US1933534A

US1933534A - Engine starting mechanism

Info

Publication number: US1933534A
Application number: US554873A
Authority: US
Inventors: Romeo M Nardone
Original assignee: Eclipse Aviation Corp
Current assignee: Eclipse Aviation Corp
Priority date: 1931-08-03
Filing date: 1931-08-03
Publication date: 1933-10-31
Anticipated expiration: 1950-10-31

Description

Oct. 31, 1933. y R M, NARDONE 1,933,534

ENGINE STARTING MECHANISM Filed Aug. 3, 1931 V fM TTo'RNEY jferred to. f

4Another object of theinvention is to'provideA Patented Qct. 31, 1933 nfsTATgs! was@ A 1,953,534f` y l l y ENGINEV'SVTART'ING MECHANISM` Romeo M. Nardone, Orange, N. J., assigner to Eclipse Aviation-f Corporation, East` Orange,

N. J., a corporation of New Jersey Aspiration Agust 3, 193i. serial N0.- 554373 o 10 Claims.

This invention relates to engine starting mechanisms and particularly to those adapted to impartuthe initial turning force to a member, such as the crankshaft,y .of an engine having other g means for maintaining itself in operation after such initial turning or cranking.Y f f An object ofthe invention is to provide a starter for the foregoing purpose embodying novel'means for 'establishing driving connectionbetweena rotatable element ofthestarter and a rotatable member `of the/engine, 'which meansfinoludes yieldable means normally adaptedto maintain positive driving connection between.. the. driving memberV of the starter and the aforesaid rotatable j member, but adapted to yield temporarily to alo-- sorb'the sudden reverse f-torque resulting inthe event of a backfire of the engine to be started.

`v.ifurther object of the invention is to provide yieldable means of the foregoing character, ycon-A j structed and disposed in respeotto the driving and driven elements of the starter, in such'm'anner asto be erlective to maintain positive driving relation between the said elements even during. the assimilation of thereverset'orqueabove re-'i in a starterof thetype employing a member 'move able longitudinallyinto.engagement with a meni= ber of` the engine `to be started and thereafter rotatable to crank the engine'novelfmeans for. rotating said'rst named member at relatively.-

highspeed following completion ofits longitudinal movement. f

Another object vof th'e'inv'ention is to provide a j simple but emcient starter for theioregoing purposes, which 'is' further. characterized by a novel arrangement of the. torque transmitting mechanism rendering the ,starter suitable-"forv installation in engines `where. space is restricted and j economy in size and weight is essential.

These and other objects andadvantages tobe derived from the use of the invention disclosed herein will become evident on an inspection of the followingv description when read withvreferv ence to the4 accompanying.1 drawing illustrating one embodiment of the invention. It is tobe, expressly understood, however, that thedrawing.

is for the purpose of illustration only,and is not to be construed as a definition "of the limits of the invention, reference, beingl had for this purpose to the appended claims.`

In the drawing,

Fig. 1 is a view in elevation withpartsl sl'lo'wn inelongitudinal section ofthe device embodying the invention. l f

(CLIM-7) `Fig. 2 is a transverse section view 2-2 of Fig. 1;y and .v c

Fig. 3 is a view in elevation with parts broken away and others in ysection of a portion` or" the assembly shown' in Fig. 1. l

Referring to the Adrawing and particularly to Fig. 1, the invention is shown embodiedin a along the line rstarter having a casing 'composed of three sections, 4, 5, and 6,-.the latter constitutingthe casingv for the prime mover, herein shown as :an electric 65 motor V'adapted to actuate an engine-engaging member ysupported within the iirst section 4fof the casing and drivably connected to the prime mover throughl reduction mechanisms mounted `within 'the 'casing section 5, the three sections being 7o; l

of considerably larger diameter and rotatableon a sleevefbearing 18 about ashaft 21 Whose.` axis preferably is in alignment with that `of the85, rotatable member of the engine with which "they starter is adapted to `be drivably connected. As shown,Y the f casing `section 5 is` provided 'with a suitablel thickened v.portion or hub 123 forming a support in v,which the shaft` 2lis held against 90v yendwise movement in eitherdirection by y'previa sionoiav shoulder 19 and'a'retaining disc 22, while `the gear 20 is providedwith a forwardlyextended hub 24 on which are'iormed teeth `2,5,

