US2422319A - Engine starter - Google Patents

Description

, June 17, 1947.

vG. s. THOMPSON `ENG1NE STARTER Filed May 4,' 1945 BEL , v if @A122275 Umm/75ml Patented June 17, 1947 UNITED STATES RTENT. OFFICE i -nNcmE STARTER Glenn S. Thompson, Milwaukee, Wis., assigner to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Application May 4, 1945, Serial No. 591,921

tation therewith through a yieldable coupling embodying both torsional and endwise resiliency for cushioning rearward end thrust of the pinion during operation of the starter. Such a driving connection between the actuator and the power shaft'has resulted in complicated structures in the past, and it is one of the objects of the present invention to provide a simple manner of effecting a splined driving connection between the actuator and a part fixed with respect to the power shaft which facilitates incorporation of endwise and torsional resiliency in said driving connection.

More specifically, it is one of the objects of this invention to provide an engine starter of the character described with a screw threaded actuator for the pinion having a sleeve extending axially therefrom and provided with a longitudinal slot to receive a driving abutment on the power shaft of the starter so that the actuator is splined' thereto, and wherein the yieldable coupling is mounted on said sleeve between said driving abutment and a partvof the actuator.

Another object of this invention resides in the provision of a novel driving connection between the pinion actuator and the power shaft which facilitates limiting axial motion of the actuator relative to the power shaft.l

With the above and other objects in View which will appear as the description proceeds, this invention resides in the novel construction, combination, and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates two complete examples of the physical embodiment of the invention constructed according to the best modes so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a side elevational view of the starter of this invention having parts thereof broken away and shown in section to better illustrate details of construction with the pinion shown in its inoperative retracted position;

11 Claims'. (Cl. I4-7) Figure 2 is a View similar to Figure 1 showing the parts in the positions they occupy with the pinion in its operative projected engine cranking position;

Figure 3 is a fragmentary perspective view of a portion of the starter illustrating the manner in which the driving connection is established between the pinion actuator and the power shaft; and

Figure 4 is a fragmentary perspective View of a portion of a slightly modified pinion actuator illustrating another manner of limiting axialV motion of the actuator relative to the power shaft.

Referring now more particularly to the accompanying drawing in which like numerals indicate like parts, the numeral 5 generally designates the starter of this invention and which includes a tube ,6 telescoped over the power shaft 'l of the starting motor 8. The tube 6 unitarily mounts all of the starter parts and is adapted to be anchored to the power shaft 'l of the starting motor, in a manner to be later described, so as toform in effect a part of the power shaft.

The customary drive pinion 9 is freely rotatable and slidable along the inner end portion of the tube 6 from an inoperative retracted position, shown in Figure 1, to an operative projected engine cranking position, shown in Figure 2, in which it meshes with an engine gear l0. 'I'he operative cranking position of the pinion is dened by the customary pinion stop collar Il on the inner extremity of the tube adjacent to the starting motor.

The pinion is provided with an externally screw threaded sleeve l2 projecting axially from the pinion toward the outer end of the power shaft and which cooperates with an externally threaded pinion actuator I3 in the customary manner to produce propulsion of the pinion to and from mesh with the engine gear upon rotation of the actuator relative to` theA pinion and to drivingly connect the pinion to the actuator for rotation therewith through the interengaging screw threads of said parts upon interference with propulsion of the pinion toward mesh with the engine gear.

The manner in which the screw threaded pinion actuator is drivingly connected to the power shaft constitutes one of the features of this invention and for this purpose the actuator is provided with a sleeve I4 encircling the power shaft and extending axially therealong in a direction away from the pinion 9 land toward the outer free end ofthe power shaft. Near the outer eX- tremity of the sleevey I4 circumferentially spaced' The collar I6 also serves to anchor thetube 5g,

to the power shaft so that the tube forms a part thereof. For this purpose a s'et screw I8 -ispr'm vided having a shank threaded into alignfdfhl's in the collar and sleeve with a, reduced end portion I9 entering a suitable Wellin the siderof the, shaft to lock the collar and tube to the power shaft.

