US3099255A - Spring starter - Google Patents

Description

L. J. HAMMAN SPRING STARTER July 30', 1963 2 Sheets-Sheet 1 Filed Nov. 30, 1960 INVENTOR LYLE' JHAMMAN ATTORNEY July 30, l963 L. J. HAMMAN 3,099,255

SPRING STARTER Filed Nov. 30, 1960 g Sheets sheet 2 INVENTQR LYLE J HAMMAN @Ww imi ATTORNEY United States Patent Oce 3,@99255 Patented July 30, 1963 3,099,255 SPRlNG SBTARTER Lyle l. Harriman, Eaton Rapids, Mich., assigner to Eaton Stamping Company, a corporation oi Michigan Filed Nov. 3l), 1.950, Ser. No. 72,698 6 Claims. (Cl. 12S- 179) The invention relates to a spring starter for internal combustion engines and particularly pertains to a heavy duty starter capable of producing a high cranking torque.

Spring powered starters yare of advantage when ernployed `with internal combustion engines, usually of the smaller sizes such as used with lawn mowers, garden tractors, auxiliary engines and the like, in that such starters are capable of cranking the engine faster than is possible with a rope pull type starter. Spring starters also have the advantage of permitting energy to be stored such that less elort is required to crank the engine than with rope pull starters. Thus, spring starters enable women and children to start engines which they would be unable to start with other types of manual starters. The invention is directed to spring starters of the type utilizing a spiral spring which are manually wound and crank the engine during unwinding. Spring starters employed with the smaller horsepower engines as used with lawn mowers and other light equipment may usually be directly wound by means of a manually actuated crank without requiring excessive torque upon the crank to produce suilicient stored spring energy, however, engines of larger ratings require considerably more cranking torque than the lighter engines and it has been found that springs directly wound from a crank require higher crank torques than is desirable. .lt is, therefore, one object of the invention to produce a spring starter having a spiral spring of high capacity which does not require high crank handle torques. To this end, mechanical force multiplying means in the form of a back gear arrangement are employed.

Another object of the invention is to provide a spring starter of high engine cranking torque capacity wherein the components winding the spring are supported by large bearing surfaces and a very strong, yet relatively lightweight, starter unit may be produced from economically produced components.

A further object of the invention is to provide a high capacity spring starter for internal combustion engines employing a spiral spring wherein the spring is housed Within a preassembled unit including the engine crankshaft drive means wherein upon failure of the spring or drive means, the spring unit may be replaced as a whole, if desired.

Yet another object of the invention is to provide a spring starter for internal combustion engines wherein a spiral spring is employed with an engine drive member such that winding of the spring is produced by rotating the outer spring end and driving of the engine resulting from rotation of the drive member from the inner end of the spring, and wherein gear reduction means are employed to rotate the outer end of the spring.

Another object of the invention is to produce a spring starter for internal combustion engines having back gearing means for winding the spring and clutch dog means actuated by centrifugal and inertia forces for engaging the starter with the engine crankshaft only during cranking of the engine.

A further object of the invention is to produce a spring starter for internal combustion engines wherein a spiral spring is wound from the outer end through a ring gear arrangement cooperating with a back gear pinion which is, in turn, rotated through a manually operated crank handle and unidirectional drive means connect the handle to the pinion such that the crank handle is operatively connected to the pinion only rupon rotation of the handle in a spring winding direction.

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

FIG. 1 is an elevational sectional view of an embodiment or the invention taken along section L-I of iFIG. 2,

FIG. 2 is a plan sectional View of the starter of the invention taken along section Il--II of FIG. l,

FIG. 3 is a plan sectional View of the embodiment of FIG. 1, taken along section lll- Ill showing only a portion of the spiral spring.

PEG. 4 is a plan sectional view of the clutch structure, showing the clutch dog in retracted position, taken along section lV-IV of FIG. 1, and

PEG 5 is a plan sectional View similar to iFIG. 4, showing the clutch dog in the extended engine cranking position.

