US3782356A

US3782356A - Kick starter

Info

Publication number: US3782356A
Application number: US00229970A
Authority: US
Inventors: L Hamman
Original assignee: Eaton Stamping Co
Current assignee: Von Weise USA Inc
Priority date: 1972-02-28
Filing date: 1972-02-28
Publication date: 1974-01-01
Anticipated expiration: 1991-01-01

Abstract

A kick starter for small internal combustion engines capable of being exteriorly attached to the engine flywheel housing in place of the usual recoil type rope starter. A pair of spaced parallel shafts are rotatably mounted at their end regions within a casing, one shaft being connected to a foot operated crank arm, and the other shaft supporting engine flywheel starter clutch mechanism. Meshing gears are mounted upon the shafts and one of the gears is connected to its associated shaft through a torque limiting connection permitting slippage to occur between the foot operated crank and flywheel clutch mechanism in the event of premature ignition or ''''backfire'''' during cranking. A recoil spring returns the crank arm to its original position after the cranking operation, and stop means insure consistent and uniform positioning of the crank arm to its original position at the end of the cranking stroke. The flywheel clutch mechanism includes a radially movable dog which engages a drive cup mounted upon the engine flywheel, and dog actuating structure radially extends the dog during cranking, and radially retracts the dog during return of the starter components to the non-cranking condition. A sheet metal crank defines a socket pivotally receiving a foot pedal and a pin limits rotation of the pedal in the socket.

Description

0 Umted States Patent 1 1 1111 3,782,356

mman 1451 Jan. 1, 1974 KICK STARTER [57 ABSTRACT [75] Inventor: Lyle J, H m Eaton R id A kick starter for small internal combustion engines Mi h, capable of being exteriorlty lattacheld to the engine fl wheel housing in lace o t e usua recoi type ro e [73] Assgnee: Stawpmg Company Eaton stirrter. A pair of sri aced parallel shafts are rotatab ly Raplds Mlch' mounted at their end regions within a casing, one shaft [22] Filed; F b. 28, 1972 being connected to a foot operated crank arm, and the other shaft su ortin en ine fl wheel starter clutch [2]] Appl' 229970 mechanism. fi shing gea rs are mounted upon the shafts and one of the gears is connected to its asso- 52 us. (:1. 123/185 c, 123/185 5 eiated shaft through a torque limiting connection P [51] Int. C1 F0211 3/04 i g lippag to ccur between the foot operated [58] Field of Search 123/185 C, 185 CA, nk n flywheel clutch mechanism in the event of 123/185 P, 185 S, 185 BA 135 B premature ignition or backfire during cranking. A

recoil spring returns the crank arm to its original posi- [56] Referen e Cited tion after the cranking operation, and stop means in- UNITED STATES PATENTS sure consistent and uniform positioning of the crank 1,960,458 5/1934 Roche u 173/185 C arm to its original position at the end of the cranking 1,972,867 9 1934 B01161 1 23/185 s X t The flywheel clutch mechamsm Includes a 3,081,759 3/1963 Mauck et al.. 123/185 BA x dlany movable dog whlch engages a drive CUP 2,926,648 3/1960 Hamman 123/185 BA mounted P the engine flywheel, and dog actuating 1,630,595 5/1927 Babcock 125 185 5 Structure radially extends the g during cranking, and radiall retracts the do durin return of the FOREIGN PATENTS OR APPLICATIONS starter com ponents to the nor n-cranki ng condition, A 532,098 8/1955 Italy 123/185 C Sheet metal crank defines a Socket pivotany receiving gzjz i i ag 22i a foot pedal and a pin limits rotation of the pedal in 852:394 1/1940 Franceihiiii..::::..........::.:: 123 185 5 the socket" Primary ExaminerAl Lawrence Smith Assistant Examiner-W. H. Rutledge, Jr. Att0meyBeaman & Beaman 8 Claims, 13 Drawing Figures PAIENIEDJAN 1 1 I 3182.356

- 'sumlnm PATENTEU JAN 1 4 SHEET 2 OF 4 PATENTED JAN 1 I974 SHEET b BF 4,

KICK STARTER BACKGROUND OF THE INVENTION The invention pertains to kick starters for internal combustion engines manually operated by forces exerted by the foot and leg.

Small internal combustion engines, such as manufactured in large quantities for powering lawn mowers, lawn and garden equipment,'small tractors, pumps, generators, mini-bikes, and the like, usually of the single cylinder type, and having horsepower ratings rang ing from less than 1 hp. to hp. normally employ rope starters of the automatic recoil type, such as shown in my US. Pat. No. 3,375,814, for instance, or may employ impulse starters using spring power for cranking, such as shown in my US. Pat. No. 2,999,490. Also, it is known to use electric starters with the larger sizes of such engines, such as used on small lawn and garden tractors. Such engines as referred to are usually of the air-cooled type having vanes mounted upon the engine flywheel for blowing air over cooling fins located adjacent the cylinder. The flywheel is encased within a housing shaped to direct the air blown by the flywheel upon the cylinder fins, and the starter mechanism is normally mounted upon the flywheel housing concentrically disposed to the flywheel axis.

