US1056418A - Engine-starter. - Google Patents

Description

P. W. HODGKINSON.

ENGINE STARTER.

ABPLIGATION FILED Amm, 1912.

41o gines without the application of manual j f UNITED s'rnfrns .PATENT OFFICE] 4minor W. Honemiisornor ROCHESTER, NEW YORK, AssIGNOR or ONE-HALF 'roA JACOB o. LOMBARD, oFnOOHEsTi-m, NEW. YORK.-

- ENGINE-STARTER.

` specintatitii oi Letters Patent.

Patented Mar. 18,1913.

l To all @hmz't mag/concern: l Y

tain Ile' ,Beit 'l own that I, Pliner W. HODGKIN- son, a-citizen of the' United States, and nresident of Rochester, in thel county of-Monroe andStaiie of New York,"ha"ve invented cerand useful Improvements'in Enof this kind vin which compressed air or.

This invention relates .to means for starting the operation 'of internal-combustion enpower thereto, and particularly to devices other, motive-fluid is employed. to furnish the' requisite power, this motive-iiuid being' l introduced directly into the cylinders ofthe engine-.under the control votsuitalole selector- Inechanism mln four-cylinder;tour-cycle l internal-come bustion engines, asusually oonstructed,ta1ll of the cranks lie in one' plane, so that it is possible for'the engine to stop in a position in ,which all of the cranks are atA or near deadlcenter. In such a case it is difficult,

and often impossible, to start the engine by the mere introduction of compressed' motive- V fluid-into thefcylinderin which thep'iston is -on the eXpansion-stroka'for the reason that this'pistonmaybe so near theend of theA stroke that vsufhci'ent momentum .cannot` be applied through it to the Aeng/ine to carry the parts' past dead-center and or the further v'reason' that the valve-mechanism is usually adjustedto open the exhaust-passage from the cylinder beforethe end Oftheiexf pension-stroke is reached- In aprevious appl cation filed November 23, 1911,- Serial No. 662 ,O74,'I have disclosed an engine-starter Ofthe pneumatic type in which lpropose to overcome.- the diiiculty just describedby-introducing compressedv lmotive-fluid iirst into a cylinder in which the piston is on the in-stroke or compressionstroke,`thus-moiri,ng the partsfof-the engine backwardly so is to vbring another piston into a posit-ion favorable for the. startingoperation. The presentinvention Vrelates to improvements upon the apparatus disclosed in .said application. 5

One object of the present invention is to render the preparatory backward movement of the amine-mechanism more certain in its ezt-tent and results. To this end I employ, in

the present apparatus, motive-fluid at two different pressures. The high pressure is employed in the motive-Huid which is used to start the 'engine in a forward direction. The lower pressure is employed in the motive-fluid which is used for the preliminary operation of moving the engine-mechanism backwardly to bring it -into a position ffl-1'A -vorable for starting. This arrangement has the advantage that the lower degree of pressure can be so selected that it is quiteisut- 1 cient to produce the required movement of the .engine-mechanism, while at the same tiInefi-t is not stiflicient in'v any case tomove the-engine part-sto'olfar, and thus bring them toor nearfthe dead-center Opposite to` that which they originally occupied.v`

Another object of the invention Ais to improve the construction and operation of'devices of the kind in question in various details which will be pointed out-in connection. with the following description of the-illus- 75 trated embodiment of the invention. -In the accompanying drawings the inventionv is illustrated as employedin conn-ec-A tion' with a four-cylinder engine.-

Figure 1 is a side-elevation of the selec- 80 tor-mechanism; Fig. 2 is a vertical section on the line 2- 2 in F ig. 1; Eig. 3 is a plan- View of the selector-mechanism; and Fig. 4 a diagrammatic"side-elevation showing the connections-between theengine andthe 8o starting-apparatus. y

lIn the illustrated embodiment of the invention the motive-fluid'i-s directed selectively to the'several cylinders of 'the engine by means/of a selectorshown particularly in Figs. 12 and 3. This device is provided with four puppet-valves 10 controlling outlets from a valve-casing 11. These outlets discharge through nipples I2' by means of which connections are made with the .respective engine-cylinders. Within the Valveca'sing, and below theva'lves, is a cham-loerJ v13 which is charged*4 with the compressed' -motive-u'id. The valves have 4stems 14 vand packing to revent the leakage of ino- 10o tive-fluid eroun the lvalve-stems. The degree of compression of the washers is controlled by adjusting-nuts 16.0n the valvestems.

