US1337331A - Impulse starting mechanism - Google Patents

Description

W. E. SCHWARZMANN. IMPULSE STARUNG MECHANJSM.

APPLICATION HLEU SEPT. 91, 1911.

Patented Am. 20,1920. l

Q O ...wz L Q uw 2. 1 i

W. E. SCHWARZMANN.

iMPiaLsE STARTING MECHANISM.

MfLiCUON HLED SEPT.21,191?.

Patented Apr. 20, 1920.

3 SHEETS-SHEET 3.

wugff UNITED sTATiis PATENT OFFICE.

MEBNE ASSIGNMENTS, YORK, Il. Y., A CORPORATION TO AMERICAN A@OSCI-I MAGNETO CORPORATION, F NEW 0F NEW YORK.

IMPULSE sirname MECHANISM.

Specification of Letters Patent.

Patented Apr. 20, 1920.

Application filed September 21, 1917. Serial No. 192,481.

T o all whom, it muy concern.'

Be it known that l, WoiiroANa E. SCHWARZ- MANN, a citizen ol' the ll'nited States, residing at l Bellclaire avenue. Long Meadow,

5 Springfield in the county of Hampden,

AState of llffassachusetts, have invented eert inknew and useful Improvements in .lm-

flse Starting Mechanism; and l do hereby declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilled in the art to which it appertains to make und use the same.

The present invention relates to impulse4 starting mechanism wherein the driven device is given one or more impulses, cach for a fraction of a turn, at a speed considerably higher than the speed of the driving device, andv it embodies the use of an impelling spring arranged to be stressed upoirrelative angular displacement of the driving and driven devices, of locking mechanism for locking the driven device against rotation While the driving device is rotating, and of releasing i'iieilianism for releasing the driven 26 device so that the spring, then stressed,.iiri

pels the driven device through an appropriate angle. Such mechanism is applicable to various kinds ot' devices, such as internal combustion engines or other prime movers 30 which are not self-starting; and particularly to magnetos for generating ignition voltages suitable for igiiiting gaseous mixture present in a cylinder of the engine with which it is associated, when the eiigine is heilig turned at low speed in starting, or is at rest in position for an ignition spark.

Many of the devices to which impulse starting mechanism is applicable, may ie-, uire rotation of the driven device in one direction or the other; `for instance, the position or arrangement provided on some engines may require clockwise rotation of the magneto. while others require anticlockwise rotation. In prior forms of construction, the impulse starting mechanism is adapted for rotation of the driven device in a single direction only` and the conditions imposed by the driving devices are niet by vusing intermediate reversing gears, or the like, when made necessary by the fixed direction of roation of the impulse mechanism` or by proreversingy dlivices or different right and left /viding different right'and lettA hand parts. Inaecordancewith my invention, the use of hand parts for the two directions of rotation 1s avoided by making the impulse mechanism itself reversible, so that it can readily be adapted for rotation of the driven device' in one direction or the other merely by changing the relative position of certain parts of the mechanism. In the specilic embodiment of the impulse starting mechanism for uagnetos hereinafter disclosed as an exampe of my invention, the impelling spring may be arranged to be stressed upon relative angular displacement in either direction of the magneto sha ft and the driving or engine shaft, which may he the engine crank shaft or ay shaft geared thereto, the locking member being arranged to lock the magneto shaft against rotation in such angular position for the direction in which it is rotating, and the releasing member being fast on the driving shaft in such angular position relatively to the crank shaft of theNengine, for the direction in which it is rotal ing, that the magneto shaft is always released just prior to the angular po'sition of maximum generation of the magneto and at substantially the beginning of the working stroke of the engine cylinder to be lired. In this way, the magneto adapted to most effectively generate a spark in the engine cylinder at the time the piston therein is at or near the beginning of its working stroke, irrespective oi the direction oflrotation of the magneto and without the use of additional gearing or different right and left hand parts. Likewise, the magneto shaft is always released after a'predetermined angular displacement of the shafts, that is, after the impelling spring is stressed to the desired degree.

