US 1274777 A
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Description (OCR text may contain errors)
's. 1. rmssconmmm c'omBus'noN ENGINE. APPLICATION -HLED OCT. 13. 191.6.
-. UNITED STATES PATENT OFFICE.
svnm I. rnEscoTT, or nnw YORK, n: it.
To all whom z'tmay concern:
Be it known that'I, SYDNEY I. PRnscoTT,
New York, county of New York, and State of New York, have invent'eda new and usea citizenof the United States,,residing at *ful Improvement in Internal-Combustion Engines, of whichthe following is a specification.
This invention relates to an improvement 7 "internal combustion engines, particularly 'to those-adapted for use as power plants for motor cars. i
The principal object of the inventionis the production of an engine embodying the ain. advantageous features of engines of the twoestroke cycle and those of the fourstroke cycle, simplifying and otherwise improving them but without importing the distinct disadvan-. tagesinherent 'in each. Another object is in the process of embodiment,
the production of an engine in which the .cycleof operation maybe changed at will I while theengine is running to convert it fromv a two-stroke cycle to a four-stroke going through mud or cycle engine, or vice versa'. y
In car starting, hill climblng, orheavy sand, great power and ,frequent power impulses are highly desir- Another object, therefore, is the production of an engine so arranged that it operates on the two-stroke cycle at such times,-
developing its maximum power by Way of frequent forceful power impulses rather than by way of a multiplicity of smaller cylinders or excessive speed, although the engine may have as many cylinders as desiredand may be run at high speeds.
During the greater part of the time a motorcar engine is running, it develops power far below its maximum car is running over average roads and carrying average loads at any speed below maxir with respect to Specification of Letters Patent.
because when the a substantial reserve power,-
temporarily sus- In the best constructions,
Application filed October 13, 1916. Serial No. 125,361.
pended .two-stroke-cycle but always available for instant use by simply re-changing the cycle of operation.
Another object of the invention is the production of throttle controls operative separately for changing the engine cycle of operation and operative separately or to- V gether for varying'the volume of 'fuel delivered to the engine. Another object is the productlon of a device whereby the engine 1s adapted to develop two different powers on two diiferent cycles ,of operation in order that car starting, most hill climbing,
and most heavy going may be accomplished by'simple throttle control manipulation and without gear changing, thus making possible simplification of change gear mechanism. 'Another object is the production of an engine adapted when operating on one cycle to develop normal working power through the agency of a small, light,'nonexpensive and highly eflicient structure, and
'to develop greatly increased power 'when operating on another cycle, without any structural changes whatsoever.
With these and other sists in certain parts, constructions and comblnations -wh1chwill be hereinafter fully described and then specifically set forth in the claims hereunto appended.
In the accompanying drawings which form a part of this specification and in which like charactersof reference indicate Figure '1 is a seethe same or like parts,
.tional elevation of a (lGVlC constructed in accordance with the lnventlon; Fig. 21s a detail elevatlon, partly 1n SeCt1on,i of the throttle controls used in connection with the structure shown in Fig. 1; and Figs. 3, 4: and 5 are fragmentary views of the intake valves and chambers diagrammatically objects not specifically mentioned 1n view, the invention conillustrating various positions of the same during the operation of the structure shown in Fig. 1.
In carrying the invention into effect, there is provided-an internal combustion engine, and means for changing its cycle of operation while running. In the best construc tions, fuel controlling means are used for this purpose. There is-further provided an engine adaptedt'o develop normal working power when running on one cycle, and maximum power when running on another cycle.
the normal workmg power is developed when the engine is running on a modified four-stroke cycle, and inaximum power is developed when the engine is running on a two-stroke cycle. There is further provided a source of fuel supply for the engine, and means for selectively controlling the transfer of fuel therefrom to the engine in accordance with successive or separated piston cyclesu In the best constructions, independent sources of fuel supply and independent controls therefor are employed.