The general appearance and relationship of a starter embodiment in accord with the invention may be best appreciated from FlGS. 1 `and 2 wherein the starter includes a substantially cylindrical housing 10 having an upper integral cover position 12. As shown in FIG. 1, the housing portion is provided with a plurality of downwardly extending leg portions 14 having a radially extending portion in which bolt holes .16 are formed to permit the housing to be affixed to the engine such that the axis of the starter housing and the axis of the crankshaft substantially coincide. The housing itl may be formed of drawn steel and preferably is formed from a single blank. An opening 118 defined by an upwardly extending ange 20 is formed in the upper cover portion and a hole 22 is also defined in the cover to receive the spring release means as will be later apparent.

The interior of the housing is provided with a cylindrical inner surface 24 and a shaft 26is welded to the underside of the cover in concentric relation to surface 24, and extends in a downward axial direction las viewed in FIG. 1. The shaft 26 is provided with la threaded bore at its lower end.

A drive member hub 28 is rotatably mounted upon the shaft 26 and i-s provided with an upper (portion 30, an intermediate arcuate recess portion 32, FIG. 3, and `a clutch mounting portion 34. A spiral :spring 36 having an inner end 4formed with a cylindrical book 38 encompasses the drive member 28 land the inner spring end 38 is held within one of the spiral recesses 40 by the tension within the spring. The outer end ot the spring 36 is lformed with a hook l2 which is received within an opening d4 defined in an axially extending portion i6 of a spring keeper 48. The spring keeper 48 isof ya cup-like configuration having a radially extending portion S0 which is centrally bored to rotatably receive the drive member 28 therein. A shoulder S2, and yadjacent washer, defined upon the drive member between the axial portion 32 and 34 limits relative axial displacement between the keeper and drive member in 4one direction. A disclike spring cover S4 `overlies the upper lateral edge of the spiral spring and a release gear 56 is placed over the spring vcover and aflixed to the drive member portion 30. The release lgear 56 is formed with a plurality of teeth upon Ithe periphery dening abutment surfaces 58 and a keeper washer 60 is forced over the drive member portion 3d to maintain the assembly of the release gear, spring cover, spiral spring, spring keeper and drive member. It will, thus, be appreciated that these elements define Ia complete spring unit which may Ibe preassembled and vminimizes the difficulty of handling the spiral spring during maintenance or initial assembling.

The spring keeper 48 is of cylindrical configuration and is provided with an exterior cylindrical bearing surface 62 which rotatably cooperates with the inner housing surface 24. In this manner, the spring keeper is exteriorly rotatably supported within the housing upon its own bearing surfaces and the drive member is rotatably mounted upon the shaft 26 for rotation relative to the shaft and to the spring keeper 48. The upper interior portion of 4the spring keeper portion 46 is provided with a plurality of teeth 64, in opposition to the bearing surface 62, which define an internal ring gear. While in the preferred embodiment, the ring 4gear teeth are defined within the keeper material itself, these gear teeth may be formed on a separate element which would be attached to the keeper.

'Il-he spring keeper 48 is rotated by a pinion gear 66 having teeth 68 which mesh with the keeper ring gear teeth 64. The pinion rgear 66 is keyed to an exterior clutch plate 70 by means of a rectangular stern 72 defined upon the pinion engaging a rectangular bore defined in the clutch plate and the flange 20 functions as a bearing for the pinion. The clutch plate 78 is provided with a cylindrical periphery upon which a clutch coil spring 74 is received. A `crank handle 76, having a knob 78, is employed to rotate the pinion rgear 66 and subsequently, wind the spiral spring 136 and this is accomplished through a drive connection which includes a cylindrical clutch shaft 80 afiixed to the crank handle. The shaft 80 is tformed with a rectangular portion 82 which cooperates with ra rectangular bore 84 within a clutch member 86 whereby the clutch member yand shaft 88 are keyed for mutual rotation. The clutch member 86 is provided with a cylindrical exterior periphery of a dimension -similar to ythat of the clutch plate 76 and also, is snugly ygripped by the coil `clutch spring '74. The shaft 80 extends through a bore within the pinion Ygear and is pro-V vided with -a screw 88 and spring washer at its lower end whereby the assembly of the pinion `gear and clutch plate, clutch `spring and handle is maintained. It will be appreciated that the pinion 66 rotates relative to the clutch shaft 80.

