US1415370A - Circuit controller for ignition systems - Google Patents

Description

J. H. LEHMAN.

CIRCUIT CUNTROLLER FOR IGNITION SYSTEMS.

APPLIcMIou flLtD fzs. 2s. 191s.

1,415,370. Patentd May 9, 1922.

nains-snaar l.

- /N vE/vron M d! a r 5W ATTORNEY I. H. LEHMAN. cmcun CONTROLLER ron mnmon svs'rgms. APPLICATION FILED FEB. 26. HI8.

2 SHEETS-SHEET Z.

/NI/ENTUI? ATTORNEY unirsi) STATES PATNT' orifice.

CIRCUIT CONTROLLER. IGNITION SYSTEMS.

speeiaeatien of Leiters raient.

Patented May 9, 1922.

application inea February. 26,1918. serial ne. 19,229.

To all whom it may concern.:

Be it known that I, Josemi H. LiziiiuAN,

a citizen of the United States, and resident i of Hasbrouck Heights, in the county of Bergen and State of New Jersey, have iiivented certain new and useful Improvements in Circuit Controlleis for Ignition Systems,

of which the following is a specification.

This invention is primarily adapted for use in a combined timer and distributor for effecting the makeandbreak of the primar) or battery circuit and the distribution of the induced secondary or high-tension current to the spark plugs or other igniters of an internal combustion engine. although certain features may be used separately in timers, distributors, or other circuit controllin devices.

n my prior Patent No. 1.251.245). issued December 25, 1917, I have illustrated and broadly claimed a construction in which the polarity of the make-and-break contacts of the primary circuit is reversed during' each rotation so as to avoid pitting the contact faces, to effect the complete discharge or collapse of the coil, and to secure other advantageous results. My present invention in 'certain of its embodiments involves means for effecting said intermittent polarity reversing by a simpler, cheaper and equally if not more elective mechanism. 4

The body or casing has connected to it the terminals of conductors leading to tliebnttery and the several spark plugs :ind it is usual to advance' or retard the spark by a rotary movement of the body or casing. This results in a continual tendency of the conductors to become loosened or disconnected :it said, terminals. By means of my invention such relative movement of the casing and conductors is rendered unnecessary and is avoided, and the objection referred to above. in regard to loosening, is obviated. In certain embodiments of my present invention, I. am able to secure this result even f though the polarity reversing feature be omitted. 4

A further important feature of my invention results in such a designing and arrangement of the parts that they maybe very easily and quickly separated for repair, replacement or cleaning. The interrupter or make-andbreak device may be disconnected upon the removal of a single fastening member and replaced by other designs. A substitution of interrupter may change the device from a normally? open circuit one to a normally closed circuit one, or vice versa.

A further important feature of my invention enables me to use stamped or pressed sheet material such as sheet metal for the cover orcasing'portion to which the secondary circuits are connected. This facilitatesstandardization and greatly increases the d urability and permits the quick and easy interchange of the small inexpensive insulation members in case they become defective or broken.

Many other'important features of my in` ventionwill 'be referred to hereinafter in connection with a detailed description of certain specific embodiments thereof. In cer-- tain respects, my present invention is an improvement on that'shown in my prior application Serial No. 199,242, and it may be used in connection with certain features of the invention shown -in my Patent No. 1,311,902, issued August 5, 1919.

In the, aocompanyin drawings, to which referencejs to be had, have illustrated cer.-. tain embodiments of my invention, but yit will of course be understood that these are Vto be considered in an illustrative rather.

than in a limiting sense,l and that various changes, rearrangements and substitutions may be effected within thescope of the Vappended claims without departing from the spirit of my invention, In these drawings,

Figure 1 is a central longitudinal section through a complete device;

Figure 2 is a transverse secton on the lines 2-2 of Figure 1;

Figure 3 is a plan view of the nterrupter housing or collar;

Figure 4 is a top plan v iew of the main body or casing;

Figure 5 `is :i central, longitudinal section through the body with the interrupter housing4 or collar in position, the view being taken substantially on the line 5-5 of Figure 4 and at right. angles to the plane of Fi ure 1';

igure 6 is a side elevation of the current interrupter or make-andbreak device;

Figure 7 is a perspective view of the lock` ing key and operating handle for the inter' Figures 9 and 10 are side elevations` show- [lange 18., for supporting ing forms in whichconstant polarity current may be delivered to the contacts of the interrupter.