In engines of the aforementioned type, an engine cranking member, often in the form of a cup, is mounted upon the flywheel concentric to the flywheel axis, and engine crankshaft, and unidirectional clutch or drive means are interposed between the starter mechanism and the flywheel mounted apparatus to permit starting or cranking torques created in the starter to be transmitted to the engine flywheel for cranking and starting the engine.

Rope starters with automatic recoil devices permit high starting torques to be applied to small internal combustion engines, and create sufficient cranking to easily start engines in good working order. However, rope starters require that the operator grasp the rope handle, which is normally located adjacent the engine flywheel housing, and rapidly pull the starter rope to create the cranking torque. Thus, strong arm and shoulder muscles are required, and if the engine is located close to the ground the operator must bend over to reach the rope handle, with the possibility of incurring a back injury.

Foot operated starters for internal combustion engines have long been used in special applications, for instance, in starting motorcycles and motor scooters. Such starters are operated by the operators foot and leg wherein a quick kick of the starter crank arm by the leg creates the starting torque. Such starters have commonly been known as kick" starters, and their use with internal combustion engines has been primarily limited to the aforementioned vehicle use in that the kick starter mechanism is normally directly incorporated into motorcycle or scooter transmissions which are directly connected to the engine crankcase, and integrally form a portion of the engine structure.

Small internal combustion engines of the conventional type, such as used with lawn mowers, garden tractors, and the like, of the horizontal crankshaft type, have recently been widely used to power small, economical, 2-wheel vehicles commonly known as minibikes, and as such vehicles are usually formed of tubing, and conventional components, not specially manufactured and tooled for mini-bike use, the costs of such vehicles is substantially less than that of a regular motorcycle or motor scooter, and such vehicles have become very popular for off-the-road use. To start the engine of a conventional mini-bike the operator, while seated upon the vehicle, leans over and pulls upwardly upon a rope starter. The starting operation is awkward, and it is difficult to position ones self to apply the maximum pull on the starter rope while simultaneously balancing the vehicle with one hand while astride the same. With an engine difficult to start, it is possible to cause back injuries, or tip the vehicle over, during starting, and the use of a rope starter does not have the appeal of a kick starter to young mini-bike riders who desire that their vehicle be as similar as possible to a conventional motorcycle.

SUMMARY OF THE INVENTION It is an object of the invention to provide a foot operated kick starter for small, conventional, internal combustion engines of the horizontal crankshaft type, such as used with mini-bikes and the like, which may be economically manufactured and exteriorly mounted upon conventional, mass produced engines.

In the kick starter in accord with the invention the desired construction is such that the likelihood of the operator engaging his shins against starter structure during cranking and the downward stroke of the crank arm, is minimized, and internal gearing is employed in the starter in order to permit the movement of the operators foot to sufficiently rotate the engine flywheel to start the engine.

Another object of the kick starter of the invention is to permit the starter structure to be mounted upon a wide variety of engine configurations, the starter being exteriorly mounted on the engine flywheel housing, and may be substituted for rope recoil starters wherein no modification to the engine is necessary to accommodate a starter in accord with the inventive concept. The kick starter of the invention may utilize identical engine flywheel mounted starter clutch mechanisms as rope or impulse starters.

The invention comprises a casing having an outer side from which extends a crank arm, and an inner side disposed toward the engine flywheel housing, casing supporting structure extending from the casing from the inner side permitting the casing to be mounted upon the engine flywheel housing. The crank arm is attached to a shaft rotatably mounted in the casing upon bearings located in the casing outer and inner sides, and the crank arm includes a foot pedal which may be angularly adjusted relative to the crank arm to extend transversely to the plane of crank arm movement during engine cranking, and may be turned to an out-ofthe-way position within the plane of movement of the crank arm when not in use.

A second shaft is mounted upon bearings located within the sides of the casing and has an end extending from the casing inner side upon which engine flywheel starter clutch engaging mechanism is located. Such mechanism includes a radially movable dog, and a dog actuator which radially locates the dog when the associaed shaft is rotated in a cranking direction. Rotation of the dog mounted shaft in a noncranking direction retracts the dog from the flywheel mounted mechanism, in order to clear such mechanism during engine operation.

A small pinion gear is fixed on the shaft supporting the flywheel driving dog, and a larger gear is concentrically disposed to the shaft connected to the starter crank arm. Torque limiting means interconnect the large gear to its associated shaft whereby, in the event of engine pre-ignition or backfire during cranking, slippage may occur between the large gear and the crank arm protecting the operator from injury. Such torque limiting means takes the form of an adjustable friction clutch interposed between the gear and its shaft utilizing a friction material. The torque transmitting characteristics are adjustable by the tightening of a nut mounted on the shaft which varies the degree of frictional engagement between the gear and a shaft mounted clutch plate. The clutch plate also serves as crank arm positioning means in that a radial projection is defined upon the clutch plate for cooperation with an abutment formed on the casing to insure that the crank arm will always assume the same angular position with respect to the casing at the termination of starter rewind to insure the most effective starting stroke. For instance, at the beginning of the cranking stroke the crank arm should be at an angle locating the crank arm foot pedal as high as possible, but not in alignment with the direction of force and the crank axis of rotation, so that as the operator applies his weight to the crank arm it may move through as great an arc of movement as possible.