There is further provided throttle controlled means for effecting. changes in the engine cycles of operation. In the best constructions, operative connections and a pair of throttle controls mounted in juxtaposition are used for this purpose. There is further provided an engine cylinder having both ends closed, a piston working within the cylinder and dividing it into a combustion chamber and an induction chamber, a source of fuel supply, and means for selectively controlling transfer of fuel from the source of supply to the induction chamber in accordance with successive or separated piston cycles; In the best constructions, this means includes a pair of rotary valves and independent throttlecontrols cooperative therewith. There is further provided a bypass in the cylinder Wall and adapted to open communication between the induction chamber and the combustion chamber only at the outer end of the piston movement. In the best constructions, this by-pass includes a chamber formed outside the outer end of the cylinder and a plurality of radial ports leading therefrom to the interior of the cylinder, the construction being such that the fuel is forced by its own pressure into the combustion chamber in a plurality of streams flowing at right angles to, the axis of the cylinder and converging at the cylinder axis, then rising in the cylinder and driving the burntfuel before it toward the inner end of the cylinder. There is also provided an exhaust port at the inner end of the cylinder so that the incoming fresh fuel need travel only the length of the cylinder to completely fillthe same, as distin guished from the double distance it has to travel in engines having the exhaust port in the cylinder wall nearly opposite the in-' take port. In the best constructions,-this port is located in the center of thecylinder head and is controlled by a mechanically operated puppet valve. There is further provided means for compressing the fuel to a higher degree than heretofore practised before its introduction into the combustion chamber in order that its own pressure will positively drive it from the induction chamber to the combustion chamber well within isruuning at high speed. All of the above elements, and others not specifically mentioned, may be varied in construction within wide limits. y
The device selected to illustrate the invention is but one of many possible concrete embodiments of the same. The invention, therefore, is not to be restricted to the precise details of the structure shown and deform'below each cylinder, is a cross head i having suitable bosses not shown but of well known construction for supporting a wrist pin 5.' On this wrist pin is mounted the 1 forked end 6 of a piston rod 7 which projects through and reciprocates' within the stuffing box 3. Journaled upon the wrist pin 5 is a connecting rod 8 which is also journaled upon the crank' of the engine crank shaft not shown but well. known in the art.
The cylinder head 2 is also piloted in the outer end of a cylinder 9, and serves not only to close the outer end of the cylinder but to. keep it in accurate alinement with the bore of the casing 1. The inner end of the piston rod? is tapered at 10 and-held to a spider 11 by means of a-nut 1E2. Threaded into this spider is a piston head 13, and] as shown in full lines in Fig. 1, to its lower most position, as shown-in dotted lines in the same figure, and back again.
accidental displacement of the sameispre- I The cylinder and its inner head are inclosed within I a water jacket I? of well known construc tion. It may be here remarked that although thedrawing shows only one cylinder, a plurality may and in most installations will be employed; and when.a plurality of cylinders are employed their construction will be like that shown, and the water jacket willbe extended to inclose all of them.
Outside of the outerend of the cylinder, or each cylinder, and preferably surroundcontinuously in the direction of the arrows,
although they ma be designed to rotate differently. The val with a port 24 leading therefrom to the c linder chamber 18. Similarly, the (Va ve chamber 21 is provided witha port 25 also leading to the cylinder chamber 18; .The.
valve 22 is provided with a channel 26 arranged to open the port 2d at proper intervals.- Similarly, the valve 23 is provided with a channel! 27 arranged to open the port 25 at proper intervals. The valve chamber 20' is further provided with a port 28 leading to a manifold 29. Similarly, the valve chamber 21'is provided with a port leadin to a manifold 31. 'Fuel for the manifo d 29 comesffrom a carbureter indicated at'32,
this carbureter being provided with a throttle operated by means of a throttle lever"33.