In the main illustrated embodiment of my invention, Irprovide a body' or casing member 104 an'da cover member 11, both preferably' formed of metal and adapted to carry and protect the -various moving parts. The 'casing or bod' 10 may be, formed of cast iron and inclu es a-.de'pending sleeve 12 constituting a bearing for the main shaft 13. rThis sleeve may extend through and be carried by afclamping collar 14 and the latter may have fa split'lportion with outwardly extending, spaced win 15 which may be drawn together by a amping bolt to rigidly hold the body in position. The 4clamping collar or support 14 may be secured to the engine frame or to' any other suitable member in any' desired manner, but preferably so as to leave a, pinion- 16 on the lower end of the shaftlltexposed for engagement with agear on the ca'm shaft or other driven part of the engine. Dbviously, the means forl transmitting power to the shaft 13 to insure the proper speed, of rotation of the latter forms no portion of my present invention.

At the upper end of the sleeve 12, the bodv has 'a dished or cup portion 17 serving to receive the rotating part of the interrupter. The upper edge ofV this cup constitutes a the interrupter housing or collar, while t e peripheral wall of `the cup has the terminals and brushesV for conducting the current to and from the interrupter. I Outside of this flange 18 is l a second upstanding collar or flange 19, substanti'ally-concentric therewith and to which is secured the cover 11 which forms the upper half of'the casing.

The shaft 13 projects upwardly through the 'cup portion 17 coaxialA therewith and the portion 20 0f the shaft above the lower or bottom wall of the cup portion is pref` erably of reduced diameter. Rigidly clamped on' this reduced portion 20 is a head or disc 21 of insulation material'which carries the relatively movable contacts of the interrupter. The head 21 may seat on a collar orwasher 22 which latter mav seat on ashoulder at the lower end of the re` duced portion 20 of the shaft, and these parts may be rigidly secured together by a nut 23 threaded on the sha't as indicated partielllarly in Figure 1. Tc prevent rotation of the head 21 on the shaft,the reduced portion of the latter may` be flattened at one side, as indicated in `Figure 2, or may be keyed vin any other suitable manner.

The head or disc 21 has embedded therein or secured thereto two semi-circular collector ring sections 24 and 25 insulated from each other. These are shown as being in the same transverse planeon the periphery and haxYA ing their peripheral surfaces in arcs of the her 28 which may be adjusted slightly in position fby means of its supporting screw. The contact member 29 is carried by a spring` metal leaf 30 secured to the post 27 -which extends up .from the collector ri/ 25.

Mounted on an upwardly extending pivot 32 is ay bell-crank lever 33 normally -retained in the position indicated in Figure v2 by a spring34 and a pair of stops 35 and 36. The outer end of this bell-crank lever, when operated by engagement with the interru ter housing or col ar, as hereinafter descri d, moves about its pivot and effects a correspending movement of a hoo spring 37 sex cured to and carried by the-contact carryingr spring 30. Thus, the contacts 28 4and 29 are permitted to come together and Separate to make and break the current during rotation of the head or disc 21 and the parts carried thereby. The bell-.crank lever itself may be of insulation material so'that its c0ntact with the spring 37 does not result in any loss or short-circuiting of the current, or the lever, if made of metal, may havean insulation face 38.

The parts of the interrupter as above described embod certain advanta es so far as simplicity, reliability and\durab11ity are concerned, but so far as certain other aspects of iriy invention are concerned they may be replaced by the construction shown in Figure 2 of my prior application Serial No. 199,242,

or Figures 7 or 9 of my5 Patent 1,311,902, or other forms may be used.

The interrupter housing or collar in its preferred form is shown separately' in `igure 3. This includes a split ring 40 of slightly reduced diameter adjacent to its upper edge so that it may be contracted, lowered into position within tleliange 18 and thenl permitted to expand and fit beneath a shoulder 41 on the flange 18 as shown particularly in Figures 1 and 5. In this position, the collar is free to oscillate but cannot move axially. The inner surface of the collar or housing presents a plurality of projections or surface irregularities 42 equally spaced and corresponding in number to the desired number of current interruptions per revolution of the rotary member including the shaft 13 and the parts carried thereby.