The forward end of the collar forms substantially a. cylindrical skirt 2il' which telescopes rover the bifurcated endv of the. sleeveV Ifa distance such that the drive slots thereof are enclosed The forward edge of the 'skirt Zil by the skirt. alsoforms an annular abutment which 'cooperates withY abutrneiits 2li. formed by. theien'ds of the threads 'on the. actuator 'adjacent t'o` the collar to 'denne an axial space for a bank 'of cupped spring washers 22 encircling the sleeve.

Iii-:and Y'confined between *said` abutments on the actuator andy skirt. 28.

These 'spring washers tend to expandiandiurge the 'actuator axially away from the collar I6 and4 inwardly alon'gthe power shaft. Such forward axial motion oi the actuator islimited; however, bylugs 23fstruck outwardly from the extremities of-'t'nefdrive fingers during assembly'o'f the parts into the slots 'I5u and engaging ove-r the outer end-oi the collar I6;

TheY spring washers 22 serv-e as cushioning meansy tofyi'eldingly-absorbinotion of the vactua-- tor toward 'the collar suchfais occurs as th'e result of end .thrust 'translated to rthe actuator 'from the pinionv during 'cranking `of the enginefa's illustratedin'llligure 2. Thus, it will befseenthat the washers inyielding axially'providea deg're of torsional resiliency in lthe driving connection be tween the power shaft and pinion toeffectively protect 'the starter against shock;

Because of 'the fact thati the Lendsofthe threads onthe actuator I3 adjacent toithe collar I6 provide `one 'of the abutments against which -the that the vinner peripheral portion of the "spring washers are prevented from entering tliespaced slots I5 in the end of 'the sleeve. thestarter parts is thus precluded.

In the modification illustratediin Figurel, axial motionof the pinion actuator inwardly along the tubefaway from the `collar is vlirnited bya novel stop f'for'rned by a "detachable spring- 'ringl 25; snapped over 4the bifurcated eXtrenilI-)yy of the sleeve. I4 .and sprung into-notches 326 cutinto the side. edges `of the `-drivengers l I5. fadjaoei'it'ito Jamming 'of their outer extremity. Hence, the spring ring 25 is brought to bear against the outer face of the collar in the same manner as the lugs 23, but the detachability thereof enables ready disassembly of the starter parts for inspection or replacement as required.

From the foregoing description taken in connection with the accompanying drawing., it will be readily apparent to those skilled in the art that the novel driving connection between the power shaft and pinion actuator lies wholly to oneside of the cushioning means by which endwise and torsional resiliency is achieved and that by reason of this fact compactness and simplicity of construction is assured.

What I claim as my invention is:

1. 'In an engin-e starter of the type having a pinionpropelled along a power shaft into and out oflmesh with an engine gear by relative rotation between screw threaded parts on the pinion and an actuator for ther/pinion 'sli'dabl'y mounted on thepow'er shaft, 4afclrivi'n'g eonnetion between the power 'shaft and actuatorfcmprisin'g: alcol-e. lar fixed 0nthe powershaft andinavin'g y ilere'ntially spacedv longitudinal groovesfin- 'it-sbore; drive ngers projecting axiallyfrom 'the actuator 'and reeiv'edwithin `sa-i'dw-'g'ro'o'ires in the bore ofthe collar toprovide 'a lsplfined; driving connectionv 'between the i actuator andl the collar per'rnittinfg*` a degree 'of *ajxiahmovenient-of the actuator towa-rdfthe 'collaifin response to-errd thrust ldeveloped asthe starter picks up theloa'd or 'ti-ie. engine, andy resilient cushioning-means encircling --th-e actuator Wfh'ollyto 'one side 'ofjsali'd splinedf'clr-iving con'ne'ction and reacting between. the actuator -andf'collar t'o yieldingly resist "s'a'ifdj` thrustof the actuator `during'operation ofjtne starter.