constituting a `'pin-ion adapted to drive the plane#l 95 tary gears 26,.each of which meshes with a stationary annulus gear 49and rotatable about 'a pin 27 on the `forwardv rend of each of which-is threaded a nut 28 adapted to retain the o operative relation with a flange 29iorn1ed'on 100 `a hollow-driving member or barrel 'qrotatably supported within thehun-'9 of the casing section 4, the annulus gear `49 being -held against"rota-V ftionbybolts 'l'. The barrel 30 .is-in turn' drivably connected to an internallythreaded sleeve 105 31 by novel means constitutingfoneofftheinajor features lof the invention now to `be described. f The' novel means for eiiectinga nornf'ially.posi-fV ytive-"c irivefrom' the barrel Sil-"to the sleeve'lgfwhile at the same time absorbing shockincijdent 110 to a sudden application of torque in the reverse direction, preferably takes the form of a pin and slot connection between these members, such a pin being indicated at 32 as having a head portion movable along a diagonally directed slot or opening 33 in the wall of the barrel 30, while the shank portion of the pin 32 is threaded or otherwisepermanently secured to an intermediate `sleeve member 34 interposed between the barrel and threaded sleeve 31 and preferably provided with a portion 35 of smaller external diameter but of the same internal diameter, such construction providing an annular recess between the members 35 and 30 in which is placed a coil spring 36 normally stressed suf.-

'ciently to maintain the pin 32 in the position indicated in Fig. 3 in which position the drive, under normal torque conditions, from the barrel 30 to the member 34 is positive and direct. Similar direct connection is provided between the member 34 and the sleeve 31 by forming external splines 37 on the latter member, adapted to register with corresponding longitudinal extensions 38 on the member 34, the length of such extension 38 being such as Ato allow a predetermined longitudinal movement thereof in the event of suddenly applied torque tending to rotate the parts in a reverse direction, the amount of permissible longitudinal movement being preferably equal to the length of the slot 33 as projected along the axis of the members. The internally formed threads on the sleeve 31 are adapted to register loosely with corresponding externally formed threads 39 on the engine-engaging member 40 which is provided at its outer end with radially disposed teeth 41 adapted to engage the corresponding teeth of a jaw 42 secured to or as shown, integral with a rotatable member of the engine. kIn order to enforce lon-- gitudinal movement of the -member 40 to mesh jaws 41 and 42, and in order to insure proper mesh of these members, detent iingers 44 are provided to engage the smooth cylindrical surface of the member 40 withia frictional pressure suicient to prevent rotation of the member 40 during the period of its longitudinal advance into engagement withr the engine member, such longitudinal advance being produced in response to the rst rotation of the sleeve 31 following energization of the prime mover. Suitable `means, such as indicated at'46, maybe employed for retaining the friction elements 44 in frictionexerting relation to the member 40. Inv the drawing, only one of the friction elements is shown, but it will be understood that others may be provided at suitable intervals about the ange 47, the latter also being provided with apertures 48 for the reception of means for attachment of the starter to the crankcase, or other supporting structure of the engine to be started.

In operation, energization of the motor 6 will rvbe transmitted at reduced speed to the barrel 30 mediately with said sleeve, and will therefore be constrained by the turningof said sleeve and by the frictional pressure of the detent fingers 44, to move ,forward without any rotary movement until the teeth 4l have meshed with those lof the engine member. isY the shaft is thus advanced, stop nut 50 is carried along, and after meshing begins, will contact with the shoulder 51 in which the threaded portion of the sleeve 31 terminates. Thereafter further longitudinal movement of the shaft 40 being impossible the latter member will rotate with the sleeve 31 and thus impart suflicient torque to the engine-member to allow the engine to develop sufcient compression for starting under its own power.

