US2077263A - Engine starting mechanism - Google Patents

Description

April 13, 1937. A. E. RAABE 2,077,263

ENGINE STARTlNG MECHANISM Filed March el, 1931 2 sheets-sheet 1 INVENTOR Arzk ar Edward Raabe.

BY n l ATTORNEY April 13 1937- A; E. RMBEv 2,077,263

ENGINE STARTING MECHANISM Filed March e, 1931 2 shetssheef 2 Patented Apr. 13, 1937 PATENT GFFICE ENGINE STARTING MEcnaNisM Arthur E. Raabe, Summit, N. J., assignor to Eclipse Aviation Corporation, East Orange, N. J., a corporition ot New Jersey Application March 6,

V(i Claims.

This invention relates to engine starters, and -more particularly to starters ci the type wherein the engine engaging member is rotated by a variable speed driving member.

In engine starters of this type, as for example, linertia starters wherein the energy stored in a rapidly rotating ywheel is applied to an engine engaging member for cranking purposes, it is desirable that the latter member be rotated at l a substantially constant speed during the major Aportion ofthe cranking' operation. In 'apparatus of this kind heretofore known such a condition has been impossible of achievement since with the known forms of transmissions between the l variable speed driving member or flywheel and the engine engaging member., the speed of rotation of the latter member continuously varies in proportion to the changes in speed of the'former. Consequently, if the engine does not start within 20 the rst iew seconds of cranking', during whichtime the speed of the ywheel is relativelyhigh, the ensuing decrease in cranking speed, due to the slowing down of the ywheel, usually renders the cranking effort insufficient for starting purposes, g5 and necessitates-another cranking operation.

n .It is therefore one of the objects gf the present invention to provide an vengine starter wherein the cranking speed is maintained substantially constant during the major portion of the crank- :zo ing operation. Another object is to provide novel engine starting mechanism wherein the speed of rotation of an engine engaging member is maintained substantially constant irrespective of changes in 35 speed of the means for driving said member.

x A further object is to provide an engine starter of the inertia type embodying novel transmission means between the inertia member and the engine engaging member whereby the driving ratio -lu of said mean/sis varied in accordance with changes in the speed of rotation of the inertia member.

Still another object is to provide engine starte ing apparatus of the type wherein an engine engaging member is rotated by a variable speed 45 driving member which embodies novel means'- for varying the ratio between the speeds of rotation of said members in accordance with variations in speed ofthe driving member. y

A still further object is to provide an engine .'.o starter of the inertia type which embodiesnovel motion transmission means between the inertia member and its energizing cranhng shaft whereby the inertia member is accelerated first more.

slowly, and then more quickly, than said crank- 55 ing shaft. Y

1931, serial No. 520,633' (ci. 12s-119) illustrated in the accompanying drawings, it is to be expressly understood that these drawings are y for the purpose of illustration only and are not to be construed as a limitation of the scope of the invention, reference being had for this purpose to the appended claims.

Referring now tothe drawings, Fig. l of which is a sectional side'view with certain parts shown in full, and Fig. 2 is an end view of the friction rollers of the drive of one embodiment of the present invention, there' is disclosed therein a hand actuated starter of the inertia type which is provided with novel means for Vautomatically varying the driving ratio between the vinertia member, and the engine engaging member and changes in the speedfof rotation ``f`\`the former. In the form shown, the starting mechanism the hand cranking shaft in accordance with comprises a ywheel 2 adapted to rotatably drive an engine engaging m'ember or clutch jaw 3 .which is movable into driving engagement with -a corresponding jaw member (not shown) provided on the crank shaft or crank shaft extension of theA engine to be started. The mechanism is housed within a suitable casing constituted by an inner section l, a pair of in-v termediate sections 5 and 6, and a flywheel cover section 1, the sections beingremovably-secured together in any suitable manner andthe inner section being provided with a ange to facilitate the mounting of the starter on the engine crank case, or in any other suitable location.

