US 3375814 A
Description (OCR text may contain errors)
April 2, 1968 L.. J. HAMMAN PULLEY CONSTRUCTION FOR RECOIL STARTER 45mm-sheet@ Filed Nov. 26, 1965 INVENTOR LYLE J. HAMMAM ATTORNEYS Aprll 2, 1968 l.. J. HAMMAN PULLEY CONSTRUCTION FOR RECOIL STARTER 4 Sheets-Sheet if,
Filed Nov. 26, 1965 ZNVENTOR LYLE J. HAMMAM ATTORNEYS April 2, 1968 L J. HAMMAN PULLEY CONSTRUCTION FOR RECOIL STARTER 4 Sheets-Sheet 5 Filed Nov. 26, 1965 m w m LYLE J. HAMMAN Baa/14W ATTORNEYS April 2, 1968 L.. J. HAMMAN PULLEY CONSTRUCTION FOR RECOIL STARTER Filed NOV. 26, 1965 4 Sheets-Sheet 4l PIG 3 v INVENTOR L YLE J. HAMMAN ATTORNEYS United States Patent `O 3,.'a75,814- PULLEY CONSTRUCTION FOR RECOIL STARTERZ Lyle J. Hamman, Eaton.RapidsMic h., assignorf to Eaton" Stamping Company, Eaton Rapidsg.` Mich., ai' corpora` tion of Michigan.
Filed"Nov.i26, 1'965,Ser. No. 509,981 9 Claims." (Cl. 1234185) Rope starters 'ofthe so-calledrecoill type a-re widely` employed on small internal -combustion enginesto per mit `the crankingandstarting of the engine by'pullingar rope. Basically, a recoil startenconsists of wa pulley mem ber which may 'be selectively connected-to the engine 25 during cranking. A ystarter rope is wound upon the pulley` member whereby rotation of .the,pulleyimemberby` unwinding the rope therefrom cranks `the Aengine.`A spiral4 spring is associated with the pulleyrnenrber wherein th spring is wound 'during cranking of the engine-and` upon 30 release of the tension in the starter rope, the-.spring un-` winds to rewind the starter rope ontherpulley member. t A number of problems have .existed-.with recoil starters of conventionalV construction. One of the mostiserious problems encountered with recoilstarters arisev from fray- 3 ing of Athe 'starter roperat the point ofconnection to the* pulley member so that'over a period of time the rope will 'break at this point. Such breakage iofthelrope usually, occurs when 'the starter` rope is.` extended during cranking, 'i permittingthe "recoil springto v ery rapidly Jrotate the `40 pulley member in a rope-rewinding'directionfbeyond their normal position whichusually results in breakage of the'1` recoil spring.` i
Another problem oftenoccurring-with recoil'starters` arises from the st'arterropefbi'nding:in therpulley= member: 45 Iii-the nomal construction, theV pulley member `includes a rope-receiving groove of a Width only slightly greater than f therdiameter of the rope.-l`hus, as thefropeis"wound"upon'A the'pulley member, theirope ormsa `spiral` Whereinadja# cent coilsare wound oneachother. in a 'radialfdirectioni' 50 When the starter rope iswithin the-pulley grooveyand the engineisat its'maximum compression poin'tvinrits oper-L ating cycle, an abrupt pullon thestarterropeloften causesl the outermost rope coil adjacent Athe' pointfofA tangencyi of the rope to its coil to radiallylslideinwardly and wedgeif55 itself between the next lowercoil anda side ofthe pulley' member forming the rope gro'ove. ThisradiaI:shifting` of-j the' starter' rope will "cause the startenropeto -bind-ref quiring abnormally high tension forces .in--the-starten'rope to` crank the engine, and often results in ant-abrupt jerk r60 and release of the starter rope which may cause-` injury to the operator.
Another objectionable feature of the recoilstarters f employing a rpulleygmember having ,a 'rope-receiving groove of a width substantiallfequal tothe width ofthe 65" rope, results `from the fact-thatasthev r'ope-unwindsfrom 1 the pulleyV member, the' effective torque arm of the pulley Imembers and rope` decreases. Th'us, 4when using .a recoil starter of this-type witha largeaengine,v such as a ten horsepower engine," it is necessary to providea relatively large 70 `Additionally, the pulley 3,375,814 Ptffte Arr. ne@
`diameter pulley member` to pro'dnceQsutiicient cranking" torque" as'the starterrope'unwinds fromits pulley' meinber.`
In the construction of arecoil starterinfaccorthvviththe1 inventionythe bove` deficiencies of" conventional recoil starters have been substantially* avoidedg'fand'tlieobjects and-Apurpos'es-fof theinventionareas set fortliin thefol-A lowing paragraphs.