2. In an yengine l starter ofthe type 'hjaying au* pinion propelled along a power shaft 'into and; out of mesh with an engine gear, by, relativer@- tatifon between screw threadediparts Amrftl'i'e pin: ion` and a-n actuator for the fpini'on VVsli ly Ino'iinted"v on lthe p ovve'r ishaftpfa ldriving.'connection between` the powerv shaft anda'ctuagtorjcoj inprising: a collar iixed'on the power shaft and having -circum-fe'rentially spacedI lon'itud' all. grooves-in itsbore; `drive 'iingersprojecti'ng jaxiajlllyv-f-rorn-.the actuator and received withnsaid; groovesv in the 'bore 'of the 'Collar t0. Til". fefa. splined driving `connec'cion,between "the 'actuator and the `collar permittin'gja Adegree offaxiailirnoyef ment off the actuator Ltoward the vcollar ref. spense to *end 'thrust' developedfas" :the starter. p'ieks up the load ofthe. engine,- andgresnient cushioning means reactingbe'tween theact at'o'r and-#collar Ito yieldingly resist' "said thrust., o .fthe actuator duringjoperation of thejst r, sa.. cushibiriinameans 'beine disnosedidn .argunbroken cirttmferentiai portieri nf theA actuator, "anni wholly to onelside of hthe colla 4 3. In Van :engine 'starterof-the 'tyiiefhavngfa pinion propelled 4'along r a` 'power sl'iaft ,Y frito and out of "mesh WitnQaneUgine'gearby'r ja'ti-vr'ota, tionbetween screwtl'ireadedjpats, lll efliriion andanv actuator forthejpinionslldablyf mounted. 0n -the l power*l Shaft, a ldlYDgCOnnebll'fn .Iiweem the, powerY 'shaft and 'aolillforjconip sle'evej'on `the, actuatorjeXte dingg'aXi 4 yfrom "in "afdirec'tion away frornftheip; ion circumferentially spaced drive V'n'glrs on fthev of fsaid Isleeve remote ffro'm the pi jon; ."c

sleeve to provide afsplined `driving`connection 'between the power shaft and the actuator; an annular skirt projecting axially from said abutments with its free end facing the actuator and telescoped over the drive fingers to cover at least the inner ends of the same and cushioning means on the sleeve reacting between said end of the skirt and apart on the actuator for yieldingly resisting axial motion of the actuator away from the pinion toward the abutments.

4. In an engine starter of the type having a pinion propelled along a power shaft into and out of mesh with an engine gear by relative rotation between screw threadedV parts on the pinion and an actuator for the pinion slidably mounted on the power shaft, a driving connection between the power shaft and actuator comprising: a sleeve on the actuator extending axially therefrom in a direction away from the pinion; circumferentially spaced drive fingers on the end of said sleeve remote from the pinion; circumferentially spaced fixed abutments on the power shaft engaged between said drive ngers -on the sleeve to provide a splined driving connection between the power shaft and the actuator; an annular skirt projecting axially from said abutments with its free end facing the actuator and telescoped over the drive fingers to cover at least the inner ends of the same; cushioning means on the sleeve reacting between said end of the skirt and a part on the actuator for yieldingly resisting axial motion of the actuator away from the pinion toward the abutments; and interengaging parts on the sleeve and said abutments for limiting axial motion of the actuator away from said abutments.

5. In an engine starter of the type having a pinion propelled along a power shaft into and out of mesh with an engine gear by relative rotation between screw threaded parts on the pinion and an actuator for the pinion slidably mounted on the power shaft, a driving connection between the power shaft and actuator comprising: a collar xed on the power shaft remote from the pinion, said collar having a longitudinal groove cut in its bore and extending to the opposite ends of the collar; a sleeve on the actuator extending axially therefrom toward the collar; a drive nger on the extremity of the sleeve remote from the pinion received within said longitudinal groove of the collar to provide a splined driving connection between the collar and actuator, the drive finger extending entirely through said groove with its outer extremity disposed exteriorly of the end of the collar opposite the actuator; a lug on said extremity of said drive finger struck therefrom over said end of the collar remote from the pinion to limit axial movement of the actuator away from the collar; and resilient cushioning means reacting between the actuator and the collar and encircling said sleeve inwardly of the drive finger for yieldingly resisting axial thrust of the actuator toward the collar during operation of the starter.