Upon -the lower end of each valve-stem purpose of camfollowers through which the valves are actuated, as-'will bepresently de scribed, and, owing to their threaded con-v nection with the valve-stems, they may be vvadjusted longitudinally thereon toA regulate lthe amount'of opening of the valves. l

The ivalve-mechanism is actuated by con. neet-ion with a rotativepart of the engine, Such, for example, as the usual half-time shaft 19, this shaftl being illustrated as in wer'tical. position and having a bearing at its upper end *in* the body of the valve-casing.

The opening movements are impart-ed vto the valves through theoperation of two :cam-projections20 and 21- which are carried, respectively, by concentric lsleeves 22 "andl 24. The sleeve 22 is loosely mounted on vthe shaft 19, so that it mayslide'longitudinally thereon, but is co ected with `the shaft by means of a spl'in 23 so as Vto rotate therewith. Thesleeve 24 siides longitudinally upon the sleeve 22, butI is connected-therewith by meansof aspline 25 4 so as to rotate with the sleeve 22 and. thus with the shaft 19. In the'normal positionl of the mechanism both of the Sleeves are'in `their lower positions, tas shown -in.Figs.1

and 2, so that the cams 20 and 21 do not engage the caps'17, but rotate idly with the shaft 19 during the normal operation of the engine. When the apparatus is to, be operate'd to start the engine, however, the sleeves and the cams are raisedv s`o as to bring the cams into operative engagement with one. or the other ofthe caps. The means for so raising the cams comprise two valve- plates 26 and 27 which are. pivotally mounted on studs 28 and 29,resp'ectively, screwed into opposite sides of the valve-casing 11. '.Springs 30 surrounding the studs, and bearing against the valve-plates, press thevplates :firmly against the'flat surfaces of the casing. The upper edge of each valve-plate constitutes a eam-surfaee, as shown particu:

larly in Fig. 1, this. cam-surface being en`y gaged by a rollen 2lrjournaled upon av camlever 32.-,Each lever 32 is pivoted, at its forward end, upon a stud 33 fixed in lugs projecting upwardly from the valve-casing,

an arm 36 which engages an annular slot' in the sleeve 24.l .The other-rod, 45, lis provided with an arm 46 which engages an annuiar slot in the sleeve 22.

' Springs 37, connecting the valveplates and the valve-casing, lnormally retain the former in the position shown in the drawings. Each valve-plate is provided, however, with an arm 47 by which it may be swung rearwardly againstthe opposition of its spring 37.

By the movement of the valve-plate just described the cam-surface, upon its upper edge, is caused to 'raise the corresponding roller 31, owing. to the form of the camsurface asillustrated in Fig. 1. This movement results in raising the corresponding rody -35 or 45, and thus raising the cam connected therewithv into operative relation with. the vcaps 17.- 'j n l i "Ihe cam 21 may be designated as the reverse-cam nce it is the one which is emfployed in causing the reverse or backward .movement of theiengine' herei'nbefore described.` Accordingly, the relative position of this cam' with respect to the shaft 19 is such as to bring it alwaysin position beneath'the cap of whichever valve l0, in any particular position of the enginemechanism, is connected with the cylinder in which the iston is in its compression-stroke. v'lheacam 2p, on the other hand, is the starting-cam, being so located with respect to the shaft as to lie always beneath the cap of `cylinder in' which the piston is in its pension-stroke.

In addition to their mechanical functions just described the valve- plates 26 and 27 iact as ,valves to introduce motive-fluid into the valve-chamber 13. derived, from a -suitable source of supply, through pipes 39 and 44 containing, respectively, low-pressure and high-pressure mo-k tive-fluid.- The pipe 39 communicates with a passage 38 in the wa-ll of the valve-casing, this passage being directed outwardly at its end so as toy form a port 40 in the surface or seat upon which 'the valve-plate slides. Directly above the port 40 is a port 42 comports are normally both closed by the inner valve-plate is swung rearwardly. that is, to the left in Fig. 1, 'a recess or passage 41 in he inner surface of the 'valvlate is brought into communication with tlie ports 40 and 42, thus forming a passage through which motive-fluid may flow into the valvechamber 13. A similar arrangement is employed in connection with the valve-plate 27. The motivelfluid from the pipe 44 flows through a passage 43, the valve-casing and the valve-plate being formed with ports similar to those just described.

After either of the valve-plates has been operated to introduce motive- Huid to the v`Valve-casing, and thence to one of theengine-cylinders, it is desirable to exhaust the whichever valve 10 is connected with the4 municating with the chamber 13. Thesef surface of `the valve-plate 26, but when the' This motive-Huid is-` noname spentmotive-fiuid before operating the engine in the opposite direction, fand accord-fingly each valve-plate is provided with an exhaust-port 60 which registers momentarily with the port42, thus Aaffordingal'l outlet to atmosphere from the valve-chamber 13. dun

., ing each operative movement of the valv`e' plate.

nism previously described is employed in connection with an engine.