The flywheel isadapted'to be rotated at high speed in order that sulcient energy may be storedtherein forv cranking the engine, and a gear train is preferably provided fortransmitting the energy stored in the flywheel to the engine engaging member 3, said gear train being so ccnstituted that member 3 will be rotated at a much lower speed than the flywheel, and embodying l novel driving-ratio changing means which are.

cess to the mechanism for adjustmentl purposes. The inner race of ball bearing I0 is maintained in a suitable cover plate l2 removable to allow acits proper position on flywheel shaft 9 abutting the hub of flywheel 2 by means'of a suitable slotted nut I3, while the outer race of said bearand rim with `a plurality of circumferentially spaced holes I5 adapted to receive pins I6 which are carried by a plate I1, the latter forming one element of the novel ratio changing device which is interposed in the transmission between iiywheel 2 and engine engaging member 3. Pins I6 are adapted to slide freely through holes I5 in flywheel 2, thereby allowing relative axial movement between said flywheel and plate at the same time that they are constrained to rotate in unision. Plate I1 is freely mounted on a sleeve I8 which in turn is slidably mounted on shaft 9 for a purpose later to be described.

The inner face of plate I1 has frictional engagement with the surfaces of a plurality of barrel shaped rollers I9, preferably three in number. Rollers I9 are rotatably mounted as by suitable bearings 20 on spindle shafts 2l carried in yokes 22, said yokes being free to oscillate about trunnions 23 which-are rotatably supported in suitable bosses 24 formed in a cage or yoke 25 intgral with sections 6 and 'I of the starter housing. In frictional contact with the diametrically opposite portions of the surfaces of rollers I9 is a second plate 26 having a hub portion 21 in which is housed a combined thrust and fric# tion bearing 29 the inner race of which surrounds and supports the inner end of flywheel shaft 9 and abuts an enlarged head.29 formed thereon.

It will be seen from the structure thus far described, that the rotation of fiywheel 2 is transmitted through pins I6 to plate I1 and thence through rollers I9 to plate 26. In the position shown in the drawings, the circles of contact between plate I1 and roller I9 on the one hand,

and between rollers I 9 and plates 26 on the other,

have radii of equal length, and it is evident that flywheel 2, plate I1 and plate 26 wouldall have the same speed of rotation.

The inner portion of hub 211 of plate 26 is slidably but non-rotatively mounted as by splines 30 on acollar member 3| which is secured to a stub shaft 32 by splines 33 and a screw threaded in shaft 32, the head of which is shown at 34. Shaft 32 is rotatably supported as by ball bearings 35 in a'central openingv in a. wall '36 formed integrally with intermediate section 5 of the starter casing. The inner end of stub shaft 32 is provided-with a pinion 31 which meshes with a spur gear 38 formed on the large end of a bell shaped. member 39 `rotatably mounted as by means of a stub shaft 4I) and bearings 4I i'n-an elongated boss 42.formed' in wall l36. Formed integrally with bell shaped member 39 and shaft 40, or rigidly connected thereto in any suitable manner, is a pinion 43 which meshes with an internal spur gear 44 coaxially disposed with respect to flywheel 2. Internal spur gear 44 is provided with a hub 45 which is rotatably mounted on a stub shaft 41 formed integrally with, and projecting centrally from, the closed end of a barrel 48 rotatably mounted in inner housing section 4 by means of ball bearings 49.

Hub 45 of internal spur gear 44' is also provided with an integrally formed pinion 50 which constitutes the sun gear for a plurality of planetary gears 5I, one of which 'is shown in section in the drawings. These planetary gears 5I, of.

which three are preferably employed, spaced at intervals of about the closed end of barrel 48, mesh with an internal ring gear 52 which is rigidly secured in any suitable manner to the inner surface of housing section 4. Each planetary gear is rotatably mounted as by a bearing 53 on a sleeve 54 theinner end of which is countersunk in the outer face ofthe closed end of barrel 48 and through which extends a screw 55 threaded into the end of said barrel. A retaining ring 56 is carried by the outer ends of screws 55 and maintains bearings 53 in their proper position on sleeves 54.

.Means are preferably interposed between the transmission gear train above described and the engine engaging member 3 for yieldingly transmitting the energy from the flywheel to the engine crank shaft without damage to the parts.

such as might result if the driving connections were entirely constituted by rigidly connected elements. For this purpose, a multiple disc clutch is preferably employed, said clutch being mounted within barrrel 48. I

As shown, the clutch comprises a plurality of annular discs 51 which are alternately splined to the inner surface of barrel 48 and to the Iouter surface of an interiorly threaded nut 58, and positioned between a flange 59 formed on the outer surface of nut 58 intermediate its ends and the closed vend of barrel 48. Suitable adjustable yielding means are also provided for holding nut 58 in operative position Withrespect to discs 51 and barrel 48, and for varying the frictional engagement of said discs. In the form shown, the

yielding means comprise a plurality of coil springs 60 extending longitudinally within the barrel with their outer ends having operative engagement with flange 59 and-their inner ends exerting a thrust against an annular ring 6I mounted within the barrel and provided with a plurality of laterally projecting studs 62 which extendinto the coils of springs4 60 thereby maintaining them in proper spaced relation within the barrel. An adjusting nut 63 is threaded into the open end o'f the barrel and has abutting engagement with the inner face of ring 6I. By adjusting the position of nut 63 longitudinally of barrel 48 the compression of springs 60 may be changed to vary the pressure with which the clutch discs 51 are engaged.