Aba"sic` object of the invention isi to provide Va` r'e=' coi1 rope starter for-internalicombustion engineswherieirtfri ing t and wear of` the starter? rope`r dieto i its engagement with a pulley member is substantially eliminated. T o this" end the starte-r1 rope and "pullymembe'r arjformeijot materials havin g compatible i durrneter "or'hardness cha`r' arcteristics Wherebyfthe pulley inem-berd will rrotcutan'd" fray the fibers of the starters rope,
Another object Vof the'-iiiven'tiori` is toj provide L ecoil rope starter having a pulley-construction a` tantiallyunifor'm eiectiveepulley ttr'quearm is maintained; throughout unwinding of the starterfropetroni thepulley member.' Additionally, thepulley construction of th`e"`in: vention permit-s va substantially vuniforrntorqne `arm to bef maintained in a relatively`- small diameter pulley member as to* reduce the overall size of the starter required 'for a given internal combustionengineicapaeity"as compared with conventional recoil starters? A 'further object ofthe inventionis jto provide a recoil'L starter for i internalconibustionfengines 4v vherein the jrecoilngr'lspring' isianehred'atit's inner-f ;i 1`dto "the starter housing and this end may'be automatically released from thel starterhousing should the `Starter'unvvidat "an 4ericessive rate of irotation.` Also, the i recoiljspring lconst rjliei'v tion is such as to permit *the spring to beeasily 'assembled` andmaintainedwithiri the starterpulleymernber an'dmay` 5 be easily`replaced,fif necessary.
An additional object of the invention iis itoprovidefaf recoil rope `starter having "a 'pulley fniember'so constructed andrelate'd to thel`starte'rlrope guidebushing that "t h e` starter Irope is `self-leveling on the pulley during recoiling. j member construction is s uclias to prevent binding of the starter rope during cranking o the engine.`
Another object of the invention is""to l` provide a recoil "j starter-having a clutch dog adapte'd"to beralially shifted" Iin'to `engagement with an enginelclutch member and wheref inthe' clutch dog isdirectly springlbiased in a radially in" ward direction away fromtlie' engine clutch memberf Yet `another object "of the` inventionis to provide "a iecoilstarter which mayibe easily assembled,f dismantled f and repaired, and wherein a single pulley member may be used in starters adapted to craukenginesi'in" either a left or a right diection.
A=A further object of the"inven`tion` `is"to provide a recoill starter `of lowlcost and lightweight desigiifwhich is' r1ependableinE operationeancl isconcis in conligtirationi These and otherobjects ofthe invention arising"f r oi`n the ldetails and 'relationshipsofthe"componefnt`srof"` an embodiment thereof will 'be apparent from the following description andaccompanying drawings wherein: j FIG.- 1 is a diametrical, elevational, sectional view of a recoil/*rope starter` in lacc'zor'cl `with "the `invention, as mounted upon an internal combustionen'gine, FIG. 2 is a perspective, exploded View' of a recoil starter in accord with the invention, i FIG.l` 3 -is a plan,'sectional vievt"'o f-`th `e` sprin'g, 'sp`r in g keeper, and pulley member ass'e'nibly;astaken` longlsec" non' mam of FIG. 1, f
FIG. 4 is an'enlarged, detalihperspetive View oftheT inner spring` anchor,
FIG. 5 is an enlarged, sectional view of the inner spring anchor and the inner spring end during assembly of the starter components, the cranking position and the release position of the spring end relative to the spring anchor being shown in dotted lines,
FIG. 6 is a sectional view of the starter dog and engine clutch cup as shown in the disengaged position, taken along section VI-VI of FIG. 1,
FIG. 7 is a sectional view similar to F-IG. 6, illustrating the relationship of the components during the engaged or cranking condition,
FIG. 8 is a sectional, elevational view of the starter pulley illustrating the relationship of the starter rope and pulley upon the starter rope being substantially fully extended,
FIG. 9 is a View similar to FIG. 8, illustrating the relationship of the starter rope on the pulley during the first complete revolution of the pulley member during recoillng:
FIG. l is a view similar to FIG. 9, illustrating the starter rope and pulley member relationship upon completion of two revolutions of the pulley member during recoiling,
FIG. 11 is a view similar to FIG. 10, illustrating the relationship of the starter rope and pulley member upon the completion of the third revolution of the pulley member during recoiling, and
FIG. l2 is an enlarged, detail View of the pulley member and starter rope bushing as if taken along XII-XII of FIG. 11 upon the rope being fully wound on the pulley member, the rope portion between the bushing and pulley member being shown in dotted lines.