My invention also provides` various improvements in construction and arrangement of impulse starting mechanism in general, whether reversible or not. In the preferred embodiment hereinafter disclosed, a disk, mounted on the driving shaft and having integral releasing cams on its periphery, carries circularly-disposed coiled impelling and buffer springs abutting anchorage posts, and a pressure-,applying member is loosely journaled on the `driving shaft., and has diametrically-dispos'ed arms extending between the impelling and buli'eisprings. A disk fast on the magneto shaft hase flanged rim with slots and with integral speed limitnfg4 vlo or safety earns. the arms of the pressureapplyingr meunier extending through the slots so as to lie last with the magneto shaft. A pawl mounted on a stud journaled in a stationary meunier is adapted to` engage the. projecting' end of the arm ol' the pressureapplyi'hgr niernlm; lo thereby look the mag- 'neto .shaft against rotation while the drivinl;r shaft is rotating, and to stress the impelling sprinpr as a result of the relative angular disjilarenieut oi' the shafts. The pan'l may he d..eui;rapged from the arm of the pressure-ap]ilying member, either hy manual operation of an operati ng handle'on the stud, if the driving shaft is stopped, or bly the releasing van), il: the drivingr shaft is allowed to continue its rotation. The irnpellingir force. ot the spring` turns the mag neto through an appropriate angle and at a. sufficiently high speed to generate a satis'- facto'ry ignition spark in the proper engine cylinder, Whieli is primed with If lasolene for the purpose` il necessary. lf. however.` the engine does not start into action, the oiiera tion is repeated. l

After the engine starts, the speed is sutfieient to drive the magneto at sparking speed without the use ofi the impulse mecha nism. ln View ot this condition, a latch is provided 'for holduigr the paal in inoperative position. preferably, it consists of a pivoted member pressed hy; a spring toward the pawl and carrying a finger pressed by a weaker spring,r to the position for retainingr the pawl in inoperative position out of' the patlrof rotation of the projecting ends oi`: the pressure-applying arms.

In this connection niy invention further comprehends the idea. oliv preventing the, locking' mechanism from fullyY or partlii7 eugaging the driven device While the driving,r device is rotating at running speed even iii the operator shouid imidvertently hold the looking mechanism in operative 'iosition.

The preferred forni of nieehanisin is made reversible-hy providing for the two diree tions of rotation two settings of the pawl and latch, and to eorresponding settings of the 4pressure-applying member and the releasing earns, the position of' the springs being Changed to rorrrsln'md therewith.

ln the aeeonipanyiin; drawings1 illustrat ing,r my preferrwl form of reversible impulse starting meehanisni. in, application. as an example, to a magneto driven hy the. engine, with Whieh it is assoriated, Fig-ure l shows on a reduced scale the rolnhination ol' theenlg'iy'i'ne, magneto and impulse meelnrnisru; Fig. 2 is :1 lonitudinal seetion through the magrneto' and the impulse mechanism; lfipgs. 3 and t enlargfel'l sections on line land resi rely, oi Fig. 2,' ,li in. 5 and i are pers'ieetive View? of the lor-king pawl and the. atoh therefor; FigY 'i is z, seetiou on line`7-7 of Fig. l g. n a section on line 8--8 of Fig. 7, and Figs. 9 and lf* show diagrammatieally the relativi;- pusniun. ol' parts of the impulse meelnmisru for the two directions of rotation.

The engine l is of the lourwylinder loure ele` type, and the bipolar magneto 2 criven from the frank shaft :i thm-ol by the like gears l, has its armature i egrlending lengthwise of the arias l, of the magnet. The meellanical interrupter i is lol-ated in the arch 8 of the magnet. and is. tlieretore` in protected, position hut readily '.uwwsihle for inspection and repair! The distrilaner segments 9 are loratedat the other end ol' the armature, and at each period ai fjnition ,they7 connect the insulated teruiimi i the high tension armature winding to two the spark plugs 1() in series. in the. weil known way. The impulse rnechanisul is arfanpgml at the outer ends of the arias ol' the magnet.

The shaft, ll., herein harmed the. driving shaft, is mounted in axial alineinani, with the shaft l2, herein termed the nungnfto or driven shaft, rl`he disl; l is fast with the driving shaft and has on its lace two diametrieally-disposed anchorage lll bolted thereto and slotted as sho-an. The pressureapplying: member 1f: is loosely imitatie,

journaled on the. hollow enlarged end lli ofu the driving shaft, and has tivo flizuuetri eallywhsposed arms l 7. The elrcularly-disf posed .coiled ilnpelllng springs 1S allai, the

anchorage` posts and the arms, and thestifl'er and shorter liuier springs 19 ahnt the other sides thereof. These parts are formed into a unitary structure, by the retaining rinpr 2() loosely threading;r the sin'ings.` the arms and the posts. The retainingr ringiF is initiall)l split at 2l and its two ends are pinned after the parts are in plaee. The dish has two diametriCally-disposed ri-ileasinpj nanas normally dsplaoed from the arms 1T by an angle of about 235 degrees.