In the specific form illustrated, the device is adapted for use in a four-cylinder engine and there are therefore four-of these projections. They are of such form` shape and position that as tlieinterruptcr head 2l ro nently in position. To better insure againsttates, the outer tip end of the bell-crank lever 33 comes into contact with these projections in succession and/effects successive relative movements of the contacts 28 and 29. The projections intercept the path of the lever 33 to onlyAa-"slight extent so that the relative movement of the contacts is small and the end of the lever may slip past each projection after being moved about its pivot to a limited extent by such engagement.`

.The timing of the spark may be advanced or retarded by an oscillation of this interrupter housing. Although this oscillation is preferably in res ect -to'.the main casing member, the latter ing stationary,'the same oscillation may be secured by turning the two tofgether if theybe rigidly connected. For e ecting such oscillation, a portion of the flange 18 is Ashown as cut away and a slot is formed through the wall of the bod)r -orcasing 10. .As illustrated, this slot 43 is through the bottom wall of the casing closely adjacent to the ange 18 or registering with the break in the latter, An operatlng member -44 projects up through this slot and has a transversely extending Vportion 45 which may be rigidly secured to the vouter surface of the interrupter housing. As

shown, this transverse portion is adapted to be secured by a pair of screws entering the interrupter housing at opposite sides of the gap in the latter so that when the operating member is secured to the housing, the latter is locked in expanded form and permacontraction of the split ring forming the interrupter housing, a portion 46 of the operating-member maybe punched out, as indicated in Figures 5 and 7, to enter between the ends of the housing. This may, in some constructions, permit of the elimination of the locking screws or, in any event, hold the parts together even though the screws should loosen or fall out. The lower end of the operating member 44, which projects to the exterionof the casing, as indicated in Figure I 5, may be connected to an operating rod in a variety of dierent ways. As shown, the lower portion is offset to space it away from the peripheral wall of the cup portion 17,

`although this is not of particular conseends of the'attaching portion, when engag;

ing with the ends of the Harige 18, whic seats the interrupter housing` may constitute stops for limiting the oscillatory movement of the housing. (ln the other hand, the length of the slot 43 may constitute the limiting'means.

For delivering current to the collector ring plete revolution.

` sive sections 24 and 25 of the nterruptenl provide a pair of brushes ,50 and 51A at diametrically opposite points. If the collector ring sectionsl be on the periphery of the head as illustrated, the brushes are in radial position but if the ring sections be on the under surface 'of the head as in my prior Patent No. 1,251,249, the brushes would fade upwardly as there shown. These brushesmay be of any suitable character similar to those used in connection with commutators and are resiliently pressed toward and` into enga ement witli/ the/ ring sections 24 and 25 Itiny suitable s rings v52. Each brush is illustrated as being` guided in a metal or other conductin sleeve 53 and each sleeve is 'carried in an supported by a sleeve or tube 54 of insulation'material.. i

The peripheral wall of the cup .portion 1() ofv the casing has diametrically opposed apertures 55 in which these brush supports are inserted and outside of each aperture and depending4 from the wall of the' casing between 'the' flanges 18 'and 19 are split clamping collars V56,"one of which is shown particularly'in Figure 5 in dotted lines. By drawing togethertthe flanged ends of the `collar sectionsby -a clamping lbolt or screw,

the brushes and their. supports may be rigidlyclamped in position. They may be very quickly and easily removed for cleaning, repair or replacement of the parts.

he conductors from the battery terminals may be electrically connected to the brushes 50 and 51 in any suitable manner. As shown, there are screws 457, beneath the heads of which the wires may be clampedwhich have their inner ends extending into and electriv cally connected to the metal guiding sleeves 53 for tlie brushes.

As the rotation of the interrupter headr bringsl first one` collector ring section and -then the other into engagementwith each Vlbrush, and as the polarity of the brushes remains constant, it will be noted that the 11'0 polarity of the collector rings is reversed twice during each completejrotation of the interrupter head. As the polarity of the collector- ,rings is always the same as that of the corresponding contacts 28 and 29, 116 it will be apparent that the polarity of these contacts is also reversed during each com- Thus, as the direction of current flow between the contacts is `reversed at regular intervals, I avoid any pitting of the contact faces suchas results from a continuous How in one direction. Contrary to the usual practice, it is possible, with my improved construction, to form the u per casing section or cover of inexpenlint rigid stamped sheet material. As the contacts are insulated from it, it may lic of sheet metal. The cover 11 serves to support the terminals of the secondary circuit which correspond in number and general 'position vto the usually acepted practice. Each secondary terminal is in the form of a rod 60 constituting a metal conductor .and

is provided at its innerend with a head 61 with which a distributer brush 62 may cooperate. Therodl'O has an insulation block 63 thereon above the head 61 andextending through an aperture in the cover. This block presents a shoulder for engagement with the Yinner surface of the cover.