The general appearance of the starter housing will best be appreciated from FIG. 2. The starter housing may be formed of stamped sheet metal and includes an inverted cup-shaped conguration defined by a cover Wall 12 and a depending wall 14. The wall 14 is shaped to form four leg portions 16 having holes 18 defined therein, whereby the starter may be affixed to an engine flywheel shroud 20 by fasteners 22, FIG. 1. The housing 10 is of a generally circular configuration but is shaped to permit a starter rope bushing 24 of a cylindrical configuration to be mounted in wall 14 having a bore 26 related in a generally tangential direction to the rope pulley member which is located within the housing, as will later be described.
The central housing cover wall 12 is formed inwardly to dene a spring inner end anchor 28 of a substantially cylindrical annular configuration, FIGS. 4 and 5. The anchor 28 also forms a central bore and a recess for receiving a supporting stud 30. The stud 30 is welded to the housing 10 and includes a cylindrical surface formed on its exterior. Internally, and at its free end, the stud 30 is provided with an enlarged cylindrical recess 32 and a concentric bore 34 adapted to receive a screw, as lwill be later described. The recess radial shoulder 36 intersects the bore 34.
The rope pulley member 38 is preferably formed of a synthetic material such as nylon and is of a molded construction. The pulley member 38 includes a hub having a metallic bushing 40 iixed therein. The bushing may be inserted during the molding of the pulley, and is adapted to be rotatably received on the stud 30 and engage the stud shoulder 42 for axially positioning the pulley on the stud.
On the side of the pulley 38 adjacent the starter housing wall 12, the -pulley is recessed at 44, and includes a plurality of radially, inwardly extending projections 46 which are best apparent in FIG. 3. The projections 46 are integrally molded into the pulley and dene a recess adapted to receive the spring keeper. The projections 46 are undercut at 50 for cooperation with the spring keeper tabs, as will be later described.
On its reverse, or lower, side, FIG. 1, the pulley 3-8 is provided with an axially extending hub portion projection 52, which includes axially extending, dog-receiving recesses 54. A pair of dog-receiving recesses 54 are deined in the projection 52 to permit a single pulley construction to be used in starters for cranking engines in either rightor left-hand directions.
The pulley 38 is provided with a starter rope-receiving groove 56 adjacent its periphery. The groove 56 includes a cylindrical inner surface 58, a radial surface 60 defining one side of the groove, and a pair of radial surfaces 62 and 64 defining the other side of the groove. An axially extending shoulder 66 interconnects the surfaces 62 and 64 and also forms a portion of the rope-receiving groove. A hole 68 is defined in the pulley inner surface 58 intersecting the groove adjacent the radial surface 62. The hole 68 is preferably provided with beveled surfaces 70 on either side thereof, extending in a circumferential direction to prevent an Vabrupt turn being formed in the starter rope. The hole 68 communicates with a recess 72 defined in the pulley for receiving the knot of the starter rope. The recess 72 is open at its lower side, as will be apparent from FIG. l.
A clutch dog operating cup 74 is mounted on the lower end of the stud 30 and encloses the pulley hub projection 52. The cup 74 is centrally provided with an opening through which the shouldered screw fastener 76 extends. A compression spring 78 is received in the stud recess 32 and is interposed between the stud shoulder 36 and the cup 74. The depth of the stud recess 32 and the shoulder on fastener 76 are such that the cup 74 is rotatably mounted upon the stud 30. However, the frictional engagement between cup 74 and the compressed spring 78 resists rotation of the cup on the stud 30 and, thus, the spring acts as a brake resisting rotation of the cup.