The disk' Q3 is fast on the mag-.meile ha i'i 1L and has a iianged rim LEE with two :liarnietrieally-disposrd speed limiting or sa hay nains 25 on its peiipher)Y and two pairs oli diametrirally-disposed slots L'l and 52T located about 27 degreeson the two aides ni' the rains. ille arnis l' are slipped. into one or the einer pair oi' slots to eminent the pressure-apply iup` member to the magneto slmit'tlnx arrangement heilig such that the arms trail the. limitingr rams and lead the releasing #anis in the direi-tion of rotation.

The pawl 3H 'is looselli7 journaled ou. the stud 25), which has an operating;r handle il() and a Crank arm Ell iast on t.` The stud is looselyy 'jourualed in a stationary member und tension sprinp'Z tends to hold the. stud `and handle in neutral position as shown liest As shown liest` in Vies. L. and in l "Ti ais crank arm, and the rotation of the crank arm is limited by the stop pin 35. The arrangement is such that with the handle in neutral position, the pawl may rest in operative position on the outer periphery of the rim 24 or it may be in inol'ierative position iu engagement with a latch, as shown in broken lines in Fig. 4. This latch consists of a member 37 loosely jonrnaled ou a stud. 38 and spring pressed toward the pawl.,l and Vcarries a. loosely journaled linger 39 spring .arms 17 of the pressure-applying member.

The housing for the impulse mechanism consists of a plate 42 having a lhuge 43 which completes with the magneto the closure for the distributingr segments The plate also has aliextension 44 formlngthe base-plate of the magneto,D and a bearing 45 for the magneto shaft 12.` l`he other end of the armature is supportedin a bearing 46 carried by the base-plate. The cover 47 carries the pawl and the latch, and fits the plate 42 to form a housing chamber for the impulse mechanism. Also, it carries a baniug 48 for the driving shaft.

The operation of the impulse starting i-nechanism will lnow bev described. For clockwise rotation'of the magneto (as viewed from the driving end) the parts are arv ranged as shown in Figs. 2. Il, 4, 7, 8 aud El, The pawl 28 and the latch 3T are set on the left side of the stud 29 (as viewed from the driving end). The arms l? of the pressure-A applj ing member are set in the slots 26 of the limiting cam disk 23 and the pawl engages the arm, to lock the magneto sha it 12 against rotation while the driving shaft i1 is rotating, just prior to the angular position of maximum generation of the magneto i?. The releasing cam disk 13 is so positioned relatively to the angular position of the crank shaft 3 of the engine l, that the :am

releases the pawl at substantially the time the piston in the cylinder to be fired starts its working stroke.

To start the engine into action under its own power, the pawl is first disengaged from the latch by pressing on the o )e1-ating handle 30, the pawl then turning reel on its stud until it rests on the periphery o the limiting cam disk. The crank shaft of the engine is then turned in any suitable way, the pawl locking the magneto shaft against rotation and causing the pressureapplyiug member to stress the iinpelling spring 18 to the desired'degree. If the engine is stolpped at or just prior to the position in whic 1 the piston starts its working stroke, as is desirable in the case of large engines,tl1e pawl is released by hand by turning the operating handle, hut if the rotation of the engine is continued, the pawl is released automatically hy the releasing rain, the magneto shaft be ing impelled in either case at a sufiiciently high speed and through an appropriate angle to generate a satisfactory sparking voltage in the magneto. In that period the mechanical interrupter 7 opens and the collector segments 9 connect the secondary winding to two spark plugs 1U in series, whereby an ignition spark occurs in the cylinder to he fired andalso in a cylinder in which the piston is at or near the end ot its exhaust stroke. In almost all cases in which the cylinder contains gas, or is properly primed with gasolene, the engine starts upon the first operation of; the impulse mechanism; hut if, for anv reason, this does not occur, the crank shaft is again turned or its rotation is continued until the piston of the' next cylinder to he fired is at or near the lueginning of its working stroke, and the; impulse mechanism is again operated.

Ordinarily the pawl is thrown into latching position when it is released by the releasing cam, hut if it remains in operative locking position, orif for any reason it comes into that position, it is thrown into latche'd position by the limiting cams and prevented thereby from partly or fully engaging the projecting ends of the arms of thc |ncssureapplying member as soon as the speed exceeds a value at which the mechanism might he damaged h v the resulting check. llveu il' the operator should then hold the handle in its extreme position limited by engagement oi' the arm 3l and pin 35, the free rotatable movement of the pawl on its stud suflices to permit the limiting cams to throw the pawl out ofthe path ofthe arms of the pressol'e-applying member as they pass.