A spiral rewind spring is located within the casing and is operatively connected to the shaft supporting the crank arm for rewinding, or returning, the starter structure to its initial position after engine cranking. The spring is preferably mounted within a separate spring housing for ease of assembly and replacement.

The crank arm is mounted to its shaft in such a manner as to be exteriorly angularly adjustable with respect to its shaft in order that the operator, if desired, may easily vary the angle, and location of the foot pedal as positioned at the beginning of the starting stroke. Additionally, the support of the starter casing shafts at each end provides maximum strength at these components, and the construction of a starter in accord with the invention provides a dependable kick starter which may be produced at an economical cost which is capable of withstanding the high torque forces imposed thereon, and is not likely to malfunction during normal usage.

BRIEF DESCRIPTION OF THE DRAWINGS The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein:

FIG. I is a perspective view of a mini-bike vehicle utilizing a kick starter in accord with the invention,

FIG. 2 is an elevational view of the outer side of a kick starter in accord with the invention, the foot pedal being rotated to the operative position,

FIG. 3 is an end view of the starter, as taken from the left of FIG. 2, he foot pedal being shown in dotted lines in the inoperative position,

FIG. 4 is an elevational, sectional view taken along Section IV-IV of FIG. 2,

FIG. 5 is an elevational view of the inner side of a starter in accord with the invention,

FIG. 6 is a detail, sectional view of the clutch plate and crank arm position abutment as taken along Section VIVI of FIG. 4,

FIG. 7 is a detail, sectional view taken along Section VII-VII of FIG. 4,

FIG. 8 is a detail, sectional view of the underside of the crank arm as taken along Section VIIIVIII of FIG. 4,

FIG. 9 is a detail, sectional view illutrating the friction brake structure for the dog actuator as taken along Section IXIX of FIG. 4,

FIG. I0 is a detail, sectional view illustrating the foot pedal support detent and slot as taken along Section XX OF FIG. 4,

FIG. 11 is a detail, sectional view taken through the starter dog supporting structure along Section XIXl of FIG. 4,

FIG. 12 is an enlarged, detail, elevational view of the starter dog and dog actuator, and flywheel mounted clutch cup, illustrating the dog in the inactive position as taken at Section XIIXII of FIG. 4, and

FIG. 13 is a view similar to FIG. 12 illustrating the dog engaging the engine flywheel mounted clutch cup during cranking of the engine.

DESCRIPTION OF THE PREFERRED EMBODIMENT A typical environment of a kick starter in accord with the invention is shown in FIG. 1 wherein the starter is illustrated as mounted upon the engine of a mini-bike 2-wheel vehicle. The mini-bike 10 includes a seat 12. and handle bars 14, and is powered by a small internal combustion engine 16 mounted between the wheels, and drivingly connected to the rear wheel by conventional transmission mechanism, not shown. The engine 16 includes a flywheel 18, FIG. 4, upon which vanes, not shown, are mounted as is well known, for producing a flow of air for cooling purposes. The airflow created by the engine flywheel is directed to the engine cylinder cooling fins by a flywheel housing 20 of sheet metal. The engine 16 is of the horizontal crankshaft type, and is usually a four-cycle engine of approximately 4 or 5 hp.

It will be noted that the kick starter 22 is located directly below the vehicle seat 12 such that the rider straddling the seat, and gripping the handle bars 14, may have ready access to the starter with his right foot, for starting the engine 1 6. In FIG. 1 the starter foot pedal is shown in the nonuse position folded toward the engine as to not interfere with the operators legs during riding of the vehicle.

The kick starter 22 includes a casing 24 which may be of diecast metal having a side 26 which defines the casing outer side. A plate-like inner side 28 is mounted to the casing by screws 30, and defines that side of the casing disposed toward the engine flywheel housing 20, when mounted thereon. Four legs 32 are integrally defined upon the casing and extend beyond the inner plate 28, and include holes 34 for receiving mounting bolts for attaching the casing to the flywheel housing. The legs 32 are of sufficient length to place the body of the casing in spaced relationship to the flywheel housing whereby adequate air passage is defined between the legs so that air may enter the flywheel housing adjacent the flywheel center for cooling purposes.

The casing side 26 is provided with an annular bearing 36, and the plate 28 supports an annular bearing 38 coaxially aligned with the bearing 36. These bearings rotatably support the shaft 40 at axially spaced locations capable of effectively resisting bending forces imposed upon the shaft during cranking.

The shaft 49 includes an outer end which extends from the casing side 26, and is formed with modified splines 42, FIG. 8, which cooperate with the crank arm, as will be described. The shaft 40 also includes a cylindrical bearing portion 44 received within bearing 36, and the reduced diameter cylindrical portion 46 adjacent portion 44 is provided with a pair of parallel flats 48, FIG. 6, for keying the shaft to a combination clutch plate or disk 50 and crank positioner. The shaft portion 52 FIG. 4, is threaded with a left hand thread, a is formed with a pair of diametrically located flats 54, and the smallest diameter cylindrical portion 56 is rotatably received within the bearing 38. A snap ring recess is defined at the innermost end of the shaft 40 receiving a snap ring 58.

