upturned end 35a forming the pivotal connection with the breaker plate, a cotter pin or the like being placed in the end of the upturned rod portion 36a to retain the same in its aperture in the breaker plate. The breaker plate is grounded to the distributor housing or body by a wire 3811 having one end thereof secured to an eyelet held by the screw mounting the condenser bracket 20a and having the other end secured to an eyelet held to the distributor housing or body by a screw 49a threaded into a suitable aperture in the housing. The breaker point unit 52:; shown in Figs. 6 and 7 functions similarly to that previously described and in large measure is physically the same, including a web 44a held to the breaker point by a pair of screws 52a passing through slots 54a. The unit further may be positioned by a pin secured to the web 44a and projecting rearwardly into a hole in the breaker plate 32a. Such pin has been omitted from the drawings. The breaker point unit is provided with a breaker arm 56a pivotally mounted on a stud 46a carried by the web 44a, it being understood that the arm is insulated from this stud. A leaf spring 60a is trapped beneath a nut on the contact screw 72a and is looped around the stud 46a and suitably afiixed to the breaker arm to bias it so as to maintain the cam follower 58a thereon against the cam 223a. A copper or other highly conductive contact strip 168 may generally parallel the spring 68a for improved electrical contact. The breaker arm is completed by the movable contact point 84a welded to the outer end thereof.

The unit further is provided with a relatively fixed contact point 86a mounted on an upstanding flange 88:: on the web 44a. The mounting of the relatively fixed breaker point 36:: is identical with that previously disclosed including a rotatable member 94a and the ratchet teeth %a for effecting orbital movement of the relatively fixed breaker point 86a. Such movement is efiected from time to time by a pawi carried by a lever arm 12% pivotally mounted at 118a on a pin upstanding from the breaker plate. A leaf spring 14 5a has one end thereof caught beneath the body of the pawl as at 146a for biasing the pawl and the lever arm as previously disclosed. The opposite end of the spring 14411 is trapped beneath the flange 73a mounting the contact screw 72a.

The means for operating the lever arm 120a and the pawl 134a in this form of the invention comprises a bell crank 168 pivotally mounted on one of the movable pins 164 fixed on the breaker plate 32a. One arm 170 of the bell crank engages the adjacent fixed pin 162, While the opposite arm 172 of the bell crank engages the lever arm 12%. Thus, when the breaker plate is rotated in a counterclockwise position (as shown in Fig. 6) from the position shown the bell crank is rotated in a counterclockwise direction by engagement of the arm 176 with the pin 162. This causes the opposite arm 172 of the bell crank to move the lever arm 126 in a clockwise direction for engaging the pawl with the ratchet teeth 96a to efiect orbital movement of the relatively fixed contact point 86a. When the breaker plate returns to its normal position, the spring 144a returns the lever arm 12%, and the pawl 134a, and the bell crank 16% to their initial positrons.

Some distributors are arranged to be rotated as a unit to effect spark advance, rather than having a separately rotatable breaker plate as previously described. My invention is shown as adapted for such a distributor in Fig. 8. The distributor in Fig. 8 is identical with that shown in Fig. 7 except that the breaker plate is fixed in position, and consequently the fixed and movable pins and the interconnecting springs are omitted. To render it unnecessary to repeat the descriptive matter already set forth, simiiar numerals have been utilized with the addition of the sufiix b. Only the parts which are different will be described. Specifically, the different parts include the means for moving the lever arm 12% and pawl 13412 to effect orbital movement of the relatively fixed contact point 8612. This means includes a vacuum unit 1.74 mounted on the side of the distributor housing 12b. The vacuum unit 174 is provided with a fitting 176 on its side for receipt of a tube 178 leading to the carburetor or to the intake manifold for applying vacuum to the unit 174.

The vacuum unit is provided internally with a diaphragm 180, and a spring 182 for holding the diaphragm in a normally substantially flat position. A plunger 184 is attached to the diaphragm and extends through the means for attaching the unit 174 to the distributor and into contact with the lever arm 12%. Each time that vacuum is applied to the unit 174 through the tube 178, the plunger 184 is pushed against the lever arm 12% to force the pawl 1341; forwardly against the ratchet teeth 36b to effect orbital movement of the relatively fixed breaker point in the manner previously described.

In Figs. 9l2 I have illustrated an improved construction similar to that shown in Figs. 6 and 7 which is somewhat more compact in structure and more positive in operation, requiring no return spring on the actuating lever. The parts shown in these figures are generally similar to those previously described, and similar numerals are utilized to identify similar parts with the addition of the sufiix c. The distributor tile is shown only fragmentarily, including the housing 12c, since many of the parts are identical with those shown in, Fig. 6 and need not be repeated. A port-ion of the breaker plate is indicated at 320 as is a portion of the breaker unit 4 3C including the breaker arm 56c and the relatively movable contact 84c carried thereby. also includes the relatively fixed point or contact 860 which is mounted by means generally similar to those previously described.