- these cylinders arefconnected, respectively,

` nected with all of themv and provided withl through pipes 49, with the nipples 12 on" the valvescasing. `In each of the pipes 49. a shut-oit cock A50 is introduced 4neantheVA engine-cylinder, `so that, during normal operationl ofl th angine,` communication 'between the cylin 'r'sahd thevalve-m'echanism .may be interrupted, andthese,2:cocks may be conveniently operated by a` rod v51 coninto the pipes 49 during the operation of the l engine.

As a convenient meas for operating thevalve-plate 26, Fig. 4 illustrates a rod 53 connected with the. arm 4 7 on the valve plate and extending rearwardly. to a position in which it is conveniently accessible,

the rod having` a handle ofLany convenient form, onitsrear end, by which it maybe pulled. The valve-plate'27 is actuated by a similar device (not shown).

The motivediuid employed in connection with the starting-mechanism may be eithercompressed air or compressed gases from the engine. In Fig. 4 I have illustrated a tank 54 adapted tocontain a suiicient supply of compressed motive-fluid, and this tank com municates, through pipes 55 and 56, with one of the engine-cylinders so as to receive compressed products 'of combustlon therefrom during the normal operation of the engine. The .usual check-valve device 57 y.imay'be introduced inthe pipe 56 to prevent the return flow of gases to the engine-cylinders. This device is not more particularly illustrated as it is familiar in connection with various well-known engine-starters. It wil-l be understood that in place-of deriving the motive-fluid from the engine-cylinder,

pure air may be 'compressed by means of a pump of any ordinary or suitable construction, or that the motive-fluid may be derived from any other convenients'ource.

yAs already stated, the pipe .44- su plies motive-fluid under highpressure, whi e thel pipe 39 supplies motive-Huid under a lower Fig. 4 illustrates, as 'a Whole, the' systemv or arrangement by Which the selector-mecha- An engine hay ing :tour cylinders 48 `isl illustrated, and

as communicating directly with the pipe 55,

a pressurerregulator or' reducingTvalve 58 is introduced, this, device being adjusted to maintain a comparatively-low pressure in ,the-pipe 39.' Theconstructionl of the reduc- 'pipe 55, so that. incase the a paratus stands unused-for a long period `o time the leakone side of the axis "off rotation and .two on the other, so that two ofV the pistonsare respectively, 1 while the other twol are on the correspondin inlet-valve andiexhausb' valve closed, 'an

the.v motive-fluid. 'Providing' thev pistonv in merely introducing the high-pressure motiveuid into,` this cylinder, this operation resulting from the movement of the valvecam-mechanism is rotated correspondingly by the shaft 19, so that the cam 21 raises the valves 10-successivel and thus transmits motive-fluid to the cy inders in order as the piston in each cylinder lreaches its expansion-stroke. The'engine may thusbe operated continuously by the compressed motive- -xi-luid untilthe induction and combustion of explosive mixture causes the en e to beginy its normaloperation. Whil it is usually suicient, therefore, to operate thevalveplate 27,it frequently occurs that the engine stops in `such a position that itis di'licult' lor-impossible to start it by introducing motivaiuid' into the cylinder in which `the piston is on the expansionestroke. This is quently come to rest' in a position in which the piston in question is so near the end of Elie expansion-stroke that it will iiot operate with sufficient leffect to move the engine over case the lengine-fails to start when the valveplate 27 is operated, the operator then allows this valve-plate to` return and operates: the

20 into operative position. Low-pressure vmotlve-iiuxd is now introduced into the c ylwhilebetween'thepipe 39 and-thev pipe V55 ,ing-valve. 58 is not illustrated, yas such vde vices are wel-l known; hand-operatedv shut-oir valve 59--mayf-be introduced in thev offdead-center, .two of the Ycranks being on on their suction-stroke and expansion-stroke', f

their, eXhaust-stroke'and compression-stroke,

respectively; Accordingly, one of the pis# tons is always on the expansion-stroke, withquestion is at a sufficiently early. point in. its stroke the engine may be started by y due to the fact .that the engine may fre- A the succeeding' dead-center. Accordingly, in

pressure.. Accordingly, the -pipelv44 is shown i age, or'gradualescape, of motive-fluid may 1 sol - this is vthe cylinder into 1 which the starting-cam is adjusted to direct plate 27 to its rearward position. As soon asthe engine begins to rotate forwardly the valve-plate 26, thus moving thereyerse-cam 'I is available to move the engine backwardly. Accordingly. `the, engine-shaft is turned through nearly ahalf-rotation, thus bringing the parts into such a,I position that the pistonon the expansion-stroke is near the dead-center at which this stroke Begins Accordingly, after this reverse movement, it is necessary only to return the valveplate 2G vto normal position, and then operate thai valve-plate 27 again to start the engine with nearly a full effective st rokeof one of v the pistons.