A clutch dog 80 having a folded, rounded end 82 received within a recess 54 selectively provides connection of the pulley 38 to the engine flywheel cup 84. The dog 80 is mounted within the associated recess 54 for limited pivotal movement, and a torsion spring 86 disposed in the recess 54 cooperates with the dog to bias the outer end 88 of the dog inwardly toward the position shown in FIG. 6.
The dog operating cup 74 includes a peripheral portion 90 which is deflected inwardly, as is apparent in FIGS. 6 and 7. The inward deflection of the portion 90 forms an opening 92 through which the dog 80 projects. It will, therefore, be appreciated that with reference to FIGS. 6 and 7 counterclockwise rotation of the pulley 38 relative to the cup 74 will cause the dog 80 to pivot from the position shown in FIG. 6 to the position shown in FIG. 7 wherein the engine flywheel cup 84 is enga-ged by the dog end 88 and, thus, the ywheel 94 is driven by the pulley during the cranking operation. Rewinding of the pulley 38 to produce relative clockwise rotation of the pulley relative to the cup 74 retracts the dog from the position of FIG. 7 to that of FIG. 6, disenga'gin-g the dog from the flywheel cup 84. It will be appreciated that, except for the limited relative rotation between the pulley 38 and the dog operating cup 74, as shown in FIGS. 6 and 7, the cup 74 will rotate with the pulley, in that the inwardly deflected portion 90 will be engaged by the pulley hub shoulder 96 when the pulley is rewinding the starter rope, and the portion 90 will be engaged by the dog `80 during the cranking operation. The aforedescribed operation of the clutch dog is similar to that shown in my United States Patent 3,081,760.
To facilitate engagement with the outer end 88 of the clutch dog and the engine flywheel cup 84, the inner surface of the flywheel cup engaged by the dog may be provided with ribs, or serrations, if desired, to increase the frictional engagement between the dog and the cup.
Rotation of the pulley 38 is accomplished by the starter rope 98 received within the pulley groove 56. Preferably, the starter rope 98 is formed of braided nylon filaments. The inner end of the starter rope is inserted through pulley hole 68, and is tied into a knot 100 received within the pulley recess 72. The outer end of the starter rope astasii extends through the bore 26 of the starter rope bushing 24 and is aiiixed to a handle 102 so shaped as to permit a rm pull, or tension, to be applied to the starter rope.
Rewinding, or recoiling, of the started rope 98 on the pulley 38 is accomplished -by means of a spiral recoil spring 104 having its inner end 106 connected to the starter housing and its outer end iixed relative to the pulley. The spring 104 is located within a lightweight, cupshaped, sheet metal keeper 108 havin-g an opening 110 defined therein. At the edge of the axial wall of the keeper, a plurality of tabs 112 radially extend therefrom, and the keeper periphery is provided with a pair of diametrically opposed radially extending abutments 114. A slot 11.6 is formed in the axial wall of the -keeper through which the outer spring end 118 extends and is bent over. The inner end 106 of the spring 104 is of a substantially U-shaped coniiguration wherein the free leg portion is formed, as shown in FIG 5, including portions 120 and 122 angularly related to each other.
The spring keeper 108 is received within the recess 44 defined in the pulley by the projections 46. The projections 46 are so located that the spring and spring keeper assembly may be inserted into this recess upon the tabs 112 being related to the projections 46, as shown in dotted lines in FIG. 3. Upon the tabs 112 engaging the pulley recess surface 124, the keeper and spring assembly may be rotated in a counterclockwise direction to the pulley, FIG. 3, to insert the keeper tabs into the projection undercuts S and, thus, lock the keeper and spring assembly to the pulley. Engagement of the keeper abutments 114 with two of the projections 46 limits rotation of the keeper relative to the pulley, and the projections 46 engaged by abutments 114 transfer the torque of the spring to the pulley and vice versa.