In the event the engine backfires during the cranking operation, a yreverse torque is transmitted from the jaw teeth through the threaded connection to the sleeve 34, causing thepin 32 to slide along the inclined slot 33, thus moving the sleeve 34 to the left as viewed in Figs. 1 and 3 and compressing the spring 36. During this compressing action, limited and predetermined torque is transmitted through the gears to the armature of the motor, thereby rst retarding it and finally bringing it to a stop. At'the same time, a greater degree of torque is applied to the engine to stop further backward rotation thereof. If equilibrium is not established before the pin reaches the end of the slot 33, the engine drives the armature shaft in a reverse direction until the energy caused by the backre has been dissipated. On the other hand, if equilibrium is established before the pin reaches theend Vof the slot 33, spring 36 will be effective to return pin 32 and member 34 to the normal position as shown in Figs. 1 and 3, thereby re-establishing direct cranking Aoperation ybetween the prime mover and the engine. In either of these events, it will be seen that the shock produced by the engine backfire has been assimilated by the yielding connection and without any possibility of serious injury to the parts of the starter, such as the gearing or motor.

After the engine has started under its own power, the inclination of the jaw teeth will cause the return of the shaft 40 back to the disconnected position, in which position it will remain until the next operation of the starter.

There is thus disclosed a novel engine starter of the inertia type which is simple and rugged in structure, inexpensive to manufacture and eicient in operation. It is especially adapted for use with small engines because of its compactness and light weight, but since it is a selfcontained unit, it may be easily attached to any engine, and requires no external supporting means other than a mounting flange or bracket provided on the engine housing.-

Whilel the embodiment above'udescribed possesses considerable practical merit, the invention is not limited to such embodiment since the novel principles may be incorporated in structures varying considerably from that above described. Thus, for example, a cam and follower` construction may be substituted for the pin and slot connection shown atf32 and 33 in the accompanying drawing, and other types of yielding means may be employed in place of the coil springs 36. Moreover, in cases where the requirements permit, the motor maybe mounted in coaxial-alignment with l the engine-engaging member and other types of gearing substituted for that shown'.

VIt is to be understood that varfous otherv changes may be made in the form, details of construction and arrangement of the parts and the uses to which they are applied, without departing 'from the spirit of the invention or the scope of the appended claims.

, means comprising a pair of concentr-ically dis.

1i. .Inan engine:startingrnechanism .of theftype employing'power operated driving means-and 1a driven member :engageable Withfa `.member oi, 'the engine to be startedwthe combination with i said vdriven member into engine engagingxpositlon and` maintaining it innsaid `position regardlessl or rany angular displacement of said .driving connection.`

In an engine starting mechs'inism off-.the type employing power operated ,driving means.. anda driven member ,.engageable with. a member ofcthe engine .to be started; the,combinationwithsaid driving lrneans; rdriven fmember" andr engine member ofA a means -for.yieldably retarding .ther'otary speedoisaid driving means andethereat'er ref versingy the direction; o rotation. of 1 said. driving means in the event of a sudden reversal ofthe directonfoi.rotationoflthe engine member during its engagementwith said driven member,` said posed sleeves, one of which is slotted oblquely of their common axisr of rotation, and means -projecting from the other of said sleeves for engagement with the slotted portion of said first named sleeve to be driven thereby, and means distinct from both said sleeves for shifting said driven member into engine engaging position.

3'. In anengine starting mechanism of the type employing power operated driving means and a driven memberengageable with a member of the engine to be started, the combination with said driving means, driven member and engine mem# ber or a sleeve drivably connected to said -driven member, a second sleeve slotted obliquely of its common axis and drivably connected to saiddriving means, 'and means projectng from said rst vnamed sleeve for engagement with the slotted portion of said second sleeve to be driven thereby, and means for yieldably preventing relative rotatio-nbetween said projecting means and said second sleeve, and means distinct from both said sleeves for shifting said driven member into engine' engaging position. Y

4. In an engine starting mechanism of the type employing vpower operated driving means and a driven member engageable with a member of the engine to be started, the combination with said driving means, driven member and engine member of means comprising a pair of con- 'centrically disposed sleeves normally rotatable in unison but capable of limited relative rotation in the event of reversal of the direction of torque transmission, anda third sleeve splined to one of said iirst named sleeves and threadedly engaging said ribbon member. l