A. second insulation block 64 telescopes with the upper end of the block 63 and enages with the outer surface of the cover.

y tightening a nut 65 on the conductor rod, the parts are rigidly secured together and the rod is held properly insulated from the cover.` This construction permits"the use of 'inexpensive yinsulation blocks, as, for instance, pieces of porcelain and ermits of the quick and `easy replacement o any block in case it becomes broken or defective.

v the latter is To properly insure the accurate centering of the terminals and toavoid the necessity of having the insulation block 63 accurately fitting the corresponding hole in the cover, referably provided `with a se riesof annu ar beads or ridges 66 concentric with the several holes and presenting inclined surfaces with which one of the blocks may register. As shown, these beads extend upwardly and form a seat for the block 64 so as to accurately center the latter. This is -a desirable but not an essential feature and the bead may be omitted or may extend inwardlyforengagement with the; block -63 instead of outwardly. I

The .upper .end of the shaft 13 carries aY distributor head 67 which is of insulation material andmay he of any construction common in the art. As shown, the brush mernber 62 is secured tothe upper side thereof and has itsY extremity in position to engage with or passin operative position in respectto the heads 61 on the conductor bars 60.' The-brush has a spring 68 which constantly engages with the central contact 61 sothat as the head rotates this is connected to the contacts of the annular series in succession.

As the casing sections'10 and 11 are both formed of metal, they are not only ldurable but may be constructed with great accuracy andy be freely interchangeable. Various means may befemployed for connecting the two sections together. Merely for illustration, I have shown the flange 19,provided .with a plurality of bayonet ridgesv 7() and have shown the lower edge of the casing section 'or cover 11 provided withl corresponding bayonet grooves 7l whereby the parts may be separated or secured together by a partial rotation of the cover in respect to the body of the casing.

To hold the parts against accidental`unlocking and to Insure the proper final irlative positioning of the parts in respect to,

,the axis, I preferably empsloy some form of'` spring catch or stop. Larly 1n Figures 2, aand 5, a button or knob 72 is carried by a spring 73 secured 'to the inner surface of the Harige 19 and rojects through an aperture in one of the bayonet ridges 70. This may enter a slot or depression in the corresponding bayonet groove 71 of the casing and insure propel' retention of the parts.

One very material advantage of m improved ccnstruction above described 1s the ease with which all of the parts ma be removed or rendered accessible 4for cleaning, replacement, or repair. The brushes may be shown -particutaken out by unclamping the collars 56 without disturbing any of the other distributor head 67 may be readi oil of the upper end of the shaft entire interrupter head and its parts may `be removed from the'shaft 13 merely by the removal of the nut 23 and without disturbing any of the other partsv other than of course removing the cover 11 and the distributor head. The secondary terminals carried by the cover are easi y and quickly removed at will.I

The only part ofthe device which requires lubrication is ther bearing of the' shaft 13 and vthis may be readily oiled merely by rearts, the y slipped an movingthe cover 11 as I have provided an the the oil passa ve, it will not come into contact with any o .the other movin parts. At most, it will'merely flow around the annular passage and leave the device through the slot' 43.

As to most of the important features of my invention, I may secure their full advantage Without the lutilization of the polarity reversing feature, if desired` As the interrupter head 21 may be easil removed, it may be replaced by a head similar to that shown in Figure -9. This head has a body portion 21 of insulation material and a singleV complete collector ring 24. This carries the post 27. The other contact carrying post 26*` is electrically connected to the shaft by a base strip held ih position by the nut 23. Only a single brush 51l is employed, this being connected to one terminal of the battery while the other terminal is grounded; in other words, connected directly or indirectly to the shaft 13. This intermpterhead may` be readily-inserted in pla/cc of that shown in -Figures l, 2 and 6 and without necessitating any change lin the conof one 4of the brush a the insulation head 21".

struction exceptthe pluggingor omission pertures. In case it is not desired to utilize the polarity reversin feature and at the same time ,it is not desire to ground the current, I may employ the construction shown in Figure 10. Here, there are two separate,l complete collector rings 24" and 25, one connected to' the contact post' 26" and theother to the contact post 27 by conductors through the body of The two separate brushes 50b and 51" engage with .the two separate collector rings and are connected to the opposite terminals of the battery. This head may be readily substituted for that Shown in VFigure l and merely necessitates theA required change in the shape of the brush supports to brin one at a higher elevation than the other. 'hese' brushes may of course beopposite to each other, rather than superposed, as somewhat diagrammatically shown in Fi re 10.

