US1560672A - Differential - Google Patents

Description

E. o. DoAK 'Find sept. 1v. 1924 Patented Nov. 10, 1925.

UNITED STATES PATENT OFFICE.-

EGBERT o. Dom, or CANIsToTA,`soUTHDAKOTA;

DIFFERENTIAL. v

Application filed September 17, 1924. Serial No. 728,124.-

To all whom t may concern.:

Be it kno-wn that I, EGBERT O. Donn, a

citizen of the UnitedStates, and aresident .i

plish the object of allowing varying ratios of speed between the rear wheels of a car when being driven in a circular path, but which will eliminate the possibility of one wheel remaining stationary while the other is driven forwardat a doubled rate of speed.

Stated in another way, my invention contemplates the positive driving of, both rear wheels lof a car at a definite speed deter- ,mined' by the propeller shaft-velocity, the varying ration of speeds between the .frear wheels being vaccomplished by vallowing either of the wheels to idle aheadat a rate faster than the rate of rotation positively communicated from the propeller'shaft.

VA further Objectis to provide means for positively transmitting the power .from the propeller shaft to the rear axlesl of a car in either forward or reversed direction, which will yet allow the rear axle shaftsto difterential in either forward or reverse directions of rotation. n l. l

' More specifically, referring to the latter object, itis my aim to provide two series of power-transmitting links adapted to selectivelyl connect the propelling mechanism with the driven axles so as to positively transmit power to the axles in the direction of rotation of the propelling mechanism, and simultaneously to allow fasterrotation'iof either driven axle, either series yof powertransmitting links being movable into 'operative positionv automatically lby the rota-v tion ofthe propellingmechanism in the direction in whichthe` particular seriesy is adapted to positively transmit rotation, the other series being .simultaneously moved out of operative position by the same factor.

A still further object is to provide actuating meansfor accomplishing the above object, controlled* by the retarding resistance to rota-tion of the driven axles.

Another objectv is to provide such an actuatingmeans which is controlled by frictional engagementV betweenv the ends of. the axles. f I i .With thesel and other objects vin view, my invention consistsA inA the constructon',fa1f

rangement and. combination of. the various parts of my device,wlierebythe'objects contemplated are attained, as hereinafter more fully set forth, pointed out innmygclaims accompanying drawand illustrated in the ings,'in which: i.

Fig. ,l is a horizontal, sectional view through the rear axle, differential andpro vpeller l shaft housingy in an automotive. ve' hiele, illustrating ,myy invention in plan, a

portiony of thecasing being broken away in order to better illustrate the parts. i.

Fig. y2 is a detail, vertical, longitudinal, sectional. View through they differential mechanism, taken onthe line 2-2 ofFig.L1.

Fig. i 3 is al vertical, l transverse,y sectional 1:1

view, taken on the line 3-f3f ofFig., 2. Fig. 4 is a perspective ,view of ,a pairof power-transmitting links. i i I Fig; 5 is an enlarged, diagrammatic, figure. illustrating ,the construction and` arrangement -of the power-transmittinglink and ratchet Wheel relative to each other.

Fig. 6 is a sectionalview,` similar Vto Fig.

3, of a slightly modifie-d form of my inveni tion.

, A'A defect that is. inherent in the ordinary differential mechanism in use on. cars is that one of the rear wheels of thecarmay become stuck and secured against rotation, and the power will contine tovbe transmitted to the other wheel alone, which will spin at a speed double the normal speed of the rear Wheels relative to the propeller shaft speed. My invention is primarily designed top eliminate this objection byproviding a posi-' tive driving connectionbetween the."propel ler shaft and each of the rear axle shaft-s.

I have used the reference characterv 410 'to indicate the comb-ined rear axle and differential housing, which isof the ordinary con- To it is4 bolted the vpropeller struction. shaft housing 1l, in the rear end, of which is rotatably `mounted in roller bearings, 12, the driving pinion, 13. l

. The rear axle shafts, 14, are journaled at 60 'hubs, 22, ot theratchet wheels.

vlto gears which form part Vot the lditle'refntial mechanism.

In nay-invention these gears are-removed Vand in their place are substituted the ratchet `wheels, 19, which afre'lkey'ed to the Vshaft in the same manner and held against longitudinal movement by thesame rings, 20, vused in the'old construction.

yIt may be mentioned here that thefteeth, '21,'ot` the ratchet wheels are square in crossseCtiOn, as illustrated inFigs. 3 andv5. 'The purpose of this construction will later be more fully explained.

The hubs, 22, of the ratchetf'wheels, i9, are slightly reduc-ed so as to iorm 'the shoulders, 23.` Y

The differential mechanism is ysupported in a housing, composed of vthering gear, 24, vand the end plate, 25, which are, provided with central circular openings th-rough whichv the hubs, 22,of the ratchets project.