Exteriorly threaded onto the inner end of barrel 48 is a retaining ring 64 for the adjacent bearing 49. Ring 64 may be locked in position by means of a Wire 65 ione end of which passes through said ring and engages one of a plurality -of longitudinal slots 66 formed in the inner end of barrel 48, said ring being adapted to coact with a shoulder formed on the outer end of the barrel and having engagement with the inner race of outer bearing 49, to prevent endwse movement of the barrel relative to inner housing section 4.

Positioned within nut 58 is an exteriorly 'threaded shaft 68 adapted for rotary and longi- .tudina l 4movement relative to said nut. fouter. end of said shaft is provided with suitable The coil spring 1| which preferably has its outer end extending into a recess formed in the inner end' of shaft 68 is interposed between said shaft and the outer face of engine engaging member 3, and yieldingly resists movement of said member toward the shaft.

Suitable manually operable means are preferably provided for rotating 4flywheel 2 in order to store energy therein. As shown, said manually operable means include a cranking shaft 12 which is rotatably mounted in intermediate housing section with the outer end thereof projecting v exterioriy of said housing and provided with suitable means such as a transverse pin 13 for, receiving an ordinary hand crank (not shown). Shaft 12 is rotatably supported in the plane of the side wall of section 5 by means of a ball bearing 14, while the inner end of said shaft, which extends substantially at right angles to the axis of rotation of flywheel 2, is rotatably supported in a boss 15 provided in. wall 36 by means of a roller bearing 16. The inner end of shaft 12 has rigidly connected thereto a bevel gear 11 which meshes with a similar bevel gear 18 drivably contive to crank the engine.

'with ange 59. The inner end nected to the outer end of .stub shaft 41, and spaced from the hub 45 by a suitable Washer 18a.

Suitable means are also provided for moving engine engaging member or gagement with a corresponding member (not shown) mounted on the engine crank shaft whereby the energy stored in ywheel 2 is effec- In the form shown, said means comprises a rod 19 which slidably extends through stub shaft 41, threaded shaft 68,

and a central opening in engine engaging member/3. 'I'he inner` end of rod 19 carries a nut 89 which engages the inner face of clutch jaw 3 and maintains the latter in operative position relative to threaded shaft 68. The inner portion of rod 19 is of reduced diameter to provide a shoulder 8| which normally engages the outer end of shaft 68. The outer end o'f rod 19 terminates closely adjacent pinion 31, and is pivotally connected to the bifurcated end 82 of an operating lever which extends through the starter housing and is provided with suitable means for manual actuation by the operator.

Means are preferably provided for preventing oil from seeping from the engine crank case into the starter housing, since such oil would impair the operation of the apparatus. For this purpose, a cup-shaped member 83, which is preferably formed of metal and provided on its outer lend with a ange 84 adapted to be clamped between flange 8 of the starterhousing and the crank case of the engine, is fitted over the inner end of the starter which projects into the crank case. Secured tothe member 83 is a flexible guard or disc 85 of annular form, the inner periphery of said guard having engagement with the outer 4surface of the laterally projecting hub portion 10 of the engine engaging member 3. A sleeve 86 surrounds and has sliding engagement with hub portion 18 and extends inwardly into abutting engagement of sleeve 86 beans against a ring 81 to hold' the latter in engagement with iiexible guard 85. 'Ihe length of sleeve 86 is preferably such that the inner portion of guard 85 is iiexed outwardly into engagement with the adjacent face of engine engaging member 3, and seepage of oil into the starter casing at this point isthereby prevented without interference kwith the longitudinal movement of the engine engaging member. A pair of washers 88, one of -which may be formed of d eible material, is mounted on clutch jaw 3 into en rod 19 intermediate spring 1I andengine engaging member 3 to prevent seepage of 'oilthrough the central opening in said member. f