The crank arm 60 isformed of sheet material and in cludes a flat hub portion 62, FIG. 2, and a tubular sleeve portion 64 radially extending from the hub portion. A radially extending flange depends from the hub portion increasing the strength of the crank arm 60, and a flat plate 66 is firmly affixed, such as by spot welding, to the underside of the hub portion and includes an opening 68, FIG. 8, of a notched configuration corresponding to the splines 42 of the shaft 40. A countersunk hole 70 is formed in the crank hub portion, FIG. 4, concentric with the plate opening 68, and an axial threaded bore defined in the shaft outer end receives the countersunk screw 72 which maintains the crank arm keyed firmly upon the shaft 40 in the selected angular position thereto. By removing the screw 72, and removing the crank arm from the splined shaft end, the crank arm may be angularly related in any desired manner to the shaft 40, and affixed in the desired angular position by the screw.

A right angled foot pedal support 74 includes a portion 76 rotatably received within the crank arm sleeve portion 64, and is also capable of limited axial movement within the sleeve. A detent slot 78 is defined in the wall of the sleeve portion 64 of a length transversely disposed to the axis of the sleeve portion and is of a length circumscribing approximately 90 of the circumference of the sleeve. A pin 80, FIG. 10, mounted within the foot pedal portion 76 radially extends into the slot 78 and limits rotation of the foot pedal support relative to the crank arm and also prevents the foot pedal support from being axially displaced out of the crank sleeve portion. The detent slot 78 includes recesses 82 and 84 defined in the slot wall 86 further-est from the hub portion 62, FIG. 5, and the recesses are adapted to receive the pin 80 at the maximum angular positions of the foot pedal support in order to lock foot pedal support in the desired angular position. The pin 80 is maintained in the recesses S2 and 84 by a compression spring 88 interposed between shoulders defined in the sleeve portion 64 by the plate 66 and the crank arm material, and the end of the portion 76, FIG. 4. Thus, the spring 88 continuously imposes a biasing force on the foot pedal support, which will maintain the pin 80 in either of the recesses 82 or 84, when the pin is aligned therewith.

The foot pedal support '74 also includes a portion 90 perpendicularly disposed to the portion 76 upon which an elongated rubber pedal 92 is mounted, and maintained thereon by a screw and washer assembly 94 threaded ino a threaded hole. The association of the pin and slot 78 permits the foot pedal portion to be rotated from the full line position shown in FIG. 3, to the dotted line position shown in FIG. 3, the angular difference between the two positions being approximately 90 and determined by the pin engaging the ends of the slot. In each of the terminal positions of the foot pedal portion 90 a slot recess 82 or 84 receives the pin 80 to hold the foot pedal in the desired position. FIG. 3 illustrates the position of the foot pedal 2 during cranking, wherein the foot pedal portion 90 is disposed substantially parallel to the shaft 40, and extends away from the engine 16, and the operators foot may readily engage the foot pedal. When the foot pedal portion 90 is swung to the dotted line position of FIG. 3, also as shown in FIG. 1, the foot pedal 9 2 is disposed in the general plane of the crank arm 60, and is out of an interfering position with respect to the vehicle riders legs.

The combination clutch plate and crank arm positioning plate 50 is shown in FIGS. 4 and 6, and consists of a generally circular plate or disk having a radially ex tending projection 96 defined on the periphery thereof forming a radial shoulder 98. The casing 24 includes an integral abutment 100, FIG. 6, within the path of rotational movement of the projection 96 limiting rotation of the plate 50, and the shaft 46, to less than 360. As will be later apparent, the projection and the abutment engage under the influence of the recoil or rewind spiral spring and locate the crank arm in the upper position for the next cranking cycle. The shaft 40 includes a radially extending shoulder 102 adjacent the

portions

44 and 46 which engages the outer side of the plate and axially locates the plate 5t upon the shaft. An annular disk of a friction material 104, such as of fiber or a synthetic composition, circumscribes the shaft 4@ in engagement with the clutch plate surface M6 for torque transmission purposes, as will be described.

A spur gear 103 circumscribes the shaft 40, and is rotatably mounted on the shaft portion 52. The gear includes an outer smooth radial surface engaging the friction material M4, and as will be appreciated in FIG. 4, the friction material is directly disposed between the gear surface 110 and the plate surface 106.

The inner side of the gear W3 is recessed at the center about the shaft and receives an annular washer 1 l2, and an annular Belleville spring washer M4. A nut 116, having a left hand thread, is threaded upon the shaft left hand threads at portion 52 for engagement with the spring washer 114, and compresses the spring washer forcing the gear 103 toward the plate 50, and firmly compressing the friction material MP4 between the surfaces 1106 and 110. Thus, it will be appreciated that the tightening of the nut i116 determines the degree of frictional engagement between the gear, friction material 104 and plate 56, and in this manner the gear 108 is connected to the shaft 40 through the plate Sll by a torque limiting clutch arrangement which may be adjusted as desired by regulating the torque imposed upon the nut 116. In the event that the predetermined torque characteristics between the gear MP8 and the shaft 40 are exceeded, slippage occurs between the gear and the plate 50 at the friction material.

In order to assure that the adjustment of the nut 1116, once made, will not change, the washer i2 is provided with an opening having flats cooperating with the shaft flats 54 keying the washer 112 to the shaft 40 for positive rotation therewith. Thus, the occurrence of relative rotation between the gear 108 and the washer will not be transferred to the spring washer 112 and the nut 116.