The spring inner end 106 is connected to the housing spring anchor 28 in a manner to prevent breaking of the recoil spring 104 should the pulley very rapidly rewind, such as during the occurrence of rope breakage or a starter rope knot becoming untied. The configuration of the housing inner spring anchor 28 is best appreciated from FIG. 4. The anchor includes an axially extending edge 126 which cooperates with the spring inner end 106 in a manner shown in dotted lines at the right in' FIG. 5. In this relationship, a positive connection between the spring 104 and the housing 10 is achieved when the spring is being wound during engine cranking, or unwinding during recoiling of the starter rope on the pulley. The spring anchor 28 is also provided with an inclined end 128 which is radially set inwardly with respect to the edge 126. Thus, relative rotation of the pulley 38 in a clockwise drection, FIG. 5, relative to the spring anchor, beyond the point where the spring end 106 will normally be biased into engagement with edge 126 permits the spring to release from the anchor edge 126, and the anchor end 128 will engage the spring end portion 120 radially deflecting the spring inner end 106 outwardly to the dotted line position shown at the left in FIG. 5. Such clockwise rotation of the pulley relative to the spring anchor permits the inner end of the spring to ride about the annular form of the spring anchor 28 without tending to wind the recoil spring in the wrong direction and cause spring breakage or bending. The full line position of the spring end 106, shown in FIG. 5, is the position of the spring end when the pulley and spring assembly is being assembled on the stud 30. The distance between the anchor edge 126 and end 128 is such as to permit the spring end 106 to be received therein, permitting the proper assembly of the pulley structure into the housing. Of course, normally the spring inner end 106 will always be in engagement with the anchor edge 126, as shown at the right in FIG. 5.
In operation the components are assembled as shown in FIG. l, and the spring 104 is prewound a rotation or so in order to maintain a biasing action on the starter rope when the handle 102 is in engagement with the bushing 24. To Ystart the engine, the operator pulls on the handle 102 which rotates the pulley 38. ljue to the rsistance of rotation of the dog operating cup 74, caused by the spring 78, initial rotation of the pulley will occur relative to the clutch cup 74 to extend the clutch dog from the position of FIG. 6to that of FIG. 7 and connect the pulley to the engine iiywheel cup 84. Continued rotation of the pulley 38 cranks the engine. When the engine starts, the clutch cup y84 will begin to rotate faster than the pulley 38 and pivot the dog 80 in the counterclockwise direction, FIG. 7. Such movement of the dog by the engine cup causes slight rotation ofV the dog operating cup 74 to retract the end 88 of the dog from the engine cup. Upon the operator reducing the tension in the starter rope, the starter rope begins to rewind on the pulley 38 due to the unwinding of the recoil spring 104, the cup portion is engaged by the projection shoulder 96 to fully retract the dog 80 and restore the clutch dog to its noncranking position. As the torsion spring 86 biases the dog end 88 inwardly, this spring will. maintain the components in the relationship shown in FIG. 6 and prevent vibration from causing the dog to accidently engage with the engine cup.
In order to fulfill the object of the invention relative to the pulley and starter rope relationship, a unique relationship exists between the pulley, its rope groove configuration, and the starter rope bushing 24. With reference to FIG. 12, the maximum Width of the rope groove 56 is that represented by the distance separating the surfaces 60 and 64. This width is approximately two and onehalf times the diameter of the starter rope when in its normal untensioned form. The distance between the groove surfaces 60 and 62 is substantially equal to twice the diameter of the starter rope. The axial distance from surface y62 to 64 is approximately equal to one-half the diameter of the starter rope. The pulley 38 and the starter rope bushing 24 are related so that the center of the bushing bore 26 is in a plane equidistantly located between the pulley groove surfaces 60 and l64.
As previously mentioned, the hole 68 receiving the inner end of the starter rope is disposed adjacent the rope groove surface 62. Thus, the inner end of the starter rope 98 is disposed adjacent the surface 62. FIG. 8 illustrates the relationship of the starter rope and pulley when the starter rope is substantially pulled to its extreme position. In the position shown in FIG. 8, the starterl rope will be substantially tangential to the innermost surface 58 of the groove 56. As the pulley rewinds from. the position shown in FIG. 8, the starter rope will be deposited on the pulley surface 58 so that the starter rope will be slightly spaced from the groove surface 62, as is apparent in FIG. 9. The location of the starter rope on the surface 58 is due to the fact that the center of the bushing bore 26 is closer to the plane of surface 60 than the center of the starter rope hole 68 by a distance. corresponding substantially to one-half the radius of the rope Cross section.
As the rope pulley 38 completes its first revolution during the recoiling operation, the rope will partially overlap the portion of the starter rope that enters vthe hole 68. However, as the center of the bushing 24 is disposed toward the plane of surface 60 with respect to the center of the hole 68, the portion of the starter rope will be deflected toward the groove surface 60 as it encounters the rope portion 132. This relationship is shown in FIG. 9. Thus, during the second revolution of the pulley 38 during the recoiling procedure, the starter rope 98 is deposited on the surface 58 adjacent the groove surface 60. As the second rope coil is received on the surface 58, it will axially push the rst coil of rope wound on the pulley into engagement with the groove surface 62.