6. In an engine starter of the type having a pinion propelled along a power shaft into and out of mesh with an engine gear by relative rotation between the pinion and power shaft: an actuator for the pinion slidably mounted on the power shaft and having external screw threads thereon cooperating with an internally screw threaded part on the pinion so that rotation of the actuator relative to the pinion effects axial motion of the pinion along the power shaft; a sleeve on the actuator encircling the power shaft and extending axially therealong away from the 6 pinion, said sleeve having circumferentially spaced longitudinal slots in its extremity remote from the pinion; a collar received on said sleeve and substantially enclosing the slots thereof; circumferentially spaced driving abutments in the bore of the collar received in said slots of the sleeve to provide a substantially enclosed splined driving connection between the collar and actuator; means rigidly anchoring said collar onto the power shaft so that rotation of the shaft is translated into rotation of the actuator; and cushioning means received on said sleeve at the pinion side of the collar and reacting between the actuator and collar to yieldingly resist axial thrust of the actuator toward the collar during operation of the starter.

v'7. In an engine starter of the type having a pinion propelled along a power shaft into and out of mesh with an engine gear by relative rotation between screw threaded parts on the pinion and an actuator for the pinion slidably mounted on the power shaft, a driving co-nnection between the power shaft and actuator comprising: a sleeve on the actuator encircling the power shaft and extending axially therealong away from the pinion, said sleeve having a longitudinal slot in its extremity remote from the actuator; a collar received on said sleeve; a driving abutment extending substantially radially into the bore of the collar and entering the slot in the sleeve so as to provide a splined driving connection between the collar and actuator; means anchoring the collar to the power shaft so that the actuator rotates therewith; a split spring ring encircling the sleeve at the side of the collar remote from the pinion and sprung into notches in the sleeve so as to form a stop thereon engaged by the collar to limit axial motion of the actuator away from the collar; and cushioning means received on said sleeve and reacting between the collar and an abutment on the actuator to yieldingly hold the actuator and collar axially separated and for yieldingly resisting thrust of the actuator toward the collar developed during operation of the starter.

8. In an engine starter of the type having a pinion propelled along a power shaft into and out of mesh with an engine gear by relative rotation between the pinion and power shaft: an actuator for the pinion slidably mounted on the power shaft and including an externally screw threaded forward portion and an unthreaded sleeve extending axially rearwardly from the threaded portion of the actuator, the screw threads on said forward portion terminating in abrupt shoulders at the junction between the sleeve and forward threaded portion of the actuator; a sleeve on the pinion having internal screw threads for cooperation with the screw threaded portion of the actuator so that rotation of the actuator relative to the pinion effects axial motion of the pinion along the power shaft, said actuator sleeve having circumferentially spaced longitudinal slots in its extremity remote from the pinion providing drive fingers; a collar received on the actuator sleeve at the slotted end portion thereof; circumferentially spaced driving abutments in the bore of the collar received in said slots of the actuator sleeve so as to cooperatewith said drive fingers in the provision of a splined driving connection between the collar and actuator; means securing said collar to the power shaft so that rotation of the shaft is translated into rotation of the actuator; and cushioning means received on said actuator sleeve between the abutments formed by the ends of thev actuator threads and said collar and reacting: therebetween to yieldingly resist aXiai thrust off the actuator toward the .collar during operation .ofthe starter, said pinion sleeve having an axial length such as to permit engagement thereofwith said cushioning. means upon relative rotation: between the; actuator and pinion in a direction to retract the pinion to an inoperative position -with respect to the engine gear whereby the nusliioning means absorbs the shock of pinion retraction.

