US1338360A - Ignition systelvi - Google Patents

Description

F. CONRAD AND .LS. KINNEY.

- IGNITI ON SYSTEM.

APPLICATION mg!) APR. 19. 19:7.

Patented Apr. 27, .1920.

II. 358,369a

INVENTOR Frank [qnraa Shy/e limney AT TORNEY FRANK CONRAD, OF PITTSBURGH, AND J. STANLEY KIENEY. OF iUILKINSBl J" PENNSYLVANIA, ASSIGNORS TO \KTESTINGEOUSE ELECTRIC 3; MANUFACT" COMPANY, A CORPORATION OF IENNSYLVANIA.

IGNITION SYSTEM.

and it has for'its object to provide an arrangement whereby the currents traversing the, contact members of interrupters shalt be automatically reversed after each operation of the interrupters.

Ignition i-nterrupters as commonly constructed, comprise movable and stationary contact members that are permanently connected to the respective poles of batteries or magnetos, as the case inay be. ilhen the contact members of an interrupter are separated to open the primary circuit, an arc tel lows in which the current always flows from. the one contact member to the other. The result is to cause thcone contact piece to be comepitted because of the surface metal. be ing carried away and to produce projec i on the surface of the other contact me nb because of the metal being, deposited dnrin the existence of an arc. The efificiency ot the interrupter is decreased by the resulting poorelectrical contact between the irregular surfaces of its contact members and the life of the mechanism is correspondingy shortened.

It has been proposed, heretofore, to reverse the electrical connections of the interrupter in order to prevent the abnormal conditions described above but such arrang ments operate to reverse not only the elcctri cal connections of the interrupter but also those of the induction coil and other e ements of the ignition circuit. It has been found that such arrangements possess a number of disadvantages that are eliminated by a system constructed in accordance with our in ention.

A material disadvantage in connection with the arrangements of the prior art resides in the fact that the spark at the electrodes of a spark plug always occurs adja;

cent to the one or the other of the electrodes;

, Specification of Letters Patent.

Application filed April 19, 1917. serial No. 1.8.1722

depending upon the direction ol" the currcnls traversing: t r. primary and the secondary circuits inder.

iacent o 1 li'hen the spark occurs ad largenbmly ot'metal, it is cooled much rapidly. and hence, it ct lower heat hit" sit and of shorter duration than one occurring adjacent to the central. electrode. The reversal of the current through the primarycoii a tter each operation of the inte-= rupter causes a ternate ignition sparks to be oroduced. adjacent to the outer electrode of ll plug. Accordingly, one-half of are oi? less heat intensity than the and uniformity oi operation oi? 3 is not possible. I

' "ll-cill in which the electrical. connections ot the interrupter contact members are ai'atoi'natically rei'ers after eachoperation. 'il tendency to transfer mi from one c. member to the theius neutru. l the result is not only hen the. lie ol." the inter-- :ease its cliiciency during; maintaining substantially the. faces of the contact This arrangement insures that ah oi the sparks shall he ot maximum heat lue and duration.

thcacco 'ipanyi2indraivin Figure l ion, taken on '.e L-li of interrupter constructed in accordance with our invention. the cover be ing ren'ioved. Fig". S2 is a. plan view of the ..ll{!l'llSZll shown i Fig. 1 parts being (en away. 7.

3 is adview partially in elevation and part ally in section, of a lever embodied in the mechanism shown in Figs.

- vention.

- S is of substantially U-shape.

1 and Figs. and 5 are, respectively, side and end views of the lever shown in Fig. 3. Fig. 6 is a plan view of the contact segments constituting parts of the reversing mechanism. 7 is a diagrammatic view of circuits and apparatus embodying our in- Similar reference numerals are employed to designate corresponding parts throughout the drawing.

Referring particularly to Figs. 1 and 2, a stationary member 1, which may be a part either of a magneto or of a direct'current .dynar'noclectric machine, supports a hollow cylindrical member 2 that is adapted for rotative movement relatively thereto. The member 2 constitutes the casing of an interrupter mechanism.

A shaft 3, which may be, for example, the armature shaft of a dynamo-electric machine, carries the rotatable portion of the interrupter mechanism. A sleeve 4, which surrounds a reduced portion of the shaft 3, is integral with a disk or plate member 5. A stationary contact member 6 is mounted upon, and insulated from, the disk 5.