More specifically, referring to Figs. 9 and 10, the relatively fixed breaker point 860 is mounted on a flange or cap M520 of the stud or shaft 980. This stud or shaft passes through a washer 186 positioned beneath the cap and spanning the opening 90c in which the hub 920 of the rotatable member 940 is journaled, this rotatable member having ratchet teeth 96c as previously described. The end of the stud 980 is flared outwardly or peened over as indicated at 188, and this outwardly flared end traps a telescoping spring between it and the rotatable member 94c. This spring serves substantially the same purpose as the springs 116 and 116a, but allows the stud 980 to be shortened substantially so that it and the spring do not project substantially beyond the ratchet teeth 960.

The pins or posts 1640 are provided with eccentric bases 188 (Fig. 11) journaled in the breaker plate 32c and eccentric relative to the pins so that the pins can be rotated eccentrically to adjust the tension on the springs 36c, all as is well known to those skilled in the art. A bell crank 190 is provided with a relatively large aperture 192 which is rotatably journaled on the upwardly projecting portion of the base 138. The bell crank 196 includes an upwardly ofiset bifurcated arm 194 receiving the pin 1620 between the bifurcations. A finger 196 extends substantially in parallelism with the bifurcated arm 194 and in the plane of the bell crank for supporting a pawl as will be brought out hereinafter. The opposite arm of the bell crank 190 is provided with an upstanding stop 198 and with a pivot opening 290 adjacent the stop.

A hook-like pawl 202 is pivotally mounted on the bell crank 19% at the pivot opening 200. A rivet 204 is fixed in the opening 200 and carries a sleeve or collar 2% having an upper shoulder 208 and a lower shoulder 219. The pawl 2% is pivotally mounted on the lower shoulder 219, while a spring 212 encircles the upper shoulder 263 and has one end bearing against the stop 193. The other end of the spring 212 bears against a stop 214 upstanding from the pawl 202 to urge a lug 216 upstanding from the end of the pawl into engagement with the ratchet teeth 960. The ratchet teeth are arranged in the proper direction for the lug 216 to jam into them and to rotate the rotatable member 960 on a return stroke as the pawl moves down in Fig. 9.

It will be observed that the tension spring 1660 serves at the post or pin 1640 as a stop for holding down av The breaker point unit a washer. 220, and. the: washer. holds down: the; bell. crank 190.

The pins or posts 162a remain fixed in position as indicated heretofore, while: the pins. 164s move with the breaker plate 32c. Accordingly, when the breaker plate is advanced by the vacuum advance mechanism, the. bell crank is pivoted about the hub 188 on which it is mounted by the bifurcations 194 following the pin 1620. This moves the pawl lug 216 backwardly over the ratchet teeth and tends to lift it from the teeth so that there is substantially no tendency to rotate the rotatable member 940 backwards. When the breaker plate returnsto its original position, the bifurcations follow the pin 1620 in the opposite direction and pivot the bell crank in the opposite direction, namely clockwise as viewed in Fig. 9. This pulls the pawl lug tightly down into the ratchet teeth and rotates the rotatable member Me to bring afresh portion of the relatively fixed breaker point 86c intoposition to contact the relatively movable breaker point 940. The relatively fixed breaker point thus is moved orbitally substantially about the axis of the relatively movable breaker point.

In this particular embodiment of the invention, the relatively fixed breaker. point is only lightly frictionally restrained against rotation about its own axis, and accordingly such rotation will take place to a limited degree, thus desirably tending to-prevent the relatively fixed and relatively movable breaker point from contacting one another similarly at difierent times.

It now will be apparent that the improved breaker point and distributor construction herein disclosed utilizes a maximum number of the standard parts and thereby bears a very close resemblance to conventional construction. In fact, no alteration need be made in conventional distributors except for the insertion of the improved breaker point unit, and this unit is so close in appearance to conventional units that it will be apparent to mechanics immediately how it should be installed, and will not meet with sales resistance due to an unusual appearance. The large number of stock parts used in the breaker point unit helps to lower its cost as well as to make it more readily acceptable from an appearance standpoint.

