US3081760A - Spring starter - Google Patents

Description

March 19, 1963 L. J. HAMMAN 3,081,760

SPRING STARTER Filed Nov. 30, 1960 2 Sheets-Sheet l INVENTOR LYLE df HAMMAN ATTORNEY March 19, 1963 L. J. HAMMAN 3,081,760

SPRING STARTER Filed Nov. 30, 1960 2 Sheets-Sheet 2 INVENTOR LYLE J HA MMAN @MMM A'I'TCRNEY 3,@8 l ,76d Patented Mar. 19, 1%63 ice 3,081,7eii SPG STARTER Lyle l'. Hammam, Eaton Rapids, Mich., assigner to Eaton Stamping Company, Eaton Rapids, Mich., a corporation of Michigan- Filed Nov. 30, 1960, Ser. No. 72,738 12 Claims. ('Cl. 1232-179) The present invention relates to improvements in spring starte-rs for internal combustion engines of the general type which are mounted on the engine in axial alignment with the crankshaft. Upon release of the energy stored in the spring of the starter, a driven member rotated by the spring is clutched to the crankshaft to start the engine.

Starters of the above described type, when installed upon small, relatively high speed engines, such as those used upon rotary lawn mowers and the like, are subject to excessive vibration. It has been found in practice that wear upon component parts of the starter, due to vibration of the engine with the starter inoperative, is more of a problem than the wear and stresses placed upon the starter during its infrequent periods of engine starting operation.

More specifically, the invention relates to spring starters of the type in which a spiral spring is wound up by wrapping the outer end of the spring about the inner held end and the energy thus stored in the spring is released by permitting the inner end of the spring to rotate.

It is one of the objects of the present invention to provide an improved starter of the type described in which the component parts of the starter are so constructed and designed that detrimental vibration eifects have been greatly reduced with the result that malfunction of control parts has been obviated to a great extent and wear rattle of the component parts of the starter, due to vibration, have been substantially reduced.

Another object of the invention is to provide an improved starter of the type described in which a ratchet action winding handle is provided at substantially no increase in cost of production as compared with present designs having nonratchet action handle winding.

Another object is to provide an improved brake structure for the winding handle for holding the same against Vibration, rattle and creeping when the starter is not being used.

A still further object is to provide a starter of the type described in which long, sturdy bearing structure is provided for the rotational parts yet the starter is compact and has relatively few parts.

A still further object of the invention is to provide a spiral spring starte-r in which the locking and release structure for the energy stored in the spring will provide extensive service without replacement and the adverse loading of the bearing structure is held to a minimum.

A still further object is to provide an improved and inexpensive ratchet clutch assembly between the winding handleI and the spring.

Another object is to provide an improved and simplified clutch for coupling the driven member of the starter and the crankshaft of the engine in which the dogs are projected by a combination of inertia and centrifugal forces and then withdrawn and held out of engagement following starting by continuously acting means.

Another object of the invention is to provide a spring starter having a spiral spring which, in operation, is wound up from the outside and is released from the inside in which the dog for holding the outer end of the spring takes the reaction of the spring through a hub located adjacent the axis about which the spring is wound while the dog for taking the reaction of the inner end of the spring acts upon a hub in which the inner end of the spring is attached, the first hub having an external bearing and the second hub being supported upon a shaft supported by the first hub.

A still further object of the invention is to provide a spiral spring starter in which the spring is externally wound to store up energy within the spring and then internally released to release the energy, there being a pair of hubs axially aligned upon a common shaft in which the inner and outer ends of the spring are attached, the shaft having a ratchet connection with one hub and the other hub being `freely rotatable upon the shaft and an external bearing for one of the hubs giving common support to both hubs as well as the shaft."

Another object of the invention is to provide a spring starter having a crank handle foldable to an inoperative position wherein folding the handle to the inoperative position automatically applies brake means restraining the crank against rotation.

These and other objects of the invention arising from the details and relationships of the components of an embodiment thereof will be apparent from the following description and accompanying drawings, wherein:

FIG. 1 is an elevational sectional view of the starter in accord with the invention having a folded handle illustrated in the folded position,

FIG. 2 is a plan sectional view of the starter of FIG. l taken along section H-II thereof illustrating only a portion of the spiral spring,

FIG. 3 is a sectional plan detail View of the upper hub ratchet structure taken along section IiI--III of FIG. l,

FlG. 4 is a plan sectional detail View of the unidirectional drive means of the crank mounted shaft and brake band as taken along section IV-lV of FIG. 1,

FIG. 5 is a plan sectional detail View of the clutch structure employed with the invention in the retracted position, as taken along section VI-V of FIG. 1,

FIG. 6 is a sectional plan view similar to FlG. 5, showing the clutch dogs in driving engagement with the drive cup, and

FIG. 7 is an elevational sectional View of the handle brake band taken along section VII- VII of- FIG. 4.