Various ot er forms of interrupter heads may be substituted as, for instance, I may put in one having normally closed contacts rather than normally open ones as shown in F igure 2. I have illustrated such a norma lyclosed Contact device in Figure 8.

In this construction, the head 21c has a bell-crank lever'33", one end of which has Y directly secured thereto a contact 29c for movement into and out of engagement with the normally stationar or adjustable contact 28. A periphera fspring 34 has one end secured to the lever Yand normally tends to swin the latter in such a direction as to normal y hold the tivo contacts in engagement with eachother. As the outer end of the bell-crank lever engages with the projections in the interrupter-hou'sing, the contact is first broken and then made. This device, per se, forms no portion of my invention but'is illustrated merely as an interrupter head which'may be inserted in my improved construction in place of the other forms theretofore described in case it is desired to control a normally closed circuit system. y

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A timer having a substantially cupshaped casing member, a shaft projecting through the end wall thereof, an interrupter head within said casing and secured to said shaft,`makeandbreak contacts carried by said head,brushes carried by the peripheral wall of said casing and engaging with said head and means in said head for connecting each brush to a separate make-and-break contact.

2. A timer having a substantially cupshaped casing provided with a depending sleeve, a shaft journalled in said sleeve, a pair of interrupter contacts carried by said rin "shaft within vsaid casing, a

f a A amelhavin i.'substantially cup-- shaped casin provi ed with a depending, sleeve, a shafgt ]ournalled in said sleeve, an insulation head carried by said shaft within said casing, a pair of semi-circular collector sections carried by said head, a pair of make-and-break Vcontacts carried by said head, a Aseparate connection between each contact member and its corresponding section, a4 pair of brushes carried -b the wall of said casing and engaging wit said collector sections, and means within said casiii for effecting a relative movement of sai contacts during the rotation of thelatter with said head.

t. A timer having a rotatable member including a body portion of insulation materialia pair of spaced contact faces on the perip eryfthereof, a air of interrupter contacts carried by sai body portion, connections between said contacts and said faces, and a pairof brushes each engaging with said contact facesyin succession .during the rotationof said member.

.5. A timer having a rotatable member including a body portion of insulation material, a. pair .of -spaced conta/ca faces on the periphery theneof, a. pair of interrupter contacts carried by said body portion, connections between said contacts and said faces, and a pair of brushes engaging with said contact faces during the rotation of said member.

6.- A timer including a substantially cupshaped casing,` a rotatable member therein, having a pair of'interrupter contacts and a pair of peripheral contact faces, a pair of brushes carried bynthe peripheral wall of said lcasing for engagement with said faces,

andV an interrupter housing also carried by Said peripheral wall for effecting a relative movement of said contacts during the rotation of said member. 7. A^\timer ,including a substantially cupshaped casing, a rotatable member therein having a pair of-interrupter contacts and a pair of peripheral rfontact faces, a pair of brushes carried by the peripheral wall lof said casing for engagement' with said faces, and an interrupter housing also c arried by said peripheral wall for effecting a relative movement of said contacts during the rotation of said member, said housing having, a limited oscillatory movement in respect to said Casing. 8. A timer including acasing presenting an annular wall, an extensible and contract-` ible interrupter collar seated within and free to oscillate in respectto said annular within said casing and having interrupterV contacts, and means for engaging withl said housing and effecting their relative movement during the rotation of said member.

10. A1 timer including a 'casing member having an annular wall presenting a seat on' the inner surfacethereof, a split annular collar extended 'into said yseat, a member for oscillating said collar and normally preventing the contraction lof the latter, a pair of inferrupter contacts, -and a member movable along said collar for effecting relat-ilve movement of said contacts.