It the impulse mechanism is to he arranged ior driving a magneto in anticlocl wise direction. instead4 of in clockwise direction as hereiulgefore described, it is only uecessanv to change the position of ce1-tain Y of the parts of the mechanism as indicated in Figs. 9 and 1U. The pawl 28 is set on the other side of its stud 29. the shoulders 33 and 34 being arranged for that purpose to permit the same limited amount of rotation of the pawl ou the Stud as before. The member 37 of the latch is reversed on its stud 38 and is mounted at 497.0n the cover '4T of the housing to c'operate with the pawl ist i mounted directly on the rrank shaft ui' ilul engine, the adjustment is etici-teil our :alluriingl it on the crank shaft. i'lasiug ihr rr leasing cam disk and the lnessureappi; in; member in their new positions-i` ilu nini-1 il," are then inserted into the slots :2T on lli# sides ot' the limiting cams opposite to non for the other direction of rotation. so im for both directions the arms trail tin l ing: cams 25 and lead the releasing; wir in the direction in ywhich they are zln this Way the magneto shaft l! in invloed against Yrotation just prior to the angular position of maximum generation ol' ihj naar, neto, and is uiilorked. after a lireilvif-riniiu ll angular dispiaconient of the shafts sulliwwni to stress the iinielling spring to tin :hcred degree, and also at the time that the rr.. shaft 3 reaches the position in uhh-li ein; piston in the cylinder to he tired is. as iwnr. at or near the beginning oi' its uni-hing stroke.

lt will ne apparent that the ump-neto olii hc of any suitable type. and that the en; n may have any nuniher o? cylinders quaint ingr on any desired cyr-le,

Having thus described my invention. what I claim is:

l. The combination with an internal foin lmstione'ngine having` a, shaft and a n ig" neto therefor having: a shaft, of rerorsrne impulse sortingr mechanism for the non@ noto comprisingn an impollingsprintf ai ranged to he strcsseifl upon reir-iw :on-niar displacement of the shafts. a nrrwnn niernlier for lurking; the magies.: fw

against rotation `while the engine snai" rotatingn Iand a releasing member for rrlcasing the locking' member from lori-fing( engagement, the lorlmn;y and rrlrasnr-L` meinhers being' construrtcd and 'urn-ingril so that for cach dirertion of rotation the inagneto shaft is locked just prior to the @insi-Y ton of maximum generation of the manor-@o and is released at snlistnntiallv the he in ning of the working strokeol' ilu` engine eylinder.Y

2. The combination with an internal coni bustion engine having a shaft and n man; netorthcrefor havin#lr a shaft, ot reversible impulseA startingincciianisnx for tho man# neto comprising: an imliclling spring or ranged to he stressed noon relativiI anffjuizw displacement of the shaftsra lot-hing; men:-

one position' for locking the just prior to thc position of huisnr: t 1ration of the magneto while the A hait is rotating in one direction and another position for locking the mag` :nio soliti; last prior to the position of maximum generation of `the magneto While the engine shaft is rotating in the other di-l rection, :ind a releasing member construct'- eil and arranged so that for each' direction of naanoo the magneto shaft is released at silli-.laniiially ilie same angular position of ille rf'nc shut.

il, l he nomhination with an internalcom vraiiori engine having a shaft and a magnr'rt thro-'for lniving a shaft, of reversible impulse dan-rag mechanism for the magirwingg an impulse spring arran ed relai upon relative angular is- Y i: o the shafts, a locking member fz renard nul arranged so that for each wion of :mation the magneto shaft is im" prior to the position of maxinnno 5mm-ation of the magneto, and a releasing nwo-ier carried by the engine shaft Tua* lowing); the locking member, the reininlaxr being; carrled at a different position for each direction ot rota that the magneto shaft is released at mostriniialv the same angular position of l En: engine shaft irrespective of the direction nml 1i, Trie rino .'sriii rangen hun iin' niacin rrlriilixt shafts. a ladron; member having one position .for 'lurking thc driven shaft While the driving; han is rotating in one direction and another grisition for locking the driven shaft n'hih tin 'lriving Shaft iS rotating in ilu: oihrr lim ion. and a releasing member for :phoning ila. locking member, the roleasiiigf member living mounted on thc driving ,slnilt Lor* having two angular positions rvlatiivly zo l' driven shaft sut-,h that for either duw-tion of rotation the releasing meunier wir the locking member at the tunic :angular elisilacclmnt of the shafts.