The starter of the invention is primarily intended to be used with small internal combustion engines such as the type used with lawn mowers, garden tractors and the like and may be employed with engines having either vertically or horizontally extending crankshafts. For purposes of description, the disclosed starter will be described as used in conjunction with a vertically extending crankshaft engine, such as those employed with rotary lawn mowers.

The starter consists of a housing 10, preferably of stamped and drawn steel, of a substantially cylindrical configuration being enclosed at the top at 12; and having a plurality of downwardly extending leg portions 14 `having engine housing mounting holes `16 formed in radially extending portions of the legs. The holes 16 receive bolts which enable the starter to be aixed to the engine housing in a substantially concentric relationship to the axis of the engine crankshaft. A cylindrical bearing member 18 having an internal bore Ztl, substantially concentric with the crankshaft axis, is iirmly aflixed to the housing top portion 12 as to become an integral part thereof, The bearing member 1S is provided with a peripheral recessed groove 2.2 adjacent its upper end, PEG. 1, for a purpose which will be later described. The bearing member is also provided with an axially extending recess 24 adjacent and intersecting the bore 2li, FIGS. 3 and 4, which receive a pivotally mounted dog member 26 in the lower region of the groove and the upper region of the groove is provided with a spring 23 bearing against the dog member to bias the outer end of the same inwardly.

An upper hub 30 is rotatably received within the bore 2t) of the bearing member 18 and is of an axial length slightly greater than that of the bearing member and is provided at its lower peripheral regions with ratchet teetn 32, FIG. 3. It will be noted that the ratchet teeth 32 are formed such that a considerable peripheral bearing surface exists between the adjacent teeth. Hub 3o is formed with a concentric bore 34 extending therethrough and three recesses 36, peripherally displaced 120 to each other, FIG. 4, are formed in the upper end of the bore lfor a purpose which will be later described. It will be noted that the hub 3l) is provided with bearing surfaces throughout its length and, hence, considerable bearing area is produced. The lower end of the hub is provided with a spring keeper 38 permanently afiixed thereto having an axial portion 40 to define a cylindrical housing in which a spiral spring `42, is received. A hole is formed in the keeper portion 40 to receive the hooked outer end 44, FIG. 2., of the spiral spring.

A shaft 46 is rotatably received and supported within the hub bore 34 and is provided at its lower end with an axially threaded bore. The upper end of shaft 46 is provided with a radially extending groove 4S which slidably receives a clutch dog S0, which, in conjunction with the recesses 36 provides a sliding pin unidirectional drive between the shaft 46 and hub Sti. The upper end of the shaft 46 is firmly afiixed to a crank portion 52 by swaging, welding or other fastening procedure wherein rotation of the crank portion will rotate the shaft.

The crank portion 52 is best illustrated in FIGS. l and 4 and consists of a member having a downwardly extending iiange portion which encompasses the upper portion of the bearing member 18. The crank member 52 is provided with a pivot pin lat 54 to which a crank handle portion 56 is pivotally affixed. Thus, upon swinging the handle crank portion 56 in a direction 180 clockwise to that of FIG. 1, the operator may grasp the knob S and rotate the shaft 46. The crank portion y556 is of U-crosssection, FIG. 7, and is provided with lateral leg portions 60 which are spaced apart a distance to receive the crank portion 52 therebetween when the portion 56 is in the folded position. The crank portion 52 supports a friction Iband 62, FIG. 4, which has an annular circular portion 63 which is received within the bearing member groove 22. The ends of the band 62 are provided with tab portions 64, having rounded upper edges, which are received within slots 66 defined in the downwardly extending flange portions of member 52. The tabs 64 are of such length as to normally project beyond the flange portions permitting the circular band portion 63 to open such that a free sliding relationship with the bearing member 1@ is produced. When the crank handle portion 56 is folded to the inoperative position of FIGS. l and 7, the portions 60 will engage the rounded ends of the tabs 64 forcing and maintaining the ends of the `band in their inwardly most position. In this relationship, the band portion 63 frictionally grips the groove 22 of bearing member 18 restraining the crank portion 52, and associated components, against rotation or creeping due to vibration of the starter while the engine is operating.