Resetting or rewinding of the starter, after a cranking stroke, is produced by a spiral spring 118 within the casing 24 and disposed about the shaft 40. The spring 118 is preferably encased within a lightweight sheet metal housing 120, FIGS. 4 and 7, which includes radially extending portions 122 which are received within recesses 124, FIG. 7 defines in an annular wall 126 formed on the casing plate 28 receiving the spring housing. In this manner the spring housing 120 is fixed against rotation with respect to the casing. The outer end 128 of the spiral spring 118 is received within a slot 130, FIG. 7, defined in the spring housing 120, and is thereby fixed with respect to the casing. The inner end of the spiral spring is received within a notch 132 defined in the nut 116 wherein torsion forces within the spiral spring are imposed upon the shaft 40, and its associated assembly, through the nut. The spring 118 is wound during the downward engine cranking motion of the crank arm 60, and the torsional forces produced in the spring 118 raise the crank arm to the position shown in FIG. 1 after the starting or cranking stroke of the crank as produced by the operators foot. The crank arm is preferably attached to the shaft 40 at such an angular position that rotation of the shaft 40 and plate 50, under the influence of the spring 118 ceases when the crank arm is oriented as shown in FIG. 1, in a generally upward direction, but not straight up, in order than an effective cranking motion of the crank arm may be produced. Uniform positioning of the crank arm prior to each cranking stroke is assured by engagement of the projection 96 with the abutment 100, as shown in FIG. 6. Shoulder the user desire to change the initial angle of the crank arm to the shaft 40, for individual preference purposes, such an adjutmerit may easily be made by removing the screw 72 as described above.

A second shaft 134 is rotatably mounted on the easing 24 within an annular bearing 136 supported on the casing outer side 26, and is also supported in the annular bearing 138 pressed into the plate 28. It will be noted that the boss 140 defined in the plate 28 in which the bearing 138 is mounted is of a considerable axial dimension wherein the bearing 138 may have an axial length at least half the length of the shaft 134 and in this manner provide heavy duty support of the shaft for resisting bending forces imposed upon the inner end of the shaft during engine cranking. A pinion gear 142 is attached to the shaft 134 as to be an integral part thereof, and meshes with the large spur gear 108.

The inner end of shaft 134 extends from the casing through plate 28 and serves as the support for the starter dog structure which drives the flywheel starter clutch mechanism. The inner end of the shaft 134 is of a slightly reduced diameter and includes flats 144, FIG. 11, which permit the dog arm 146 to be keyed to the shaft in a positive manner. The dog arm 146 consists of two stamped sheet metal parts spot welded together to form an integral unit for supporting the dog pivot pin 148, which extends in a direction parallel to the axis of the shaft 134, but radially offset therefrom. The dog arm is recessed at 150, FIG. 4, providing clearance for receiving the torsion spring 152, FIG. 11, and the starter dog 154 is pivotally mounted upon the pin 148. A recess and cooperating snap ring 156 maintain the dog upon the pivot pin. An end 158 of the torsion spring, FIG. 11, bears upon a surface of the dog arm 146, while the other spring end 160, FIG. 13, of the torsion spring engages the dog 154 to pivot the outer end of the dog toward the axis of the shaft 134, as will be later described.

The dog actuator plate 162 is mounted for rotation about the axis of the shaft 134 upon the shoulder surface 164 of the screw 166 screwed into a threaded bore in the inner end of shaft 134, and as will be apparent from FIG. 4, a washer 168 resting on the inner end of the shaft 134 overlays the dog arm 146 to maintain the dog arm firmly on the shaft, and simultaneously, the screw 166, permits the dog actuator to rotate about the axis of shaft 134.

The dog actuator 162 is adapted to rotate about the axis of the shaft with a predetermined frictional resistance. This resistance is produced by a brake 178 in the form of a wire having a generally rectangular base configuration frictionally gripping an annular groove 172 defined on the bearing 138. The brake wire includes an inwardly extending arm 174 received within a notch 176 defined in the dog actuator, and the innermost end of the brake wire arm is turned inwardly in order to resist displacement of the wire arm from the notch. In this manner the frictional engagement of the wire brake in the annular groove 172 resists rotation of the dog actuator 162, but permits rotation of the dog actuator once the frictional resistance to rotation of the wire brake is overcome.

The kick starter of the invention cooperates with starter clutch mechanism mounted upon the engine flywheel 18, and this clutch mechanism may be very similar to clutch mechanisms used with rope recoil starters. As shown in FIG. 4, a form of clutch mechanism includes a cup 178 of a dished configuration having an axis concentrically related to the engine flywheel axis. The cup 178 is bolted or otherwise firmly affixed to the flywheel, and includes axially extending sides having inwardly deflected lanced projections 180 for selective engagement by the starter dog. The lanced construction of the projections form the projections with an inclined foward surface 182, while the projections abutment surface 184 is substantially radial with respect to the axis of rotation.