Similarly, fuelfor the manifold 31 comes from a carburetor indicated at 34, this can buret'erbeing provided with a throttle operated by means of a' throttle lever 35. The
particular constructionof the carbureters cylinder into an stood that fuel inspired 'in the induction chamber and cylinder chamber .18, comm lies wholly outside of the present invention and a detailed description thereof is omitted herefrom in the interest of brevity and clear- .ness. The valves 22 and 23 are rotated at 'half enginespeed so that they will alternatelycontrol admission of fuel from the two manifolds to the outer part of the cyl-y inder below the piston.
remarked that the piston serves to divide the induction =chamber, that part below the piston, and a combustion chamber, that part above the piston. The
particular construction of the mechanismused for drivingtheyalves 22 and 23'lies wholly outside the present invention and therefore a detailed description of thesame isomitt'ed herefrom in'the interest of brevity and 'clearness. It is sufficient for present purposes to say the ports 2i and 25, or in accordance with alternate piston cycles :From what' hasl been said, and by' an inspection of Fig. 1, it will be readlly underfrom either carbureter and manifold, wi
be compressed between the lower side of the piston and; the lower cylinder head 2 as the 'nder chamber-is provided with a plu-r.
open communication between the cylinve chamber 20 is provided.
It may be here that they are driven at half engine speed] and therefore alternately open piston travels downward. It willalsc be readil understood that this compressed fuel will be stored as compression rogresses .,w1th1n the induction chamber an cylinder chamber 18 until the piston reaches a PQS1- tion where its upper edge uncovers the radial ports 19. The induction chamber and cylinder chamber 18 are so proportioned that the fuel will be compressed to a considerably higher degree than is customary in twostroke cycle engines, andno leak can-occur because of the action of the stuifing box 3 and close fit of the valves 22 and 23. It will vtherefore be readily understood that when v the piston reaches the position where it be gins to'uncover theradial ports 19', the fuel will be drivenbyits own relatively high pressure into the combustion chamber at highspeed and that when so driven it will pass into the combustion chamber in a plurality of streams converging at the axis-of thecylinder, thus causing the inflowing fuel to rise in a mass in the cylinder, drivingthe burntfuel before it.
In order to rovide means for emptyingthe cylinder 0 fuel, and to avoid loss of fresh fuel, the cylexhaust port 36 which'is large andlocated burnt fuel in such a way as to avoid impeding the inflow of the fresh inder upper head 16 is provided with an at the center of the cylinder head.' This port is controlled by means of a puppet valve 3 i g within a bush 39 provided with a large flange 40 resting uponfthe top wall of the water a stem 38. arranged to reciprocate.
jacket 17 above the exhaust conduit 41, this conduit being in open'communication with y the exhaust port/36. Theupper end of'the.
valve stem 38 cargs a spring retainer 4i;
which is held in place by means of'a retaim ing' lock 43. A sprin to ,nornially tion Mounted in suitable hearings in the cyl I 44 in engagement h s with the retainer 42 an the flange 40 serves hold the valve 37 in closed posi-- inder casting a little' distance from the valve 1 7 Stem 38' is a rotating'cam shaft 45 whichro tates at engine speed so'that the exhaust ing each'piston cycle, or in other words once thiscam shaft is a rocker lever 46-417 whic is fulcrumed on a bar :or pivot 48 suitably mounted in the cylinder casting. The arm 47 of the rocker-lever 46+47 isprovided with an adjusting screw 49-ofwell known valve is-opened at the'p'roper time once dur I during each engine revolution. Engaging W a construction and operation. The upper. part I of the cylinder casting is closed by an oil tight cover 50, so that the exhaust valve operating mechanism may be. run in a bath of oil. The" construction of Y the particular mechanism used for driving the cam shaft 45 lies wholly outside the present invention ted in the interest, of brevityand clearness,
and a descriptionthereof is therefore 'omit- An aperture 51 leading to the interior ofthe combustion chamber is provided, and in this aperture a spark plug may be secured.
There is further provided a pair of throttle controls by means of which admission of fuel from the manifolds 29 and 31 may be controlled,-either separately or together, for
purposes hereinbefore mentioned. These a semicircular sector 55.
throttle; controls consist in levers 52 and 53 mounted in juxtaposition or one over the other in convenient position for manipula tion together or separately. The control lever 52 is provided with a lug'54 engaging Similarly, the throttle control 53is provided with a similar lug 56 also engaging the sector 55. The
throttle control 52.is secured to a stem 57 and .the throttle control 53 is similarly secured to a concentric hollow stem 58. These stems may be mounted on the steering post of the car in connection with which the enin any other. convenient position.