With the structure thus may be stored in flywheel 2, preparatory to cranking the engine, by engaging a hand crank with the outer end of cranking shaft 12 ,and rotating the latter. This motion is vtransmitted through the gear train to plate 26, and thence through 'rollers I9, plate I1, and pins I6 to iiywheei 2 yvhereby -the latter is rotated a large number of times for each revolution of .cranking shaft 12. Actuation of shaft 12 also results in rotation of barrel48 and all the parts therein with the exception of rod 19 which maintains engine engaging member 3 out of driving engagement with the engine member. After -the flywheel has been brought to the desired speed of rotation, i. e., after suicient energy for cranking the engine has been stored therein, the operator actuates the lever having the bifurcated end 82 whereupon rod 19 is forced to the left, as viewed in the drawings. Shoulder 8| forces shaft '68 to the left, the latter having a combined' rotary and longitudinal movement due to its threaded connection with the nut 58, and yieldingly moved, through spring 1I, into full meshing engagement with the engine member. 'I'he energyofthe ywheel is now effectiveto crank the engine.

When the engine starts under its own power the speed of rotationkof the engine clutch jaw .-is greater than that of engine engaging lclutch far described, energyV jaw 3, and the inclined teeth of said jaw melnbers are now effective to move member 3 to the right out of driving engagement.

Withthis structure; however, the speed of rotation of the engine engaging member 3 is always proportionate to the speed of rotation of flywheel 2. Also, when storing energy in the flywheel preparatory to cranking the engine, the acceleration which can be imparted to the flywheel during this operation depends directly upon the acceleration of cranking shaft 12. To Overcome these disadvantages inherent to starters of this type employing a. fixed-ratio gear train, novel means have been provided whereby, in effect, the multiplying'factor 'of the transmission means drivably connecting 12, may be automatically variedv plurality of circumferentialiy spaced bosses 89 in eachof which is Divoted, intermediate its ends, a lever 9,0 weighted at its outer end and of such shape as to be oscillatable about its pivot under the action of centrifugal force. The inner ends of levers 99 operatively engage a collar or washer 9i I mounted on sleeve I8 and adjustable in Llongitudinal position thereon as by a'nut 92 threaded onto the outer end of ASaid sleeve.v The inner end of sleeve I `Ii is provided with a suitable thrust bearing 93 and a thrust ring 94 between which are held the inwardly projecting ends 95 of spindle shafts 2| of rollers I 9. Suitable resilient means such as coil springs 96 are interposed between thrust ring 94 and the central portion of plate I 1, and resist the movement of sleeve I8 and inner ends 95 of spindle shafts 2l to the right under the action of centrif` holes I in flywheel 2, thereby axial movement between plate shaft 12, the drive from plate 26 to plate I1 is such as to cause the latter to rotate more slowly than the former. As flywheel 2 accelerates, however, the weighted ends of levers 90 move outward under the action of centrifugal force and rotate said levers about their pivots in bosses 89, causing the inner ends to press against collar 9i and thereby move sleeve I8 to the right, as viewed in the drawings, against the resistance of springs 96. The motion of sleeve I8 in turn'carries projecting ends 95 of spindle shafts 2| to the right and oscillates yokes 22 about their trunnio'ns23, thereby causing the rollers I9 to return -first to the. vertical position and from such position to move into the opposite inclined position; This mo-vement causes a change in the loci of the" frictional engagement circles on plates 26 and I1,'thereby changing the driving ratio so that the latter rotates faster than the former. cranking operation proceeds, the inertia member is accelerated first more slowly and then more quickly than the cranking shaft 12. As shown in the drawings, an increase from the angle of cocking of rollers I9 causes plate I1 to rotate faster than plate 26.

Since cooking of rollers I9 causes the distance between plates I1 and 26 to increase slightly, suitable means are provided for allowing relative movement of the parts involved and for returning saidparts to their original positions when the angle of tilt. ofthe rollers is reduced. As previously mentioned, pins I6 are freely slidable through allowing relative I1 and flywheel 2, while the splined engagement at 30 between hub 21 of plate 26 and collar member 3l of stub shaft 32 permits similar movement between these parts. To maintain plates I1 and 26 in frictional engagement with the surfaces of rollers I9, and to resiliently urge said plates toward theirat-rest positions, suitable resilient means are provided such as a. plurality of coil springs 91 encircling pins I6 between the inner face of flywheel 2 and the outer face of plate I1.