11. A timer including an annular wall provided with an annular seat upon the inner surface thereof, an annular split interrupter housing supported in said seat, a handle member secured to said housing and having aiportion between the spaced ends ofthe latter for normally preventing the contraction of the housing and serving to oscillate the, latterJ a pair of interrupter contacts, and a member rotatable within said' housing for engagement with the latter at successive spaced pointsfor effecting relative movement of said contacts.

12. A combined timer and distributor in-v cluding two metal vcasing sections, a rota table head within said casing, interrupter contacts carried by said head, a pair of brushes carried by one casing section and insulated therefrom and engaging with said head for delivering primary current to said head, aJ plurality of secondary contacts carriedby the other casing section and insulated therefrom', and a secondary current distributor rotatable with said head.

13. A device of the class described, including a cast metal casing member having tivo annular concentric flanges, a cover member having bayonet joint connections with the outer flange, an ntermper housing seated in and free to osillate in respect to the other fiange, an interrupter head coricentric With said flanges and having make and break contacts, a shaft carrying said head and .journaled in said casing, and an oil passageleadin from between said flanges to the bearing ozsaid shaft.

14. A casing for timers including a cupshaped body portion having an outwardl extending Wall, a pair of upwardly extendving concentric 'annular flanges, one of said flanges 'having means for the attachment of a cover thereto and the other serving as a seat for an interrupter housing, shaft bearing concentric with said flanges.

15. A head for timers including an insulation body, a p air'of semi-circular coll lector rings insulated-from each other, aV

pair of posts connected to said rings and extending Ato one end surface of said head,'sep

arate contacts connected to said posts, and4 means for effecting a relative movement of said contacts during a rotation of said-head. 16. A combined timer and'distributor, including a'cast metal casing member, a sheet metal cover member having bayonet joint connections with said cast metal casing mem-v ber, a shaft rotatably mounted in said cast metal .casing member, a head carried thereby, make-and-,break contacts carried by said head, means for delivering current to said and a make-and-break contacts, including a pri- ,mary circuit brush carried by said cast tact for cooperation vwith the first mentionedcontact, said lever vbeing electrically connected to the other post, a casing supporting said member and havingan annular series of projections in the path' of movement of one end of said lever for swinging said lever and .effecting the separationand engagement of said make and break contacts a plurality of times during each rotation of said meinber, and a pair of brushes carried by said casing and engaging with said collector ring sections for supplying current to said makeand break contacts and reversin ,the direction of flow of current throug said contacts a plurality of times during each rotation of said member. l

18. A timer having a head formed of"insulation material, a shaft for supporting and Vrotating the same, a casing having a cup shaped body portion receiving said head and having a bearing sleeve within which said shaft is mounted, said casing having an'outwardly extending annular flange substantially in the plane of the upper surface of said head, make-and-break contacts carried by the upper surface of said head,` an annular member Within said casing and having :i plurality of spaced projections adjacent to extending to one t the inner edge of said flange, means carried by said head for engaging with said projections in succession during the rotation of the head to move one iiiake-aiul-break contact in respect to the other. and a eover member serured to said casing at the outer edge of said flange.

19. A tiuier including a head formed of insulation material, a pair of substantially Semi-cylindrical collector ring sections upon the periphery thereof and insulated from each other, a cup shaped easing`r receiving said head and of a. depth substantially equal to the depth of said head, niake-and-breale contacts carried upon the outer surfaee of said head and separatel) connected to said collector ring Sections, a lever pivoted on the outer surface of said head and an annular member carried by said easing.r above the plane of the upper surface of said head and having a plurality of projections with which one end of said lever may engage to effect a movement of one of said make-and-break eontaets in respect to the other duriugrr a rotation of said head.

2U. tilner havingr a head formed of insulation material. a shaft for rotatably supportin, r the saine, a rup shaped casing;r reveivinrr said head and of a depth substantiall)- equal to the thirkness of said head and provided with a bearilu,Y sleeve portion supporting said shaft. a pair of make-audbreak contacts carried by said head a bell crank lever 'carried by said head. and au annular member carried by lzaid easing above said head and having a plurality of projertions formed integral therewith aud with which one end of said hell crank lever may engage insuceession during the rotation of the head to move one of said make-and` break contacts in respect to the other.

Signed at New York, in the county of A\'ew York, and State of New York, this 23rd da v of February, A. D. 1918.

JOSEPH H. LEHMAN.

lill

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