US3819884A - Multiple contact ignition interrupter assembly - Google Patents

Abstract

AN IGNITION INTERRUPTER ADAPTED TO CAUSE A SUCCESSION OF A PAIR OF SPARKS FOR EACH GAS CHARGE IN EACH CYLINDER OF AN INTERNAL COMBUSTION ENGINE, INCLUDES AN ARM PIVOTALLY MOUNTED ON A MOUNTING PLATE, A STATIONARY CONTACT MOUNTED ON THE PLATE AT THE FRONT SIDE OF THE ARM, A FIRST MOVABLE CONTACT MOUNTED ON THE FRONT SIDE OF THE ARM OPPOSITE THE STATIONARY CONTACT, A SECOND MOVABLE CONTACT MOUNTED ON THE REAR SIDE OF THE ARM AND ELECTRICALLY CONNECTED TO THE FIRST MOVABLE CONTACT, A THIRD MOVABLE CONTACT POSITIONED OPPOSITE THE SECOND MOVABLE CONTACT TO THE REAR OF THE ARM AND SLIDABLY MOUNTED WITHIN A HOUSING FIXED TO THE MOUNTING PLATE, THE THIRD MOVABLE CONTACT BEING ELECTRICALLY CONNECTED TO THE STATIONARY CONTACT, A CAM ROTATABLY MOUNTED ON THE PLATE, AND A FINGER MOUNTED ON THE FRONT SIDE OF THE ARM FOR FOLLOWING THE CAM TO CAUSE THE ARM TO PIVOT RECIPROCATIVELY FORWARDLY AND REARWARDLY SO THAT THE STATIONARY CONTACT AND THE FIRST CONTACT ARE CAUSED TO ENGAGE ELECTRICALLY TO CAUSE THE PRODUCTION OF A FIRST SPARK DURING A FORWARD MOTION OF THE ARM AND THE SECOND AND THIRD CONTACTS ARE CAUSED TO ENGAGE ELECTRICALLY TO CAUSE THE PRODUCTION OF A SUBSEQUENT SPARK DURING A REARWARD MOVEMENT OF THE ARM. A FIRST SPRING FIXED TO THE MOUNTING PLATE URGES RESILIENTLY THE FINGER FORWARDLY INTO ENGAGEMENT WITH THE CAM, AND A SECOND SPRING MOUNTED WITHIN THE HOUSING URGES RESILIENTLY THE THIRD MOVABLE CONTACT FORWARDLY INTO A FORWARD POSITION TO ABUT THE SECOND CONTACT DURING THE REARWARD MOTION OF THE ARM, THE CAM BEING ARRANGED TO CONTINUE TO DRIVE THE ARM AGAINST THE FORCE OF THE SECOND SPRING AFTER THE SECOND CONTACT ENGAGES THE THIRD CONTACT.

Description

United States Patent [191 Janci 1 1 MULTIPLE CONTACT IGNITION INTERRUPTER ASSEMBLY [76] Inventor: John Janci, 1125 N. Karlov Ave,

Chicago, Ill. 60651 [22] Filed: Dec. 13, I972 [2]] Appl. No.: 316,262

Primary E.raminer.l. R. Scott Attorney, Agent, or Firm-John C. Brezina et a1.

[57 1 ABSTRACT An ignition interrupter adapted to cause a succession of a pair of sparks for each gas charge in each cylinder of an internal combustion engine, includes an arm pivotaJly mounted on a mounting plate, a stationary cont- [11] 3,819,884 1 1 :June25, 1974 act mounted on the plate at the front side of the arm, a first movable contact mounted on the front side of the arm opposite the stationary contact, a second movable contact mounted on the rear side of the arm and electrically connected to the first movable contact, a third movable contact positioned opposite the second movable contact to the rear of the arm and slidably mounted within a housing fixed to the mounting plate, the third movable contact being electrically connected to the stationary contact, a cam rotatably mounted on the plate, and a finger mounted on the front side of the arm for following the cam to cause the arm to pivot reciprocatively forwardly and rearwardly so that the stationary contact and the first contact are caused to engage electrically to cause the production of a first spark during a forward motion of the arm and the second and third contacts are caused to engage electrically to cause the production of a subsequent spark during a rearward movement of the arm. A first spring fixed to the mounting plate urges resiliently the finger forwardly into engagement with the cam, and a second spring mounted within the housing urges resiliently the third movable contact forwardly into a-forward position to abut the second contact during the rearward motion of the arm, the cam being arranged to continue to drive the arm against the force of the second spring after the second contact engages the third contact.