The clutch spring 74 is `coiled in such a direction that a ydrive `connection is produced between the clutch member 86 and the clutch plate 70, through the spring 74, when the crank handle is wound in the direction which will result in winding of the spiral spring. Upon winding the crank handle in the opposite direction, the clutch spring tends to uncoil and disengage the frictional drive connection between the clutch member and clutch plate. It will, therefore, be appreciated that upon rotating the crank handle 76 in a clockwise direction, FIG. 2, the spring keeper 48 will likewise be rotated in a clockwise direction to wind the spiral spring and the mechanical advantage derived between the pinion igear 66 and ring gear 64, usually about 3 to l, reduces the crank handle torque necessary to wind the spring.

Rotation lof the pinion gear 66 in the counterclockwise direction, FIG. 3, under the influence of the stored energy within the spiral spring, is prevented by means of a ratchet dog 90 which is pivotally mounted upon a stud 92 welded to the underside of the housing spring cover 12. Rotation of the drive member 2S, yduring winding of the spiral spring 36, is prevented by the engagement of one of the release gear abutment surfaces 58 with a housing mounted lever 94 having an upstanding portion having an `abutment surface 96 which cooperates with the release gear abutment surfaces. The lever 94 is pivotally mounted upon a stud 98 welded to the underside of the housing cover 12 and is biased toward an inward position by a bow spring 100 circumscribing the stud 98 having one end biasing the lever 94 counterclockwise, FIG. 2 and another portion of the spring 100 circumscribes the stud 92 yand the other end engages the ratchet dog 90 to bias the dog into engagement with the teeth 68 of the pinion gear.

The actuator yfor the release lever 94 includes a manually operated lever 162 having a stud 104 extending through the opening 22 defined in the housing cover. A triangular plate 166 is afiixed to the stud 104 within the housing and is provided with a downwardly extending flange 188 having a slot 118 defined therein which receives the free end of the lever 94. The spring 100 biases the lever 94 into engagement with lthe lleft end of the slot 110, FIGS. 1 and 2, and upon rotation of the release handle 102 the lever 94 may be moved between the operative position, shown in full lines in FIG. 2, to the inoperative position, shown in dotted lines, wherein the drive member is free to rotate. The side 112 of the plate 106 engages the head portion 114 of the shaft 26, FIG. 2, and acts as a stop defining the degree of rotative movement of the release handle lever 102.

The clutch struct-ure supported upon the drive member portion 34 is best illustrated in FIGS. 4 and 5 and includes three downwardly extending boss portions 116 having a cylindrical recess 118 defined therein. A plurality of clutch dog members 128 are employed in the clutch structure which consists `of a rectangular steel pant having one end deformed in a cylindrical configuration as to be received Within a recess 118 providing a pivotal connection between the dog fand the drive member. An annular cup-like clutch dog retainer 122 is rotatably mounted upon the lower end of the shaft 26 by means yof a headed screw 124 screwed in the shaft and the dog retainer is provided with an inner axially extending portion 126 and an outer 'axially `extending portion 128. The outer axially extending portion 130 is provided with three slots 139 formed by lancing the portions 132 therefrom whereby the slots permit the dogs to project beyond the retainer. lt will be noted that the lanced portions 132 aot as a guide for the ends of the dog members. A friction brake element 148 is interposed between the screw 124 and the clutch retainer portion 126 such that the friction member imposes a drag upon the clutch dog retainer rota-tion with respect to the shaft 26. The friction brake member is preferably of a configuration similar to that of the brake member of my U.S. Patent No. 2,926,648. A drive cupi 142 is aliixed to the crankshaft of the engine with which the starter is `associated and is usually mounted upon the engine flywheel. The cup `142 is provided with internal teeth 144 -about its entire inner periphery, only a portion of the teeth being illustrated, which are engaged by the ends of the dogs 129 during .fthe cranking operation, as will be later described. The screw 124 maintains the assembly of the drive member 28 with the shaft 26 and, therefore, holds the entire spring unit within the starter housing.