- side the present invention. Specific description of such connections is therefore omitted in the interest of brevity and clearness.
The operation of the engine is as follows; and in describingits operation it will be first assumed that the parts are in the position shown in Fig. 1, and that the engine is installed in a motor car and is running idly or out of gear with the driving axle, both throttle controls and both carbureter throttles being open equally. The piston has reached the uppermost point of its movement and fuel is now flowing by its own momentum through the manifold port 28, the valve channel 26, and the valve chamber port 24 into the induction chamber and cylinder chamber 18. The valve chamber port 25 is closed at this time by the valve 23. When the piston has reached a point 20 degrees beyond upper dead center, the valve 22 closes the port 24 and fuel compression within the induction chamber begins. There is no escape for the fuel imprisoned .within the induction chamber and therefore loss as the piston descends.
compression continues without danger of ton reaches a point about 50 degrees ahead .of lower dead center, the exhaust port 36 it begins to uncover the radial ports 19, thepressure in the. combustion chamber has been reduced by theexhausting of the burnt +0 about. atmn nhelic pressure. As soon When the pisports 19, the fresh fuel begins to fiow,.under the influence of its own relatively high pres- I sure, in a plurality of streams radially inwardly and converging at the axis of the cylinder above the piston. The fuel contamed in these streams expands in all direct1ons possible as soon as it passes through the radial ports into the combustion cham-- her. It rushes" radially inward toward the axls of the cylinder and at the same time expandslaterally toward contiguous streams and upwardly toward the cylinder head. The effective result is the rapid formation of a stratum of fresh fuel occupying the lower part of the combustibn chamber below the burnt fuel not then fully exhausted from sald' chamber. This stratum of fresh fuel rapidly builds up in depth as the fuel continues to rush in through the radial ports, and in so doing drives the remaining burnt fuel above it out through the exhaust port at corresponding high speed. It may be here remarked that since the fresh fuel has to travel only the length of the cylinder to. completely fill the combustion chamber, a higher engine speed is attainable than when the exhaust port is located in the cylinder wall and the fresh fuel must travel both up and down the combustion chamber before the same can be completely filled. It may be noted that the displacement of the induction chamber is slightly less than the displacement of the combustion chamber. This is due to the presence therein of the piston rod. For this reason, the exhaust port 36 is kept open a little longer than would otherwise be necessary so that all of the burnt fuel is expelled from the combustion chamber before the exhaust port closes. This slight loss in combustion chamber displace-' position, the position of the valves 22 and 23 will be as shown in Fig 3. It will be noted that the valve chamber port 24 is then closed and the valve chamber port 25 is about to open. 'When the piston reaches a position to cut ofli the radial ports 19, the
. valve chamber port 25 begins to open and a fresh charge of fuel is inspired therethrough from the carbureter 34 and manifold 31.
upper dead center 20 degrees at which time it closes. Fig. 4 shows the valves 22 and 23 inthe position they occupy when the p ston is at upper dead center. The piston now descends under the force of the explosion in the combustion chamber and. a fresh charge of fuel is compressed inythe induc-.
' This action continues until the piston passes tion chamber. On this down st ok'e, as 1lJ'e-,-I '-180'- Assuming now that the engine. has been dinary' four-stroke cycle of operation. T his cycleis hereincycle because l action,
as before. will be note continues as was about 5 degreesahead of lowerdead-center,
and when the radial ports. are uncovered transfer of fresh; fuel from the induction chamberto the combustion chamber occurs:- By an inspection of Fig. 5, it
valve chamber port 24 is open, this opening j is without effect because themanifold port 281s still closed anddoes not open until the piston has traveled upwardly a distance suf -fic1ent to close the radial ports 19. -This are caused to hold both carbureter throttles open. It will of coursebe readily under- Lstood that bysimultaneous manipulation of both throttle'f controls the' volum'e of fuel v ,delivered to the trolled.