A movable contact member 7, which coacts with the stationary contact member, is carried by a lever 8 that is pivotally mounted, at an intermediate portion, upon a pin 9. A spring 10, which is connected, at one end, to a stationary member 11, is connected, at the other end, to a bar 12- that is rigidly se cured to lever 8.

The memliier 11 has an integral projecting portion 13 which extends adjacent to one end of the lever 8. A strip of leather 14, that is slightly wider than the projecting portion 13, is provided with two transverse slits near its respective ends through which the pro jection may be inserted. The leather strip is placed on the projection 13 in such manner that the intermediate and end portions of the former are respectively upon opposite sides of the latter. The leather strip may be retained in position by cement, shellac or other suitable adhesive material. The intermediate portion of the strip 14, which is parallel to the projection, forms a resilient stop for the lever 8.

Reference may now be had to Figs. 3, 4.- and 5, in which the lever member 8 is illustrated. As shown in Figs. 2 and 4;, the lever It comprises two side members 15 and 16 that may be punched from any suitable sheet material,

such, for example, as steel. Corres ending 16 are end portions of the members 15 an bent at right angles to the plane of the members in opposite directions. These projecting portions are of such length as to overlap each other, as shown in Figs. 3. and 5. The

movable contact member 7 is then riveted or otherwis utably fastened to these portions. T- .te end portions of the members which are also bent inwardly,

are of such length that a small space separates them. A block 17, of suitable insulating material, such, for exam 1e, as fiber, is rigidly secured to the mem ers 15 and 16, between their end portions, by suitable means, such, for example, as rivets or pins 18. The bar 12, to which the spring is connected, extends between the side members and 16 and is riveted to these members at its respective end portions.

As best shown in Fig. 1, the intermediate portions of the side members 15 and 16 are connected by a tubular shoulder in 20, the end portions of which are rivete in a suitable manner. A bearing sleeve 21, which is within the shoulder pin 20, is of insulating material. Insulating washers 22 and 23 are at each end of the pin in order to effectively insulate the latter from its supporting means.

he means for reversing the electrical connections of the interrupter contact members 6 and 7 comprises a pair of contact segments 24 and 25, shown in Fig. 6, that are secured to the disk 5 and insulated therefrom. The ends of the contact segments 24 and 25 are separated b smaller segments 26, for a purpose to be later described. The contact segments 24 and 25 are respectively electrically connected to the interrupter contact members and 7. The contact segments 24 and 25 coact with a pair of stationary brushes 27 and '28, only one of the brushes appearing in Fig. 1.

The member 1 is provided with a chamber 29, within whichis located a condenser 30. The chamber 29 communicates with'the interior of the casing member 2 by means of an opening 31 in the base member 1 and a notch or slot 32 in the casing member 2. This arrangement provides that a conductor may extend from the condenser 30 to the brush 28 to electrically connect these parts.

The stationary portion of the interrupter comprises two cams 33 that are located diametrically o posite to each other within the casing mem r 2 andare ri idly secured thereto. The cams 33 are wit in the path of movement of the block 17 of insulati material and efi'ect,the disengagement o the contact members twice during each revolutionof the shaft 3. The time at which the sparks occur in the several engine cylinders may be adjusted by means 0 an arm 34, only a portion of which. is shown, that controls the .angular position of casing 2 '7, lever the, several contact segments of the distribQ uter 38.

it may be assumed that the shalt 3 is rotating in coimter-clockwise direction, Fig.

2, and that the various parts are in their respective positions in which they are illus-.

trated, Fig. 2. The contact members (3 and 7 are in engagement and the fiber block 17 occupies .a position between the cams with which it coacts. it may be assumed,

further, that the brushes 2? and respectively e gage the contact segments 2-1 and t urrent then traverses the primary circuit oi the ignition system winch extends from the battery 35, through the primary Winding 36 of the induction coil, brush 28, contact segment 25, contact members (i and i 8, spring ll), contact segment 2%, brush 2?, which is grounded, and thence to the other terminal of the battery which is also grounded.

l l hen the bearing block 17 the inclined end portion of one of the cams 33, the lever B is moved about its point of pivotal support to separate the contact members ii and 7 and thereby open the primary circuit traced above. An electromotive :t'orce of high value is inducted in the secondary circuit, and a. spark occurs across the terminals of the spark plug 39 that is connected to the rotatable contact member of the distributor 3S.