In use, the kick starter 22 is attached to the engine flywheel housing 20 by bolts, not shown, extending through the support leg holes 34. The mounting holes defined on the flywheel housing are normally uniformly located and positioned about the axis of the flywheel 18, and permit the attachment of either a rope recoil starter or a kick starter. It is one of the advantages of the invention that the kick starter disclosed may be mounted upon existing intemal combustion engines as a replacement for a rope recoil starter. In mounting the starter 22 upon the flywheel housing 20 the axis of the shaft 134 is coaxially aligned with the flywheel axis of rotation, and the dog 154, and other starter mounted components directly associated therewith will be located within the flywheel mounted starter clutch cup 178, FIG. 4.

The assembly of the starter and engine will now appear as in FIG. 1, and when it is desired to start the engine the operator normally straddles the vehicle seat 12, and grasps the vehicle handle bars 14 to maintain the vehicle in an upright position. The foot pedal 92 will normally be turned inwardly to the position shown in FIG. 1, and the operator will rotate the foot pedal support 74 90 to dispose the foot pedal in the outward or cranking position shown in full lines in FIG. 3. Turning of the foot pedal support causes the pin 80 to move to the other end of the associated detent slot 78 and engage the other recess 82. The recesses 82 and 84 insure that the foot pedal support will remain in either of the two positions illustrated in FIG. 3, and will not vibrate or otherwise inadvertently rotate in the sleeve portion 76 to a position not purposely adjusted by the operator.

With the foot pedal 92 disposed outwardly as in FIG. 3, the operator places his foot upon the pedal and rapidly applies his weight downwardly on the pedal, or kicks the pedal downwardly. This action, of course, rotates the shaft 40, the plate 50 and the gear 108 through the friction clutch connection defined by friction material 1114. Rotation of the gear 108 rotates pinion 142 and shaft 134 and the starter dog structure mounted thereon. The operation of the dog structure is best appreciated from FIGS. 5, 12 and 13.

At the normal rest position of the starter components, the dog actuator plate 162 and the dog 154 will be positioned as shown in FIGS. and 12. The previous rotation of the shaft 40 under the influence of the spiral spring 1 18 rotates the shaft 134 in a noncranking direction, i.e., clockwise, as viewed in FIGS. 5 and 12. Clockwise rotation of the dog arm 146 causes the dog hub 186 to engage the complementary shaped surface 188 defined on the actuator plate 162.

In this condition the rear projection 190 defined upon the dog 154 overlaps the end 192 of actuator plate which prevents the forward end 194 of the dog from moving radially outward for possible inadvertent engagement with the flywheel mounted clutch cup 178. The spring 152 and spring end 1611 continually bias the dog 15 1 in a counterclockwise direction, FIG. 12, and the configuration of the dog hub is such as to conform to the configuration defined on the actuator plate and engage the actuator plate at point 196 to maintain the dog position shown in FIG. 12.

As soon as the shaft 134 is rotated in an engine cranking direction the dog arm and pin 148 move in a counterclockwise direction, FIGS. 12 and 13, with respect to the axis of the shaft. Such action disengages the dog projection 1911 from the dog actuator end 192, and causes the convex dog surface 198 to engage the radially disposed dog actuator surface 201). The continued counterclockwise rotation of the shaft 134, dog arm, and dog 154 relative to the stationary actuator plate 162 causes the dog end 194 to ride outwardly on the dog actuator surface 200 pivoting the dog about its pivot 148 and radially extending the dog forward end outwardly until the dog forward end engages one of the radial abutments 184 defined upon the clutch cup 178, as shown in FIG. 13. Engagement of the dog end with a cup projection abutment establishes a positive interconnection between the starter 22 and the flywheel 18 and continued rotation of the shaft rotates the clutch cup and the flywheel for engine starting purposes. During cranking, the engagement of the dog with the outer apex of the surface 200, FIG. 13, causes the dog actuator plate 162 to rotate about the axis of shaft 134 as the frictional drag produced by the brake wire 170 will be overcome.

The termination of the cranking stroke of crank arm 60 is normally determined by the crank arm pivoting to its lowermost position, and, normally, the rotation of the shaft 411 is not so great that the projection 96 will engage the casing abutment 100. At the end ofa cranking stroke the operator either removes his foot from the foot pedal 92, or raises his foot in order to permit the crank arm to rotate in a clockwise direction, FIGS. 1 and 2, to its predetermined initial position as shown in FIG. 1. The starter components return to the rewound or recocked position under the influence of the torque produced by spiral spring 118 which rotates shaft 40 in the opposite direction than occurred during engine cranking due to the force that was stored within the spiral spring during the winding thereof during cranking. As soon as the shaft 134 rotates in a clockwise direction, FIGS. 12 and 13, the biasing force imposed upon the dog 154 by the spring 152 maintains the engagement of the dog with the actuator surface 206, and as the resistance to rotation of the actuator plate 162 as produced by the brake wire initially holds the actuator plate stationary, the dog surface 198 rides inwardly on the actuator surface 201 clearing the dog end 194 from the associated cup abutment 194, permitting the outer end of the dog to move radially inward toward the axis of shaft 134. Clockwise rotation of the dog arm and dog pin, and counterclockwise pivoting of dog 154 continues until the relationship shown in FIG. 12 is achieved, thereupon continued clockwise rotation of the dog arm causes rotation of the dog actuator plate 162 until rotation of the starter components cease upon engagement of the projection 96 with the casing abutment 1110.