"Iliev'members, 24 and 25, are secured'together at the periphery ot the plate, A25, bythe arched plates, 26. `Screws, 27, received through openings in the members, v24 and 25, and threaded into the plates, 26 are used for this purpose. 'Vhen assembled, the members, 24 and '25, snugly engage the vshoulders, 23, of the ratchet wheels, 19, in

order toV secure them against outward movement. ,Y y

I provide the llanged sleeves, 28, which, engaged between the inwardly-extending bearing-retaining sleeves, .29, of the casing, '10, 'through the medium of the 'friction washers, v30; andthe outer faces ofthe members, 24' and 25, respectively, serve to position Vthe 'differential mechanism when ythe yhalves 'of the housing, 10, are secured "to- V'gether, and 'to maintain 'the vengagement of Lthe teeth, 31, of the ring gear, 24, with the pinion, 13. It`will be understood that the ltriction washers, 30 are of the, ordinary construct-ion. L' y It'willnow be seen that the unit V,comprising the members, y24, 25 and 26 is rotatably mounted relative to the. shatts,"'l4, on the to transmit rotation trom "this unitto the ratc'hets, Ipro'vi-jde the pairs ot pawls, 32, which are pivotally mounted on '.bolts, v33, supported between the members, 24 and 25, respectively. In the form ot'my invention illustrated herewith, I have shown `three In order of such pairs of pawls equi-distantly spaced around each ot the ratchets, 19. It will be understood that mo-re 'or less might be utilized, :but I find that three or tour pairs prove the most practical.

Referring to Fig-4 it will be noted that `the'free end of each p'awl is enlarged so "as to occupy the entire width ot the space in which the pivoted shanks, 34, ot thev pawls are-confined. Thewidth of these engaging teeth, 35, is the same as the width ot the teeth, 21, of the ratchets. 'Thus I- obtain a maximum ot strength in a minimum ot `ALspace,- the outer-portions for the pawls which `be allowed to'engage the ratchets at one time. In order to control this yengagement of thefpawls I provide the following mechf 4anis-m.

Between the inner 'endsot the vratchets,'19, fand rotatably mounted on the inner' ends ot vthe axle shafts, 14, by means `ot the hub,

' 36, is a 1disk,'37, which separates thepawls Vengaged with one ratchet from those 'engagedwith the other. (The hub, 36, extendsV vin either direction from the fdisk, '37, and is lrotatably received within fthe rat'chets, 19, which are provided with enlarged bores tor that pur oose. Betweenthe edges ot'the hub, 36, an 'the shoulders, 38,1tormed "by the venlarged 'bo-re and received `with-in said bore, are the springs, 39 which are fot relatively heavy material. The'objectfottf-these springs is to 'provide a resilient, friction-al connection between the 'ratchets, 19,and the plate, 37, so that when the direction of rotation ot' the pawl, 24, is reversed this triction will retard the rotation ot the'plate,l37,

in the new direction. This retarding action shifts 'the pawls, 32, into Vthe positionrequired vbythe change in rotation, as will now be explained. f

Pins, 40, aresecurely mounted in the plate,

.37, 'extending from either side thereof, and

arereceived'between the pawls, 3201i each pair. Springs, 41, maintain the Vengagement ot the pawls, 32, with the pins, 40, tending to draw thepawls =toward' learch other.

Shouldered bolts, 42,- l'secured to fthe "memb.ers,24 and 25, respectively, pass throughY ring gear, 24. "The-bo`lts, 42, also serve as a bracing means fto space fthefmemleers, 24 and 25, vapa-rt in addition to'- the plates, '26.

vrslots, 43, in the plat-e, 37, and :serve to `v limit the 'movement' of 'the 'plate relative to the l The bolts, 42,vr may be dispensed with' as fark CII as their function in f limiting vthe movement of the plate, 37, is concerned, and thebolts, 33, 'allowed tol performthat function. A modified form in which this is accomplished isillustrated in Fig. 6, in which the plate, has formed on its `periphery a pair of spaced lugs, 44, the path of 'which is intercepted by the bolt, 33.

Referring nowy to the operation-of the device and: for illustration to'Fig. 3, it `will be assumed that the ring gear, 24, is rotating in the direction indicated by the arrow, A45.

The force opposed to the pulling power of the propelling meanslwhich tends to retard the rotation of the shafts,1l4, and ratchets, 19,'frictionally operating upon lthe plate, 37, through the medium of the springs, 39, will maintain the plate, 37,-in the position shown y in Fig. 3.l In this-positionv the pins, 40, being positioned a little to the rear ofthe bolts, 33, 'in thedirection of rotation,"\vill maintain' one ofthe pawls of each pair out of engagement with the ratchets, 19.