engine may bereadily con- I clutched to the driving mechanism of the car and that the car 1s runnlng under condi- ,tions requiring only normal working power:
The engine cycle of operation may now bechan ed without may 'e'- done by throttle control manipula- --vtion.; Either of the throttle controls may be altering its speed, and this operated to close the carbureter throttle actuated by it,
to openthe carbureter throttle actuated by it a little more. Assume ing: that the throttle control 53 is theyone operated to close the throttle of the carbugas reter 34: actuated by it: The closure of the throttle of the carbureter 3 L throws the manifold 31 out, of action as a source of fuel and the valve cham i rated or alternate-piston cycles, or in other 'justhalf as-often 1 cycle of operation manifold 29 in action as. a 2.4'0'
supply, leaving only the carbnreter 32 and supply. The valve 22 will continue its function of controlling flow of fuel from the manifold 29 'throu h the valve channel 26 manifold 31 to be inspired into the induction chamber and cylinder chamber 18 while the valve chamber port 25 is open. The effective result isthat the'engine will inspire a fresh charge of fuel only in accordance with sepawords once every other engine revolution, as before." The two-stroke has now been interrupted 'andthe' engine isnow running on a diiferent cycle of operation ,a power impulse occurrmge've'ry fourth PlStOll stroke as 1n an '01- ed four-stroke termed a modi the method of diet 1211 a t d that while at this time the I gain power mechanically.
and the other throttleconeration,
source of fuel er port 24 to the induction chamber and cylinder chamber 18, while case the reserve power fied four-stroke to the two-stroke although the power impulses J em ' power;
in connect-ion with' one or] both of the throttle controls,
The closureof one, carbureter as a source 7 I of fuel supply establishes a reserve source wh ch s on a true two-stroke cycle,
long as both throttle controls of fuel supply which at any desired time may be brought into actionby means of its throttle control to augment the, normal working power.
1 modified four-stroke cycle,'the throttle being wide open so that'theengineis developing its full normal working power, anda hill is reached: More power is needed and must be applied" or gears will haveto be, shifted to Under these circumstancespthe driverignores his gears and again throws the carbureter 34 and manifold 31 into operation, thereby converting the engine. cycle of operation into a two-stroke cycle,v hus increasing the power by doubling the number of power impulses. When the top of the hill is reached, he again cuts out the carbureter 34: and the engine returns to its former modified four stroke cycle of op- On a heavy road, through deep mud or sand, a like change of'cycle of operation may be resorted to; and also in starting. Since two-powers are available withoutgear shifting, o'negear shift-will provide four powers which is enough to meet all contingencies, and accordingly the change gear mechanism may be materially simplified. I
It will be readily understood that since the additional power derived from a change of cycle of operation from the modified four-stroke cycle to a two-stroke cycle does notv involve additional cylinder displacement, the engine need be only large enough to develop the normal working power when operating on the modified four-stroke cycle, thus effecting almaterial saving-in initial cost, in cost of'maintenance, in weight and in efiicienc'y. a 1
Where greater power for a: given bore of engine is considered of more importance 12 than economy of installation and operation,
the bore may be made the same; and in this derived from the change of cycle of operation from the modibe a clear power gain.
Where both greater power and economy is desired, the engine may be somewhat smaller than present practice and yet develop more cycle will 15 What is claimed is:
1. The combination with an internal combustion engine cylinder having both ends closed, of a piston working therein and dividing the cylinder into a combustion cham her, and an induction" chamber the induction chamber having a, plurality of induction ports formed into its Wall, a plurality of valves arranged and adapted to open the in- I closed, of a piston working therein and di viding the cylinder into a combustion chamher and an induction chamber'the induction chamber having a plurality of induction ports formed in its wall, an exhaust valve working in the head of the combustion chamher, a plurality of valves arranged and adapted to open the induction ports in accordance with separated piston cycles, a by pass formed in the cylinder wall and adapted to open communicationbetween the inductionchamber and'the combustion chamber only at the outer end of the piston stroke, a source of fuel supply for the valves and induction chamber, and independent throttles for said valves.