V. ln ri-rrrsiiih impulse starting mecha? a a drrngshafttadriven-shaft, a spring sis arranged to be stressed upon relative angular displacement of the shafts, a pivoted pawl aving one position for locking the driven shaft while the driving shaft is rotating in one direction and, another position for JLonliing the driven shaft while the driving shaft is rotating in the other direction, said pavvl being arranged on one side of its pivot for rotation in one direction and on the other side of its pivot for rotation in the opposite direction, and a paivl-releasingcam mounted on the driving shaft to release the pawl at one angular position of the driven shaft for rotation in one direction and at another angular position for rotation in the opposite direction.

7. In reversible impulse starting mechanism, a driving shaft,a driven shaft, aspring connected to one of the shafts, a pressureapplying member adeptedtostress the spring upon relativey angular displacement of the shafts', a locking memberhavingone position for locking said member and the driven shaft while the driving shaft is rotating in one direction and another position for locking said member and the driven shaft while the driving shaft is rotating in the other direction, and a releasing member for releasing the locking member, the releasing member being;r mounted on the drivin shaft in either of two angular positions re atively to the driven shaft such that for either direction of rotation thereleasingmcmberreleases the locking member at the same angular displacement of the shafts. v

8. ln reversible impulse starting mechm nism. a driving shaft, a driven shaft, a spring connected to the driving shaft, a pressnre-applying member for the spring connected in one angular position relatively to the driven shaft-for rotation in one direction and in another angular position for rotation in the opposite direction, a locking member having one position for locking the lnessnre--applying member and the driven shaft while the driving shaft is rotating in one direction and another position for lockingr the pressnre-applying member and the driven shaft While the driving shaft is rotating in' the other direction, said members cooperating at one angular position of the driven shaft for rotation in one direction and at another angular position for rotation in the opposite direction, and a releasing member for releasing the locking member at one angular position of the driven shaft for rotation in one direction and at another angular direction.

Sl. ln reversible impulse starting mecha nism. a driving r shaft, a d riven shaft, a

spring connected to the driving shaft, a pressarc-applying member adapted to stress the spring upon relative angular displacenicht of the shafts, said member being faaposition for rotation in the oppositecam carried by the driving shaft in one angnlar position relatively to the driven shaft for rotation in one direction and in another angular position for rotation in the opposite direction. f

1U. In reversible impulse starting mechanism, a drivin spring arran e to be stressen u on relative angular disp acement of the sha a pivoted pawl having che position for locking the driven shaft while the driving shaft is rotating in one direction and another position.

for lof-,hing the driven shaftiwhile the driving shaft is rotating in the other direction, the pawl being arranged on one side of its pivot for rotation in one direction and on the other side of the pivot for rotation in the opposite direction, a latch for holding the pa wl in inoperative position, a mounting for supporting the latch for one position of the pand, another mounting for supporting the latch for the other position of the pawl, and a releasing member actuated by the driving shaft for releasing the pawl from locking position with the driven shaft.

il. ln reversible impulse starting mechanism, a driving shaft, a driven shaft, a. spring connected to the drivingl shaft, a. disk fast with the driven shaft and having a flange with two adjacent slots, Aa pressureapplying arm adapted to stress the spring upon relative angular displacement of the shaft, said arm projecting through one of said slots for rotation in one direction and through the other of said slots for rotation in the opposite direction, a pawl engageable with the projecting end of said arm to lock thc driven shaft against rotation, and a pand-releasing cam mounted on the driving shaft, the pawl and its releasing cam being arranged to coperate for releasin said arm at one angular position of the riven shaft for rotation in one direction and at another angular opposite direction.

12. ln reversible impulse starting mechw nisin, a driving shaft, a driven shaft, a spring connected to the driving shaft, a limiting cam fast with the driven shaft, a pressarenpplying member adapted to stress the spring upon relative angular displace ment of the shafts, said member being connected in one position to the limiting cam shaft, a driven shaft, a

position for rotation in the for rotation in one diret-tion and in. another position for rotation in the. opposite direetion, a pawl engageable with said member to lori; the driven sha It against rotation, and. a pand-releasing ram 'fast with the driving sli-att, the pawl and its releasing cam being arranged to cooperate at two angular positions oi' the driven shaft for the two directions of rotation.