Forv convenience' inl describing vthe operation, I will referto this series of' pawls, `which is inoperative when the ratchet is being driven forward', as they pawls, B, and the lother series as the pawls, A.

At the same time lthe pawls, A, will be allowed to remain in engagement with the ratchet wheels, and will transmit positively 'the rotation of the gear, 24 to the ratchet wheels. In going around a corner the wheel on the outside,` traveling through a rlarger arc, will becaused to rotate at a rate faster than that ofthe wheel on the inside; car will'thenbe driven entirely from the inner wheel, and the outer wheel'will idle forward at the proper speed, the ratchet on the outershaft being allowed'v thus to rotate by the pawls,-A. It will be noted that when this occurs the rotational friction against the plate, 37, of the two ratchets, instead of being inthe same direction' will be in opposite directions, the two forces tending to neutralize each other. I-Iowevenin addition to the retarding force exerted by the ratchet on the vaxle which is driving the car, my device provides an `additional factor tending to maintain the plate, 37. in its initial position.

Referring now to Fig. 5, it will be noted Vthat the face `ofthe ratchet tooth., 21, is inclined toward-the bolt, 33, within the arc of movement Vof each of the teeth, 35, as indicated by the broken line, 46. Thus any tendency of the pawl, 32, to disengage itself from the ratchet would lat the same time'tend to f orce the ratchet ahead against its resistance to rotation. vSince this force is considerable, it will be seen that the p-awls 32.

"will be `securely locked in position and will thus retain' the plate, 37V against this unwanted movement.

Assuming that the car is still `moving for- The driven forward positively, thus rotating the ratchets, 19,1 forwardly relative tof the ring gear, 24. The frictionalk engagement ofthe ratchet-s will lalso carry the plate, 37,'-in`the direction'indicated by the arrow, 47, until the slot, 43, limits'the 'motion of the plate relative to the ring gear.l This `forward irotation of the plate carries the pawls, A, out of engagement with the ratchets and lowers the pawls, B, to position where. the' forward rotation of the ratchets will, through the pawls, B, transmit rotation to the-ring gear, 24, in order to drivethe engine forwardly.

When the' driver yshifts gears l and l causes the propeller shaft to roitate in a reverse direction,`the same operationis effected'as that just described. -The `ring gear' rotates rearwardly andthe plate, A37, is lheldv against ,y

rotationby the frictionalresistance ofthe ratchetsV It will-be seen that-the` samedif ferential action ywill take place- 'in driving the Vcar around a ycurve backward asin driving forward around vra corner. Some 'changes may be made in the-construction and arrangement of ythexparftsfof my invent-ion'withont departing vfrom lthe real spirit and'purpose of my invention, and it' is'my intention to cover by-.myclaimsfany modifiedformsVr of structureor use of mechanical"equivalent`s which may be' reasoni ably included within their scope.V -I claim-'as my invention: 'Y

' l.`In, a differential, driven elements and a` driving element,the` latter carrying two series, oppositely disposed, of power transmitting links movable alternately' to positions for rotating the driven-element in either direction, and means ycontrolled-by the reta'rding resistance to rotation of the drivenelements, for simultaneously moving one series of links to operative, and the other series to inoperative position, said 'means includinga single :plate frictionally engaged between the driven elements, and projections 'carried by the plate enga-ged with the `links the power transmitting links being arranged Vto resist f disengagement fromy the ldriven element when in engagement therewith.

2. lIn a differential, driven elements l'and al driving element, th'e'latter carrying t'wo series, oppositely disposed, ofpower trans- Vno V Y of an automotive-vehicle, a pair of vratchet wheels on the y@abutting y.endszyoi said axles, a plurality of pairs yof pawls, oppositejly directed-and engageable with the.ratchets,eacn Apair.being `pivoted onfa single stud ycarried by adriving element, a pla-te frictionally engagedbet-ween' the ratchet wheels and cars fryinga plurality of projections each .projecftionlbeing engaged :between-@the paWls and in lcontact `with. each pawl of its respective paar fand-,adapted to retain ione pawl of each pair -`out of engagement-With theragtchet :wh-eels. y f' Y 4.7111 combination:Withthe driven axles voi van automotive vehicle, a-pair of ratchet wheels .0n fthe abutting ,endsof said aXles, .afpl-urality offpairs of vpa-wls, loppositelj)7 di- Arected, .fpivoted cna driving element, and .engageable with the ratchets,and means ac- `.tuateolfbynotation of the driving element in either direction, Afor bringing into -operative .engagement iwith l the ratchet wheels, the gpawlsfdirected to rotate the axles inv that v-cl'iirection, -saidmeans including a plate' having a hub rotatably amountedv on the abutting ends ofthe axles, :the ratchet Wheels be- ,jing recessed to receive the rends-of the fhub,

and .coil springssurrounding the axles and engaged between the wheels and Vthe hub.