4 Claims, 2 Drawing Figures ASSEMBLY The present invention relates to an ignition interrupter, and it more particularly relates to an interrupter for ignition systems to cause a plurality of sparks to be supplied to each gas charge in each cylinger of an internal combustion engine.

Ignition interrupters having multiple sets of contact points have been provided for causing a plurality of sparks to be supplied to the cylinders of an internal combustion engine. Several types of such mechanisms have been employed, but they have been unnecessarily and unduly complex in nature. For example, reference may be made to US. Pat. Nos. 2,674,663; 2,685,622; 2,713,096; 2,854,534; 2,94l,049 and 3,319,0l8. In each of the foregoing patents, there is disclosed an ignition interrupter which includes a plurality of sets of contact points and a plurality of arms for actuating the contact points. For example, in US. Pat. No. 2,674,663 there is disclosed a pair of spaced-apart stationary contacts, and a pair of pivotally movable arms each having a movable point mounted thereon for moving alternately into engagement with the two corresponding stationary contacts under the control of a cam and a cam follower. The cam is a polygonal cam, and in order for the pair of contacts which close when the cam follower approaches the point of the cam, the arm carrying the movable contact of such pair of contacts is made flexible so that as the camfollower approaches the point of the cam, the flexible arm bends so as not to damage the contacts as the follower continues to move toward a point of the cam. A device is provided for connecting the two arms together so that they can readily move toward one another during the bending of the flexible arm, but they are restrained from moving apart when the flexible arm moves in the reverse direction as the cam follower moves past the point of the cam. Therefore, it would be highly desirable to have an ignition interrupter which is efficient in operation and simplified in construction.

Therefore, the principal object of the present invention is to provide a new and improved ignition interrupter, which causes a plurality of sparks to be supplied to each combustible mixture in each engine cylinder, and which is efficicnt in operation and simplified in construction.

Briefly, the above and further objects are realized in accordance with the present invention by providing an ignition interrupter having a single arm pivotally mounted on a mounting plate, a stationary contact mounted on the plate at the front side of the arm, a first movable contact mounted on the front side of the arm opposite the stationary contact, a second movable contact mounted on the rear side of the arm and electrically connected to the first movable contact, a third movable contact positioned opposite the second movable contact to the rear of the arm and electrically connected to the stationary contact, a slide mounted within a housing fixed to the plate for mounting slidably the third movable contact on the mounting plate, a cam rotatably mounted on the plate for moving a finger mounted on the front side of the cam to cause the arm to pivot reciprocatively forwardly and rearwardly so that the stationary contact and the first contact are caused to engage electrically during a forward motion of the arm and the second and third contacts are caused to engage electrically during a rearward motion of the arm. A first spring mounted on the mounting plate urges resiliently the finger forwardly into engagementwith the cam, and a second spring urges resiliently the third movable contact forwardly into a forward position to abut the second contact during the rearward motion of the arm, the cam being arranged to continue to drive the arm against the face of the second spring after the second contact engages the third contact. As a result, only a single arm is provided in accordance with the present invention, and a mechanism is provided to adjust the tension on the second spring to thereby facilitate adjustment of the interrupter mechanism.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following detailed description taken in connection with the accompanying sheet of drawings, wherein:

FIG. 1 is a front elevational view of the ignition interrupter constructed in accordance with the present invention, showing the contact arm in a first position; and

FIG. 2 is a front elevational view of the interrupter similar to FIG. 1, but showing the arm in a second position.