When flywheel 2 has been accelerated to its maximum or proper driving speed for starting the engine, rollers I9 are in the position of maximum cooking or tilt and the speed reduction ratio from plate I1 to plate 26 is a maximum. Engine engaging member 3 maybe now moved into engagement with the engine member to be started, and the engine is cranked by the application of the energy stored in flywheel 2.` As this cranking operation progresses, the speed o f rotation of flywheel 2 decreases, and were there provided only the usual fixed-ratio transmission gear train between said flywheel and engine engaging member 3, the speed of the latter would be decreased in proportion. However, due to the movement of weighted lever arms 90 in response to variations in centrifugal force, the degree of tilt of rollers I9 is decreased with a decrease in speed of rotation of flywheel 2, with a consequent decrease in the speed reduction ratio between plate I1 and plate 26. The result of this operation is that the speeds of plate 26 and engine engaging member 3 re- Hence, as the...

main substantially the same as they were at the instant of initial engagement of 'the latter with the engine.

There is thus provided by the present invention a novel engine starter wherein the speed of rotation of the engine' engaging member is maintained substantially constant during the major portion of the engine cranking operation irrespective of variations in the speed of the driving member from which the engine engaging member derives its energy. Novel transmission means have been provided for driving an engine engaging member from a variable speed member, such as a flywheel, whereby the vdriving ratio is automatically varied in accordance with changes in the speed of rotation of the driving member. When applied to a hand energized inertia starter, the invention also permits more rapid acceleration of the inertia 'member to its maximum or designed operative speed than would be` possible with a'fxed ratio set of gearing. Since the speed of :rotation of the engine engaging member is thus4 maintained substantially constant, torque conditions are also proportionately better and the starter is made more eillcient in operation.

It will be obvious that the invention `is not limited to the form shown in the drawings, but

iscapable of a variety of mechanical embodi- For example. any jsuitable type of.

ments'. variable speed driving means may be substituted for the inertia flywheel shown. Also, the manual cranking means may be replaced or supplemented by suitable electrical means, and other'forms of gearing and yieldable driving connections may obviously be employed in place of those illustrated. Various other changes, which will now appear to those skilled in the art, may be made in the form, detailsof construction and arrangement of the parts without departing 'from the spirit of the invention, and reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

l 1. In an engine starter, an engine engaging member, a variable speed driving member, means including a pair of parallel plates rotatable about a common axis to drivably connect said driving f member and said engine engaging member, and

centrifugally actuated means for imparting relative axial movement to said plates to automatically change the driving ratio in accordance with the speed of the driving member.

2. Driving means for an engine starting member comprising an inertia member in which energy is stored for subsequent transmission to said engine starting member, and means operating in response to'variations in the speed of said inertia member to maintain said engine starting member'in rotation at substantially constant speed.

3. Driving means for an engine starting mernber comprising an inertia member in which energy is stored for subsequent transmission to said engine starting member, andmeans operating in response to variations in the speed of said inertia member to maintain said engine starting member in rotation 4at substantially cons-tant speed said maintaining means comprising a lpair of parallel plates rotatable about a common axis, and means for imparting relative axial movement to said plates to maintain the speed of the driven plate substantially 'constant irrespective of changes in the speed of the driving plate.

4. Driving means for 'an engine starting member comprising an inertia member in` which energy is stored forv subsequent transmission to said engine starting member, and means operating in response to variations in the speed of said inertia member to maintain said engine starting member in rotation at substantially constant speed said maintaining means comprising a pair oi' parallel plates rotatable about a common axis for driving said engine engaging member, and means for imparting relative axial movement to said plates to automatically vary the driving ratio between said last named means and said engine engaging member in accordance with changes in the speed of said driving means.

5. Driving means for an engine starting member comprising an inertia member in which energy is stored for subsequent transmission to said engine starting member, and means operating in response to variations in the speed of said inertia member to maintain said engine starting member in rotation at substantially constant speed said maintaining means comprising a pair of parallel plates rotatable about a common axis to drivably connect said driving member and said 5 engine engaging member and centrifugally actuated means for imparting relative axial movement to said plates to automatically change the driving ratio in accordance with the speed of the driving membe 6. Driving means for an engine starting member comprising an inertia member in. which energy is stored for subsequent transmission to said engine starting member, and-'means operating in response to variations in the speed of said inertia member to maintain said engine starting member in rotation at substantially constant speed said maintaining means comprising a 'pair of plates having parallel friction surfaces, and a roller engaging said friction surface along a single circle of contact when the distance between said opposing friction surface is smallest; and along separate circles of contact with respect to each of said surfaces in the event of an increase in the distance between said opposing friction surfaces due to a change in the rotary speed of said driving member.

AR'I'HUR. E. RAABE.

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