5. In a'diflferential, in combinationvvith zthe driven axles of anrautomotive vehicle, .a pair .of ratchet Wheels on the abuttingA ends of. saidfaXle-s, ay driving element,` including ,spaced iside 1nembers,-shafts connecting said side members, .a friction plate rotatably -vmounted ontheabutti-nglends of the shafts .and friction ally engaged between sai'd ratchet wheelsa series .of vpairs of opposlitelyvdisposedpawls .mounted on the shafts l.oneither side of said plate, the plateserving sto rsepa-rate..the,series of pai-rs on onerside from .thatonthe other, and l.means carried by 7the'` plate to bring into engagement 'with the ratchet wheels, the `gpawls j directed -to trans.- .mit rotation in the direction.otrotatiofn or' the drivingyelgement. Y

.. In a differential, Yin combination with ythe driven .axles -of .an automotive vehicle, avipair ofratchet Wheelsjon the abutting ends 4ofgsaid axlesra'drivi-ng element, including ,spaced side members, lshafts Vconnecting said .side members, a friction plate ,rotatably ,mounted lion. the abutting .ends of the' shafts ,and `4frictionally i engaged between ysaid `ratchet,vw\v*-lieels, .a series of pairs of oppol-sitelv ,disposed pawls-1nountedon the shafts Qn either side hof said :plate'fthe pla-te serving -to .separate/thesseries'of pa-irs on one side madera fromthatxonntlae other, thetwo paavlsfof each pairheing Widenedat their 'l-lfglgllg ends-so kas :to ouerelieeacliotherfand means carried by the plateto bring into l.engagement with the ratchetv'wheels the pawls directed -to transmitrotation in the :direction of rotation of the! driving -.element.

7. 11i-a fditfereigitial, -in*combinatiolglwith the driven axles of .an automotive vlehiielafa of. each pai-r, and studs-extendingthnough the plateY andieififgaging each pawliof 'the ref .spectiver pairs, :sa-id studs being-.disposed fbetween the pawls and the springs.

F8. In a differential, in combination Vwith the driven axles of anautomotive vehicle, a pair of ratchet wheels fon vtheabutting; ends of said axles provided avidi/annular' recesses, fa friction-plate having afhubrotatabl-y mounted @on the :ends @of the ax-les `and enclosed in @the recessed portions Ioit' the ratchet avheels, Acoil springs (engaged between the ratchet wheels and fthe ends of the'-;l1ub,

.in said recesses, the Iratchetwheels lbeing provided with' reduced hubs, a Vdriving ele,- ment including two .side gmembersxj o ur-nalled on said reduced'hubsf-,and engaged fagainst the sides off the .ratchet-wheele shayftswcoin necting the two side members, a series pairs lof @ogpfpositely disposed paiwls -piafoted .on the f shafts, one-it'her si de `oit the plate,- lthe `plate servi-ng to-ispaee the two series apart,

springs connect-in-gtthzfe twof pawls of each jecting between 'the springs and ipaW-,ls lof .each pair, engaging :each pawl of each-pair.

v9. Ina differential, in combination Vwith -the driven axles vof a-n-,aa1tornoti.ve vehicle,-a pair of ra-tchets .mounted Afon fthe yabutting ends of the axles, a relatively thinirietion .diskrotat-ablyimounted onthe abutting ends of the aXlesza/nd received between ithe spa-ced sides of theeratchets, a driving member,.ga l.series fof pairs of 'oppositeliy disposed pawls pivoted4 on .the driving member onffeit-ner side .of the plate, the .twopawls ofeacllf Pair .being `:connected by ,tension springe-studs carried .by lvthe .plate `and projecting in either direction, .the ',respecti'veqends of each ;.stud being-engaged between the pawls and sprgigng respectivelyiof the adjacentvpaiyrsfand .simultaneously engaging eachpawlof the respective pairs, the pawlsbeing .fplovided ldisposed inthe/planes vseparating the pawls With engaging ends engage-able with the ratchet teeth, the ratchet teeth being inclined toward the shafts and Within the arcs of swing ot' t-he engaging ends of the paWls.

l0. In combination with the driven aXles of an automotive vehicle, a pair ot ratchets mounted on the abutting ends of the axles, and having reduced hubs, a driving member comprising a pair of side elements rotatably mounted on said hubs, casing members removably connecting said side elements in positions engaging the faces of the ratchets, the ratchets being recessed on their inner faces next to the axles, a friction disk engaged between the opposed faces of the ratchets and having a hub rotatably mounted on the axles landreceived Within the recessed portions of the ratchets, a series of pairs of oppositely disposed paWls `pivoted on the driving member on either side of the disk and engageable with the ratchets, and Y

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