It will be noted that the angle at which the pawl engages the ratchet in each case is such as to wedge the pawl into place against the teeth, thereby rendering unnecessary the use of a heavy biasing spring which might cause retrograde movement of the ratchet upon reverse movement of the pawl. In fact, I have found it possible to position the pawl and to bias the lever arm carrying the pawl. by a single, rather light, spring. The ratchet mechanism for imparting orbital movement to the relatively fixed breaker point is simple in construction, thus leading to a low initial cost and little chance of breakdown in use. The tab 164 positioned beneath the relatively fixed breaker point in each of the embodiments of the invention positively provides a frictional resistance to rotation of the fixed breaker point about its own axis, thereby insuring a fresh surface for contact with the movable breaker point each time that the relatively fixed breaker point is moved orbitally substantially about the axis of the relatively movable breaker point.

It will be understood that the specific embodiments of my invention herein shown and described are by way. of illustration only. Various additional structural modifications doubtless will occur to those skilled in the art and are to be understood as forming a part of my invention insofar as they fall within the spirit and scope of the appended claims.

I claim:

l. A circuit maker and breaker for ignition systems comprising a relatively stationary contact point, a periodically movable breaker arm, a relatively movable contact point carried by said arm in substantially confronting;

relationto the first contact point and'movable into and out of en'gagement therewith, means for advancing and retarding such movement into and out of engagement, ratchet means connected to one of said contacts for orbitally moving that contact substantially about the axis of the other, a pawl for moving said ratchet and means for moving said pawl from time to time to effect such movement, said pawl moving means being operated in accordance with the movement of said advancing and retarding means.

2. A circuit maker and breaker for ignition systems comprising a relatively stationary contact point, a periodically movable breaker arm, a relatively movable contact point carried by said arm in substantially confronting relation to the first contact point and movable into and out of engagement therewith, means including a pawl and ratchet for moving one of said contacts orbitally substantially about the axis of the other, and means for restraining the orbitally moving contact against rotation about its own axis.

3. A circuit maker and breaker for ignition systems comprising a rotatable member, a relatively stationary contact point eccentrically carried by said rotatable member, a periodically movable breaker arm, a relatively movable contact point carried by said arm in substantially confronting relation to the relatively fixed contact point and movable into and out of engagement therewith, means for advancing and retarding such movement into and out of engagement, a ratchet mechanism for rotating said rotatable member to move the eccentrically mounted relatively fixed contact point orbitally substantially about the axis of the relatively movable contact point, pawl means for engaging said ratchet mechanism, and means for moving said pawl means to operate said ratchet mechanism, said pawl moving means being operated in accordance with the movement of said advancing and retarding means.

4. in a distributor for ignition systems having a part advancing and retarding in accordance with engine requirements as to spark timing, the combination comprising a rotatable member, a relatively stationary contact point eccentrically carried by said rotatable member, a periodically movable breaker arm, a relatively movable contact point carried by said arm in substantially confronting relation to the relatively fixed contact point and movable into and out of engagement therewith, and means including a pawl and ratchet mechanism for rotating said rotatable member to move the eccentrically mounted relatively fixed contact point orbitally substantially about the axis of the relatively movable contact point, said ratchet being integral with the rotatable member, and said pawl being moved by said advancing and retarding part.

5. A circuit maker and breaker for ignition systems comprising a rotatable member, a relatively stationary contact point eccentrically carried by said rotatable member, a periodically movable breaker arm, a relatively movable contact point carried by said arm in substantially confronting relation to the relatively fixed contact point and movable into and out of engagement therewith, and means including a pawl and ratchet mechanism for rotating said rotatable member to move the eccentrically mounted relatively fixed contact point orbitally substantially about the axis of the relatively movable contact point, said ratchet comprising teeth extending axially from the rotatable member as a crown thereon.

6. A circuit maker and breaker for ignition system comprising a rotatable member, a relatively fixed breaker point eccentrically carried by said rotatable member, ratchet means interconnected with said rotatable member, a periodically movable breaker arm, a relatively movable contact point carried by said arm in substantially confronting relation to the relatively fixed contact point and movable into and out of engagement therewith, a pawl engageable with said ratchet for effecting rotation of said rotatable member to move the relatively fixed contact point orbitally substantially about the axis of the relatively movable contact point, a movable arm carrying said pawl, and actuating means for moving said arm from time to time to effect such orbital movement.

7. A circuit maker and breaker as set forth in claim 6 wherein the pawl is pivotally mounted on the arm by a substantially knife edge pivot.

8. A circuit maker and breaker as set forth in claim 6 and further including a single spring biasing the pawl into engagement with the ratchet and biasing the movable arm against the actuating means.

9. A circuit maker and breaker as set forth in claim 8 wherein the pawl has a tongue engageable with the ratchet and a body portion extending at an angle to the tongue, and wherein the single spring comprises a leaf spring engaging the body of the pawl to bias the pawl against the ratchet and to bias the movable arm against the actuating means.