When two coils of the rope have been wound upon the pulley 38, the beginning of the third coil rides over the beginning portion 130 of the second coil, as shown in FIG. l0. As the center of the bushing 24 is closer to the plane of surface -62 than the plane of the surface 60 as the third coil rides over the second coil, as in FIG. 10, the rope is pulled toward alignment with the bight, or valley, between the first and second coils Wound on the groove surface 58. Thus, the third coil of rope will be supported on the first and second coils in the valley, or bight, defined thereby.
At the completion of the third coil of starter rope being wound -on the pulley, the rope portion 134, representing the lbeginning of the fourth coil, engages the inclined rope portion 136 of the third coil wherein the third coil enters the bight of the first and second coils. Thus, due to the existence of the inclined rope portion 136 and the fact that the center of bore 26 is intermediate surface 64 and the center of the third coil, the fourth coil is deflected by the third coil toward the groove surface 64 and, thus, the fourth coil is Wound on the pulley between the third coil and the surface 64, and is partially received on the radial shoulder 66.
With reference to FIG. 12, the first coil wound on the pulley is represented at A, the second coil at B, the third coil at C, and the fourth coil at D.
When the starter rope is tensioned during the cranking operation, there is, of course, a tendency for the fourth coil D to radially move inwardly. Also, tensioning of the starter rope slightly decreases the diameter due to the compression of the rope fibers. However, radial movement of the coil D inwardly is prevented, as this coil is supported on the shoulder 66 and on coil A. When the coil D is unwound from the pulley during the cranking operation, the coil C receives tension forces and inward radial movement of the coil C is prevented, as this coil is supported by coils A and B and located in the bight thereof. As the dimension between the groove surfaces 60 and 62 substantially corresponds to twice the diameter of the rope 98, the coils A and B cannot move axially to permit the coil C to move radiallyy inwardly. Thus, coil C will maintain its position while this Coil has the rope tension forces pulled thereon.
The final two cranking revolutions of the pulley occur when coils B and A are unwound. As these coils are directly supported on the pulley groove surface 58, radial movement of these coils is, of course, prevented.
Therefore, it will be appreciated that due to the relationship of the starter rope bushing 24 to the rope groove 56 defined in the pulley 3S, rewinding and unwinding of the starter rope on the pulley can be controlled to provide optimum operating characteristics. The use of the shoulder 66 and groove configuration substantially eliminates all heretofore experienced problems of starter rope binding during the cranking operation. As the aforedescribed relationship produces a self-leveling of the starter rope in the pulley groove, the rope is positioned in the groove in a most efficient manner and, thus, the dimension of the pulley groove need be no larger than necessary.
As the pulley groove construction in accord with the invention permits two starter rope coils to be located on each layer, it is possible to locate all of the starter rope adjacent the periphery of the starter rope pulley. Thus, a greater effective torque arm relationship of the starter rope to the pulley can be maintained throughout unwinding of the starter rope, than in those constructions wherein successive rope coils are Wound upon each other in a radial direction.
In recoil starter constructions wherein the rope pulley is formed of sheet metal, or is die-cast, several secondary operations are required to the pulley to remove the burrs thereform which might cause fraying of the starter rope. Particularly, it is important that any sharp edges or burrs be removed from the hole through which the inner end of the rope is afiixed to the pulley. In the invention wherein the pulley is formed of a synthetic plastic material having a durometer substantially equal to the characteristics and durometer of the starter rope fibers, wearing and fraying of the starter rope by the pulley has been substantially eliminated. In tests the rope of the starter of the invention was pulled and recoiled eighteen thousand times without noticeable wear to the starter rope due to engagement With the pulley, even adjacent the hole 68.
When a similar test is applied to starters using a metallic pulley, starter rope breakage often occurs in less than one thousand cycles of operati-on.
Another advantage of the described construction results from the anchoring of the inner end of the recoil spring 104 to the housing and attaching the spring outer end to the rope pulley. This arrangement simplifies assembly and the construction of the starter and permits a lightweight spring keeper to be employed.