A lower hub or drive member 68 is rotatably mounted upon the lower portion of the shaft 46 wherein the upper portion of this hub is located within the confines of the keeper portion 4o and the lower portion of hub extends toward the engine upon which the starter is mounted. The upper portion of the hub member 68 is formed with a plurality, .three in the illustrated embodiment, of spiralshaped recesses '70, FIG. 2, any one of which may receive the coiled inner end 72 of the spiral spring 42. In this Vmanner, the inner end of the spring is attached to the hub 6d to drive the hub in an engine cranking direction. A radially extending spring cover 74 is permanently affixed to the hub 68 `and provides a supporting surface for the spiral spring. The outer configuration of the cover 74 is best shown in FIG. 2, wherein the cover is of a substantially square configuration having notches adjacent the corners thereof defining an abutment surface 76 at each corner.

The hub 68 is restrained against rotation by means of a release lever 7S which is pivotally mounted upon a radially extending portion 80 of the housing by a pivot pin S2. Spring 84 biases the release lever 78 toward the cover 74 such that an abutment portion 86 defined upon the release lever may selectively engage one of the cover abutment surfaces 76. A trip lever 8S is pivotally mounted upon the pin 82 below the release lever and includes an opstanding portion -9o which engages the release lever wherein a Bowden wire or similar actuating means affixed to the trip lever may be employed to pivotally r-adially move the release lever and trip lever away from the cover to selectively release the hub 68 for rotation in an engine cranking direction. It will be noted from FIG. 1 that the outer region of the cover 74 is deflected downwardly to provide proper clearance for the operation of the release lever for engagement with the cover.

The lower end of the hub 68 is of an annular ring configuration wherein the center is recessed and a headed screw 92 threaded into the threaded bore of the shaft 46 overlaps the hub and maintain the same upon the shaft. Referring to FIGS, 5 and 6, it will be seen that the lower hub por-tion is provided with three boss elements 94 having cylindrical recesses 96 and a clutch dog member 98 lhaving a cylindrically formed end is pivotally mounted within each recess 96 having an outer end for radial movement relative to the hub. A circular cup-like clutch dog retainer 160' is rotatably mounted upon the shaft 46, being interposed between the head of the screw 92 and the hub '68 and the clutch retainer includes an oulter periphery in which three portions 162 are refiected inwardly to define slots 104 or openings through which the dogs 98 may project. The portions 102 of the outer retainer wall are angularly disposed to guide the outward dog movement. A tension spring 106 is anchored at one end to the hub 68 and is anchored a-t the other end to the retainer 10E)` through a hole defined in one of the lanced portions 162. Spring 106 tends to bias the Vretainer in a counterclockwise direction, FIGS. 5 and 6. A friction brake element 110 is interposed between the inner surface 112 of the clutch retainer and the hub 68, FIG. l, to create a frictional drag between the retainer and the shaft 46. The brake member 11i)` consists of a spring steel member having a plurality of fingers and is similar to the brake element shown in U.S.V Patent No. 2,926,648.

The engine crankshaft is provided with a cup-like driving member 114, which is usually afiixed to the top of the iiywhe'el, and a plurality of teeth 116 are formed on the inside surface of the cup for engagement by the clutch dogs 98 during the engine cranking operation.

The operation of the starter is as follows: The spring biased release lever 78 will normally be in a radially inward position so as to engage one of the abutments 76 upon any rotation of the hub 68. The operator will unfold the handle portion 56 to the operative spring cranking position, which releases brake bands 62 grip upon bearing member 18, and rotate the crank handle in a direction which will rotate the hub 36 and keeper 38 to wind the spiral spring 42. Rotation of the hub 63 is prevented by the engagement of the abutments 76 and S6. As the spiral spring is wound, the engagement of the dog 26 and the ratchet teeth 32 prevents rotation yof the hub 30 in an unwinding direction and the unidirectional drive connection between the shaft 46 and hub 30 by means of the sliding clutch dog element S0 and recesses 36 permits the operator to wind the spring by rotating the crank through a. limited arc motion and does not necessarily require a complete 360 rotation of the crank member S6. After the spring 42 has been sufficiently wound, the trip lever 8? is pivoted away from the housing 1G to disengage the abutments 76 and 86 and permit rotation of the' hub 68 under influence of the energy within the spiral spring. The rotation of the hub 68 due to the spiral spring is initially very rapid in that there are no restraining forces imposed upon the hub and this initial rapid hub rotation will cause the hub to rotate relative to the clutch retainer 100 and extend the spring 106. As this initial rotation causes relative movement between the hub and retainer, the combination of the centrifugal forces acting upon the clutch dogs 98 and the guiding iniiuence of the retainer portions 162 will cause the dogs to radially project outwardly from the outer periphery of the retainer and engage the teeth 116 'of the drive cup 114, as shown in FIG. 6. Upon the clutch dogs engaging the drive cup the energy within the spiral spring 42 will be employed to crank and start the engine. The capacity 0f the spiral spring is such as to rapidly rotate the engine through several cycles and should the engine fail to start upon the first firing of the sparkplug, the engine will pass through several other firing cycles during the unwinding of the spring.