,The object in usinga comparatively low iessure in the motive-fluid employed tor the :reverse movement of the engine is to prevent the engine -from'moving too far in a reverse direction. -This is particularly important when the engine is started after having stood idle for a long time in cold weather. Under-these conditions the lubricant in the cylinders becomes so stiff that considerable forcev is necessary to start the parts in motion. Where motive-fluid under high pressure has been used for this purpose I have found that the pistons would remain stationary until considerable pressure had accumulated in the'cylinder into.v which the moti've-fiuid-was' introduced, and that then the engine would start suddenly into reverse movement with such momentum as t-o `1nove it past the succeeding dead-center, and

even 'cause it to perform a continuous reverse rotation. By properly adjusting .the reducing-valve 58, however, according to the size of the engine and other conditicnswhich 4Q vary more or less in each case, a pressure may be selected for the low-pressure niotive- `Huid which is sufficient tol insure the reverse movement of the engine under all condi-A tions, but not suiiiclent to carry the'parts epast dead-center against the normal compression `.occurring in the cylinders, and accordingly the reverse movement always terininates'at a point in which the engine parts are most effectively positioned for the,s'uc

ceeding starting-operation.

.My invention is not limited t-o the embodiment thereof hereinbefore described and `illustrated in the accompanying drawing,

but may be embodied in various other Jforms 55 `within the nature... of the invention as v1t is deinedin the `following claims.

I claim 4 A )1. A nengine-starter having, in combina` tion, means for supplyingcompressed motive-fluid'V at two different pressures` and s'elector-mechanism adapted, in any given position of the engine Iwhich is to bestarted, to direct the motive-fluid at the lower pressure to one of the engine-cylinders in which the piston is on the in-stroke, to impart re.-

verse movement to the engine-shaft, or to direct the motive-fluid at higher pressure toanother of the engine-cylinders in which the piston is on the out-stroke, to impart a starting-impulse to the engine, the lower of said -two pressures being insuiicient to cause a movement of the engine-pistons past v'dead-center.

`The combination, with a multicylinder internal-combustion engine, of an enginestarter comprising a source of supply of .compressed motive-Huid at two di'erent pressures, and a selector connected with said source of supply and with the respective ,en-

gine-cylinders, the selector being operatively connected with the engine-mechanism and adapted, in any given position thereof, to direct the motive-Huid at the lower pressure vto the engine-cylinder in which the piston is on the compression-stroke, to impart reverse movementl to the engine-shaft,l or to direct the motive-.fluid at the higher pressure to the'engine-cylinder in which the piston is on the expansion-stroke, to. impart a start- .ing-impnlse'tofthe engine, the lower of said two pressures being insufficient to cause a movementtfthe engine-pistons past deadcenter.

3. An engine-starter having, in combination, a 'valve-casing with outlets adapted to bc connected with the respect-ive cylinders said 'out1ets,means for supplying motivefluid under two different pressures to the valve-casing, and cam-mechanism for operating said valves, the cam-mechanism being adapted for connection with a moving part of the engine and being operative alternatively under manual control to operatie the valves either to discharge low-pressure moto discharge high -pressure motive- Huid' through another of said outlets, in any given position of the cam-mechanism.

et. An engine-starter having, in combination, a valve-casing provided with a pluralthe respective cylinders of theengine to be startedv` a cam-follower connected with each valve, a shaft' adapted to be connected with a'ro'tativc element of the engine-mechanism, two calns-'rotatively connected with said shaft so as to occupy definite positions with respect to each other and with the enginemechanisnrin any position in which the latter may come to rest, said cams both having coperative relation with said cam-follow- `ers but being normally out of engagement therewith, a source of supply of motive-Huid connected with the valve-casing,a manuallyoperable valve-member controlling the admission of motive-fluid to the valve-casing, mechanical connections between said valvemember and one of said cams whereby the cam may be moved into operative engage` orn the engine to be started, valves controllingtive-fluid through one of. said outlets, or;

ity of outlets adaptedto be connected with lfluid to the valve-casing and ,mechanical ment .with one or the other of the Cam-folwith one or enother of the cam-followers lowers When' the valve-member is manually when said-Sedond valve-member" is manually 10 operated,'a `second manuallympera-bl v al-v- Operated.- l member controlling the admi'sslon of motivel PERCY W -HODGKINSON connections between, seid lsecor'l'd valve-mem- I Wtnesse: ber and the othe1' cam.whereby the letter D. GURNEE, may be moved into operative engagement L. TH0N.--

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A Washington, D. C'.

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