In operation, the spring is assumed to be in the unwound condition rand the operator first rotates the release y in a clockwise direction, FIG. 2, which will rotate the clutch plate 78 through the coil spring 74 and cause the pinion gear 66 to rotate keeper 48 and wind the spring 36. The drive member 28 will be restrained against rotation by the cooperation of the abutment surfaces SS and 96. Rotation of the crank handle may be in a complete circle or may consist of a ratchetting of the crank handle, in either case, the pinion 66 will be rotated in only the spring winding direction. After sufficient energy is stored within the spiral spring 36, the operator will shift the release lever 102 to rotate the plate 106 to the dotted line position of FIG. 2. This action disengages the abutment surfaces 518 and 96 and permits the drive member to be very rapidly rotated under the influence of the spiral spring. In that the abutment `96 is remote from the slot 110 a mechanical advantage is produced which decreases the force necessary to shift lever 102. The initial rapid rotation of the drive member 28 causes the drive member to rotate with respect to the clutch retainer :122 due to the inertia of the clutch retainer and the trictional drag imposed thereon against rotation by the brake element 14d. This initial relative rotation causes the clutch dogs llll to extend through the slots 130 and engage the teeth ldd of the drive cup due to centrifugal forces and the guiding of portions 132. The relative rotation between the drive member and the clutch retainer is not extensive and the engagement of the dogs with pontions 132 soon rotate the clutch retainer with the drive member. The clutch components will remain in the relationship of FG. 5 during the cranking action until the engine starts. As the engine starts, :the rotation of the drive cup T42 will force the dogs 120 into engagement with the lance portions 132 of the clutch retainer, rotating the retainer und the edges 133 will retract the clutch dogs into the outer retainer periphery to the position of FIG. 4. It will, therefore, be appreciated that the clutch components automatically engage tlre drive cup only during the operative cranking phase.

The external bearing surface 62 of the keeper minimizes the possibilities of bearing failures due to the forces imposed upon the keeper during spring winding and permits a relative lightweight housing to be employed in that the area rotatably supporting the keeper is considerable with respect to the ovenall dimensions of the keeper. Should the spiral spring break and require replacement, or should the drive member need maintenance, the entire spring unit may be quickly removed from the starter by removing the screw 124 and the spring unit may be sent to the factory for servicing or a completely new unit may be installed by using only a screwdriver. The preassembly 'of the keeper, spiral spring and drive member is of definite advantage in the original assembly of the starter, as well as during disassembly and assembly of the starter during maintenance, in that special equipment is usually required for handling the spiral spring 36 such that it may be installed within the keeper and the preassembled starter unit eliminates the problems relating to the installation of the spiral spring of conventional starter constructions. It will be appreciated that the invention produces a lrelatively simple spring starter in employing easily manufactured components of stampings and die castings and the starter is of such construction as to be very dependable in operation.

Other embodiments of 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.

l claim:

1. A preassembled spring unit subassembly for spring starters comprising, in combination, a spring keeper member adapted to house and maintain a spiral spring therein, a cylindrical bearing surface detined ion the eX- terior of said keeper, a spiral spring lhaving inner and outer ends lwithin said keeper `and having the outer end attached thereto, a drive member rotatably mounted within said keeper, said spring inner end being drivingly associated with said :drive member, :abutment means and clutch mounting means deiined upon said drive mernber and gear means `defined upon said keeper concentrically related to the axis of said bearing surface.

2. A spring starter for internal combustion engines comprising, `in combination, a housing, a preassernbled spring unit Irotatably mounted in said housing, said uni-t comprising a spiral spring having inner and outer ends, a spring keeper encompassing the periphery of said spring having the spring outer end attached thereto, a cylindrical bearing surface dened on the exterior of said keeper rotatably :operatively engaging said housing,

a drive 4member rotatably supported within said keeper operatively `associated with the spring inner end, clutch means mounted upon said drive member and gear teeth yformed upon said keeper dening `a ring gear; a pinion gear within said housing in mesh with said ring gear, a `crank drivingly associated with `said pinion and releasable means mounted upon said housing selectively retaining said drive member against rotation.