The hub 68 will only rotate slightly relative to the clutch retainer during the radial extension of the clutch dogs 98 and upon the dogs engaging the cup 114 and portions 102 the retainer 160 will rotate with the drive member. Once the engine starts the drive cup will rotate faster than the hub 68 and the teeth 116 will rotate the retainer which will pivot the dogs 98 inwardly and thereuponv the retainer 160 will be maintained as in FIG. 5 under the influence of the spring 166 -to maintain the clutch dogs into the retainer as shown in FIG. 5. The operator may then fold the handle 56 into the position of FIG. l. Should the engine fail to start upon completion of the unwinding of the spiral spring, the spring is once again wound by means of the crank and Ithe starting sequence is repeated.

Considerable vibration is produced during the operation of the engine and these vibrational forces are imposed upon the components of the starter. It has been found that much of the wear produced in starters of this type occur during the operation of the engine rather than during the starting cycle and by the use of the friction brake band 62, this vibrational wear has been minimized in that rotation of the shaft 46, the handle members 52 and 56 and the other components rotatably associated with the shaft is prevented. Also, in that the construction of the starter in accord with the invention provides large bearing areas, the forces imposed upon the starting components by the spring during the winding and starting phases, as well as by vibration, are widely distributed which minimizes wear. In that winding lof the spring occurs through the rotation `of the hub 3@ and the unwinding through the rotation of the hub 68 none of the starter components are subjected to a major portion of the rotation and this fact contributes to a longer operative life. The substantial abutment surfaces 76 provided in the cover portion minimize the opportunities for the release lever to improperly or insufficiently engage the abutment surfaces and also minimize fracturing or failure of the abutment areas which restrain rotation of the hub. A hole 118 may be provided in the housing portion 80 for cooperation with a hole 120 defined in the release lever wherein a padlock may be inserted through these holes, when aligned, to render the release lever inoperative for safety purposes.

It will, therefore, be appreciated that the invention produces a spring starter which is of relative simple configuration, yet is of sufficient strength and ruggedness to withstand the heavy forces imposed upon it. The desirable features produced by the sliding pin clutch and ratchet member and ratchet teeth are economically provided at a cost very little more than with a starter not having such features.

It is Vto be understood 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 following claims.

I claim:

1. A spring starter `for in-ternal combustion engines comprising, in combination, -a housing, a bearing having an internal bore mounted upon lsaid housing, a first hub rotatably supported within said bore, a shaft rotatably mounted within a bore defined in said hub, a second hub rotatably mounted on said shaft, a spiral spring circumscribing said second hub having an outer end operatively connected to one of said hubs and the other end operatively connected to the other hub, spring windup means operatively associated with one of said hubs and clutch means associated with the other hub, means limiting rotation of said windup means to the spring windup direction and release means mounted on said housing selectively retaining said hub associated with said clutch means against rotation.

2. A spring starter for internal combustion engines comprising, in combination, a supporting housing, a bearing member -mounted on said housing, a first hub rotatably supported by said bearing member, a spring keeper portion defined upon said first hub, a spiral spring within said keeper having an outer end attached thereto, a shaft rotatably journaled in said hub, a second hub rotatably mounted on said shaft having the inner end of said spring attached thereto, means supported by said bearing member operatively engaging said first hub preventing rotation thereof in a direction tending to unwind said spring, a crank attached to said shaft and operatively associated with said first hub, releasable means selectively engaging said second hub controlling the rotation thereof and ciutch means operatively associated with said second hub.

3. In a spring starter as in claim 2 wherein said means supported by said bearing rnember engaging said rst hub comprises a dog pivotally mounted in said bearing member and ratchet teeth defined on said first hub engaged by said dog.

4. In a spring starter as in claim 2 wherein said second hub includes a radially extending spring cover portion and said releasable means comprises a lever pivotally mounted upon said housing engageable with said cover portion.

5. In a spring starter as in claim 2 wherein said clutch means includes at least one -dog member pivotally mounted in said second hub for selective radial projection therefrom and clutch dog retracting means operatively associated with said second hub.

6. In a spring starter as in claim 2 wherein unidirectional drive means are interposed between said first hub yand shaft whereby rotation of said crank and shaft in a spring winding direction rotates said first hub `and said shaft rotates relative to said first hub upon rotating said crank in the opposite direction.