13. In reversible impulse starting mei-hanism, a driving shaft, "it driven shaft, a spring connect-ed to the driving shaft, a

limiting earn fast with the driven shaft, a

pressureapplying member adapted to stress the spring upon relative angular displacement olf the shafts, a loel'iing member adapted to look the pressureapplying member against rotation while the drivin? member is rotating, and a releasing mem er for releasing the locking member, said pressureapplying and releasing members beingr arranged for connection to th'e driven and driving shafts, respectively, in twopositions so that For each dirertion of rotation the pressurenpplying member trails the limiting cam and leads the releasing member.

i4. ln rewrsil'ile impulse starting mechanism, a driving shaft, a driven shaft, a spring '-onnerted to the drivingr shaft, a iimiting cam. a pressure-applying member adapted to stress the spring upon relative angular displaeemei'd of the shafts, a looking member adapted to loek `the pressureapplving member against rotation while the driving i veinlwr is rotating. and a releasing member lor releasing the locking member` the limiting earn and the pressnre-applying member being arranged for connection to the driven sha lt in two positions and the releasing narinber being arranged for rennertion to the driving @shaft in two positions so that for eaeh direi-tion ol' rotation the pressnreapplying member trails the limiting earn and load" the releasing member.

15. In im le@ starting meehanisim a driving shaft., a driven sha lit. a member tast with the driien "i aft, a roiled impelling' spring. a preesnre apli-'ing member looself.r jourv naled on the driving shaft and'having radially nrqieeting arms engaging the spring, a retainii member threadingr the spring and the. erin. looking merhanism eonstrueted and arranged to lock the driven shaft against rotation whiie the driving shaft is rotating and thereby stress the spring, and releasing mechanism ltor the lorking merlinnisrn.

lli. ln impulse starting inerhanlsnna dri\' ing shaft. a driren shaft, a disk mounted on the driving shaft and having an anrborage post on its tace. a eireulaily-disposed coiled impelling spring abutting the posh a pressore-applying member loosely7 journalecl on the driving shaft' and having radially projecting arms engaging the `rieallyalisposerl anchorage po sprii'1g,a retaining ring tlvand the posti looking me am i i'zstrurtei and arranged to lorli; the driven shaft against rotation while the driving shaft in rotating and thereby stress. die spring, and releasing mechanism lfor the looking mechanisro.

17. ln impulse Starting mechanism, a` driving shaft, a driven shai' a member tast on the driving shalt, and hai ing anchorage post-s, eirealarlydisposed rolled impelling springs abutting the posts. :l` pressure-applying member loosely Jionrizaied on 'the driving shaft and having radialljiprojeoting arms engaging the springs. a retaining ring threading said springs and arms. locking mechanism ronstrnrttni and arranged to lock the driven shal'tagainst rotation while, the driving shaft is vrotating and thereby stress the impelling spring. and releasing mechanism for the looking mechanism.

1H. In impulse starting nierhauism, a driving sha'l't. a driven shaft. a disk mounted on the driving shalt and haring dialnet e. ri-roularlyz nge abutting ling the .eprinhl disposed coiled inipelling ep the posts, a looselyv journaled on the dril iisg shaft and having diametrirailvdis;ai arms engaging the springs, a retaining ring threading the springs and arms anzi gaging the posts.y looking inrrlmnism f-onatrurted and arranged to lori; the drin-f: `hatt against rotation while the driving di x lt is rotating and thereby7A stress tin: si. and releasing mechanism for the hr inerlnmism.

19. lu impulse starting;- iwahanisnn a unitary driving efemen' rom rising :t shaft. a disk fast on said ar wing anchorage posts on its lac-e and z in portion on its periphery. dirt-niarljr-dl .posed coiled impelling and loniler springe.abutting the posts, a pri'iesnroapplying member loosely journaled on said shaft and haring arms projecting betweeirthe nii-ailing and buffer springs, and a retaining ring threading said springs, posts and arms; a driven shaft; and locking mechanism for lori-ing the pres sure-applying member and time iii-iron shaft against rotation while the uriving shaft is rotating: said vom portion being engageaole with said merbanisni to roh-uw: ii from locking position.

20. In impulse starting nnirhanism. a driving shalt, a driven ehaii. an impelling spring nonnen-ted to the driving shaft. a disk fast on the driven shaft and haring a flange with a slot and a eannned portion. a pressure-applying member loosely iournaled on the drii'ing alzati and extending through said slot. said member being adapted to stress the spring upon relative angular displal'ement of the shafts, a locking member for lovliing the driven shaft prei-sure -a in ing member.

Images