Referring now to the drawings, and more particularly to FIG. 1 thereof, there is shown an ignition interrupter 10, which is constructed in accordance with the present invention, and which is adapted to control an ignition system to supply a pair of sparks sequentially to each gasoline-air mixture charge in each cylinder of an internal combustion engine (not shown). The interrupter generally comprises an arm 12 pivotally mounted at 14 to a mounting plate 16 and has a finger or cam follower 18 which is pressed into engagement with an octagonal cam 20 which in turn is rotatably driven by the cam shaft 22 of the engine. A leaf spring 24 urges the arm 12 and thus the finger 18 into engagement with the cam 20, and the distal end portion of the arm I2 carries a pair of movable contacts 24 and 26 on opposite sides thereof to cooperate with a pair of spaced- apart contacts 28 and 31.

For the purpose of enabling the contact 31 to be movable relative to the plate 16 to permit the arm 12 to continue to pivot rearwardly after the contacts 26 and 31 engage one another as shown in FIG. I, a coil spring 33 mounted within a housing 35 fixed to and electrically connected to the mounting plate 16 resiliently urges forwardly a rodlike slider 37 having the movable contact 31 fixed to its outer end. As a result, as the arm 12 pivots rearwardly after the contacts 26 and 31 engage, the cam 20 continues to drive the arm 12 rearwardly and the spring 33 compresses to permit the arm to continue its rearward motion. After the arm 12 reverses its motion under the control of the cam 20 and commences its forward motion, the spring 33 expands to cause the contacts 31 and 26 to remain in engagcment with one another until an enlarged internal end portion or head 37A engages an annular shoulder 38 of the housing 35. Thereafter, the contacts 26 and 31 move apart.

Considering now the interrupter 10 in greater detail with reference to the drawings, the ignition interrupter 10 of the present invention is disposed in a distributor 39 having a circular support plate 40 on which is secured the mounting plate 16 fixed thereto by two screws 42 and 44 extending through respective elongated slots 46 and 48 and threaded into engagement with threaded holes (not shown) in the support plate 40. The mounting plate 16 is adjustably mounted on the support plate 40 to permit adjustment of the position of the contacts by permitting the plate 16 to be adjusted positionally relative to the support plate 40, whereby such an adjustment varies the timing of the closing of the contacts. An upstanding car 51 of the grounded mounting plate 16 supports and is electrically connected to a stud 53, which is fixed to the stationary contact 28. It should be understood that the movable contact 26 connect via the housing 35 to the plate 16 and the contact 28 are both connected electrically to the grounded plate 16. An upstanding car 55 of the plate 16 carries an insulated bushing 57 extending through an opening in the car 55 and supports'a bolt 59 extending therethrough to serve as a terminal post for a terminal 60 of a cable 62 electrically connected to the coil (not shown) of the ignition system, the terminal 60 having a hole (not shown) therein for receiving the bolt 59 between a nut 63 threaded onto the bolt 59 against the bushing 57 and a nut 64 threaded onto the bolt 59 against the terminal 60. The end portion of the spring 24 is apertured to fit over and receive the bolt 59 between the nut 63 and the bushing 57 to connect electrically the arm 12 to the terminal 60 and to mechanically secure the spring 24 to the plate 16. The arm 12 is insulated by an insulating washer (not shown) from the plate 16, and the opposite end of the spring 24 is connected mechanically and electrically to the arm 12, the cam being composed of insulating material so that the arm 12 and its movable contacts 24 and 26 are electrically connected via the spring 24 to the terminal 60 and are insulated from the grounded plate 16.