If the engine did not previously start, the starter is now ready for further engine cranking and the operator repeats the cycle described above. If the engine started, the operator pivots pedal 92 to the position of FIG. 1.

Upon the engine starting, the flywheel 18 will begin to rotate faster than the rotation of the starter shaft 134. Siuch action causes the lanced projection forward surface 182 of the projection 181) immediately behind that cup projection engaged by the dog during cranking, to engage the dog outer surface 262, FIG. 13. Such engagement of a cup surface 182 with the dog imposes a force on the forward end of the dog rotating the dog in a conterclockwise direction about its pin 148, and simultaneously rotating the actuator plate 162 in a counterclockwise direction. In this manner the dog 154 is automatically cleared from the clutch cup 178 when the enginge starts, and even before the operator can release the foot pedal 92, the dog will be out of engagement with the cluch cup and no hammering[ of the dog or undesirable ratcheting noise will occur. When the operator permits the crank arm 60 to rotate upwardly towards its initial position, the at rest position of FIG. 12 will be assumed between the dog and the actuator plate 162, and the spring 152 and the engagement of projection and end 192 insures that the dog will not inadvertently swing outwardly for engagement with the rotating clutch cup.

If, during cranking of the engine, a premature combustion of the fuel creates a backfire, high torque forces will be imposed upon the starter components in a direction against the forces being applied to the starter by the operatorQSuch sudden forces could be transmitted through the starter components reversing the direction of rotation of the crank arm 61) and possibly injurying the operator, and it has been known for kick starters on motorcycles to break a leg or ankle, or unseat the vehicle user. Additionally, the possibility of damaging the starter exists during the imposing of such excessive forces on the components thereof.

However, in accord with the invention, the nut 116 is adjusted such that the torque transmitting characteristics between the gear 108 and the shaft 40 are such that slippage occurs between the gear 108 and the plate 50 prior to the transmission of such torque forces as might possibly injure the operator, or damage the starter mechanism. The accurate tightening of the nut 116, and the uniform biasing force imposed upon the gear 108 in an axial direction toward the plate 50 through the spring washer 114 permits the starter safety clutch to be very accurately adjusted for safety purposes. Additionally, the safety friction clutch feature requires no resetting, and the protection provided is always present without attention by the operator.

The flat construction of the crank hub portion 62 and the countersinking of the screw 72 eliminates many of the hazards of conventional kick starters wherein it is common for the operator to engage his shin against starter structure while cranking. Further, the support of the

shafts

40 and 134 by axially spaced bearings permit a concise kick starter to be constructed which is of a high strength, yet may be exteriorly mounted upon in ternal combustion engines, and the kick starter may serve as a replacement for other types of starters, such as of the rope recoil type.

It is appreciated that various modifications to the described embodiment may be apparent to those skilled in the art without departing from the spirit and scope of the invention.

1 claim:

1. A kick starter for internal combustion engines having a flywheel, a starter clutch member concentrically mounted on the flywheel, and a flywheel housing, wherein the starter is exteriorly mounted upon the flywheel housing comprising, in combination, a casing having outer and inner sides, engine flywheel housing mounting means defined on said casing extending beyond said inner side, a first shaft rotatably mounted upon said casing having an end exteriorly accessible from said outer side, a foot operated crank attached to said shaft end exteriorly of said casing and adjacent said outer side, a second shaft rotatably mounted in said casing substantially parallel to and spaced from said first shaft having an end extending from said casing inner side, a first gear within said casing concentrically related to said first shaft, means drivingly connecting said gear to said first shaft, a second gear within said casing concentrically fixed upon said second shaft in mesh with said first gear, a spiral spring within said casing disposed about said first shaft having an outer end fixed with rspect to said casing and an inner end operatively connected to said first shaft imposing a rewinding torque on said first shaft, crank positioning means connected to said first shaft limiting rotation of said first shaft to position said crank prior to engine cranking, a radially movable dog mounted upon said second shaft end extending from said casing, and a dog actuator mounted on said second shaft end radially positioning said dog for driving engagement with the flywheel starter clutch member upon rotation of said crank, gears, and shafts in an engine cranking direction.

2. In a kick starter for internal combustion engines as in claim 1, wherein said crank is formed of stamped sheet metal having a substantially flat hub portion adjacent said first shaft end, a plate integrally attached to said hub portion having a generally circular notched opening, a spline defined on said first shaft end selectively angularly receivable within said notched opening, an axial threaded bore defined in said first shaft end and a screw threaded into said bore extending through said hub portion maintaining the assembly of said crank hub portion and plate upon said splined first shaft end.

3. In a kick starter for internal combustion engines as in claim 1, axially aligned first bearing means mounted on said casing outer and inner sides rotatably supporting said first shaft, and second axially aligned bearing means mounted on said casing outer and inner sides rotatably supporting said second shaft.

4. In a kick starter as in claim 1 wherein said crank positioning means comprises a disk plate within said casing keyed to said first shaft, a radial projection defined on said disk plate, and an abutment defined on said casing within the path of movement of said projection upon rotation of said first shaft and disk plate whereby upon engagement of said projection with said abutment rotation of said first shaft is terminated.

5. In a kick starter for internal combustion engines as in claim 1, wherein said means drivingly connecting said first gear to said first shaft comprises torque limit ing means transmitting a predetermined torque between said first shaft and said first gear.