Further rotation of the shaft 3 and the mechanism carried by it causes the Contact z-seginents 2 and to be disengaged from the respective stationary brushes 2 and 28 and to respectively engage the other brushes. The segments :26, which are between the end portioi'is ot the contact segments 2% and 25, are not elect -ically connected to any of the elements oi the ignition system. inserted for the purpose ot'providing a. con tinuous surface for the brushes 2? and 28 and for insuring that the brushes may be entirely disconnected from the segments 24 and 555 during the period of reversal of the connections.

The primary circuit is again closed at contact members 6 and '5' when the bearing blocii 1'! moves oil? the min 33 with which i is; in engagement. Current then flows the opposite direction through that pori oi primary circuit which is he- ;wecn the brushes 27 and 28. W hen the They are r block 17 engages the second cam 32) lo cll'ect the disengagement of contact members (3 and 7,'the arc which follows between the contact memb -rs (5 and T will be produced by a eurrent having a direction opposite to that of the preceding arc, and an opposite eli'ect will thereby be produced upon the respective interrupter contact members.

The point in the engine strokes at which the various sparlis occur may be adjusted,

as; desired, by \ill'Xillgf the angular position ol the cams 33 to cause the block 17 to engage them earlier or later.

The arrangement constructed in accordance with our invention possesses a number of advantages. The life of the mecbanism is materially i'irolouged by periodically reversing the direction of the current through the interrupter contact members. is pre-' viously set forth, therevcrsing oi' the cuz rent through the interrupter contact mem bers does not, in any way, all'ecl. llie elii r-iency of operation since the polarities ol' the spark plugs are unchanged.

The 'arious parts of the interrupter mechanism are: simple in construction and few in number. The movin parts are oi relatively small weight in omer that they may oscillate with great rapidity in case they are used in connection with engines which operate at high speeds. The iuterrupter lever is so arranged as to possess great strength while it is composed oi relatively light materials. The above and other advantage, will be apparent to those Bill in the art to which our inwutioii up tains.

lVe claim as our invention:

1. In an inttu'rupter, the combination with a pair of relatively movable contact mcm-" hers, of a lever for actuating one oi said contact members, said lever comprising two plate members having rigidly connected end portions, to which one contact member is secured and a pivot upon which the lever is mounted having its axis transvt-irse to l planes of the main portions of the plate members.

2. In an interrupter, the combination with a pair of relatively m fable contact members, of a. lever for actuating one of said contact members, said lever comprisiugtwo substantially similar members having bent overlapping end portions that are rigidly connected, and form a support for one of said contact members, a member for pivotally supporting said lever, and a spacing member between. said lever members and surrounding said supporting member.

3. in an interrupter, the c mibinatioii with a pair oi relatively movable costar members, of a lever for actuating one of said contact members, said lever comprising two rigidly connected plate members arranged in parallel relation and spaced apart, bar exill) tending between said plate members, and a sprin secured to said bar.

'4. 11 an interrupter, the combination with apair of relatively movable contact members of a lever for actuating one of said contact members, said lever comprising two plate members having bent end portions to which said one contact member is secured, and a pivot upon which the lever is mounted having its axis transverse to the planes of the main portions of the plate members.

5. In an interru ter,the combination with a pair of relative y movable contact members, of a lever for actuating one of said contact members, saidl lever com rising two plate members, a block of insu ating material between said plate members and secured thereto at one end thereof, and a member movable relatively to said block for coacting therewith.

6. In an interrupter, the combination with a pair of relatively movable contact mem bers, of a lever for actuating one of said contact members, said lever com rising two plate members spaced apart an connected.

at their respective end portions, means for pivotally supporting said lever, a block of insulating material secured to said lever at one end thereof, and means coacting with said block for actuating said lever.

7. In an interru ter, the combination with a pair of relative y movable contact-members and a lever for actuating one of said contact members, of a sprm connected to sald lever, and a member or supporting said spring having an inte ral pdrtion for constitutin a stop for said lever.

8. In an interru ter, the combination with a pair of relative y movable. contact members and a lever for actuatin one of said contact members, of a stop -or said leverstationary brushes for successively engaging the respective contact segments.

10. In an interrupter, the combination with a rotatable member and a pair of relatively movable contact members carried thereby, of a pair of contact segments carried by said rotatable member and electrically connected to said contact members, and a pair of stationary brushes for successi'vely engaging the respective contact segments.

In testimony whereof we have hereunto subscribed our names this 3rd day of April, 1917.

' FRANK 'UONRAD.

J. STANLEY KINNEY.

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