An upstanding car 66 is apertured to receive and support the housing 35 which includes an externally threaded tubular member 68 extending through the opening in the car 66 and held in place by a pair of nuts 71 and 73 threaded onto the tubular member 68 on opposite sides of the car 66 and tightened thereagainst. The enlarged internal end 37A of the slider 37 has a boss 77 for seating the end portion of the spring 33 and is adapted to engage the internal shoulder 79 of the tubular member 68 to limit the extent of the outward movement ofthe slider 37, the annular shoulder 79 surrounding an opening in the end of the tubular member 68. At the opposite end of the tubular member 68 a plug 82 has an externally threaded shank portion 84 threaded into the internal threaded interior chamber or compartment of the tube-like member 68 for adjusting the tension of the spring 33, thereby adjusting the spacing between the contacts 31 and 26. An enlarged external head 86 of the plug 82 is slotted to facilitate the adjustment thereof. It should be understood that gross adjustments of the housing 35 may be made by adjusting its position relative to the ear 66 by in turn adjusting the nuts 71 and 73, and a fine adjustment may be made by the plug 82.

As the cam 20 rotates in a counter-clockwise direction, the arm 12 is first moved to a position where the finger 18 is near a low surface on the cam 18 and the contacts 24 and 28 engage as shown in F IG. 1 to cause subsequently a first spark to be generated by the ignition system for igniting a gas charge in a cylinder. The first spark is generated when the contacts 24 and 28 separate. Thereafter, the finger l8 follows the cam toward a point thereon. and in so doing, as shown in FlG.- 2, the arm 20 pivots backwardly and the contacts 26 and 31 engage to cause the generation of a second spark subsequently thereto for the same cylinder to insure proper and complete combustion of the gas charge contained therein. The finger 18 continues to move along the cam to the next point thereon and then past the point toward the next low surface, and in so doing the arm 12 is driven backwardly against the force of the spring 33 and then moves forwardly under the force of the spring 24 while the spring 33 maintains the contacts 26 and 31 in interengagement until the end portion 37A abuts the shoulder 38. The second spark is generated when the contacts 26 and 31 separate. 1n the preferred embodiment, the cam and the other parts of the interrupter are arranged such that the second spark follows the first one by a time interval, which includes a coil build-up time interval sufficient to permit a field to be established in the coil of the ignition system for causing subsequently the second spark. The build-up time of the coilfor the second spark is determined by the length of time between the make and the break of the contact points 26 and 31.

While the present invention has been described in connection with a particular embodiment thereof, it will be understood that many changes and modifications of this invention may be made by those skilled in the art without departing from the true spirit and scope thereof. Accordingly, the appended claims are intended to cover all such changes and modifications as fall within the true spirit and scope of the present invention.

What is claimed is:

1. An interrupter for an ignition system, comprising:

a mounting plate;

an arm pivotally mounted on said plate;

a stationary contact mounted on said plate at the front side of said arm;

a first movable contact mounted on the front side of said arm opposite said stationary contact;

a second movable contact mounted on the rear side of said arm and electrically connected to said first movable contact;

a third movable contact positioned opposite said second movable contact to the rear of said arm and electrically connected to said stationary contact;

mounting means for connecting slidably said third movable contact to said mounting plate;

cam means rotatably mounted on said plate;

a finger mounted on the front side of said arm for following said cam to cause said arm to pivot reciprocatively frontwardly and rearwardly so that said stationary contact and said first contact are caused to engage electrically during a forward motion of said arm and said second and third contacts are caused to engage electrically during a rearward motion of said arm;

first spring means mounted on said mounting plate for urging resiliently said finger forwardly into engagement with said cam; and

second spring means for urging resiliently said third movable contact forwardly into a forward position to abut said second contact during said rearward motion of said arm, said cam being arranged to continue to drive said arm against the force of said second spring means after said second contact engages said first contact.

mounting means further includes a retaining plug extending within the back end of said chamber for retaining said second spring means therein, said plug being adjustably positioned within said chamber to adjust the tension on said second spring means.

4. An interrupter according to claim 3, wherein said plug is externally threaded and said chamber is internally threaded to receive threadably said plug for adjustment purposes.

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