6. In a kick starter for internal combustion engines as in claim 5, wherein said first gear is axially displaceable on said first shaft and said torque limiting means comprises an axially fixed clutch plate keyed to said first shaft having a frist radial surface, a second radial surface defined on said first gear in opposed axial alignment with said first radial surface, a friction material interposed between and engaging said first and second radial surfaces, and adjustable means imposing an axial force on said first gear in the direction of said clutch plate and friction material determining the extent of frictional engagement beteen said friction material and said first and second radial surfaces.

7. In a kick starter for internal combustion engines as in claim 6, wherein said adjustable means imposing an axial force on said first gear comprises a nut threaded upon threads defined on said first shaft axially located on the opposite side of said first gear with respect to said second radial surface, and a compression spring located between said nut and said first gear imposing an axial force on said first gear having a magnitude determined by the position of said nut.

8. A kick starter for internal combustion engines adapted to be exteriorly mounted upon engine structure comprising, in combination, a casing having outer and inner sides, engine mounting means defined on said casing, a first shaft rotatably mounted upon said casing having an end exteriorly accessible from said outer side, a foot operated crank attached to said shaft end exteriorly of said casing and adjacent said outer side, said crank including a tubular portion defining a socket having an axis transversely disposed to the length of said first shaft, a foot pedal support having a first portion pivotally and axially movably supported in said socket and a second portion angularly disposed to said first portion, a foot pedal mounted on said second portion, a slot defined in said crank tubular portion by side walls having a length transversely disposed to said socket axis, a pin mounted on said foot pedal support first portion movably received within said slot whereby said slot limits the degree of pivoting of said pedal support within said socket, a spring mounted on said crank within said socket axially biasing said support first portion and frictionally engaging said pin against a slot wall, and spaced detent recess means defined in said slot wall engageable by said pin for selectively angu larly positioning said foot pedal support, a second shaft rotatably mounted in said casing substantially parallel to and spaced from said first shaft having an end extending from said casing inner side a first gear within said casing concentrically related to said first shaft, means drivingly connecting said gear to said first shaft,

said casing inner side.

Claims

1. A kick starter for internal combustion engines having a flywheel, a starter clutch member concentrically mounted on the flywheel, and a flywheel housing, wherein the starter is exteriorly mounted upon the flywheel housing comprising, in combination, a casing having outer and inner sides, engine flywheel housing mounting means defined on said casing extending beyond said inner side, a first shaft rotatably mounted upon said casing having an end exteriorly accessible from said outer side, a foot operated crank attached to said shaft end exteriorly of said casing and adjacent said outer side, a second shaft rotatably mounted in said casing substantially parallel to and spaced from said first shaft having an end extending from said casing inner side, a first gear within said casing concentrically related to said first shaft, means drivingly connecting said gear to said first shaft, a second gear within said casing concentrically fixed upon said second shaft in mesh with said first gear, a spiral spring within said casing disposed about said first shaft having an outer end fixed with respect to said casing and an inner end operatively connected to said first shaft imposing a rewinding torque on said first shaft, crank positioning means connected to said first shaft limiting rotation of said first shaft to position said crank prior to engine cranking, a radially movable dog mounted upon said second shaft end extending from said casing, and a dog actuator mounted on said second shaft end radially positioning said dog fOr driving engagement with the flywheel starter clutch member upon rotation of said crank, gears, and shafts in an engine cranking direction.

5. In a kick starter for internal combustion engines as in claim 1, wherein said means drivingly connecting said first gear to said first shaft comprises torque limiting means transmitting a predetermined torque between said first shaft and said first gear.

8. A kick starter for internal combustion engines adapted to be exteriorly mounted upon engine structure comprising, in combination, a casing having outer and inner sides, engine mounting means defined on said casing, a first shaft rotatably mounted upon said casing having an end exteriorly accessible from said outer side, a foot operated crank attached to said shaft end exteriorly of said casing and adjacent said outer side, said crank including a tubular portion defining a socket having an axis transversely disposed to the length of said first shaft, a foot pedal support having a first portion pivotally and axially movably supported in said socket and a second portion angularly disposed to said first portion, a foot pedal mounted on said second portion, a slot defined in said crank tubular portion by side walls having a length transversely disposed to said socket axis, a pin mounted on said foot pedal support first portion movably received within said slot whereby said slot limits the degree of pivoting of said pedal support within said socket, a spring mounted on saiD crank within said socket axially biasing said support first portion and frictionally engaging said pin against a slot wall, and spaced detent recess means defined in said slot wall engageable by said pin for selectively angularly positioning said foot pedal support, a second shaft rotatably mounted in said casing substantially parallel to and spaced from said first shaft having an end extending from said casing inner side, a first gear within said casing concentrically related to said first shaft, means drivingly connecting said gear to said first shaft, a second gear concentrically fixed upon said second shaft in mesh with said first gear, a spiral spring within said casing disposed about said first shaft having an outer end fixed with respect to said casing and an inner end operatively connected to said first shaft, crank positioning means connected to said first shaft limiting rotation of said first shaft to position said crank prior to engine cranking, and engine cranking clutch means mounted upon said second shaft end extending from said casing inner side.