10. A circuit maker and breaker for ignition systems comprising a rotatable member, ratchet means for rotating said rotatable member, a relatively fixed contact point eccentrically carried by said rotatable member, a periodically movable breaker arm, a relatively movable contact point carried by said arm in substantially confronting relation to the relatively fixed contact point and movable into and out of engagement therewith, a pawl, means for supporting said pawl in engagement with said ratchet for roving the same, means for actuating the pawl supporting means to effect movement of the ratchet means to cause orbital movement of the relatively fixed contact point substantially about the axis of the relatively movable contact point, and a single spring biasing said pawl against said ratchet and biasing the pawl supporting means against the actuating means.

11. A distributor for ignition systems comprising a housing, a breaker plate carried by said housing, a relatively stationary contact point carried from said breaker plate, a periodically movable breaker arm carried from said breaker plate, a relatively movable contact point carried by said arm in substantially confronting relation to the relatively fixed contact point and movable into and out of engagement therewith, a part of said distributor being movable relative to said housing in accordance with engine requirements for advancing and retarding of spark, means for moving the relatively fixed contact point substantially orbitally about the axis of the other, said last named means including a pawl and a ratchet driven by said movable part.

12. A distributor as set forth in claim 11 wherein the breaker plate is mounted for rotation relative to the distributor housing, and further including a cam on said housing for moving the pawl to effect movement of the ratchet.

13. A distributor as set forth in claim 11 wherein the breaker plate is mounted for rotation relative to the distributor housing, and further including a pin fixed relative to the housing, a pin carried by the breaker plate and movable relative to the housing, a lever pivoted on one of said pins and engageable with the other or" said pins for movement of said lever, and means interconnecting said lever and said pawl for moving the pawl to operate the ratchet in response to relative movement of the breaker plate and the distributor housing.

14. A distributor as set forth in claim 11 wherein the breaker plate is fixed relative to the housing, and further including a vacuum fitting carried from said housing and having means for moving the pawl to operate the ratchet for effecting orbital movement of the relatively fixed contact point.

15. A distributor for ignition systems comprising a housing, a breaker plate carried by said housing and rotatable relative thereto, a relatively stationary contact point carried from said breaker plate, a periodically movable contact point carried by said arm in substantially confronting relation to the relatively fixed Contact point and movable into and out of engagement therewith, a rotatable member eccentrically mounting the relatively about the axis of the relatively movable contact point, a ratchet on said rotatable member for rotatingthe same, a bell crank pivotally mounted on said breaker plate, apawl carried by said bell crank, and means for pivoting said.- bell crank in response to relative movement of the breaker plate and housing for causing said pawl torotate said rotatable member orbitally to move said relatively fixed contact point.

16. A circuit maker and breaker for ignition systems comprising a relatively stationary contact point, a periodically movable breaker arm, a relatively movable contact point carried by said arm in substantially confronting relation to the fixed contact point and movable into and out of engagement therewith, ratchet mechanism for or-- bitally moving the relatively stationary contact point, a-

bell crank, and a pawl pivotally mounted on said bell crank and engageable with said ratchet mechanism upon pivoting of said bell crank orbitally to move said'relatively stationary contact.

17, A distributor construction comprising a housing, a rotary distributor shaft in said housing, a cam on said shaft, a breaker plate pivotally movable about said shaft and having an opening therein, a post in said housing projecting through said opening, a post on said breaker plate, spring means stretched between said posts-and urging said breaker plate in a predetermined direction of pivotal movement, means for pivoting said breaker plate in the opposite direction in accordance with engine requirements to advance or retard the spark, a bell crank 1'2 pivoted about one-of said posts and having a slot in one arm receivingthe' other of said posts, said bell crank thereby being; pivoted in: response to pivotal movement of said breaker plate and consequent relative'movement of said'po'sts, a-breaker point unit mounted on'saicl breaker plate, and means'for connecting lead wires to said breaker point unit, said breaker point unit including a movable arm carrying a relatively movable contact point, a relatively fixed contact point mounted for orbital movement about the relatively movable contact point, a cam follower on said arm engaging said cam for periodically moving said relatively movable contact'point into and out of engagement withsaid relatively fixed contact point, and a=ratchet wheel connected'to said relatively fixed contact point and eccentric relative thereto, the other arm of said bell crauk carrying a pawl engageable-with said ratchet Wheel for moving. saidratchet wheel eccentrically to move said relatively fixed contact point in response to movement of said breaker plate relative tosaid' housing.

ReferencesCited in the file of this patent UNITED STATES PATENTS 2,066,640 Melcher et al Ian. 5, 1937 2,127,957 lveset al. Aug. 23, 1938 2,387,961 Wihanto Oct. 30, 1945 2,569,991 Hofmann' Oct. 2, 1951 2,572,105 Bronstein Oct. 23, 1951 2,634,343 Rainey Apr. 7, 1953