7. In a spring starter as in claim 2 wherein brake means are interposed between said crank and said `bearing member selectively resisting rotation of said crank relative to said supporting housing.

8. In a spring starter for internal combustion engines including a housing, a -spiral spring within said housing, rotatable crank means operatively associated with said spring for the winding thereof rotatably about a given -axis during winding of said spring, and drive means associated with said spring for cranking the engine, the improvement comprising selectively actuated brake means interposed between said crank means and said housing selectively restraining said crank means against rotation abou-t said given axis.

9. A spring starter for internal combustion engines, comprising in combination, a housing, a spiral spring within said housing, crank means operatively associated with said spring for the winding thereof rotatably about a given aXis during winding of `said spring, engine drive means operatively associated with said spring and rotated thereby, said crank means including a handle por-tion movable between operative and inoperative positions, brake means interposed between said crank means and housing and means mounted on said handle portion actuating said brake means when said handle portion is in the inoperative position preventing rotation of said crank means about saidrgiven axis.

10. In a spring starter as in claim 9 wherein said brake means comprises an annular band mounted upon said crank means selectively frictionally embracing a cylindrical portion defined upon said housing.

11. A spring stanter for internal combustion engines comprising, in combination, a supporting housing, a bearing member having a cylindrical outer surface `and a concentric bore affixed to said housing, a first hub rotatably supported within said bore having a bore concentric to said bearing member bore, a shaft rotatably supported within said hub bore extending substantially through said housing, a second hub rotatably mounted upon said shaft, a spiral spring within said housing circumscribing said second hub, a spring keeper portion defined on said first hub encompassing the periphery of said spring and attached to the outer end thereof, a radially extending spring cover portion defined on said second hub having `abutment portions defined thereon, a releasable lever pivotally mounted on `said housing selectively engaging yone of said abutment portions restraining said second hub against rotation, means attaching the inner end of said spring to said second hub, ratchet teeth formed on said first hub, a ratchet dog mounted in said bearing member engaging said teeth preventing rotation of said first hub in a spring unwinding direction, unidirectional drive means interconnecting said first hub and shaft in a spring Winding direction, a crank member aixed to one end of said shaft, selectively actuatable friction brake means interposed between said bearing member and said crank, clutch means mounted on said second hub and clutch actuating means mounted on Ithe other end of said shaft operatively associating with said clutch means.

12. In a spring starter as in claim 11 wherein said clutch means comprises at least one clutch dog pi'votally mounted upon said second hub for movement in a radial direction thereto and said clutch actuating means includes a clutch dog retracting member rotatably mounted on said shaft, spring means interposed between said retracting member and said second hub biasing said retracting member in a dog retracting direction and friction brake means mounted on said shaft resisting rotation of said retracting member relative to said shaft.

References Cited in the iile of this patent UNITED STATES PATENTS 2,744,586 Blakenburg May 8, 1956 2,869,682 De Millar Jan. 20, 1959 2,926,648 Hammam Mar. 1, 1960 2,950,780 De Millar Aug. 30, 1960 2,974,658 Russell Mar. 14, 19611 2,987,057 Kopp June 6, 1961 2,997,997 Glenn Aug. 29, 1961 2,999,489 Coughlin et al Sept. 12, 1961 FOREEGN PATENTS 767,471 France Mar. 1, 1934

Claims (1)

1. A SPRING STARTER FOR INTERNAL COMBUSTION ENGINES COMPRISING, IN COMBINATION, A HOUSING, A BEARING HAVING AN INTERNAL BORE MOUNTED UPON SAID HOUSING, A FIRST HUB ROTATABLY SUPPORTED WITHIN SAID BORE, A SHAFT ROTATABLY MOUNTED WITHIN A BORE DEFINED IN SAID HUB, A SECOND HUB ROTATABLY MOUNTED ON SAID SHAFT, A SPIRAL SPRING CIRCUMSCRIBING SAID SECOND HUB HAVING AN OUTER END OPERATIVELY CONNECTED TO ONE OF SAID HUBS AND THE OTHER END OPERATIVELY CONNECTED TO THE OTHER HUB, SPRING WINDUP MEANS OPERATIVELY ASSOCIATED WITH ONE OF SAID HUBS AND CLUTCH MEANS ASSOCIATED WITH THE OTHER HUB, MEANS LIMITING ROTATION OF SAID WINDUP MEANS TO THE SPRING WINDUP DIRECTION AND RELEASE MEANS MOUNTED ON SAID HOUSING SELECTIVELY RETAINING SAID HUB ASSOCIATED WITH SAID CLUTCH MEANS AGAINST ROTATION.

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