' 5. In an engine starting mechanism of the type employing power operated driving means and a driven member engageable with a member of the engine to be started, the combination with said driving means, driven member and engine member of a sleeve interposed between said driving meansand driven member, said sleeve having a v screw threaded driving connection with said driven member and means for yieldably retarding ,disposed units. f Y l l 6.: In ani enginestarting imechanism of l.the type-,employing` power operated driving. means thelrotar-y speedioisaididrvng.means andthereafterfreversingthe direction ofrotation ofy said driving.' means' in the. event of a sudden `reversalA .of they direction of rotation of `the enginemember during its 'engagement with saiddriven member,zs`aid means ycomprising a pair .of concentrioallydisposed members surrounding said threaded'slceve and normally rotatable 1in unison but capable fof limited`r relative rotation in the eventv of reversal or" the direction .of torque "transmise sion,:.said screw threaded drivingv connectionbeing eiective `.to maintain said` drivenmember: in .engagement with said-engine member during- .the entire cranking process `regardless of'any change in the relative positionsy of said .and adriven member .engageable withxa .member of the engine to be started, the combination with said xdrfivingi means,- driven `member Vand engine member of asleeve fthreadedly engaging :said

driven member, and means ior [causing a revert y sal. of the direction of rotation of ysaid.,driving means in they event of a' suddenreversalv` of the direction of; rotation ofA the engine.. member? dur:

ing .itsl `engagement with .said-'driven member, and means for delayingsnch reversal of ,rotation until: `absorption 4oi.a;.predetermined amount of torque Y"generated in said kengine member, saidy vversal of the direction of torque transmission,

concentrically L' and means constituted'by said. threadedv sleeve n formaintaining said driven'member in engagement with thel engine member during the entire cranking process regardless of anyrelative rotation Whiohmight occur between said concen' trically disposed members. v

'7. In an engine starting. mechanismA of the type employing power operated drivingfmeans k and a driven member engageable with a `member.

of the engine to be started, the combination with said driving means,` driven rmember and engine of concentrically disposed sleeves,'one of which 'has splined engagement with said rst named sleeve and the other of whichiis provided with inclined surfaces, and a member engageable with one portion of said. `inclined surfaces during transmission of torque in one direction and with another portion of said surfaces during transmission of torque in theA opposite direction.

8. In an enginey starting mechanism of `the type employing poweroperated driving means and a driven member engageable with a mem-.y

ber of the engine toube started, the combination with said driving means,drive n member and engine member of a sleeve'threadedly engaging said driven member, and means for yieldablyretarding the rotary speed of said driving means and ythereafter reversing thedirection of rotation of said driving means in the event of a sudden reversal of the direction of rotation of the engine member and without producing any corresponding disengaging movement on the part of said driven member during its engagement with said driven member, said means comprising a pair of concentrically disposed sleeves, one of which has driving engagement with said rst named sleeve and the other of which is provided with inclined surfaces and a member engageable with one vportion of said inclined surfacesdurmg transmission of torque in one directionand with another portion of said surfaces during torque transmission in the opposite direction.

9. In an engine starting mechanism of the type employing power operated driving means and a driven member engageable with a member of the engine to be started, said driven memberhaving a threaded portion, the combination with said driving means, driven member and engine member of a means for causing a reversal of the direction of rotation of said driving means in the event of a. sudden reversal of the direction f of rotation of the engine member during its engagement with said driven member, and means for delaying such reversal of rotation until absorption of a Lpredetermined amount of torque generated'in said engine member, said means comprising a pair of concentrically disposed sleeves one of which is threaded internally to engage the correspondingly threaded portion of said engine engaging member and the other of which is provided with inclined surfaces, and a radially disposed pin engageable with one portion of said inclined surfaces during transmission of torque in one direction and with another portion of said surfaces during torque transmission in the opposite direction, said radially disposed pin constituting the torque transmitting connection between said driving means and threaded sleeve, said threaded sleeve and driven member remaining axiallyxed during the en'- tire cranking period regardless of any movement of said pin along said inclined surfaces.

l0. In a device of the class described, a driving member, a driven member, and a two-way driving connection between said members, said Aconnection comprising a radially disposed pin positively 'connecting' said driving and driven members and also adapted toppositively: connect said members for reversetorque transmission after a limited' degree of relative rotation between said pin and driving member, said driven member remaining in fixed axial position during the entire cranking period regardless of any relative rotation between said pin and driving member.

' ROMEO M. NARDONE.