It will be appreciated that various modifications to the invention may be apparent to those skilled in the art without departing from the spirit and scope thereof, and it is intended that the invention be defined only by the scope of the following claims.
1. A` recoil starter for internal combustion engines comprising, in combination:
(a) a supporting housing,
(b) pulley bearing means mounted on said supporting housing,
(c) a pulley having a peripheral rope-receiving groove defined therein rotatably mounted on said bearing means,
(d) an annular recoil spring keeper having an axial wall and mounted on said pulley and fixed against angular rotation thereto,
(e) a spiral recoil spring located within Said axial wall, said spring having an inner end and an outer end, said outer end being affixed to said keeper, said keeper and spring forming a unit and mounted upon said pulley as a unit,
(f) a spring anchor defined on said housing, said spring inner end engaging said spring anchor,
(g) engine driving means associated with said pulley,
(h) a starter rope having an inner end afiixed to said pulley adapted to be received in said pulley groove.
2. In a recoil starter as in claim 1 wherein:
(a) a recess is defined in said pulley concentric with the axis of rotation thereof, said keeper and recoil spring unit being received Within recess, and
(b) releasable interlocking means defined on said pulley and said keeper mounting said keeper on said pulley.
3. In a recoil starter as in claim 1 wherein:
(a) said spring anchor defined on said housing comprises an annular element mounted on said housing substantially concentric to the axis of rotation of said pulley and axially extending with respect to said axis,
(b) said element including an edge adapted to abuttingly engage said recoil spring inner end, and
(c) said element including a deflecting portion in circumferentially opposed relation to said edge adapted to deflect said spring inner end from operative engagement with said spring anchor upon said pulley being rotated in a recoil spring unwinding direction beyond the normal spring unwound condition.
4. A recoil starter for internal combustion engines comprising, in combination:
(a) a supporting housing,
(b) pulley bearing means mounted upon said housing,
(c) a starter rope pulley rotatably mounted on said bearing means, said pulley having a starter ropereceiving groove defined therein, said groove being defined by first and second radially extending sides and a base surface,
(d) recoil spring means operatively interposed between said housing and said pulley adapted to rotate said pulley in a rope-recoiling direction,
(e) a starter rope having an inner end connected'to said pulley and an outer end, said starter rope adapted to be coiled in said pulley groove,
(f) =a rope bushing mounted in said housing, a rope guide bore dened in said lbushing having a central axis, said starter rope being closely slidably received within said guide bore,
(g) the axial dimension of said pulley groove delined by said radially extending sides adjacent said base surface being substantially equal to a multiple of the diameter of said starter rope and said rope bushing being related to said pulley groove in the axial direction of said groove such that upon said starter rope having a single layer of coils disposed on said base surface during recoiling, said bushing guides the subsequent rope coil in the bight of the rope coils received on the base surface-supported coils.
5. In a recoil starter as in claim 4 wherein:
(a) said inner end of said starter rope is attached to said pulley within said groove 'adjacent the intersection of said first radially extending side and said base surface and said bushing guide bore axis is located in the axial direction of said groove away from said first groove side a distance greater than one-half the diameter of said rope and less than one and one-half times the diameter thereof.
6. In a recoil starter as in claim 5 wherein:
(a) the axial distance separating said rst and second groove sides is substantially equal to twice the diameter of said starter rope.
7. In a recoil starter as in claim 6 wherein:
(a) said pulley rope-receiving groove includes Ian axially extending surface radially spaced outwardly from said base surface and intersecting said first surface and a third radially extending side intersecting said axially extending surface, said axially extending surface and third side being so positioned on said pulley as to support and locate the fourth coil of rope wound on said pulley in enga-gement with the rst and third wound coils and at a radial position on said pulley corresponding to that of the third coil.
8. In a recoil starter as in claim 7 wherein:
(a) said bushing guide bore axis is located in the axial direction of said groove a distance away from said rst groove side less than the diameter of said rope.
9. In a recoil starter as in claim 8 wherein:
(a) said axially extending surface is radially spaced from said groove base surface a distance greater than one-half the diameter of said rope and less than the diameter thereof, and
(b) said bushing guide bore axis is located in the axial direction of said pulley substantially equidistant from said second and third radially extending sides.
References Cited UNITED STATES PATENTS 30 RALPH D. BLAKESLEE, Primary Examiner.