3. An internal combustion engine provided with mechanism for changing its cycle of operation, said mechanism comprising two intake valves alternately opening communication with the engine on alternate piston cycles, and dual devices cooperative therewith for controlling flow of fuel to said valves. i
4. An internal combustion engine provided with mechanism for changing its cycle of operation, said mechanism comprising two intake valves alternately opening communication With the engine on alternate piston cycles, and dual throttle controlled devices cooperative therewith for controlling flow of fuel to said valves.
5. An internal combustion engine provided with mechanism for changing its cycle of operation, said mechanism comprising two intake valves alternately opening communication with the engine on alternate piston cycles, and dual carbureters provided with throttles cooperative therewith for controlling flow of fuel to said valves.
p 6. An internal combustion engine pro-'- vided with mechanism for changing itscycle of operation, said mechanism comprise ing two intake valves alternately opening communication with the engine on alternate pistoncycles, dual carburetors provided with throttles cooperative therewith for oontrol- I ling flow of fuel to said valves, and means ior selectively operating said carburetors.
7. An internal combustion engine provided with mechanism for changing its cycle of operation, said mechanism comprising two intake valves alternately opening communication with the engine on alternate piston cycles, dual carbureters provided with throttles cooperative therewith for controllingfiow of fuel to said valves, and. a pair of lovers and operating connections for selectively operating the carburetors.
8. An internal combustion enginepro- I vided with mechanism for'changing its cycle of operatiomsaid mechanism comprising two intake valves alternately opening communication With the engine on alternate piston cycles, dual carbureters provided with 'throttles cooperative therewith for controlling .flow of fuel to said valves, and operating munication with the engine on alternate piston cycles, dual carhureters provided with throttles cooperative therewith for control 1mg flow of fuel to said valves and operating juxtaposition and on a common axis for operatlng selectively the .throttles.
' connections and a pair of levers mounted in 10. An internal combustion engine pro- I vided' with mechanism -for changing its cycle of operation, said mechanism compria ing two intake valves: inbuilt with the en I gine and alternatelyopenmg communication with the engine on alternate piston cycles,
and dual devices cooperative w th the valves for controlling flow of fuel to said valves.
11. An internal combustion engine pro.
was with mechanism for changing its cycle'of operation, said mechanism compris- .ing two intake valves alternately opening. COIBIIHmICELtIOII with the engine on alter nate piston cycles, and dual devices one on either side of the engine and cooperative therewith for'controlling flow of fuel to said valves.
1. An internal combustion engine provided w-with mechanism for changing its cycle of operation, said mechanisn'iv com prising two rotary intake valves alternately I opening communication with the engine on alternate piston cycles, and dual devices co. operative therewith for controlling flow of fuel to said valves.
13. An internal combustion engine provided with mechanism. for changing its cycle of operation, said mechanism comprising two rotary intake valves one on either sine oi: the engine and alternately opening eommunication with the engine on alternate piston cycles, and dual devices cooperative therewith for controlling flow of fuel to said valves:
M. An internal combustion engine having separate combustion and induction chambers and provided with mechanism for changing its cycle of operation, said mechanism comprising two intake valves alternately opening communication with the induction enamher on. alternate piston cycles, and dual devices cooperative therewith for controlling tiow 'offuel to said valves.
15. An internal combustion enginehaving a cylinder and piston working therein and dividing the engine into separate combustion anelinduction chambers and provided with mechanism for changing its cycle of operation, said mechanism comprising two intake valves alternately opening communication with the induction chamber on alterdividing the engine into separate combus-- time and induction chambers and provided with mechanism for changing its cycle of operation, said mechanism comprising two rotary intake valves one on either side of the induction chamber alternately opening communication with the induction chamber on alternate piston cycles, and dual devices 00- operative therewith for controlling flow of fuel to said valves.
In testimony whereof, I have signed my name to this specification.
SYDNEY I. PRESCOTT.-