:95.1 In an engine starter of the type having a pinion propelled along a power shaft into and out of mesh with an engine gear bv relative rotation between the pinion and power shaft: a substantially tubular actuator for the pinion having external screw threads on its forward portion wit-l1 the root diameter of. said threads substantially egual to 4the diameter of the unthreaded rear portion ofthe actuator; a sleeve on the pinion having internal screw threads for cooperation with 'th-e threads on the actuator so that Vrotation of :the .actuator relative ,to the pinion enects axial motion of trie pinion along the power shaft; a collar fared on the power lshaft and having cir.- cumerentially spaced longitudinal grooves in its bor-cito provide driving abutments therebetween; drive :fingers on the iin-threaded rear portion of theactnator and received within said grooves in the bore of 'the col-lar for cooperation with the ents thereon in the provisionof a ed drang `cannection between the actuator anoxcolglar :permitting a degree of axialmovement of actuator toward the coll-ar in response to enel thrust developed as the sta-rter pic-ks up the load of the engine; and resilient cushioning nmeans received on the unth-readed rear portion of the actuator fin a posi-,tion to be engaged bythe pinion sleeve `d ring axial Amotion of the pinion toward the collar .cto itsV inoperative retracted `posit-ion for absorbing the shock `of pinion retraction, said cushioning means reacti-ngbetween the actuator and' collar to `yieldingly resist said thrust of the actuator during operation of Athe starter.

10. In an engine starter of the type having a pinion propelled along a power shaft into and out of mesh with an engine gear by relative rotation between screw threaded parts on the pinion and an actuator for the pinion slidably mounted on the power shaft, a driving connection between the power-shaft and actuator, comprising: circumfer entiall-y spaced abutments on the power shaft re.- rnote from the pinion; a sleeve on the actuator extending outwardly from one end thereof toward said shaft abutments; -circumferentially spaced 8 abutments on said; sleeve engaged with the shaft abutments to prov-ide a splined ,drivingconneetion between the shaft. and actuator allow-ingY a degree of axial motion of the actuator along the shaft; a stop `on the actuator located between the pinion and said shaft abutments; means'l on the shaft providing aistop so located along the shaft as to lie lbetween the actuatorv stop and said actua.- tor and shaft abutments and resi-lient cushioning. means encircling the actuator inwardly of' said splineddrivng connection and` confined between saidactuator andl shaft stops' for yie-ldingly resiste ingaxial motion of the actuator toward the shaft ehutments. Y

lll- In ,engine starter .of the type havingia pinion propelled along a power shaft into and out or mesh with an engi-ne: gear by relative rotation betweenscrew threaded parts on the pinion and an actuator for .the pin-.ion slidablv mounted .on the power shaft, a idriving,connection between the tower ,shaft and actuator, comprising: circumferential-ly -spasmi abutments on the power shaft remote from: the pinion; a sleeveon the actuator extend-ing outwardly from .one end thereof towardsaiel shaft labutnients; ,ci-rcumferentially spaced chatrooms ce :Saidsleeve engaged with the shaft abtrtifnents to prov-ide asplined driving connection between the simo-ft and actua-tor allowing a degree of axial motion `ot Ythe actuator along theV shaft; s Y n the actuatorlocated between lthe pinion andasse @l actuator abutments: means onthesbaft il relies-.seid shaft aridvsleeve ab-utments to Sub.-

gv enclose .the semasad means having@ part trending a Sion so lated alone the Shaft as to be positioned between the acgllatonstop and said sleeve and shaft fabu'trnents; vand `resilient cushioning means ,encircling the actuator inwardly of vsaid splined driving connection and coz fined between-said actuator and shattstops for yieldingly resisting axial motion .of the .actuator toward the .shaft abutments.

GLENN. Ys. 'reco/tesori.

REEERENCES GITE!) lThe following references are lof record in the fil-.e o f. ;tliis patent:

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