3. In a spring starter as in claim 2 wherein a bore is define-d in said drive member, a shaft afxed to said housing .and extending through said bore rotatably supporting said drive member and spring unit within said housing, and fastening means maintaining said spring unit upon said shaft.

4. A spring starter tfor internal combustion engines comprising, in combination, a housing, .a shaft affixed to said housing, a drive member rotatably supported on said shaft, a spiral spring having inner and outer ends circumscribing said drive member, said inner end being operatively connected to said drive member, a cylindrical spring keeper encompassing the periphery of said spring having the outer spring end attached thereto, means rotatably supporting said keeper within said housing, said means rotatably supporting said keeper comprising an external cylindrical bearing surface defined on said keeper operatively associated with an internal cylindrical bearing surface delined within said housing, said keeper external cylindrical bearing surface Ihaving a diameter greater than the diameter of said spring, gear teeth deiining a ring gear formed -on said keeper, a pinion .gear rotatably mounted on said housing in mesh with said ring gear, a crank drivingly associated with said pinion, housing mounted releasable means selectively engageable Iwith said drive member restraining rotation thereof and clutch means mounted upon said drive member.

5. lx1 a spring starter as in claim 4 wherein unidirectional drive means couple said crank to said pinion only upon rotation of said crank in a spring vvinding direction.

i y6. A preassembled spring unit subassernbly for spring starters comprising, in combination, `a spring keeper member having an external cylindrical bearing surface, said keeper having `an axially extending portion encompassing a spiral spring therein having the spring outer end aixed thereto and a radially extending portion covering one lateral edge of the spring, `a drive member concentrically rotatably mounted within said keeper having the spring inner end ailixed thereto, a radially extending spring cover affixed to said drive member covering the other lateral edge of the spring, abutment means mounted upon said drive member yfor cooperation with releasable abutment means for controlling rotation of said `drive member, an annular radial shoulder defined on said drive member engaging said keeper radial portion, said shoulder and cover limiting axial displacement between said drive member and keeper, clutch mounting means defined upon said drive member and ring gear means donned upon said keeper.

References Cited in the file of this patent UNITED STATES PATENTS 2,744,586 Blankenburg 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, I1961 3,032,024 Furlong May 1, -1962 FOREIGN PATENTS 767,471 France Mar. 1, l1934

Claims (1)

1. 4. A SPRING STARTER FOR INTERNAL COMBUSTION ENGINES COMPRISING, IN COMBINATION, A HOUSING, A SHAFT AFFIXED TO SAID HOUSING, A DRIVE MEMBER ROTATABLY SUPPORTED ON SAID SHAFT, A SPIRAL SPRING HAVING INNER AND OUTER ENDS BEING CUMSCRIBING SAID DRIVE MEMBER, SAID INNER END BEING OPERATIVELY CONNECTED TO SAID DRIVE MEMBER A CYLINDRICAL DPRING KEEPER ENCOMPASSING THE PERIPHERY OF SAID SPRING HAVING THE OUTER SPRING END ATTACHED THERETO, MEANS ROTATABLY SUPPORTING SAID KEEPER WITHIN SAID HOUSING, SAID MEANS ROTATABLY SUPPORTING SAID KEEPER COMPRISING AN EXTERNAL CYLINDRICAL BEARINGS SURFACE DEFINED ON SAID KEEPER OPERATIVELY ASSOCIATED WITH AN INTERNAL CYLINDRICAL BEARING SURFACE DEFINED WITHIN SAID HOUSING, SAID KEEPER EXTERNAL CYLINDRICAL BEARING SURFACE HAVING A DIAMETER GREATER THAN THE DIAMETER OF SAID SPRING, GEAR TEETH DEFINING A RING GEAR FORMED ON SAID KEEPER, A PINION GEAR ROTATABLY MOUNTED ON SAID HOUSING IN MESH WITH SAID RING GEAR, A CRANK DRIVINGLY ASSOCIATED WITH SAID PINION, HOUSING MOUNTED RELEASABLE MEANS SELECTIVELY ENGAGEABLE WITH SAID DRIVE MEMBER RESTRAINING ROTATION THEREOF AND CLUTCH MEANS MOUNTED UPON SAID DRIVE MEMBER.

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